1.Subclavian
and axillary arteries and veins
2.Brachial,
ulnar and radial arteries, topography and branches on arm, forearm and hand
3.Superficial
and deep veins, lymphatics of upper extremity
Lesson # 36
Theme
1. Subclavian and axillary arteries and veins
Left Subclavian artery starts
from aortic arch and right one - from the brachiocephalic trunk. It
leaves thoracic cavity through the superior aperture, rounds a pleura
cupola and gets into interscalenus space. Then artery
lies under clavicle into same name sulcus of first rib and runs into axillary
cavity, where has a name axillary artery. Subclavian
artery conventionally subdivides into three portions: before interscalenus space, in interscalenus
space and after interscalenus space.
Before interscalenus space subclavian
artery gives off the following branches:
Vertebral artery is a largest
branch of subclavian artery, passes in foramens of
transversal processes of cervical vertebrae, transfixes a
atlanto-occipital membrane and dura
mater encephali and through occipital foramen magnum
gets into skull cavity. Behind pons this right and left artery flows together
and forms basillar artery. Vertebral
artery gives off anterior spinal artery and posterior spinal artery,
and posterior inferior cerebellar artery. From basillar artery start: anterior inferior cerebellar
artery, labyrinthic artery, pontini
arteries and artery mesencephalic.
Vertebral artery together with anterior spinal arteries forms around medulla
oblongata circle of Zakharchenka.
Basillar artery on
level of anterior margin pons ramifies on two posterior cerebral arteries,
which supply occipital lobes of cerebrum. Posterior cerebral arteries connect
by posterior communicating artery with internal carotid artery.
Also thank to anterior communicating and cerebral arteries arterial
circle of brain (circle of Willis) forms.
Superficial dissection of the right side of the neck,
showing the carotid and subclavian arteries.
Internal thoracic artery begins from inferior surface
of subclavian artery and passes along ²-VII
cartilages of ribs near sternum, where disintegrates on two terminal branches
are musculî-phrenic artery and superior
epigastric artery. Internal thoracic artery gives
off rami for thymus, bronch³, pericardium and
sternum. Also from this artery moves away rami mammarii,
tracheal rami, anterior intercostal branches, which supply intercostal muscles. Superior epigastric
artery gets into sheath of rectus abdominal muscle, supplies this muscle
and anastomoses with inferior epigastric artery on
navel level.
Thyro-cervical
trunk is has length 1-2 cm and
subdivides into four branches: inferior thyroid artery, (supplies
thyroid gland, cervical esophagus department,
cervical trachea portion and inferior laryngeal artery reaches mucous
membrane of the larynx), ascending cervical artery (to neck muscles), superficial
cervical artery (to trapezius, rhomboid and other neck muscles) and suprascapular artery (for supraspinatus and infraspinatus muscles).
In interscalenus
space subclavian artery gives off
costo-cervical trunk, which ramifies
into deep cervical artery, which supplies semispinalis
capitis and cervicis
muscles and suprema intercostal artery,
which ramifies into I and ²² intercostal spaces,
supplying intercostal muscles.
After interscalenus space space subclavian artery gives off
transverse colli artery, which continues into dorsal
scapulae artery. They supply rhomboid, levator
scapulae and shoulder girdle muscles.
The artery which supplies the upper extremity continues as a single
trunk from its commencement down to the elbow; but different portions of it
have received different names, according to the regions through which they
pass. That part of the vessel which extends from its origin to the outer border
of the first rib is termed the subclavian;
beyond this point to the lower border of the axilla it is named the axillary;
and from the lower margin of the axillary space to the bend of the elbow it is
termed brachial; here the trunk ends by dividing into two branches the radial
and ulnar.
The internal mammary artery and its branches.
The Subclavian Artery (A. Subclavia)
—On the right
side the subclavian artery arises
from the innominate artery behind the right sternoclavicular
articulation; on the left side it springs from the arch of the aorta. The two
vessels, therefore, in the first part of their course, differ in length,
direction, and relation with neighboring structures.
In
order to facilitate the description, each subclavian artery is divided into
three parts. The first portion extends from the origin of the vessel to the
medial border of the Scalenus anterior; the second lies behind this muscle; and
the third extends from the lateral margin of the muscle to the outer border of
the first rib, where it becomes the axillary artery. The first portions of the
two vessels require separate descriptions; the second and third parts of the
two arteries are practically alike.
First
Part of the Right Subclavian Artery .—The
first part of the right subclavian artery arises from the innominate
artery, behind the upper part of the right sternoclavicular articulation, and
passes upward and lateralward to the medial margin of the Scalenus anterior. It
ascends a little above the clavicle, the extent to which it does so varying in
different cases.
Relations.—It is covered, in front, by the integument,
superficial fascia, Platysma, deep fascia, the clavicular origin of the
Sternocleidomastoideus, the Sternohyoideus, and Sternothyreoideus, and another
layer of the deep fascia. It is crossed by the internal jugular and vertebral
veins, by the vagus nerve and the cardiac branches of the vagus and
sympathetic, and by the subclavian loop of the sympathetic trunk which forms a
ring around the vessel. The anterior jugular vein is directed lateralward in
front of the artery, but is separated from it by the Sternohyoideus and
Sternothyreoideus. Below and behind the artery is the pleura, which
separates it from the apex of the lung; behind is the sympathetic trunk,
the Longus collie and the first thoracic vertebra. The right recurrent nerve
winds around the lower and back part of the vessel.
First
Part of the Left Subclavian Artery—The first
part of the left subclavian artery arises from the arch of the aorta,
behind the left common carotid, and at the level of the fourth thoracic
vertebra; it ascends in the superior mediastinal cavity to the root of the neck
and then arches lateralward to the medial border of the Scalenus anterior.
Relations.—It is in relation, in front, with the vagus,
cardiac, and phrenic nerves, which lie parallel with it, the left common carotid
artery, left internal jugular and vertebral veins, and the commencement of the
left innominate vein, and is covered by the Sternothyreoideus, Sternohyoideus,
and Sternocleidomastoideus; behind, it is in relation with the
esophagus, thoracic duct, left recurrent nerve, inferior cervical ganglion of
the sympathetic trunk, and Longus colli; higher up, however, the esophagus and
thoracic duct lie to its right side; the latter ultimately arching over the
vessel to join the angle of union between the subclavian and internal jugular
veins. Medial to it are the esophagus, trachea, thoracic duct, and left
recurrent nerve; lateral to it, the left pleura and lung.
Second
and Third Parts of the Subclavian Artery —The second portion of the subclavian
artery lies behind the Scalenus anterior; it is very short, and forms the
highest part of the arch described by the vessel.
Relations.—It is covered, in front, by the skin,
superficial fascia, Platysma, deep cervical fascia, Sternocleidomastoideus, and
Scalenus anterior. On the right side of the neck the phrenic nerve is separated
from the second part of the artery by the Scalenus anterior, while on the left
side it crosses the first part of the artery close to the medial edge of the muscle.
Behind the vessel are the pleura and the Scalenus medius; above,
the brachial plexus of nerves; below, the pleura. The subclavian vein
lies below and in front of the artery, separated from it by the Scalenus
anterior.
The
third portion of the subclavian artery runs downward and lateralward
from the lateral margin of the Scalenus anterior to the outer border of the
first rib, where it becomes the axillary artery. This is the most superficial
portion of the vessel, and is contained in the subclavian triangle (see page
565).
Relations.—It is covered, in front, by the skin, the
superficial fascia, the Platysma, the supraclavicular nerves, and the deep
cervical fascia. The external jugular vein crosses its medial part and receives
the transverse scapular, transverse cervical, and anterior jugular veins, which
frequently form a plexus in front of the artery. Behind the veins, the nerve to
the Subclavius descends in front of the artery. The terminal part of the artery
lies behind the clavicle and the Subclavius and is crossed by the transverse
scapular vessels. The subclavian vein is in front of and at a slightly lower
level than the artery. Behind, it lies on the lowest trunk of the
brachial plexus, which intervenes between it and the Scalenus medius. Above
and to its lateral side are the upper trunks of the brachial plexus and
the Omohyoideus. Below, it rests on the upper surface of the first rib.
Peculiarities.—The subclavian arteries vary in their origin, their
course, and the height to which they rise in the neck.
The
origin of the right subclavian from the innominate takes place, in some cases,
above the sternoclavicular articulation, and occasionally, but less frequently,
below that joint. The artery may arise as a separate trunk from the arch of the
aorta, and in such cases it may be either the first, second, third, or even the
last branch derived from that vessel; in the majority, however, it is the first
or last, rarely the second or third. When it is the first branch, it occupies
the ordinary position of the innominate artery; when the second or third, it
gains its usual position by passing behind the right carotid; and when the last
branch, it arises from the left extremity of the arch, and passes obliquely
toward the right side, usually behind the trachea, esophagus, and right
carotid, sometimes between the esophagus and trachea, to the upper border of
the first rib, whence it follows its ordinary course. In very rare instances,
this vessel arises from the thoracic aorta, as low down as the fourth thoracic vertebra.
Occasionally, it perforates the Scalenus anterior; more rarely it passes in
front of that muscle. Sometimes the subclavian vein passes with the artery
behind the Scalenus anterior. The artery may ascend as high as 4 cm. above the
clavicle, or any intermediate point between this and the upper border of the
bone, the right subclavian usually ascending higher than the left.
The
left subclavian is occasionally joined at its origin with the left carotid.
The
left subclavian artery is more deeply placed than the right in the first part
of its course, and, as a rule, does not reach quite as high a level in the
neck. The posterior border of the Sternocleidomastoideus corresponds pretty
closely to the lateral border of the Scalenus anterior, so that the third
portion of the artery, the part most accessible for operation, lies immediately
lateral to the posterior border of the Sternocleidomastoideus.
Collateral
Circulation.—After ligature of the third part
of the subclavian artery, the collateral circulation is established mainly by
three sets of vessels, thus described in a dissection:
1.
A posterior set, consisting of the transverse scapular and the descending ramus
of the transverse cervical branches of the subclavian, anastomosing with the
subscapular from the axillary.
2.
A medial set, produced by the connection of the internal mammary on the one
hand, with the highest intercostal and lateral thoracic arteries, and the
branches from the subscapular on the other.
3.
A middle or axillary set, consisting of a number of small vessels derived from
branches of the subclavian, above, and, passing through the axilla, terminating
either in the main trunk, or some of the branches of the axillary below. This
last set presented most conspicuously the peculiar character of newly formed
or, rather, dilated arteries, being excessively tortuous, and forming a
complete plexus.
The
chief agent in the restoration of the axillary artery below the tumor was the
subscapular artery, which communicated most freely with the internal mammary,
transverse scapular and descending ramus of the transverse cervical branches of
the subclavian, from all of which it received so great an influx of blood as to
dilate it to three times its natural size.
When
a ligature is applied to the first part of the subclavian artery, the
collateral circulation is carried on by: (1) the anastomosis between the
superior and inferior thyroids; (2) the anastomosis of the two vertebrals; (3)
the anastomosis of the internal mammary with the inferior epigastric and the
aortic intercostals; (4) the costocervical anastomosing with the aortic
intercostals; (5) the profunda cervicis anastomosing with the descending branch
of the occipital; (6) the scapular branches of the thyrocervical trunk
anastomosing with the branches of the axillary, and (7) the thoracic branches
of the axillary anastomosing with the aortic intercostals.
Branches.—The branches of the subclavian artery are:
Vertebral.
Internal
mammary.
Thyrocervical.
Costocervical.
On
the left side all four branches generally arise from the first portion
of the vessel; but on the right side the costocervical trunk usually
springs from the second portion of the vessel. On both sides of the neck, the
first three branches arise close together at the medial border of the Scalenus
anterior; in the majority of cases, a free interval of from 1.25 to 2.5 cm.
exists between the commencement of the artery and the origin of the nearest
branch.
1.
The vertebral artery (a. vertebralis), is the first branch of the
subclavian, and arises from the upper and back part of the first portion
of the vessel. It is surrounded by a plexus of nerve fibers derived from the
inferior cervical ganglion of the sympathetic trunk, and ascends through the
foramina in the transverse processes of the upper six cervical vertebræ it then winds behind the superior articular process of the
atlas and, entering the skull through the foramen magnum, unites, at the lower
border of the pons, with the vessel of the opposite side to form the basilar
artery.
Relations.—The vertebral artery may be divided into four
parts: The first part runs upward and
backward between the Longus colli and the Scalenus anterior. In front of it are
the internal jugular and vertebral veins, and it is crossed by the inferior
thyroid artery; the left vertebral is crossed by the thoracic duct also. Behind
it are the transverse process of the seventh cervical vertebra, the sympathetic
trunk and its inferior cervical ganglion. The second part runs upward through the foramina in the transverse
processes of the upper six cervical vertebræ, and is surrounded by
branches from the inferior cervical sympathetic ganglion and by a plexus of
veins which unite to form the vertebral vein at the lower part of the neck. It
is situated in front of the trunks of the cervical nerves, and pursues an
almost vertical course as far as the transverse process of the atlas, above
which it runs upward and lateralward to the foramen in the transverse process
of the atlas. The third part issues
from the latter foramen on the medial side of the Rectus capitis lateralis, and
curves backward behind the superior articular process of the atlas, the
anterior ramus of the first cervical nerve being on its medial side; it then
lies in the groove on the upper surface of the posterior arch of the atlas, and
enters the vertebral canal by passing beneath the posterior
atlantoöccipital membrane. This part of the artery is covered by the
Semispinalis capitis and is contained in the suboccipital triangle—a triangular space bounded by the Rectus capitis
posterior major, the Obliquus superior, and the Obliquus inferior. The first
cervical or suboccipital nerve lies between the artery and the posterior arch
of the atlas. The fourth part pierces
the dura mater and inclines medialward to the front of the medulla oblongata;
it is placed between the hypoglossal nerve and the anterior root of the first
cervical nerve and beneath the first digitation of the ligamentum denticulatum.
At the lower border of the pons it unites with the vessel of the opposite side
to form the basilar artery.
Branches.—The branches of the vertebral artery may be divided
into two sets: those given off in the neck, and those within the cranium.
Cervical
Branches.
Cranial
Branches.
Spinal.
Meningeal.
Muscular.
Posterior
Spinal.
Anterior
Spinal.
Posterior
Inferior Cerebellar.
Medullary.
Spinal
Branches (rami spinales) enter the vertebral canal through the
intervertebral foramina, and each divides into two branches. Of these, one
passes along the roots of the nerves to supply the medulla spinalis and its
membranes, anastomosing with the other arteries of the medulla spinalis; the
other divides into an ascending and a descending branch, which unite with
similar branches from the arteries above and below, so that two lateral
anastomotic chains are formed on the posterior surfaces of the bodies of the
vertebræ, near the attachment of the pedicles. From these anastomotic chains
branches are supplied to the periosteum and the bodies of the vertebræ,
and others form communications with similar branches from the opposite side;
from these communications small twigs arise which join similar branches above
and below, to form a central anastomotic chain on the posterior surface of the
bodies of the vertebræ.
Muscular
Branches are given off to the deep muscles of the neck, where the vertebral
artery curves around the articular process of the atlas. They anastomose with the
occipital, and with the ascending and deep cervical arteries.
The
Meningeal Branch (ramus meningeus; posterior meningeal branch)
springs from the vertebral opposite the foramen magnum, ramifies between the
bone and dura mater in the cerebellar fossa, and supplies the falx cerebelli.
It is frequently represented by one or two small branches.
The
Posterior Spinal Artery (a. spinalis posterior; dorsal spinal artery)
arises from the vertebral, at the side of the medulla oblongata; passing
backward, it descends on this structure, lying in front of the posterior roots
of the spinal nerves, and is reinforced by a succession of small branches,
which enter the vertebral canal through the intervertebral foramina; by means
of these it is continued to the lower part of the medulla spinalis, and to the
cauda equina. Branches from the posterior spinal arteries form a free
anastomosis around the posterior roots of the spinal nerves, and communicate,
by means of very tortuous transverse branches, with the vessels of the opposite
side. Close to its origin each gives off an ascending branch, which ends at the
side of the fourth ventricle.
The
Anterior Spinal Artery (a. spinalis anterior; ventral spinal artery)
is a small branch, which arises near the termination of the vertebral,
and, descending in front of the medulla oblongata, unites with its fellow of
the opposite side at the level of the foramen magnum. One of these vessels is
usually larger than the other, but occasionally they are about equal in size.
The single trunk, thus formed, descends on the front of the medulla spinalis,
and is reinforced by a succession of small branches which enter the vertebral
canal through the intervertebral foramina; these branches are derived from the
vertebral and the ascending cervical of the inferior thyroid in the neck; from
the intercostals in the thorax; and from the lumbar, iliolumbar, and lateral
sacral arteries in the abdomen and pelvis. They unite, by means of ascending
and descending branches, to form a single anterior median artery, which extend
as far as the lower part of the medulla spinalis, and is continued as a slender
twig on the filum terminale. This vessel is placed in the pia mater along the
anterior median fissure; it supplies that membrane, and the substance of the
medulla spinalis, and sends off branches at its lower part to be distributed to
the cauda equina.
The
Posterior Inferior Cerebellar Artery (a. cerebelli inferior posterior),
the largest branch of the vertebral, winds backward around the upper part of
the medulla oblongata, passing between the origins of the vagus and accessory
nerves, over the inferior peduncle to the under surface of the cerebellum,
where it divides into two branches. The medial branch is continued
backward to the notch between the two hemispheres of the cerebellum; while the lateral
supplies the under surface of the cerebellum, as far as its lateral border,
where it anastomoses with the anterior inferior cerebellar and the superior
cerebellar branches of the basilar artery. Branches from this artery supply the
choroid plexus of the fourth ventricle.
The
Medullary Arteries (bulbar arteries) are several minute vessels
which spring from the vertebral and its branches and are distributed to the
medulla oblongata.
The
Basilar Artery (a. basilaris), so named from its position at the
base of the skull, is a single trunk formed by the junction of the two
vertebral arteries: it extends from the lower to the upper border of the pons,
lying in its median groove, under cover of the arachnoid. It ends by dividing
into the two posterior cerebral arteries.
Its
branches, on either side, are the following:
Pontine.
Anterior
Inferior Cerebellar.
Internal
Auditory.
Superior
Cerebellar.
Posterior
Cerebral.
The
pontine branches (rami ad pontem; transverse branches) are a
number of small vessels which come off at right angles from either side of the
basilar artery and supply the pons and adjacent parts of the brain.
The
internal auditory artery (a. auditiva interna; auditory artery),
a long slender branch, arises from near the middle of the artery; it accompanies
the acoustic nerve through the internal acoustic meatus, and is distributed to
the internal ear.
The
anterior inferior cerebellar artery (a. cerebelli inferior anterior)
passes backward to be distributed to the anterior part of the under surface of
the cerebellum, anastomosing with the posterior inferior cerebellar branch of
the vertebral.
The
superior cerebellar artery (a. cerebelli superior) arises
near the termination of the basilar. It passes lateralward, immediately below
the oculomotor nerve, which separates it from the posterior cerebral artery,
winds around the cerebral peduncle, close to the trochlear nerve, and, arriving
at the upper surface of the cerebellum, divides into branches which ramify in
the pia mater and anastomose with those of the inferior cerebellar arteries.
Several branches are given to the pineal body, the anterior medullary velum,
and the tela chorioidea of the third ventricle.
The
posterior cerebral artery (a. cerebri posterior) is larger than
the preceding, from which it is separated near its origin by the oculomotor
nerve. Passing lateralward, parallel to the superior cerebellar artery, and
receiving the posterior communicating from the internal carotid, it winds
around the cerebral peduncle, and reaches the tentorial surface of the
occipital lobe of the cerebrum, where it breaks up into branches for the supply
of the temporal and occipital lobes.
The
branches of the posterior cerebral artery are divided into two sets, ganglionic
and cortical:
Ganglionic
Posterior-medial.
Cortical
Anterior
Temporal.
Posterior
Choroidal.
Posterior
Temporal.
Postero-lateral.
Calcarine.
Parietoöccipital.
Ganglionic.—The postero-medial ganglionic branches are a group of small arteries which arise at
the commencement of the posterior cerebral artery: these, with similar branches
from the posterior communicating, pierce the posterior perforated substance,
and supply the medial surfaces of the thalami and the walls of the third
ventricle. The posterior choroidal branches run forward beneath the splenium of the corpus callosum, and supply
the tela chorioidea of the third ventricle and the choroid plexus. The postero-lateral
ganglionic branches are small arteries which arise
from the posterior cerebral artery after it has turned around the cerebral
peduncle; they supply a considerable portion of the thalamus.
Cortical.—The cortical branches are: the anterior
temporal, distributed to the uncus and the
anterior part of the fusiform gyrus; the posterior temporal, to the fusiform and the inferior temporal gyri; the
calcarine, to the cuneus and gyrus
lingualis and the back part of the convex surface of the occipital lobe; and
the parietoöccipital, to the
cuneus and the precuneus.
2.
The thyrocervical trunk (truncus thyreocervicalis; thyroid axis)
is a short thick trunk, which arises from the front of the first portion
of the subclavian artery, close to the medial border of the Scalenus anterior,
and divides almost immediately into three branches, the inferior thyroid,
transverse scapular, and transverse cervical.
The
Inferior Thyroid Artery (a. thyreoidea inferior) passes upward,
in front of the vertebral artery and Longus colli; then turns medialward behind
the carotid sheath and its contents, and also behind the sympathetic trunk, the
middle cervical ganglion resting upon the vessel. Reaching the lower border of
the thyroid gland it divides into two branches, which supply the
postero-inferior parts of the gland, and anastomose with the superior thyroid,
and with the corresponding artery of the opposite side. The recurrent nerve
passes upward generally behind, but occasionally in front, of the artery.
The
branches of the inferior thyroid are:
Inferior
Laryngeal.
Esophageal.
Tracheal.
Ascending
Cervical.
Muscular.
The
inferior laryngeal artery (a. laryngea inferior) ascends upon the
trachea to the back part of the larynx under cover of the Constrictor pharyngis
inferior, in company with the recurrent nerve, and supplies the muscles and
mucous membrane of this part, anastomosing with the branch from the opposite
side, and with the superior laryngeal branch of the superior thyroid artery.
The
tracheal branches (rami tracheales) are distributed upon the
trachea, and anastomose below with the bronchial arteries.
The
esophageal branches (rami æsophagei) supply the esophagus,
and anastomose with the esophageal branches of the aorta.
The
ascending cervical artery (a. cervicalis ascendens) is a small
branch which arises from the inferior thyroid as that vessel is passing
behind the carotid sheath; it runs up on the anterior tubercles of the
transverse processes of the cervical vertebræ in the interval between the
Scalenus anterior and Longus capitis. To the muscles of the neck it gives twigs
which anastomose with branches of the vertebral, and it sends one or two spinal
branches into the vertebral canal through the intervertebral foramina to be
distributed to the medulla spinalis and its membranes, and to the bodies of the
vertebræ, in the same manner as the spinal branches from the vertebral.
It anastomoses with the ascending pharyngeal and occipital arteries.
The
muscular branches supply the depressors of the hyoid bone, and the
Longus colli, Scalenus anterior, and Constrictor pharyngis inferior.
The
Transverse Scapular Artery (a. transversa scapulæ suprascapular
artery) passes at first downward and lateralward across the Scalenus
anterior and phrenic nerve, being covered by the Sternocleidomastoideus; it
then crosses the subclavian artery and the brachial plexus, and runs behind and
parallel with the clavicle and Subclavius, and beneath the inferior belly of
the Omohyoideus, to the superior border of the scapula; it passes over the
superior transverse ligament of the scapula which separates it from the
suprascapular nerve, and enters the supraspinatous fossa. In this situation it lies close to the
bone, and ramifies between it and the Supraspinatus, to which it supplies
branches. It then descends behind the neck of the scapula, through the great
scapular notch and under cover of the inferior transverse ligament, to reach
the infraspinatous fossa, where it anastomoses with the scapular circumflex and
the descending branch of the transverse cervical. Besides distributing branches
to the Sternocleidomastoideus, Subclavius, and neighboring muscles, it gives
off a suprasternal branch, which crosses over the sternal end of the
clavicle to the skin of the upper part of the chest; and an acromial branch,
which pierces the Trapezius and supplies the skin over the acromion,
anastomosing with the thoracoacromial artery. As the artery passes over the
superior transverse ligament of the scapula, it sends a branch into the
subscapular fossa, where it ramifies beneath the Subscapularis, and anastomoses
with the subscapular artery and with the descending branch of the transverse
cervical. It also sends articular branches to the acromioclavicular and
shoulder-joints, and a nutrient artery to the clavicle.
The
scapular and circumflex arteries.
The
Transverse Cervical Artery (a. transversa colli; transversalis colli
artery) lies at a higher level than the transverse scapular; it passes
transversely above the inferior belly of the Omohyoideus to the anterior margin
of the Trapezius, beneath which it divides into an ascending and a descending
branch. It crosses in front of the phrenic nerve and the Scaleni, and in
front of or between the divisions of the brachial plexus, and is covered by the
Platysma and Sternocleidomastoideus, and crossed by the Omohyoideus and
Trapezius.
The
ascending branch (ramus ascendens; superficial cervical artery)
ascends beneath the anterior margin of the Trapezius, distributing branches to
it, and to the neighboring muscles and lymph nodes in the neck, and
anastomosing with the superficial branch of the descending ramus of the
occipital artery.
The
descending branch (ramus descendens; posterior scapular artery)
passes beneath the Levator scapulæ to the medial angle of the scapula,
and then descends under the Rhomboidei along the vertebral border of that bone
as far as the inferior angle. It supplies the Rhomboidei, Latissimus dorsi and
Trapezius, and anastomoses with the transverse scapular and subscapular
arteries, and with the posterior branches of some of the intercostal arteries.
Peculiarities.—The ascending branch of the transverse cervical
frequently arises directly from the thyrocervical trunk; and the descending
branch from the third, more rarely from the second, part of the subclavian.
3.
The internal mammary artery (a. mammaria interna) arises from the under surface of
the first portion of the subclavian, opposite the thyrocervical trunk. It
descends behind the cartilages of the upper six ribs at a distance of about 1.25
cm. from the margin of the sternum, and at the level of the sixth intercostal
space divides into the musculophrenic and superior epigastric
arteries.
Relations.—It is directed at first downward, forward, and medialward
behind the sternal end of the clavicle, the subclavian and internal jugular
veins, and the first costal cartilage, and passes forward close to the lateral
side of the innominate vein. As it enters the thorax the phrenic nerve crosses
from its lateral to its medial side. Below the first costal cartilage it
descends almost vertically to its point of bifurcation. It is covered in front
by the cartilages of the upper six ribs and the intervening Intercostales
interni and anterior intercostal membranes, and is crossed by the terminal
portions of the upper six intercostal nerves. It rests on the pleura, as far as
the third costal cartilage; below this level, upon the Transversus thoracis. It
is accompanied by a pair of veins; these unite above to form a single vessel,
which runs medial to the artery and ends in the corresponding innominate vein.
Branches.—The branches of the internal mammary are:
Pericardiacophrenic.
Intercostal.
Anterior
Mediastinal.
Perforating.
Pericardial.
Musculophrenic.
Sternal.
Superior
Epigastric.
The
Pericardiacophrenic Artery (a. pericardiacophrenica; a. comes nervi
phrenici) is a long slender branch, which accompanies the phrenic nerve,
between the pleura and pericardium, to the diaphragm, to which it is
distributed; it anastomoses with the musculophrenic and inferior phrenic
arteries.
The
Anterior Mediastinal Arteries (aa. mediastinales anteriores; mediastinal
arteries) are small vessels, distributed to the areolar tissue and lymph
nodes in the anterior mediastinal cavity, and to the remains of the thymus.
The
Pericardial Branches supply the upper part of the anterior surface of
the pericardium; the lower part receives branches from the musculophrenic
artery.
The
Sternal Branches (rami sternales) are distributed to the
Transversus thoracis, and to the posterior surface of the sternum.
The
anterior mediastinal, pericardial, and sternal branches, together with some
twigs from the pericardiacophrenic, anastomose with branches from the
intercostal and bronchial arteries, and form a subpleural mediastinal
plexus.
The
Intercoastal Branches (rami intercostales; anterior intercostal
arteries) supply the upper five or six intercostal spaces. Two in number in
each space, these small vessels pass lateralward, one lying near the lower
margin of the rib above, and the other near the upper margin of the rib below,
and anastomose with the intercostal arteries from the aorta. They are at first
situated between the pleura and the Intercostales interni, and then between the
Intercostales interni and externi. They supply the Intercostales and, by branches
which perforate the Intercostales externi, the Pectorales and the mamma.
The
Perforating Branches (rami perforantes) correspond to the five or
six intercostal spaces. They pass forward through the intercostal spaces, and,
curving lateralward, supply the Pectoralis major and the integument. Those
which correspond to the second, third, and fourth spaces give branches to the
mamma, and during lactation are of large size.
The
Musculophrenic Artery (a. musculophrenica) is directed obliquely
downward and lateralward, behind the cartilages of the false ribs; it
perforates the diaphragm at the eighth or ninth costal cartilage, and ends,
considerably reduced in size, opposite the last intercostal space. It gives off
intercostal branches to the seventh, eighth, and ninth intercostal spaces;
these diminish in size as the spaces decrease in length, and are distributed in
a manner precisely similar to the intercostals from the internal mammary. The
musculophrenic also gives branches to the lower part of the pericardium, and
others which run backward to the diaphragm, and downward to the abdominal
muscles.
The
Superior Epigastric Artery (a. epigastrica superior) continues in
the original direction of the internal mammary; it descends through the
interval between the costal and sternal attachments of the diaphragm, and
enters the sheath of the Rectus abdominis, at first lying behind the muscle,
and then perforating and supplying it, and anastomosing with the inferior
epigastric artery from the external iliac. Branches perforate the anterior wall
of the sheath of the Rectus, and supply the muscles of the abdomen and the
integument, and a small branch passes in front of the xiphoid process and
anastomoses with the artery of the opposite side. It also gives some twigs to
the diaphragm, while from the artery of the right side small branches extend into
the falciform ligament of the liver and anastomose with the hepatic artery.
4.
The costocervical trunk (truncus costocervicalis; superior
intercostal artery) arises
from the upper and back part of the subclavian artery, behind the Scalenus
anterior on the right side, and medial to that muscle on the left side. Passing
backward, it gives off the profunda cervicalis, and, continuing as the highest
intercostal artery, descends behind the pleura in front of the necks of the
first and second ribs, and anastomoses with the first aortic intercostal. As it
crosses the neck of the first rib it lies medial to the anterior division of
the first thoracic nerve, and lateral to the first thoracic ganglion of the
sympathetic trunk.
In
the first intercostal space, it gives off a branch which is distributed in a
manner similar to the distribution of the aortic intercostals. The branch for
the second intercostal space usually joins with one from the highest aortic
intercostal artery. This branch is not constant, but is more commonly found on
the right side; when absent, its place is supplied by an intercostal branch
from the aorta. Each intercostal gives off a posterior branch which goes to the
posterior vertebral muscles, and sends a small spinal branch through the
corresponding intervertebral foramen to the medulla spinalis and its membranes.
The
Profunda Cervicalis (a. cervicalis profunda; deep cervical branch)
arises, in most cases, from the costocervical trunk, and is analogous to
the posterior branch of an aortic intercostal artery: occasionally it is a
separate branch from the subclavian artery. Passing backward, above the eighth
cervical nerve and between the transverse process of the seventh cervical vertebra
and the neck of the first rib, it runs up the back of the neck, between the
Semispinales capitis and colli, as high as the axis vertebra, supplying these
and adjacent muscles, and anastomosing with the deep division of the descending
branch of the occipital, and with branches of the vertebral. It gives off a
spinal twig which enters the canal through the intervertebral foramen between
the seventh cervical and first thoracic vertebræ.
Axillary artery is immediate continuation of subclavian artery. It passes
in depth of armpit and covered by trunks of brachial plexus. According to
topography of anterior wall of axillary cavity, axillaró artery subdivide into
three portions: in clavipectoral triangle, pectoral triangle and subpectoral
triangle.
In
clavipectoral triangle
axillar artery gives off:
·
superior
thoracic artery, which ramifies in intercostal I-²² intercostal muscles;
·
thoracoacromial
artery, which supplies acromial process, acromiî-clavicular joint, subclavius
muscle, deltoid muscle, major and minor pectoral muscles.
In
pectoral triangle from
axillar artery moves away
-
lateral thoracic artery, which supplies anterior serratus muscle and gives
off the branches to mammary gland.
In
subpectoral triangle
axillar artery gives off:
·
anterior
circumflex humeri artery - passes in front of
surgical neck of humerus supplies shoulder joint and deltoid muscle;
·
posterior
circumflex humeri artery - passes through
quadrilaterum foramen and, anastomosing with previous artery, supplies shoulder
joint and muscles, that are situated around it;
subscapular
artery, which divides into thoracodorsal
artery (supplies latissimus dorsi muscle and
teres major muscle) and circumflex scapulae artery (passes through trilateral foramen and supplies
muscles of back scapular surface).
The
axilla is a pyramidal space, situated between the upper lateral part of the chest
and the medial side of the arm.
Boundaries.—The apex, which is directed upward toward
the root of the neck, corresponds to the interval between the outer border of
the first rib, the superior border of the scapula, and the posterior surface of
the clavicle, and through it the axillary vessels and nerves pass. The base,
directed downward, is broad at the chest but narrow and pointed at the arm; it
is formed by the integument and a thick layer of fascia, the axillary
fascia, extending between the lower border of
the Pectoralis major in front, and the lower border of the Latissimus dorsi
behind. The anterior wall is formed by the Pectorales major and minor,
the former covering the whole of this wall, the latter only its central part.
The space between the upper border of the Pectoralis minor and the clavicle is
occupied by the coracoclavicular fascia. The posterior wall, which
extends somewhat lower than the anterior, is formed by the Subscapularis above,
the Teres major and Latissimus dorsi below. On the medial side are the
first four ribs with their corresponding Intercostales, and part of the
Serratus anterior. On the lateral side, where the anterior and posterior
walls converge, the space is narrow, and bounded by the humerus, the
Coracobrachialis, and the Biceps brachii.
Contents.—It contains the axillary vessels, and the brachial
plexus of nerves, with their branches, some branches of the intercostal nerves,
and a large number of lymph nodes, together with a quantity of fat and loose
areolar tissue. The axillary artery and vein, with the brachial plexus of
nerves, extend obliquely along the lateral boundary of the axilla, from its
apex to its base, and are placed much nearer to the anterior than to the
posterior wall, the vein lying to the thoracic side of the artery and partially
concealing it. At the forepart of the axilla, in contact with the Pectorales,
are the thoracic branches of the axillary artery, and along the lower margin of
the Pectoralis minor the lateral thoracic artery extends to the side of the
chest. At the back part, in contact with the lower margin of the Subscapularis,
are the subscapular vessels and nerves; winding around the lateral border of
this muscle are the scapular circumflex vessels; and, close to the neck of the
humerus, the posterior humeral circumflex vessels and the axillary nerve curve
backward to the shoulder. Along the medial or thoracic side no vessel of any
importance exists, the upper part of the space being crossed merely by a few
small branches from the highest thoracic artery. There are some important
nerves, however, in this situation, viz., the long thoracic nerve, descending
on the surface of the Serratus anterior, to which it is distributed; and the
intercostobrachial nerve, perforating the upper and anterior part of this wall,
and passing across the axilla to the medial side of the arm.
The
position and arrangement of the lymph nodes are described on pages 699 and 700.
1.
The Axillary Artery— (A. Axillaris)
The
axillary artery, the continuation of the subclavian, commences at the
outer border of the first rib, and ends at the lower border of the tendon of
the Teres major, where it takes the name of brachial. Its direction varies with
the position of the limb; thus the vessel is nearly straight when the arm is
directed at right angles with the trunk, concave upward when the arm is
elevated above this, and convex upward and lateralward when the arm lies by the
side. At its origin the artery is very deeply situated, but near its
termination is superficial, being covered only by the skin and fascia. To
facilitate the description of the vessel it is divided into three portions; the
first part lies above, the second behind, and the third below the Pectoralis minor.
Relations.—The first portion of the axillary artery is covered anteriorly by the clavicular
portion of the Pectoralis major and the coracoclavicular fascia, and is crossed
by the lateral anterior thoracic nerve, and the thoracoacromial and cephalic
veins; posterior to it are the first intercostal space, the
corresponding Intercostalis externus, the first and second digitations of the
Serratus anterior, and the long thoracic and medial anterior thoracic nerves,
and the medial cord of the brachial plexus; on its lateral side is the
brachial plexus, from which it is separated by a little areolar tissue; on its medial,
or thoracic side, is the axillary vein which overlaps the artery. It is
enclosed, together with the axillary vein and the brachial plexus, in a fibrous
sheath—the axillary sheath—continuous
above with the deep cervical fascia.
The
second portion of the axillary artery is covered, anteriorly, by
the Pectorales major and minor; posterior to it are the posterior cord of the
brachial plexus, and some areolar tissue which intervenes between it and the
Subscapularis; on the medial side is the axillary vein, separated from
the artery by the medial cord of the brachial plexus and the medial anterior
thoracic nerve; on the lateral side is the lateral cord of the brachial
plexus. The brachial plexus thus surrounds the artery on three sides, and
separates it from direct contact with the vein and adjacent muscles.
The
third portion of the axillary artery extends from the lower border of
the Pectoralis minor to the lower border of the tendon of the Teres major. In
front, it is covered by the lower part of the Pectoralis major above, but
only by the integument and fascia below; behind, it is in relation with
the lower part of the Subscapularis, and the tendons of the Latissimus dorsi
and Teres major; on its lateral side is the Coracobrachialis, and on its
medial or thoracic side, the axillary vein. The nerves of the brachial
plexus bear the following relations to this part of the artery: on the lateral
side are the lateral head and the trunk of the median, and the
musculocutaneous for a short distance; on the medial side the ulnar
(between the vein and artery) and medial brachial cutaneous (to the medial side
of the vein); in front are the medial head of the median and the medial
antibrachial cutaneous, and behind, the radial and axillary, the latter
only as far as the lower border of the Subscapularis.
Collateral
Circulation after Ligature of the Axillary Artery.—If the artery be tied above the origin of the thoracoacromial, the
collateral circulation will be carried on by the same branches as after the
ligature of the third part of the subclavian; if at a lower point, between the
thoracoacromial and the subscapular, the latter vessel, by its free anastomosis
with the transverse scapular and transverse cervical branches of the
subclavian, will become the chief agent in carrying on the circulation; the lateral
thoracic, if it be below the ligature, will materially contribute by its
anastomoses with the intercostal and internal mammary arteries. If the point
included in the ligature is below the origin of the subscapular artery, it will
most probably also be below the origins of the two humeral circumflex arteries.
The chief agents in restoring the circulation will then be the subscapular and
the two humeral circumflex arteries anastomosing with the a. profunda brachii.
The
axillary artery and its branches.
Branches.—The branches of the axillary are:
From
first part,
Highest
Thoracic.
From
second part
Thoracoacromial.
Lateral
Thoracic.
From
third part
Subscapular.
Posterior
Humeral Circumflex.
Anterior
Humeral Circumflex.
1.
The highest thoracic artery (a. thoracalis suprema; superior thoracic
artery) is a small vessel, which may arise from the thoracoacromial.
Running forward and medialward along the upper border of the Pectoralis minor,
it passes between it and the Pectoralis major to the side of the chest. It
supplies branches to these muscles, and to the parietes of the thorax, and
anastomoses with the internal mammary and intercostal arteries.
2.
The thoracoacromial artery (a. thoracoacromialis; acromiothoracic
artery; thoracic axis) is a short trunk, which arises from the
forepart of the axillary artery, its origin being generally overlapped by the
upper edge of the Pectoralis minor Projecting forward to the upper border of
this muscle, it pierces the coracoclavicular fascia and divides into four
branches—pectoral, acromial, clavicular, and deltoid. The pectoral branch
descends between the two Pectorales, and is distributed to them and to the
mamma, anastomosing with the intercostal branches of the internal mammary and
with the lateral thoracic. The acromial branch runs lateralward over the
coracoid process and under the Deltoideus, to which it gives branches; it then
pierces that muscle and ends on the acromion in an arterial network formed by
branches from the transverse scapular, thoracoacromial, and posterior humeral
circumflex arteries. The clavicular branch runs upward and medialward to
the sternoclavicular joint, supplying this articulation, and the Subclavius.
The deltoid (humeral) branch, often arising with the
acromial, crosses over the Pectoralis minor and passes in the same groove as
the cephalic vein, between the Pectoralis major and Deltoideus, and gives
branches to both muscles.
3.
The lateral thoracic artery (a. thoracalis lateralis; long thoracic
artery; external mammary artery) follows the lower border of the Pectoralis
minor to the side of the chest, supplying the Serratus anterior and the
Pectoralis, and sending branches across the axilla to the axillary glands and
Subscapularis; it anastomoses with the internal mammary, subscapular, and
intercostal arteries, and with the pectoral branch of the thoracoacromial. In
the female it supplies an external mammary branch which turns round the
free edge of the Pectoralis major and supplies the mamma.
4.
The subscapular artery (a. subscapularis) the largest branch of
the axillary artery, arises at the lower border of the Subscapularis,
which it follows to the inferior angle of the scapula, where it anastomoses
with the lateral thoracic and intercostal arteries and with the descending
branch of the transverse cervical, and ends in the neighboring muscles. About 4
cm. from its origin it gives off a branch, the scapular circumflex artery.
The
scapular and circumflex arteries.
The
Scapular Circumflex Artery (a. circumflexa scapulæ; dorsalis
scapulæ artery) is generally larger than the continuation of the
subscapular. It curves around the axillary border of the scapula, traversing
the space between the Subscapularis above, the Teres major below, and the long
head of the Triceps laterally; it enters the infraspinatous fossa under cover
of the Teres minor, and anastomoses with the transverse scapular artery and the
descending branch of the transverse cervical. In its course it gives off two
branches: one (infrascapular) enters the subscapular fossa beneath the
Subscapularis, which it supplies, anastomosing with the transverse scapular
artery and the descending branch of the transverse cervical; the other is continued
along the axillary border of the scapula, between the Teres major and minor,
and at the dorsal surface of the inferior angle anastomoses with the descending
branch of the transverse cervical. In addition to these, small branches are
distributed to the back part of the Deltoideus and the long head of the Triceps
brachii, anastomosing with an ascending branch of the a. profunda brachii.
5.
The posterior humeral circumflex artery (a. circumflexa humeri
posterior; posterior circumflex artery)
arises from the axillary artery at the lower border of the
Subscapularis, and runs backward with the axillary nerve through the
quadrangular space bounded by the Subscapularis and Teres minor above, the
Teres major below, the long head of the Triceps brachii medially, and the
surgical neck of the humerus laterally. It winds around the neck of the humerus
and is distributed to the Deltoideus and shoulder-joint, anastomosing with the
anterior humeral circumflex and profunda brachii.
6.
The anterior humeral circumflex artery (a. circumflexa humeri
anterior; anterior circumflex artery), considerably smaller than the
posterior, arises nearly opposite it, from the lateral side of the
axillary artery. It runs horizontally, beneath the Coracobrachialis and short
head of the Biceps brachii, in front of the neck of the humerus. On reaching
the intertubercular sulcus, it gives off a branch which ascends in the sulcus
to supply the head of the humerus and the shoulder-joint. The trunk of the vessel
is then continued onward beneath the long head of the Biceps brachii and the
Deltoideus, and anastomoses with the posterior humeral circumflex artery.
Peculiarities.—The branches of the axillary artery vary
considerably in different subjects. Occasionally the subscapular, humeral
circumflex, and profunda arteries arise from a common trunk, and when this
occurs the branches of the brachial plexus surround this trunk instead of the
main vessel. Sometimes the axillary artery divides into the radial and ulnar
arteries, and occasionally it gives origin to the volar interosseous artery of
the forearm.
Theme 2. Brachial, ulnar and radial arteries, topography and
branches on arm, forearm and hand
Brachial
artery is immediate continuation of axillary
artery and, starting to on level of inferior margin of major pectoral muscle,
passes in medial biceps brachii sulcus, and in cubital fossa subdivides into
its terminal branches are radial and ulnar.
Brachial
artery gives off:
·
deep
brachial artery - takes beginning from upper
third of brachial artery, passes along the radial nerve in radial canal, where
gives off the branches to posterior brachial muscles group and to deltoid
muscle. Deep brachial artery ramifies into middle collateral artery, which anastomoses with recurrent interossea artery,
and radial collateral artery, which
anastomoses with radial recurrent artery;
·
superior
ulnar collateral artery starts from brachial
artery beneath deep brachial artery and
passes to posteriomedial surface of elbow joint, where anastomoses with
posterior branch of ulnar recurrent artery;
·
inferior
ulnar collateral artery starts from brachial
artery in inferior its third, passes to anteriomedial surface of elbow joint,
where anastomoses with anterior branch of ulnarî¿ recurrent artery.
All
named above collateral arteries, anastomosing with recurrent arteries, take
part in forming of arterial cubital rete, from which blood
supplies joint and muscles around it.
Arteries
of forearm and hand.
Forearm and hand originate from terminal branches of brachial artery - radial
and ulnar arteries.
Radial
artery lies in radial anrebrachial sulcus and,
rounding a styloid process of radius bone, passes on dorsal surface of hand,
and then through the first interosseus space gets on palm, where its terminal
portion, anastomosing with deep palmar branch from ulnar artery, makes deep palmar arc. Last gives off palmar metacarpeal arteries which
anastomose with branches of superficial
palmar arch - common palmar digital arteries.
Radial
artery gives off follow branches:
-
radial
recurrent artery, which anastomoses with radial
collateral artery;
-
superficial
palmar branch, which anastomoses with terminal
portion of ulnar artery, and muscular branches, which supply forearm muscles;
-
dorsal
carpal branch and palmar carpal branch take hand in formation of dorsal carpal rete and palmar carpal rete;
-
first
dorsal metacarpeal artery gives branches into
three dorsal digital arteries, which
feed dorsal surface of I and II fingers;
-
principal
artery of pollex, which ramifies on three proper
palmar digital arteries to I finger and radial
side of palmar surface of ²² finger. From dorsal carpal net four dorsal
metacerpeal arteries start, each from which subdivides into two dorsal digital
arteries. Last supply dorsal surfaces ²²-V of fingers.
Ulnar
artery lies into ulnar antebrachial sulcus and
through the carpal canal gets on palm, where its terminal portion anastomoses
with superficial palmar branch from radial artery and forms superficial palmar arc.
Ulnar
artery gives off:
-
ulnar
recurrent artery, which subdivides into anterior
branch and posterior branch.
They anastomose with collateral brachial arteries inferior and superior and take hand in formation of cubital
articulate net (rete articulare cubiti);
-
common
interossea artery, which divides into anterior
interossea artery and posterior
interossea artery. These arteries supply deep
forearm muscles and take hand in formation of wrist nets. Recurrent
interossea artery moves away from posterior
interossea artery, then anastomoses with media collateral artery, and is take
part in forming of cubital articulate net (rete articulare cubiti);
-
dorsal
carpal branch and palmar carpal branch take hand in formation of dorsal carpal rete and palmar carpal rete;
-
deep
palmar branch, which anastomoses with terminal
portion of radial artery and takes hand in formation of deep palmar
arc.
From
superficial palmar arch three common palmar digital arteries
move away, which ramify each on two proper palmar digital arteries.
From
deep palmar arch 4 palmar metacarpeal arteries moves away, which
fall into common palmar digital arteries and into principal artery of
pollex in area of their division into proper palmar digital arteries.
The
brachial artery commences at the lower margin of the tendon of
the Teres major, and, passing down the arm, ends about 1 cm. below the bend of
the elbow, where it divides into the radial and ulnar arteries.
At first the brachial artery lies medial to the humerus; but as it runs down
the arm it gradually gets in front of the bone, and at the bend of the elbow it
lies midway between its two epicondyles.
Relations.—The artery is superficial throughout its entire
extent, being covered, in front, by the integument and the superficial and
deep fasciæ; the lacertus fibrosus (bicipital fascia) lies in
front of it opposite the elbow and separates it from the vena mediana cubiti;
the median nerve crosses from its lateral to its medial side opposite the
insertion of the Coracobrachialis. Behind, it is separated from the long
head of the Triceps brachii by the radial nerve and a. profunda brachii. It
then lies upon the medial head of the Triceps brachii, next upon the insertion
of the Coracobrachialis, and lastly on the Brachialis. Laterally, it is
in relation above with the median nerve and the Coracobrachialis, below with
the Biceps brachii, the two muscles overlapping the artery to a considerable
extent. Medially, its upper half is in relation with the medial
antibrachial cutaneous and ulnar nerves, its lower half with the median nerve.
The basilic vein lies on its medial side, but is separated from it in the lower
part of the arm by the deep fascia. The artery is accompanied by two venæ
comitantes, which lie in close contact with it, and are connected together at
intervals by short transverse branches.
The
Anticubital Fossa.—At the bend of the elbow
the brachial artery sinks deeply into a triangular interval, the anticubital
fossa. The base of the triangle is directed
upward, and is represented by a line connecting the two epicondyles of the
humerus; the sides are formed by the medial edge of the Brachioradialis and the
lateral margin of the Pronator teres; the floor is formed by the Brachialis and
Supinator. This space contains the brachial artery, with its accompanying
veins; the radial and ulnar arteries; the median and radial nerves; and the
tendon of the Biceps brachii. The brachial artery occupies the middle of the
space, and divides opposite the neck of the radius into the radial and ulnar
arteries; it is covered, in front, by the integument, the superficial
fascia, and the vena mediana cubiti, the last being separated from the artery
by the lacertus fibrosus. Behind it is the Brachialis which separates it
from the elbow-joint. The median nerve lies close to the medial side of the
artery, above, but is separated from it below by the ulnar head of the Pronator
teres. The tendon of the Biceps brachii lies to the lateral side of the artery;
the radial nerve is situated upon the Supinator, and concealed by the
Brachioradialis.
Peculiarities
of the Brachial Artery as Regards its Course.—The
brachial artery, accompanied by the median nerve, may leave the medial border
of the Biceps brachii, and descend toward the medial epicondyle of the humerus;
in such cases it usually passes behind the supracondylar process of the
humerus, from which a fibrous arch is in most cases thrown over the artery; it
then runs beneath or through the substance of the Pronator teres, to the bend
of the elbow. This variation bears considerable analogy with the normal
condition of the artery in some of the carnivora; it has been referred to in
the description of the humerus.
As
Regards its Division.—Occasionally, the artery
is divided for a short distance at its upper part into two trunks, which are
united below. Frequently the artery divides at a higher level than usual, and the
vessels concerned in this high division are three, viz., radial, ulnar, and
interosseous. Most frequently the radial is given off high up, the other limb
of the bifurcation consisting of the ulnar and interosseous; in some instances
the ulnar arises above the ordinary level, and the radial and interosseous form
the other limb of the division; occasionally the interosseous arises high up.
Sometimes,
long slender vessels, vasa aberrantia, connect the brachial or the
axillary artery with one of the arteries of the forearm, or branches from them.
These vessels usually join the radial.
The
brachial artery.
Varieties
in Muscular Relations.—The brachial artery is
occasionally concealed, in some part of its course, by muscular or tendinous
slips derived from the Coracobrachialis, Biceps brachii, Brachialis, or
Pronator teres.
Collateral
Circulation.—After the application of a
ligature to the brachial artery in the upper third of the arm, the circulation
is carried on by branches from the humeral circumflex and subscapular arteries
anastomosing with ascending branches from the profunda brachii. If the artery
be tied below the origin of the profunda brachii and superior ulnar
collateral, the circulation is maintained by the branches of these two arteries
anastomosing with the inferior ulnar collateral, the radial and ulnar
recurrents, and the dorsal interosseous.
Branches.—The branches of the brachial artery are:
Profunda Brachii.
Superior Ulnar Collateral.
Nutrient.
Inferior
Ulnar Collateral.
Muscular.
1.
The arteria profunda brachii (superior profunda artery) is a
large vessel which arises from the medial and back part of the brachial,
just below the lower border of the Teres major. It follows closely the radial
nerve, running at first backward between the medial and lateral heads of the
Triceps brachii, then along the groove for the radial nerve, where it is
covered by the lateral head of the Triceps brachii, to the lateral side of the
arm; there it pierces the lateral intermuscular septum, and, descending between
the Brachioradialis and the Brachialis to the front of the lateral epicondyle of
the humerus, ends by anastomosing with the radial recurrent artery. It gives
branches to the Deltoideus and to the muscles between which it lies; it
supplies an occasional nutrient artery which enters the humerus behind
the deltoid tuberosity. A branch ascends between the long and lateral heads of
the Triceps brachii to anastomose with the posterior humeral circumflex artery;
a middle collateral branch descends in the middle head of the Triceps
brachii and assists in forming the anastomosis above the olecranon; and,
lastly, a radial collateral branch runs down behind the lateral
intermuscular septum to the back of the lateral epicondyle of the humerus,
where it anastomoses with the interosseous recurrent and the inferior ulnar
collateral arteries.
2.
The nutrient artery (a. nutricia humeri) of the body of the
humerus arises about the middle of the arm and enters the nutrient canal near
the insertion of the Coracobrachialis.
Diagram
of the anastomosis around the elbow-joint.
3.
The superior ulnar collateral artery (a. collateralis ulnaris
superior; inferior profunda artery), of small size, arises from the
brachial a little below the middle of the arm; it frequently springs from the
upper part of the a. profunda brachii. It pierces the medial intermuscular
septum, and descends on the surface of the medial head of the Triceps brachii
to the space between the medial epicondyle and olecranon, accompanied by the
ulnar nerve, and ends under the Flexor carpi ulnaris by anastomosing with the
posterior ulnar recurrent, and inferior ulnar collateral. It sometimes sends a
branch in front of the medial epicondyle, to anastomose with the anterior ulnar
recurrent.
4.
The inferior ulnar collateral artery (a. collateralis ulnaris
inferior; anastomotica magna artery) arises about 5 cm. above the
elbow. It passes medialward upon the Brachialis, and piercing the medial
intermuscular septum, winds around the back of the humerus between the Triceps
brachii and the bone, forming, by its junction with the profunda brachii, an
arch above the olecranon fossa. As the vessel lies on the Brachialis, it gives
off branches which ascend to join the superior ulnar collateral: others descend
in front of the medial epicondyle, to anastomose with the anterior ulnar
recurrent. Behind the medial epicondyle a branch anastomoses with the superior
ulnar collateral and posterior ulnar recurrent arteries.
5.
The muscular branches (rami musculares) three or four in number,
are distributed to the Coracobrachialis, Biceps brachii, and Brachialis.
The
Anastomosis Around the Elbow-joint.—The
vessels engaged in this anastomosis may be conveniently divided into those
situated in front of and those behind the medial and lateral
epicondyles of the humerus. The branches anastomosing in front of the
medial epicondyle are: the anterior branch of the inferior ulnar collateral,
the anterior ulnar recurrent, and the anterior branch of the superior ulnar
collateral. Those behind the medial epicondyle are: the inferior ulnar
collateral, the posterior ulnar recurrent, and the posterior branch of the
superior ulnar collateral. The branches anastomosing in front of the
lateral epicondyle are: the radial recurrent and the terminal part of the
profunda brachii. Those behind the lateral epicondyle (perhaps more
properly described as being situated between the lateral epicondyle and the
olecranon) are: the inferior ulnar collateral, the interosseous recurrent, and
the radial collateral branch of the profunda brachii. There is also an arch of
anastomosis above the olecranon, formed by the interosseous recurrent joining
with the inferior ulnar collateral and posterior ulnar recurrent
The
radial artery appears, from its direction, to be the
continuation of the brachial, but it is smaller in caliber than the ulnar. It
commences at the bifurcation of the brachial, just below the bend of the elbow,
and passes along the radial side of the forearm to the wrist. It then winds
backward, around the lateral side of the carpus, beneath the tendons of the
Abductor pollicis longus and Extensores pollicis longus and brevis to the upper
end of the space between the metacarpal bones of the thumb and index finger.
Finally it passes forward between the two heads of the first Interosseous
dorsalis, into the palm of the hand, where it crosses the metacarpal bones and
at the ulnar side of the hand unites with the deep volar branch of the ulnar
artery to form the deep volar arch. The radial artery therefore consists of
three portions, one in the forearm, a second at the back of the wrist, and a
third in the hand.
Relations.—(a) In the forearm the artery extends
from the neck of the radius to the forepart of the styloid process, being
placed to the medial side of the body of the bone above, and in front of it
below. Its upper part is overlapped by the fleshy belly of the Brachioradialis;
the rest of the artery is superficial, being covered by the integument and the
superficial and deep fasciæ. In its course downward, it lies upon the
tendon of the Biceps brachii, the Supinator, the Pronator teres, the radial
origin of the Flexor digitorum sublimis, the Flexor pollicis longus, the
Pronator quadratus, and the lower end of the radius. In the upper third of its
course it lies between the Brachioradialis and the Pronator teres; in the lower
two-thirds, between the tendons of the Brachioradialis and Flexor carpi
radialis. The superficial branch of the radial nerve is close to the lateral
side of the artery in the middle third of its course; and some filaments of the
lateral antibrachial cutaneous nerve run along the lower part of the artery as
it winds around the wrist. The vessel is accompanied by a pair of venæ
comitantes throughout its whole course.
The
radial and ulnar arteries.
Ulnar
and radial arteries. Deep view.
(b)
At the wrist the artery reaches the back of the carpus by passing
between the radial collateral ligament of the wrist and the tendons of the
Abductor pollicis longus and Extensor pollicis brevis. It then descends on the
navicular and greater multangular bones, and before disappearing between the
heads of the first Interosseus dorsalis is crossed by the tendon of the
Extensor pollicis longus. In the interval between the two Extensores pollicis
it is crossed by the digital rami of the superficial branch of the radial nerve
which go to the thumb and index finger.
(c)
In the hand, it passes from the upper end of the first interosseous
space, between the heads of the first Interosseus dorsalis, transversely across
the palm between the Adductor pollicis obliquus and Adductor pollicis
transversus, but sometimes piercing the latter muscle, to the base of the
metacarpal bone of the little finger, where it anastomoses with the deep volar
branch from the ulnar artery, completing the deep volar arch.
Peculiarities.—The origin of the radial artery is, in nearly one
case in eight, higher than usual; more often it arises from the axillary or
upper part of the brachial than from the lower part of the latter vessel. In
the forearm it deviates less frequently from its normal position than the
ulnar. It has been found lying on the deep fascia instead of beneath it. It has
also been observed on the surface of the Brachioradialis, instead of under its
medial border; and in turning around the wrist, it has been seen lying on,
instead of beneath, the Extensor tendons of the thumb.
Branches.—The branches of the radial artery may be divided
into three groups, corresponding with the three regions in which the vessel is
situated.
In
the Forearm.
At
the Wrist.
In
the Hand.
Radial
Recurrent.
Dorsal Carpal.
Princeps Pollicis.
Muscular.
First Dorsal
Metacarpal.
Volaris Indicis Radialis.
Volar Carpal.
Volar Metacarpal.
Superficial
Volar.
Perforating.
Recurrent.
The
radial recurrent artery (a. recurrens radialis) arises
immediately below the elbow. It ascends between the branches of the radial
nerve, lying on the Supinator and then between the Brachioradialis and
Brachialis, supplying these muscles and the elbow-joint, and anastomosing with
the terminal part of the profunda brachii.
The
muscular branches (rami musculares) are distributed to the
muscles on the radial side of the forearm.
The
volar carpal branch (ramus carpeus volaris; anterior radial carpal
artery) is a small vessel which arises near the lower border of the
Pronator quadratus, and, running across the front of the carpus, anastomoses
with the volar carpal branch of the ulnar artery. This anastomosis is joined by
a branch from the volar interosseous above, and by recurrent branches from the
deep volar arch below, thus forming a volar carpal net-work which
supplies the articulations of the wrist and carpus.
The
superficial volar branch (ramus volaris superficialis; superficialis
volœ artery) arises from the radial artery, just where this
vessel is about to wind around the lateral side of the wrist. Running forward,
it passes through, occasionally over, the muscles of the ball of the thumb,
which it supplies, and sometimes anastomoses with the terminal portion of the
ulnar artery, completing the superficial volar arch. This vessel varies
considerably in size: usually it is very small, and ends in the muscles of the
thumb; sometimes it is as large as the continuation of the radial
The
dorsal carpal branch (ramus carpeus dorsalis; posterior radial carpal
artery) is a small vessel which arises beneath the Extensor tendons
of the thumb; crossing the carpus transversely toward the medial border of the
hand, it anastomoses with the dorsal carpal branch of the ulnar and with the
volar and dorsal interosseous arteries to form a dorsal carpal network.
From this network are given off three slender dorsal metacarpal arteries,
which run downward on the second, third, and fourth Interossei dorsales and
bifurcate into the dorsal digital branches for the supply of the adjacent sides
of the middle, ring, and little fingers respectively, communicating with the
proper volar digital branches of the superficial volar arch. Near their origins
they anastomose with the deep volar arch by the superior perforating
arteries, and near their points of bifurcation with the common volar
digital vessels of the superficial volar arch by the inferior perforating
arteries.
The
first dorsal metacarpal arises just before the radial artery
passes between the two heads of the first Interosseous dorsalis and divides
almost immediately into two branches which supply the adjacent sides of the
thumb and index finger; the radial side of the thumb receives a branch directly
from the radial artery.
The
arteria princeps pollicis arises from the radial just as it turns
medialward to the deep part of the hand; it descends between the first Interosseous
dorsalis and Adductor pollicis obliquus, along the ulnar side of the metacarpal
bone of the thumb to the base of the first phalanx, where it lies beneath the
tendon of the Flexor pollicis longus and divides into two branches. These make
their appearance between the medial and lateral insertions of the Adductor
pollicis obliquus, and run along the sides of the thumb, forming on the volar
surface of the last phalanx an arch, from which branches are distributed to the
integument and subcutaneous tissue of the thumb.
The
arteria volaris indicis radialis (radialis indicis artery) arises
close to the preceding, descends between the first Interosseus dorsalis and
Adductor pollicis transversus, and runs along the radial side of the index
finger to its extremity, where it anastomoses with the proper digital artery,
supplying the ulnar side of the finger. At the lower border of the Adductor
pollicis transversus this vessel anastomoses with the princeps pollicis, and
gives a communicating branch to the superficial volar arch. The a. princeps
pollicis and a. volaris indicis radialis may spring from a common trunk termed
the first volar metacarpal artery.
The
deep volar arch (arcus volaris profundus; deep palmar arch) is
formed by the anastomosis of the terminal part of the radial artery with the
deep volar branch of the ulnar. It lies upon the carpal extremities of the
metacarpal bones and on the Interossei, being covered by the Adductor pollicis
obliquus, the Flexor tendons of the fingers, and the Lumbricales. Alongside of
it, but running in the opposite direction—that is to say, toward the radial
side of the hand—is the deep branch of the ulnar nerve.
The
volar metacarpal arteries (aa. metacarpeæ volares; palmar
interosseous arteries), three or four in number, arise from the convexity
of the deep volar arch; they run distally upon the Interossei, and anastomose
at the clefts of the fingers with the common digital branches of the
superficial volar arch.
The
perforating branches (rami perforantes), three in number, pass
backward from the deep volar arch, through the second, third, and fourth
interosseous spaces and between the heads of the corresponding Interossei
dorsalis, to anastomose with the dorsal metacarpal arteries.
The
recurrent branches arise from the concavity of the deep volar
arch. They ascend in front of the wrist, supply the intercarpal articulations,
and end in the volar carpal network.
Theme 3. Superficial and deep veins, lymphatics of upper
extremity
Subclavian
vein continues from axillary vein, lies
in same name sulcus of first rib and collects blood from thoracic veins and dorsal
scapular vein.
Veins
of upper limb are subdivided into superficial and deep. They are
communicated by numerous anastomoses and have valves.
Superficial
veins are developed richer
than deep one.
Cephalic
vein starts from radial part of dorsal venous
hand net. From dorsal hand surface it passes on anterior surface of radial
margin across forearm, lies into lateral
biceps brachii sulcus, then into
sulcus between deltoid and major pectoral muscles and empties under clavicle
into axillaró vein.
Basilica
vein collects blood from ulnar part of dorsal
venous hand net, lies on ulnar side of anterior forearm surface, passes on medial biceps brachii sulcus and empties into one of brachial veins.
Intermediate
cubiti vein passes obliquely in area of cubital
fossa from cephalic to basilica veins.
The
Deep veins of upper limb are
double, they start from superficial palmar venous arch and deep palmar venous
arch then accompanies same name arteries and.
Axillar
vein is odd, it accompanies same name artery
and continues into subclavian vein.
The
veins of the upper extremity are divided into two sets, superficial and deep;
the two sets anastomose frequently with each other. The superficial veins are
placed immediately beneath the integument between the two layers of superficial
fascia. The deep veins accompany the arteries, and constitute the venæ
comitantes of those vessels. Both sets are provided with valves, which are more
numerous in the deep than in the superficial veins.
The
Superficial Veins of the Upper Extremity
The
superficial veins of the upper extremity are the digital, metacarpal,
cephalic, basilic, median.
Digital
Veins.—The dorsal digital veins pass along the sides of the fingers and are joined
to one another by oblique communicating branches. Those from the adjacent sides
of the fingers unite to form three dorsal metacarpal veins, which end in a
dorsal venous net-work opposite the middle of the metacarpus. The radial part
of the net-work is joined by the dorsal digital vein from the radial side of
the index finger and by the dorsal digital veins of the thumb, and is prolonged
upward as the cephalic vein. The ulnar part of the net-work receives the dorsal
digital vein of the ulnar side of the little finger and is continued upward as
the basilic vein. A communicating branch frequently connects the dorsal venous
network with the cephalic vein about the middle of the forearm.
The
volar digital veins on each finger are connected to the dorsal digital
veins by oblique intercapitular veins. They drain into a venous plexus
which is situated over the thenar and hypothenar eminences and across the front
of the wrist.
The
veins on the dorsum of the hand.
The
cephalic vein begins
in the radial part of the dorsal venous net-work and winds upward around the
radial border of the forearm, receiving tributaries from both surfaces. Below the
front of the elbow it gives off the vena mediana cubiti (median
basilic vein), which receives a communicating branch from the deep veins of
the forearm and passes across to join the basilic vein. The cephalic vein then
ascends in front of the elbow in the groove between the Brachioradialis and the
Biceps brachii. It crosses superficial to the musculocutaneous nerve and
ascends in the groove along the lateral border of the Biceps brachii. In the
upper third of the arm it passes between the Pectoralis major and Deltoideus,
where it is accompanied by the deltoid branch of the thoracoacromial artery. It
pierces the coracoclavicular fascia and, crossing the axillary artery, ends in
the axillary vein just below the clavicle. Sometimes it communicates with the external
jugular vein by a branch which ascends in front of the clavicle.
The
accessory cephalic vein (v. cephalica accessoria) arises
either from a small tributory plexus on the back of the forearm or from the
ulnar side of the dorsal venous net-work; it joins the cephalic below the
elbow. In some cases the accessory cephalic springs from the cephalic above the
wrist and joins it again higher up. A large oblique branch frequently connects
the basilic and cephalic veins on the back of the forearm.
The
basilic vein (v. basilica) begins in the ulnar part of the
dorsal venous network. It runs up the posterior surface of the ulnar side of
the forearm and inclines forward to the anterior surface below the elbow, where
it is joined by the vena mediana cubiti. It ascends obliquely in the groove
between the Biceps brachii and Pronator teres and crosses the brachial artery,
from which it is separated by the lacertus fibrosus; filaments of the medial
antibrachial cutaneous nerve pass both in front of and behind this portion of
the vein. It then runs upward along the medial border of the Biceps brachii,
perforates the deep fascia a little below the middle of the arm, and, ascending
on the medial side of the brachial artery to the lower border of the Teres major,
is continued onward as the axillary vein.
The
superficial veins of the upper extremity.
The
median antibrachial vein (v. mediana antibrachii) drains the
venous plexus on the volar surface of the hand. It ascends on the ulnar side of
the front of the forearm and ends in the basilic vein or in the vena mediana
cubiti; in a small proportion of cases it divides into two branches, one of
which joins the basilic, the other the cephalic, below the elbow.
The
Deep Veins of the Upper Extremity
The
deep veins follow the course of the arteries, forming their venæ
comitantes. They are generally arranged in pairs, and are situated one on
either side of the corresponding artery, and connected at intervals by short
transverse branches.
Deep
Veins of the Hand.—The superficial and deep
volar arterial arches are each accompanied by a pair of venæ comitantes
which constitute respectively the superficial and deep volar venous arches,
and receive the veins corresponding to the branches of the arterial arches;
thus the common volar digital veins,
formed by the union of the proper volar digital veins, open into the superficial, and the volar
metacarpal veins into the deep volar venous arches.
The dorsal metacarpal veins receive
perforating branches from the volar metacarpal veins and end in the radial
veins and in the superficial veins on the dorsum of the wrist.
The
deep veins of the forearm are the venæ comitantes of the radial
and ulnar veins and constitute respectively the upward continuations of the
deep and superficial volar venous arches; they unite in front of the elbow to
form the brachial veins. The radial veins are smaller than the ulnar and
receive the dorsal metacarpal veins. The ulnar veins receive tributaries from
the deep volar venous arches and communicate with the superficial veins at the
wrist; near the elbow they receive the volar and dorsal interosseous veins and
send a large communicating branch (profunda vein) to the vena mediana cubiti.
The
deep veins of the upper extremity.
The
brachial veins (vv. brachiales) are placed one on either side of
the brachial artery, receiving tributaries corresponding with the branches
given off from that vessel; near the lower margin of the Subscapularis, they
join the axillary vein; the medial one frequently joins the basilic vein.
These
deep veins have numerous anastomoses, not only with each other, but also with
the superficial veins.
The
axillary vein (v. axillaris) begins at the lower border of
the Teres major, as the continuation of the basilic vein, increases in size as
it ascends, and ends at the outer border of the first rib as the subclavian
vein. Near the lower border of the Subscapularis it receives the brachial veins
and, close to its termination, the cephalic vein; its other tributaries
correspond with the branches of the axillary artery. It lies on the medial side
of the artery, which it partly overlaps; between the two vessels are the medial
cord of the brachial plexus, the median, the ulnar, and the medial anterior
thoracic nerves. It is provided with a pair of valves opposite the lower border
of the Subscapularis; valves are also found at the ends of the cephalic and
subscapular veins.
The
subclavian vein (v. subclavia), the continuation of the axillary,
extends from the outer border of the first rib to the sternal end of the
clavicle, where it unites with the internal jugular to form the innominate
vein. It is in relation, in front, with the clavicle and Subclavius; behind
and above, with the subclavian artery, from which it is separated
medially by the Scalenus anterior and the phrenic nerve. Below, it rests
in a depression on the first rib and upon the pleura. It is usually provided with
a pair of valves, which are situated about 2.5 cm. from its termination.
The
veins of the right axilla, viewed from in front.
The
subclavian vein occasionally rises in the neck to a level with the third part
of the subclavian artery, and occasionally passes with this vessel behind the
Scalenus anterior.
Tributaries.—This vein receives the external jugular vein,
sometimes the anterior jugular vein, and occasionally a small branch, which
ascends in front of the clavicle, from the cephalic. At its angle of junction
with the internal jugular, the left subclavian vein receives the thoracic duct,
and the right subclavian vein the right lymphatic duct.
Lymphatic
nodes of upper limb may be divided into two sets, superficial and
deep.
The
superficial vessels and nodes of upper limb pass along the course
of vena basilica and vena cephalica and compose lateral, medial and middle groups.
Lateral group of superficial vessels carries lymph from skin of I-²²²
fingers, lateral forearm surface and arm to axillar lymphatic nodes. Medial
group of superficial vessels carries lymph from IV-V fingers, hand, medial forearm
side and brachium to cubital and axillar lymphatic nodes. Middle group
carries lymph from palmar forearm surface to cubital fossa and here part of
vessels joins to lateral grand, and part to medial group. The superficial
lymphatic nodes accompany the superficial hand veins. They collect lymph from
skin and subcutaneous tissue. From them lymph passes to cubital nodes and
axillar nodes.
Deep vessels and nodes of upper limb
accompany the deep big vessels and carry lymph into deep nodes and superficial
nodes, and from here - into cubital
nodes and axillar lymphatic nodes. Axillar nodes receive the
vessels from upper limb, thoracic wall, and mammary gland. The efferent vessels
from axillar nodes form a subclavian trunk (left and right).
The
Lymph Nodes of the Upper Extremity.—The lymph
nodes of the upper extremity are divided into two sets, superficial and deep.
The
superficial lymph nodes are few and of small size. One or two supratrochlear
nodes are placed above the medial epicondyle of the humerus, medial to the
basilic vein. Their afferents drain the middle, ring, and little fingers, the
medial portion of the hand, and the superficial area over the ulnar side of the
forearm; these vessels are, however, in free communication with the other
lymphatic vessels of the forearm. Their efferents accompany the basilic vein
and join the deeper vessels. One or two deltoideopectoral nodes are
found beside the cephalic vein, between the Pectoralis major and Deltoideus,
immediately below the clavicle. They are situated in the course of the external
collecting trunks of the arm.
Lymphatics
of the mamma, and the axillary nodes
The
deep lymph nodes are chiefly grouped in the axilla, although a few may
be found in the forearm, in the course of the radial, ulnar, and interosseous
vessels, and in the arm along the medial side of the brachial artery.
The
Axillary Nodes (lymphonodeulæ axillares) are of large size,
vary from twenty to thirty in number, and may be arranged in the following
groups:
1.
A lateral group of from four to six nodes lies in relation to the medial
and posterior aspects of the axillary vein; the afferents of these nodes drain
the whole arm with the exception of that portion whose vessels accompany the
cephalic vein. The efferent vessels pass partly to the central and
subclavicular groups of axillary nodes and partly to the inferior deep cervical
nodes.
2.
An anterior or pectoral group consists of four or five nodes
along the lower border of the Pectoralis minor, in relation with the lateral
thoracic artery. Their afferents drain the skin and muscles of the anterior and
lateral thoracic walls, and the central and lateral parts of the namma; their
efferents pass partly to the central and partly to the subclavicular groups of axillary
nodes.
3.
A posterior or subscapular group of six or seven nodes is placed
along the lower margin of the posterior wall of the axilla in the course of the
subscapular artery. The afferents of this group drain the skin and muscles of
the lower part of the back of the neck and of the posterior thoracic wall;
their efferents pass to the central group of axillary nodes.
4.
A central or intermediate group of three or four large nodes is
imbedded in the adipose tissue near the base of the axilla. Its afferents are
the efferent vessels of all the preceding groups of axillary nodes; its
efferents pass to the subclavicular group.
5.
A medial or subclavicular group of six to twelve nodes is
situated partly posterior to the upper portion of the Pectoralis minor and
partly above the upper border of this muscle. Its only direct territorial
afferents are those which accompany the cephalic vein and one which drains the
upper peripheral part of the mamma, but it receives the efferents of all the
other axillary nodes. The efferent vessels of the subclavicular group unite to
form the subclavian trunk, which opens either directly into the junction
of the internal jugular and subclavian veins or into the jugular lymphatic
trunk; on the left side it may end in the thoracic duct. A few efferents from
the subclavicular nodes usually pass to the inferior deep cervical nodes.
The
Lymphatic Vessels of the Upper Extremity—The
lymphatic vessels of the upper extremity are divided into two sets, superficial
and deep.
Lymphatic
vessels of the dorsal surface of the hand.
The
superficial lymphatic vessels commence in the lymphatic plexus which
everywhere pervades the skin; the meshes of the plexus are much finer in the
palm and on the flexor aspect of the digits than elsewhere. The digital
plexuses are drained by a pair of vessels which run on the sides of each digit,
and incline backward to reach the dorsum of the hand. From the dense plexus of
the palm, vessels pass in different directions, viz., upward toward the wrist,
downward to join the digital vessels, medialward to join the vessels on the
ulnar border of the hand, and lateralward to those on the thumb. Several
vessels from the central part of the plexus unite to form a trunk, which passes
around the metacarpal bone of the index finger to join the vessels on the back
of that digit and on the back of the thumb. Running upward in front of and
behind the wrist, the lymphatic vessels are collected into radial, median, and
ulnar groups, which accompany respectively the cephalic, median, and basilic veins
in the forearm. A few of the ulnar lymphatics end in the supratrochlear nodes,
but the majority pass directly to the lateral group of axillary nodes. Some of
the radial vessels are collected into a trunk which ascends with the cephalic
vein to the deltoideopectoral nodes; the efferents from this group pass either
to the subclavicular axillary nodes or to the inferior cervical nodes.
Lymph
nodes of popliteal fossa.
The
deep lymphatic vessels accompany the deep bloodvessels. In the forearm,
they consist of four sets, corresponding with the radial, ulnar, volar, and
dorsal interosseous arteries; they communicate at intervals with the
superficial lymphatics, and some of them end in the nodes which are
occasionally found beside the arteries. In their course upward, a few end in
the nodes which lie upon the brachial artery; but most of them pass to the
lateral group of axillary nodes.
Prepared
by
Reminetskyy
B.Y.