Lesson 4
Muscles of neck
and head
GENERAL
ANATOMIC AND PHYSIOLOGICAL DATA ABOUT MUSCLES. AGE PECULIARITIES OF THE
STRUCTURE OF THE MUSCULAR SYSTEM
THE MUSCLES are connected with the bones,
cartilages, ligaments, and skin, either directly, or through the intervention
of fibrous structures called tendons or aponeuroses. Where a muscle is attached
to bone or cartilage, the fibers end in blunt extremities upon the periosteum
or perichondrium, and do not come into direct relation with the osseous or
cartilaginous tissue. Where muscles are connected with its skin, they lie as a
flattened layer beneath it, and are connected with its areolar tissue by larger
or smaller bundles of fibers, as in the muscles of the face.
The muscles vary extremely in their form. In the limbs, they
are of considerable length, especially the more superficial ones; they surround
the bones, and constitute an important protection to the various joints. In the
trunk, they are broad, flattened, and expanded, and assist in forming the walls
of the trunk cavities. Hence the reason of the terms, long, broad, short,
etc., used in the description of a muscle.
There is considerable variation in the arrangement of the
fibers of certain muscles with reference to the tendons to which they are
attached. In some muscles the fibers are parallel and run directly from their
origin to their insertion; these are quadrilateral muscles, such as the
Thyreohyoideus. A modification of these is found in the fusiform muscles, in
which the fibers are not quite parallel, but slightly curved, so that the
muscle tapers at either end; in their actions, however, they resemble the
quadrilateral muscles.
The Direction of the Muscle Pull.—In
those muscles where the fibers always run in a straight line from origin to
insertion in all positions of the joint, a straight line joining the middle of
the surface of origin with the middle of the insertion surface will give the
direction of the pull. If, however, the muscle or its tendon is bent out of a
straight line by a bony process or ligament so that it runs over a pulley-like
arrangement, the direction of the muscle pull is naturally bent out of line.
The direction of the pull in such cases is from the middle point of insertion
to the middle point of the pulley where the muscle or tendon is bent. Muscles
or tendons of muscles which pass over more than one joint and pass through more
than one pulley may be resolved, so far as the direction of the pull is
concerned, into two or more units or single-joint muscles .
The tendons of the Flexor profundus digitorum, for example, pass through
several pulleys formed by fibrous sheaths. The direction of the pull is
different for each joint and varies for each joint according to the position of
the bones. The direction is determined in each case, however, by a straight
line between the centers of the pulleys on either side of the joint (Fig. 363). The direction of the pull in any of the segments would not be altered
by any change in the position or origin of the muscle belly above the proximal
pulley.
The Action of the Muscle Pull on the Tendon.—Where
the muscle fibers are parallel or nearly parallel to the direction of the
tendon the entire strength of the muscle contraction acts in the direction of
the tendon.
A, fusiform; B, unipinnate; C,
bipinnate; P.C.S., physiological cross-section
The Scalp is
thicker than in any other part of the body. It is intimately adherent to the
superficial fascia, which attaches it firmly to the underlying aponeurosis and
muscle. Movements of the muscle move the skin. The hair follicles are very
closely set together, and extend throughout the whole thickness of the skin. It also contains a
number of sebaceous glands.
The superficial fascia in the cranial region is
a firm, dense, fibro-fatty layer, intimately adherent to the integument, and to
the Epicranius and its tendinous aponeurosis; it is continuous, behind, with
the superficial fascia at the back of the neck; and, laterally, is continued
over the temporal fascia. It contains between its layers the superficial
vessels and nerves and much granular fat.
The Epicranius (Occipitofrontalis)
is a broad, musculofibrous layer, which covers the whole of one side of the
vertex of the skull, from the occipital bone to the eyebrow. It consists of two
parts, the Occipitalis and the Frontalis, connected by an intervening tendinous
aponeurosis, the galea aponeurotica.
The Occipitalis, thin and
quadrilateral in form, arises by tendinous fibers from the lateral
two-thirds of the superior nuchal line of the occipital bone, and from the
mastoid part of the temporal. It ends in the galea aponeurotica.
Muscles
of the head, face, and neck.
The Frontalis is thin, of a
quadrilateral form, and intimately adherent to the superficial fascia. It is
broader than the Occipitalis and its fibers are longer and paler in color. It
has no bony attachments. Its medial fibers are continuous with those of the
Procerus; its immediate fibers blend with the Corrugator and Orbicularis oculi;
and its lateral fibers are also blended with the latter muscle over the
zygomatic process of the frontal bone. From these attachments the fibers are
directed upward, and join the galea aponeurotica below the coronal suture. The
medial margins of the Frontales are joined together for some distance above the
root of the nose; but between the Occipitales there is a considerable, though
variable, interval, occupied by the galea aponeurotica.
The galea aponeurotica (epicranial
aponeurosis) covers the upper part of the cranium; behind, it is attached,
in the interval between its union with the Occipitales, to the external
occipital protuberance and highest nuchal lines of the occipital bone; in
front, it forms a short and narrow prolongation between its union with the
Frontales. On either side it gives origin to the Auriculares anterior and
superior; in this situation it loses its aponeurotic character, and is
continued over the temporal fascia to the zygomatic arch as a layer of
laminated areolar tissue. It is closely connected to the integument by the
firm, dense, fibro-fatty layer which forms the superficial fascia of the scalp:
it is attached to the pericranium by loose cellular tissue, which allows the
aponeurosis, carrying with it the integument to move through a considerable
distance.
Variations.—Both
Frontalis and Occipitalis vary considerably in size and in extent of
attachment; either may be absent; fusion of Frontalis to skin has been noted.
Nerves.—The Frontalis
is supplied by the temporal branches of the facial nerve, and the Occipitalis
by the posterior auricular branch of the same nerve.
Actions.—The Frontales raise the eyebrows
and the skin over the root of the nose, and at the same time draw the scalp
forward, throwing the integument of the forehead into transverse wrinkles. The
Occipitales draw the scalp backward. By bringing alternately into action the
Frontales and Occipitales the entire scalp may be moved forward and backward.
In the ordinary action of the muscles, the eyebrows are elevated, and at the
same time the aponeurosis is fixed by the Occipitales, thus giving to the face
the expression of surprise; if the action be exaggerated, the eyebrows are
still further raised, and the skin of the forehead thrown into transverse
wrinkles, as in the expression of fright or horror.
A thin muscular slip, the Transversus
nuchæ, is present in a considerable proportion (25 per cent.) of
cases; it arises from the external occipital protuberance or from the
superior nuchal line, either superficial or deep to the Trapezius; it is
frequently inserted with the Auricularis posterior, but may join the
posterior edge of the Sternocleidomastoideus.
Muscles of the Head subdivided
into
Mastication and Facial Expression (mimetic) groups
Muscles of Mastication
Masseter
•
Origin:
•
Superficial: 1.zygomatic process of the maxilla 2.inferior border of zygomatic
arch
•
Intermediate: inner surface of zygomatic arch • Deep: posterior aspect of
inferior border of zygomatic arch
•
Insertion:
• Superficial:
1.angle of mandible 2.lateral surface of mandibular ramus
•
Intermediate: ramus of mandible • Deep: 1.superior ramus of mandible 2.coronoid
process of mandible
•
Action: 1.closes the lower jaw (clenches the teeth) 2.may deviate mandible to
opposite side of contraction
•
Blood: masseteric artery • Nerve:
masseteric nerve
Medial
pterygoid
•
Origin:
1.medial
surface of lateral pterygoid plate of the sphenoid 2.palatine bone 3.pterygoid
fossa
•
Insertion:
1.inner
surface of mandibular ramus 2.angle of the mandible
•
Action:
1.closes
the lower jaw (clenches the teeth) 2.can protrude the mandible in combination
with the lateral pterygoid
•
Blood: medial pterygoid artery • Nerve: medial pterygoid nerve
Lateral
pterygoid
•
Origin:
1.Superior
head: lateral surface of the greater wing of the sphenoid 2.Inferior head:
lateral surface of the lateral pterygoid plate
•
Insert together:
1.neck
of the mandibular condyle 2.articular disk of the TMJ
•
Action:
1.deviates
mandible to side opposite of contraction (during chewing) 2.opens mouth by
protruding mandible (inferior head) 3.closes the mandible (superior head)
•
Blood: lateral pterygoid artery • Nerve: lateral pterygoid nerve
Temporalis
•
Origin:
•
Temporal fossa
•
Insertion: coronoid process of the mandible
•
Action:
1.closes
the lower jaw (clenches the teeth) 2.retraction, pulles back
Muscles of Facial Expression (mimetic
muscles) have such peculiarities:
1.
Originate in bones of face and insert
into skin
2.
Do not throw over joints
3.
Do not have proper fasciae (exception
is buccinator muscle)
4.
Placed round natural orifices of the
face (eyes, nostrils, ears and mouth)
5.
They have an antagonists – elastic
skin
Muscles of Facial Expression
(mimetic)
Orbicularis
oculi
•
Origin:
1.orbital
portion: nasal process of frontal bone 2.palpebral portion: palpebral ligament
3.lacrimal portion: lacrimal crest of lacrimal bone
•
Insertion: circumferentially around orbit meeting in palpebral raphe
•
Action: powerfully closes the eye • Blood: ophthalmic artery • Nerve: zygomatic
branch of facial nerve
Corrugator
supercilii
•
Origin: frontal bone just above the nose • Insertion: skin of the medial
portion of the eyebrows • Action: draws the eyebrows downward and medially •
Blood: ophthalmic artery • Nerve: zygomatic branch of facial nerve
Orbicularis
oris
Scheme showing arrangement of fibers of
Orbicularis oris.
•
Origin:
1.alveolar
border of maxilla 2.lateral to midline of mandible
•
Insertion:
1.circumferentially
around mouth 2.blends with other muscles
•
Action:
1.closes
the lips 2.protrudes the lips
•
Blood: facial artery • Nerve: buccal branch of facial nerve
Levator
labii superioris
•
Action: 1.elevates the upper lip 2.flares the nostrils
Zygomaticus
minor
•
Action: elevates the upper lip
Zygomaticus
major
•
Action: lifts and draws back the angle(s) of the mouth (as in smiling)
Risorius
(may be absent)
•
Action: draws the mouth laterally (as in smiling)
Levator
anguli oris
•
Action: lifts the angle(s) of the mouth (as in smiling)
Buccinator
• Action:
compresses the cheek(s)
Depressor
anguli oris
•
Action: lowers the angle(s) of the mouth (as in frowning)
Depressor
labii inferioris
•
Action: draws the lower lip downward and laterally
Epicranial Musculature
Occipitalis
(2 bellies)
•
Origin:
1.lateral
2/3 of superior nuchal line 2.external occipital protuberance
•
Insertion: galea aponeurosis, over the occipital bone • Action: draws back the
scalp to raise the eyebrows and wrinkle the brow • Blood: occipital artery •
Nerve: posterior auricular branch of facial nerve
Frontalis
(2 bellies)
•
Origin: galea aponeurosis, anterior to the vertex • Insertion: skin above the
nose and eyes • Action: draws back the scalp to raise the eyebrows and wrinkle
the brow • Blood: ophthalmic artery • Nerve: temporal branch of facial nerve
Anterior, posterior and superior auricularis
muscles
•
Action: draws the auricle
There are parotid
fascia, masseteric fascia and boccopharyngeal fascia in head region.
Regions of head: frontal,
parietal, occipital, temporal, auditory, mastoid and facial regions. Facial
area has orbital, infraorbital, parotidomasseteric, zygomatic, nasal, oral and
mental regions.
Neck Musculature
Subdivides
into superficial and deep groups
Superficial Neck Musculature
Platysma
•
Origin: subcutaneous skin over delto-pectoral region • Insertion: invests in
the skin widely over the mandible • Action: 1.depress mandible and lower lip
2.tenses the skin over the lower neck
•
Blood: superficial vessels of the neck • Nerve: cervical branch of facial nerve
(VII cranial)
Sternocleidomastoid
•
Origin: (two heads)
1.manubrium
of sternum 2.medial portion of clavicle
•
Insertion: mastoid process of temporal bone • Action:
1.rotates
to side opposite of contraction 2.laterally flexes to the contracted side
3.bilaterally flexes the neck
•
Blood:
1.occipital
artery 2.superior thyroid artery
•
Nerve:
1.motor:
spinal accessory (XI cranial) 2.sensory: ventral rami of C2,(C3)
Suprahyoid group
1.
Stylohyoid
•
Origin: styloid process of temporal bone • Insertion: lateral margin of hyoid
(near greater horn) • Action:
1.pulls
the hyoid superiorly & posteriorly during swallowing 2.fixes the hyoid bone
for infrahyoid action
•
Blood: facial & occipital artery • Nerve: facial nerve (VII cranial)
2.
Digastric
•
Attachments:
1.post
belly: mastoid process of temporal bone 2.anterior belly: digastric fossa of
internal mandible
•
both bellies meet and attach at the lateral aspect of body of hyoid by a pulley
tendon • Action:
1.open
mouth by depressing mandible 2.fixes hyoid bone for infrahyoid action
•
Blood: branches of the external carotid • Nerve:
1.posterior
belly: facial nerve (VII cranial) 2.anterior belly: mylohyoid nerve
3.
Mylohyoid
•
Origin: inner surface of mandible off the mylohyoid line • Insertion:
1.body
of hyoid 2.along midline at mylohyoid raphe
•
Action:
1.elevates
the hyoid bone 2.raises floor of mouth (for swallowing) 3.depresses mandible
when hyoid is fixed
•
Blood: lingual artery • Nerve: mylohyoid nerve (branch of mandibular division,
V3 cranial)
4.
Geniohyoid
•
Origin: inner surface of the mandible
•
Insertion: body of hyoid (paired muscles)
•
Action:
1.pulles
the tongue 2.depress the mandible 3.works with mylohyoid
•
Blood: lingual artery • Nerve:
Infrahyoid group
1.
Sternohyoid
•
Origin:
1.posterior
aspect of manubrium 2.sternal end of clavicle
•
Insertion: body of hyoid • Action:
1.depresses
hyoid & larynx 2.acts eccentrically with the suprahyoid muscles to provide
them a stable base
•
Blood:
1.inferior
thyroid artery (primary) 2.superior thyroid artery
•
Nerve:
1.upper
portions: superior root of ansa cervicalis, C2 2.lower portions: inferior root
of ansa cervicalis, C2,3
2.
Omohyoid
•
Attachments:
1.superior
belly: hyoid bone (lateral to sternohyoid) 2.inferior belly: superior scapular
border (medial to suprascapular notch)
•
both bellies meet at the clavicle & are held to the clavicle by a pulley
tendon • Action:
1.depresses
hyoid & larynx 2.acts eccentrically with the suprahyoid muscles to provide
them a stable base
•
Blood:
1.inferior
thyroid artery (primary) 2.superior thyroid artery
•
Nerve:
1.upper
portions: superior root of ansa cervicalis, C2 2.lower portions: inferior root
of ansa cervicalis, C2,3
3.
Sternothyroid
•
Origin: posterior aspect of manubrium • Insertion: oblique line of thyroid
cartilage • Action:
1.depresses
hyoid & larynx 2.acts eccentrically with the suprahyoid muscles to provide
them a stable base
•
Blood:
1.inferior
thyroid artery (primary) 2.superior thyroid artery
•
Nerve:
1.upper
portions: superior root of ansa cervicalis, C2 2.lower portions: inferior root
of ansa cervicalis, C2,3
4.
Thyrohyoid
•
Origin: oblique line of thyroid cartilage • Insertion: body of hyoid • Action:
1.depresses
hyoid 2.may assist in larynx elevation
•
Blood:
1.inferior
thyroid artery (primary) 2.superior thyroid artery
•
Nerve:
1.upper
portions: superior root of ansa cervicalis, C2 2.lower portions: inferior root
of ansa cervicalis, C2,3
Deep Neck Muscles
have lateral, medial groups
Deep Lateral Neck Musculature
Anterior scalene
•
Attachment A: anterior tubercles of transverse processes of C3-C6 • Attachment
B: 1st rib • Action:
if
transverse process fixed: 1.elevates the ribs for respiration
if
ribs fixed: 2.rotates to side opposite of contraction 3.laterally flexes to the
contracted side 4.bilaterally flexes the neck
•
Blood: inferior thyroid artery (branch of the thyrocervical trunk) • Nerve:
ventral rami C3-C6
Middle scalene
•
Attachment A: transverse processes of all cervical vertebrae • Attachment B:
1st rib (behind anterior scalene) • Action:
if
transverse process fixed: 1.elevates the ribs for respiration
if
ribs fixed: 2.rotates to side opposite of contraction 3.laterally flexes to the
contracted side 4.bilaterally flexes the neck
•
Blood: ascending cervical artery • Nerve: ventral rami C3-C8
Posterior scalene
•
Attachment A: posterior tubercles of transverse processes of C5 & C6 •
Attachment B: 2nd and/or 3rd rib • Action:
if
transverse process fixed: 1.elevates the ribs for respiration
if
ribs fixed: 2.rotates to side opposite of contraction 3.laterally flexes to the
contracted side 4.bilaterally flexes the neck
•
Blood: ascending cervical artery • Nerve: ventral rami C5-C7
Neck prevertebral deep Musculature
Longus colli
• Origin: lower anterior vertebral bodies and
transverse processes • Insertion: anterior vertebral bodies and transverse
processes several segments above • Action: flexes the head and neck • Blood:
muscular branches of the aorta • Nerve: ventral rami C2-C6
Longus capitis
•
Origin: upper anterior vertebral bodies and transverse processes • Insertion:
anterior vertebral bodies and transverse processes several segments above •
Action: flexes the head and neck • Blood: muscular branches of the aorta •
Nerve: ventral rami C1-C3
Rectus capitis anterior
•
Origin: anterior base of the transverse process of the atlas • Insertion:
occipital bone anterior to foramen magnum • Action: flexes the head • Blood:
muscular branches of the aorta • Nerve: ventral rami C2,3
Rectus
capitis lateralis
•
Origin: transverse process of the atlas • Insertion: jugular process of the
occipital bone • Action: bends the head laterally • Blood: muscular branches of
the aorta • Nerve: ventral rami C2,3
THE TOPOGRAPHY AND FASCIAE OF THE HEAD AND NECK
Topography of
the neck
Neck
has follow regions:
Anterior region is bordered overhead by lower margin
of mandible, from below by sternum, from one side – by the sternocleidomastoid
muscle. Median line of the neck divides anterior region into right and left anterior triangles. There are some areas in each triangle:
1.
Submandibular trigone
bordered by lower margin of mandible and both bellies of digastric muscle
2.
There is lingual trigone of Pyrohov
in Submandibular triangle that bordered by back margin of mylohyoid muscle,
tendon of posterior belly of digastric muscle and hypoglossal nerve. There is
lingual artery in this triangle.
3.
Carotid trigone bordered
by posterior belly of digastric muscle, superior belly of omohyoid, anterior
margin of the sternocleidomastoid and linea alba of the neck.
4.
Muscular (omotracheal) trigone
bordered by superior belly of omohyoid, anterior margin of the
sternocleidomastoid and linea alba of the neck.
5.
Mental trigone
bordered by anterior bellies of both digastric muscles, hyoid bone and
mandible.
The Fascia Colli (deep cervical fascia) lies under cover of the Platysma, and invests the neck; it also forms
sheaths for the carotid vessels, and for the structures situated in front of
the vertebral column.
The investing portion of the fascia is
attached behind to the ligamentum nuchæ and to the spinous process of the
seventh cervical vertebra. It forms a thin investment to the Trapezius, and at
the anterior border of this muscle is continued forward as a rather loose
areolar layer, covering the posterior triangle of the neck, to the posterior border
of the Sternocleidomastoideus, where it begins to assume the appearance of a
fascial membrane. Along the hinder edge of the Sternocleidomastoideus it
divides to enclose the muscle, and at the anterior margin again forms a single
lamella, which covers the anterior triangle of the neck, and reaches forward to
the middle line, where it is continuous with the corresponding part from the
opposite side of the neck. In the middle line of the neck it is attached to the
symphysis menti and the body of the hyoid bone.
Above, the fascia is attached to
the superior nuchal line of the occipital, to the mastoid process of the
temporal, and to the whole length of the inferior border of the body of the
mandible. Opposite the angle of the mandible the fascia is very strong, and
binds the anterior edge of the Sternocleidomastoideus firmly to that bone.
Between the mandible and the mastoid process it ensheathes the parotid
gland—the layer which covers the gland extends upward under the name of the parotideomasseteric
fascia and is fixed to the zygomatic arch. From the part which passes under
the parotid gland a strong band extends upward to the styloid process, forming
the stylomandibular ligament. Two other bands may be defined: the sphenomandibular
(page 297) and the pterygospinous ligaments. The pterygospinous
ligament stretches from the upper part of the posterior border of the
lateral pterygoid plate to the spinous process of the sphenoid. It occasionally
ossifies, and in such cases, between its upper border and the base of the
skull, a foramen is formed which transmits the branches of the mandibular nerve
to the muscles of mastication.
Below, the fascia is attached to
the acromion, the clavicle, and the manubrium sterni. Some little distance
above the last it splits into two layers, superficial and deep. The former is
attached to the anterior border of the manubrium, the latter to its posterior
border and to the interclavicular ligament. Between these two layers is a
slit-like interval, the suprasternal space (space of Burns); it
contains a small quantity of areolar tissue, the lower portions of the anterior
jugular veins and their transverse connecting branch, the sternal heads of the
Sternocleidomastoidei, and sometimes a lymph gland.
Section of the neck at about the level
of the sixth cervical vertebra.
Showing the arrangement of the fascia
coli.
The fascia which lines the deep surface of
the Sternocleidomastoideus gives off the following processes: (1) A process
envelops the tendon at the Omohyoideus, and binds it down to the sternum and
first costal cartilage. (2) A strong sheath, the carotid sheath,
encloses the carotid artery, internal jugular vein, and vagus nerve. (3) The prevertebral
fascia extends medialward behind the carotid vessels, where it assists in
forming their sheath, and passes in front of the prevertebral muscles. It forms
the posterior limit of a fibrous compartment, which contains the larynx and
trachea, the thyroid gland, and the pharynx and esophagus. The prevertebral
fascia is fixed above to the base of the skull, and below is continued into the
thorax in front of the Longus colli muscles. Parallel to the carotid sheath and
along its medial aspect the prevertebral fascia gives off a thin lamina, the buccopharyngeal
fascia, which closely invests the Constrictor muscles of the pharynx, and
is continued forward from the Constrictor pharyngis superior on to the
Buccinator. It is attached to the prevertebral layer by loose connective tissue
only, and thus an easily distended space, the retropharyngeal space, is
found between them. This space is limited above by the base of the skull, while
below it extends behind the esophagus into the posterior mediastinal cavity of
the thorax. The prevertebral fascia is prolonged downward and lateralward
behind the carotid vessels and in front of the Scaleni, and forms a sheath for
the brachial nerves and subclavian vessels in the posterior triangle of the
neck; it is continued under the clavicle as the axillary sheath and is attached
to the deep surface of the coracoclavicular fascia. Immediately above and
behind the clavicle an areolar space exists between the investing layer and the
sheath of the subclavian vessels, and in this space are found the lower part of
the external jugular vein, the descending clavicular nerves, the transverse
scapular and transverse cervical vessels, and the inferior belly of the
Omohyoideus muscle. This space is limited below by the fusion of the
coracoclavicular fascia with the anterior wall of the axillary sheath. (4) The pretrachial
fascia extends medially in front of the carotid vessels, and assists in
forming the carotid sheath. It is continued behind the depressor muscles of the
hyoid bone, and, after enveloping the thyroid gland, is prolonged in front of
the trachea to meet the corresponding layer of the opposite side. Above, it is
fixed to the hyoid bone, while below it is carried downward in front of the
trachea and large vessels at the root of the neck, and ultimately blends with
the fibrous pericardium. This layer is fused on either side with the
prevertebral fascia, and with it completes the compartment containing the
larynx and trachea, the thyroid gland, and the pharynx and esophagus.
Variations.—The
Sternocleidomastoideus varies much in the extent of its origin from the
clavicle: in some cases the clavicular head may be as narrow as the sternal; in
others it may be as much as
Triangles of the Neck.—This
muscle divides the quadrilateral area of the side of the neck into two
triangles, an anterior and a posterior. The boundaries of the anterior
triangle are, in front, the median line of the neck; above,
the lower border of the body of the mandible, and an imaginary line drawn from
the angle of the mandible to the Sternocleidomastoideus; behind, the
anterior border of the Sternocleidomastoideus. The apex of the triangle is at
the upper border of the sternum. The boundaries of the posterior triangle
are, in front, the posterior border of the Sternocleidomastoideus; below,
the middle third of the clavicle; behind, the anterior margin of the
Trapezius. The apex corresponds with the meeting of the Sternocleidomastoideus
and Trapezius on the occipital bone. The anatomy of these triangles will be
more fully described with that of the vessels of the neck (p. 562).
Nerves.—The
Sternocleidomastoideus is supplied by the accessory nerve and branches from the
anterior divisions of the second and third cervical nerves.
Actions.—When only one Sternocleidomastoideus
acts, it draws the head toward the shoulder of the same side, assisted by the
Splenius and the Obliquus capitis inferior of the opposite side. At the same
time it rotates the head so as to carry the face toward the opposite side. Acting
together from their sternoclavicular attachments the muscles will flex the
cervical part of the vertebral column. If the head be fixed, the two muscles
assist in elevating the thorax in forced inspiration.
Sternocleidomastoid
region answers the projection of the same name muscle.
Lateral region of the neck is bordered by back
margin of the sternocleido-mastoid, anterior margin of the trapezius muscle and
upper margin of clavicle. There are follow areas in this region:
1.
Omo-trapezial trigone is bordered by
back margin of the sternocleidomastoid, lower belly of omohyoid and anterior
margin of the trapezius muscles.
2.
Omo-clavicular (greater
supraclavicular) trigone of neck is bordered by back margin of the
sternocleidomastoid, lower belly of omohyoid and upper margin of the clavicle.
Posterior
region answers the projection of the trapezius muscle.
Cervical fascia
According V.M.Shevkunenko there are 5 cervical fasciae:
I - superficial cervical fascia envelops the platizma
Proper cervical fascia has two sheets:
II - superficial lamina of the proper cervical fasciae starts from
front surface of the sternum and clavicle, lower margin of mandible and
attaches the spinous processes of the cervical vertebrae. It forms the sheath
for sternocleidomastoid and trapezius muscles.
III - deep lamina of the proper cervical fasciae starts from back
surface of the sternum and clavicle and attaches to the hyoid bone from sides
bordered by omohyoid muscles. This fascia forms linea alba of neck and the
sheath for infrahyoid muscles.
Suprasternal interaponeurotic space made up
between superficial and deep lamina of the proper cervical fasciae. It contains
jugular venous arch and fat tissue. Suprasternal space connects with lateral
recesses located behind the lower part of sternocleidomastoid muscle.
IV - internal cervical fascia subdivides into parietal and visceral
sheets. Parietal lamina envelopes all organs of neck together and visceral –
each organ separately. Previsceral space positioned between
parietal and visceral laminae and contains adipose tissue, lymphatic nodes, and
nerves and communicates with anterior mediastinum. Pretracheal space located
before trachea between parietal and visceral sheets.
V - prevertebral fascia envelops all deep cervical muscles forming
their sheathes. Retropharyngeal space made up between V fascia and parietal
lamina of IV fasciae. Retrovisceral space positioned
between internal cervical and prevertebral fasciae and contains adipose tissue
and continues into posterior mediastinum.
According international nomenclature (PNA)
there are 3 laminae of cervical fasciae:
1.
Superficial lamina
meets the superficial lamina of the proper cervical fasciae according
V.M.Shevkunenko and contains the suprasternal
space.
2.
Pretracheal lamina meets
the deep lamina of the proper cervical fasciae according V.M.Shevkunenko and
forms carotid sheath.
3.
Prevertebral lamina meets
the same fasciae according V.M.Shevkunenko.
Interscalenum space positioned between anterior and middle scalene muscles where subclavian
artery passes. Anterscalenum space located
in front of scalene muscles where subclavian vein passes.
Deep lamina of the proper cervical fasciae (V.M.Shevkunenko) associating
infrahyoid muscles forms omoclavicular aponeurosis or cervical sail (Rishe). Cervical sail assists to drain superficial
veins of neck that spliced with it.
Muscles of the head, face, and neck.
The Frontalis is thin, of a
quadrilateral form, and intimately adherent to the superficial fascia. It is
broader than the Occipitalis and its fibers are longer and paler in color. It
has no bony attachments. Its medial fibers are continuous with those of the
Procerus; its immediate fibers blend with the Corrugator and Orbicularis oculi;
and its lateral fibers are also blended with the latter muscle over the
zygomatic process of the frontal bone. From these attachments the fibers are
directed upward, and join the galea aponeurotica below the coronal suture. The
medial margins of the Frontales are joined together for some distance above the
root of the nose; but between the Occipitales there is a considerable, though
variable, interval, occupied by the galea aponeurotica.
The galea aponeurotica (epicranial
aponeurosis) covers the upper part of the cranium; behind, it is attached,
in the interval between its union with the Occipitales, to the external
occipital protuberance and highest nuchal lines of the occipital bone; in
front, it forms a short and narrow prolongation between its union with the
Frontales. On either side it gives origin to the Auriculares anterior and
superior; in this situation it loses its aponeurotic character, and is
continued over the temporal fascia to the zygomatic arch as a layer of
laminated areolar tissue. It is closely connected to the integument by the
firm, dense, fibro-fatty layer which forms the superficial fascia of the scalp:
it is attached to the pericranium by loose cellular tissue, which allows the
aponeurosis, carrying with it the integument to move through a considerable
distance.
Variations.—Both
Frontalis and Occipitalis vary considerably in size and in extent of
attachment; either may be absent; fusion of Frontalis to skin has been noted.
Nerves.—The Frontalis
is supplied by the temporal branches of the facial nerve, and the Occipitalis
by the posterior auricular branch of the same nerve.
Actions.—The Frontales raise the eyebrows
and the skin over the root of the nose, and at the same time draw the scalp
forward, throwing the integument of the forehead into transverse wrinkles. The
Occipitales draw the scalp backward. By bringing alternately into action the
Frontales and Occipitales the entire scalp may be moved forward and backward.
In the ordinary action of the muscles, the eyebrows are elevated, and at the
same time the aponeurosis is fixed by the Occipitales, thus giving to the face
the expression of surprise; if the action be exaggerated, the eyebrows are
still further raised, and the skin of the forehead thrown into transverse
wrinkles, as in the expression of fright or horror.
A thin muscular slip, the Transversus
nuchæ, is present in a considerable proportion (25 per cent.) of
cases; it arises from the external occipital protuberance or from the
superior nuchal line, either superficial or deep to the Trapezius; it is
frequently inserted with the Auricularis posterior, but may join the
posterior edge of the Sternocleidomastoideus.
Muscles of the Head subdivided
into
Mastication and Facial Expression (mimetic) groups
Muscles of Mastication
Masseter
•
Origin:
•
Superficial: 1.zygomatic process of the maxilla 2.inferior border of zygomatic
arch
•
Intermediate: inner surface of zygomatic arch • Deep: posterior aspect of
inferior border of zygomatic arch
•
Insertion:
•
Superficial: 1.angle of mandible 2.lateral surface of mandibular ramus
•
Intermediate: ramus of mandible • Deep: 1.superior ramus of mandible 2.coronoid
process of mandible
•
Action: 1.closes the lower jaw (clenches the teeth) 2.may deviate mandible to
opposite side of contraction
•
Blood: masseteric artery • Nerve:
masseteric nerve
Medial
pterygoid
•
Origin:
1.medial
surface of lateral pterygoid plate of the sphenoid 2.palatine bone 3.pterygoid
fossa
•
Insertion:
1.inner
surface of mandibular ramus 2.angle of the mandible
•
Action:
1.closes
the lower jaw (clenches the teeth) 2.can protrude the mandible in combination
with the lateral pterygoid
•
Blood: medial pterygoid artery • Nerve: medial pterygoid nerve
Lateral
pterygoid
•
Origin:
1.Superior
head: lateral surface of the greater wing of the sphenoid 2.Inferior head:
lateral surface of the lateral pterygoid plate
•
Insert together:
1.neck
of the mandibular condyle 2.articular disk of the TMJ
•
Action:
1.deviates
mandible to side opposite of contraction (during chewing) 2.opens mouth by
protruding mandible (inferior head) 3.closes the mandible (superior head)
•
Blood: lateral pterygoid artery • Nerve: lateral pterygoid nerve
Temporalis
•
Origin:
•
Temporal fossa
•
Insertion: coronoid process of the mandible
•
Action:
1.closes
the lower jaw (clenches the teeth) 2.retraction, pulles back
Muscles of Facial Expression (mimetic
muscles) have such peculiarities:
6.
Originate in bones of face and insert
into skin
7.
Do not throw over joints
8.
Do not have proper fasciae (exception
is buccinator muscle)
9.
Placed round natural orifices of the
face (eyes, nostrils, ears and mouth)
10.
They have an antagonists – elastic
skin
Muscles of Facial Expression
(mimetic)
Orbicularis
oculi
•
Origin:
1.orbital
portion: nasal process of frontal bone 2.palpebral portion: palpebral ligament
3.lacrimal portion: lacrimal crest of lacrimal bone
•
Insertion: circumferentially around orbit meeting in palpebral raphe
•
Action: powerfully closes the eye • Blood: ophthalmic artery • Nerve: zygomatic
branch of facial nerve
Corrugator
supercilii
•
Origin: frontal bone just above the nose • Insertion: skin of the medial
portion of the eyebrows • Action: draws the eyebrows downward and medially •
Blood: ophthalmic artery • Nerve: zygomatic branch of facial nerve
Orbicularis
oris
Scheme showing arrangement of fibers of
Orbicularis oris.
•
Origin:
1.alveolar
border of maxilla 2.lateral to midline of mandible
•
Insertion:
1.circumferentially
around mouth 2.blends with other muscles
•
Action:
1.closes
the lips 2.protrudes the lips
•
Blood: facial artery • Nerve: buccal branch of facial nerve
Levator
labii superioris
•
Action: 1.elevates the upper lip 2.flares the nostrils
Zygomaticus
minor
•
Action: elevates the upper lip
Zygomaticus
major
•
Action: lifts and draws back the angle(s) of the mouth (as in smiling)
Risorius
(may be absent)
•
Action: draws the mouth laterally (as in smiling)
Levator
anguli oris
•
Action: lifts the angle(s) of the mouth (as in smiling)
Buccinator
•
Action: compresses the cheek(s)
Depressor
anguli oris
•
Action: lowers the angle(s) of the mouth (as in frowning)
Depressor
labii inferioris
•
Action: draws the lower lip downward and laterally
Epicranial Musculature
Occipitalis
(2 bellies)
• Origin:
1.lateral
2/3 of superior nuchal line 2.external occipital protuberance
•
Insertion: galea aponeurosis, over the occipital bone • Action: draws back the
scalp to raise the eyebrows and wrinkle the brow • Blood: occipital artery •
Nerve: posterior auricular branch of facial nerve
Frontalis
(2 bellies)
•
Origin: galea aponeurosis, anterior to the vertex • Insertion: skin above the
nose and eyes • Action: draws back the scalp to raise the eyebrows and wrinkle
the brow • Blood: ophthalmic artery • Nerve: temporal branch of facial nerve
Anterior, posterior and superior auricularis
muscles
•
Action: draws the auricle
There are parotid
fascia, masseteric fascia and boccopharyngeal fascia in head region.
Regions of head:
frontal, parietal, occipital, temporal, auditory, mastoid and facial regions.
Facial area has orbital, infraorbital, parotidomasseteric, zygomatic, nasal,
oral and mental regions.
Neck Musculature
Subdivides
into superficial and deep groups
Superficial Neck Musculature
Platysma
•
Origin: subcutaneous skin over delto-pectoral region • Insertion: invests in
the skin widely over the mandible • Action: 1.depress mandible and lower lip
2.tenses the skin over the lower neck
•
Blood: superficial vessels of the neck • Nerve: cervical branch of facial nerve
(VII cranial)
Sternocleidomastoid
•
Origin: (two heads)
1.manubrium
of sternum 2.medial portion of clavicle
•
Insertion: mastoid process of temporal bone • Action:
1.rotates
to side opposite of contraction 2.laterally flexes to the contracted side
3.bilaterally flexes the neck
•
Blood:
1.occipital
artery 2.superior thyroid artery
•
Nerve:
1.motor:
spinal accessory (XI cranial) 2.sensory: ventral rami of C2,(C3)
1.
Stylohyoid
•
Origin: styloid process of temporal bone • Insertion: lateral margin of hyoid
(near greater horn) • Action:
1.pulls
the hyoid superiorly & posteriorly during swallowing 2.fixes the hyoid bone
for infrahyoid action
•
Blood: facial & occipital artery • Nerve: facial nerve (VII cranial)
2.
Digastric
•
Attachments:
1.post
belly: mastoid process of temporal bone 2.anterior belly: digastric fossa of
internal mandible
•
both bellies meet and attach at the lateral aspect of body of hyoid by a pulley
tendon • Action:
Suprahyoid group
1.open
mouth by depressing mandible 2.fixes hyoid bone for infrahyoid action
•
Blood: branches of the external carotid • Nerve:
1.posterior
belly: facial nerve (VII cranial) 2.anterior belly: mylohyoid nerve
3.
Mylohyoid
•
Origin: inner surface of mandible off the mylohyoid line • Insertion:
1.body
of hyoid 2.along midline at mylohyoid raphe
•
Action:
1.elevates
the hyoid bone 2.raises floor of mouth (for swallowing) 3.depresses mandible
when hyoid is fixed
•
Blood: lingual artery • Nerve: mylohyoid nerve (branch of mandibular division,
V3 cranial)
4.
Geniohyoid
•
Origin: inner surface of the mandible
•
Insertion: body of hyoid (paired muscles)
•
Action:
1.pulles
the tongue 2.depress the mandible 3.works with mylohyoid
•
Blood: lingual artery • Nerve:
Infrahyoid group
1.
Sternohyoid
•
Origin:
1.posterior
aspect of manubrium 2.sternal end of clavicle
•
Insertion: body of hyoid • Action:
1.depresses
hyoid & larynx 2.acts eccentrically with the suprahyoid muscles to provide them
a stable base
•
Blood:
1.inferior
thyroid artery (primary) 2.superior thyroid artery
•
Nerve:
1.upper
portions: superior root of ansa cervicalis, C2 2.lower portions: inferior root
of ansa cervicalis, C2,3
2.
Omohyoid
•
Attachments:
1.superior
belly: hyoid bone (lateral to sternohyoid) 2.inferior belly: superior scapular
border (medial to suprascapular notch)
•
both bellies meet at the clavicle & are held to the clavicle by a pulley
tendon • Action:
1.depresses
hyoid & larynx 2.acts eccentrically with the suprahyoid muscles to provide
them a stable base
•
Blood:
1.inferior
thyroid artery (primary) 2.superior thyroid artery
•
Nerve:
1.upper
portions: superior root of ansa cervicalis, C2 2.lower portions: inferior root
of ansa cervicalis, C2,3
3.
Sternothyroid
•
Origin: posterior aspect of manubrium • Insertion: oblique line of thyroid
cartilage • Action:
1.depresses
hyoid & larynx 2.acts eccentrically with the suprahyoid muscles to provide
them a stable base
•
Blood:
1.inferior
thyroid artery (primary) 2.superior thyroid artery
•
Nerve:
1.upper
portions: superior root of ansa cervicalis, C2 2.lower portions: inferior root
of ansa cervicalis, C2,3
4.
Thyrohyoid
•
Origin: oblique line of thyroid cartilage • Insertion: body of hyoid • Action:
1.depresses
hyoid 2.may assist in larynx elevation
•
Blood:
1.inferior
thyroid artery (primary) 2.superior thyroid artery
•
Nerve:
1.upper
portions: superior root of ansa cervicalis, C2 2.lower portions: inferior root
of ansa cervicalis, C2,3
Deep Neck Muscles
have lateral, medial groups
Deep Lateral Neck Musculature
Anterior scalene
•
Attachment A: anterior tubercles of transverse processes of C3-C6 • Attachment
B: 1st rib • Action:
if
transverse process fixed: 1.elevates the ribs for respiration
if
ribs fixed: 2.rotates to side opposite of contraction 3.laterally flexes to the
contracted side 4.bilaterally flexes the neck
•
Blood: inferior thyroid artery (branch of the thyrocervical trunk) • Nerve:
ventral rami C3-C6
Middle scalene
•
Attachment A: transverse processes of all cervical vertebrae • Attachment B:
1st rib (behind anterior scalene) • Action:
if
transverse process fixed: 1.elevates the ribs for respiration
if
ribs fixed: 2.rotates to side opposite of contraction 3.laterally flexes to the
contracted side 4.bilaterally flexes the neck
•
Blood: ascending cervical artery • Nerve: ventral rami C3-C8
Posterior scalene
•
Attachment A: posterior tubercles of transverse processes of C5 & C6 •
Attachment B: 2nd and/or 3rd rib • Action:
if
transverse process fixed: 1.elevates the ribs for respiration
if
ribs fixed: 2.rotates to side opposite of contraction 3.laterally flexes to the
contracted side 4.bilaterally flexes the neck
•
Blood: ascending cervical artery • Nerve: ventral rami C5-C7
Longus colli
• Origin: lower anterior vertebral bodies and
transverse processes • Insertion: anterior vertebral bodies and transverse
processes several segments above • Action: flexes the head and neck • Blood:
muscular branches of the aorta • Nerve: ventral rami C2-C6
Longus capitis
•
Origin: upper anterior vertebral bodies and transverse processes • Insertion:
anterior vertebral bodies and transverse processes several segments above •
Action: flexes the head and neck • Blood: muscular branches of the aorta •
Nerve: ventral rami C1-C3
Rectus capitis anterior
•
Origin: anterior base of the transverse process of the atlas • Insertion:
occipital bone anterior to foramen magnum • Action: flexes the head • Blood:
muscular branches of the aorta • Nerve: ventral rami C2,3
Rectus
capitis lateralis
•
Origin: transverse process of the atlas • Insertion: jugular process of the
occipital bone • Action: bends the head laterally • Blood: muscular branches of
the aorta • Nerve: ventral rami C2,3
Neck prevertebral deep Musculature
Theme 3. THE TOPOGRAPHY AND FASCIAE OF THE HEAD AND NECK
Topography of
the neck
Neck
has follow regions:
Anterior region is bordered overhead by lower margin
of mandible, from below by sternum, from one side – by the sternocleidomastoid
muscle. Median line of the neck divides anterior region into right and left anterior triangles. There are some areas in each triangle:
6.
Submandibular trigone
bordered by lower margin of mandible and both bellies of digastric muscle
7.
There is lingual trigone of Pyrohov
in Submandibular triangle that bordered by back margin of mylohyoid muscle,
tendon of posterior belly of digastric muscle and hypoglossal nerve. There is
lingual artery in this triangle.
8.
Carotid trigone bordered
by posterior belly of digastric muscle, superior belly of omohyoid, anterior
margin of the sternocleidomastoid and linea alba of the neck.
9.
Muscular (omotracheal) trigone
bordered by superior belly of omohyoid, anterior margin of the
sternocleidomastoid and linea alba of the neck.
10.
Mental trigone
bordered by anterior bellies of both digastric muscles, hyoid bone and
mandible.
The Fascia Colli (deep cervical fascia) lies under cover of the Platysma, and invests the neck; it also forms
sheaths for the carotid vessels, and for the structures situated in front of
the vertebral column.
The investing portion of the fascia is
attached behind to the ligamentum nuchæ and to the spinous process of the
seventh cervical vertebra. It forms a thin investment to the Trapezius, and at
the anterior border of this muscle is continued forward as a rather loose
areolar layer, covering the posterior triangle of the neck, to the posterior
border of the Sternocleidomastoideus, where it begins to assume the appearance
of a fascial membrane. Along the hinder edge of the Sternocleidomastoideus it
divides to enclose the muscle, and at the anterior margin again forms a single
lamella, which covers the anterior triangle of the neck, and reaches forward to
the middle line, where it is continuous with the corresponding part from the
opposite side of the neck. In the middle line of the neck it is attached to the
symphysis menti and the body of the hyoid bone.
Above, the fascia is attached to
the superior nuchal line of the occipital, to the mastoid process of the
temporal, and to the whole length of the inferior border of the body of the
mandible. Opposite the angle of the mandible the fascia is very strong, and
binds the anterior edge of the Sternocleidomastoideus firmly to that bone.
Between the mandible and the mastoid process it ensheathes the parotid
gland—the layer which covers the gland extends upward under the name of the parotideomasseteric
fascia and is fixed to the zygomatic arch. From the part which passes under
the parotid gland a strong band extends upward to the styloid process, forming
the stylomandibular ligament. Two other bands may be defined: the sphenomandibular
(page 297) and the pterygospinous ligaments. The pterygospinous
ligament stretches from the upper part of the posterior border of the
lateral pterygoid plate to the spinous process of the sphenoid. It occasionally
ossifies, and in such cases, between its upper border and the base of the
skull, a foramen is formed which transmits the branches of the mandibular nerve
to the muscles of mastication.
Below, the fascia is attached to
the acromion, the clavicle, and the manubrium sterni. Some little distance
above the last it splits into two layers, superficial and deep. The former is
attached to the anterior border of the manubrium, the latter to its posterior
border and to the interclavicular ligament. Between these two layers is a
slit-like interval, the suprasternal space (space of Burns); it
contains a small quantity of areolar tissue, the lower portions of the anterior
jugular veins and their transverse connecting branch, the sternal heads of the
Sternocleidomastoidei, and sometimes a lymph gland.
The fascia which lines the deep surface of
the Sternocleidomastoideus gives off the following processes: (1) A process
envelops the tendon at the Omohyoideus, and binds it down to the sternum and
first costal cartilage. (2) A strong sheath, the carotid sheath,
encloses the carotid artery, internal jugular vein, and vagus nerve. (3) The prevertebral
fascia extends medialward behind the carotid vessels, where it assists in
forming their sheath, and passes in front of the prevertebral muscles. It forms
the posterior limit of a fibrous compartment, which contains the larynx and
trachea, the thyroid gland, and the pharynx and esophagus. The prevertebral
fascia is fixed above to the base of the skull, and below is continued into the
thorax in front of the Longus colli muscles. Parallel to the carotid sheath and
along its medial aspect the prevertebral fascia gives off a thin lamina, the buccopharyngeal
fascia, which closely invests the Constrictor muscles of the pharynx, and
is continued forward from the Constrictor pharyngis superior on to the
Buccinator. It is attached to the prevertebral layer by loose connective tissue
only, and thus an easily distended space, the retropharyngeal space, is
found between them. This space is limited above by the base of the skull, while
below it extends behind the esophagus into the posterior mediastinal cavity of
the thorax. The prevertebral fascia is prolonged downward and lateralward
behind the carotid vessels and in front of the Scaleni, and forms a sheath for
the brachial nerves and subclavian vessels in the posterior triangle of the
neck; it is continued under the clavicle as the axillary sheath and is attached
to the deep surface of the coracoclavicular fascia. Immediately above and
behind the clavicle an areolar space exists between the investing layer and the
sheath of the subclavian vessels, and in this space are found the lower part of
the external jugular vein, the descending clavicular nerves, the transverse
scapular and transverse cervical vessels, and the inferior belly of the
Omohyoideus muscle. This space is limited below by the fusion of the
coracoclavicular fascia with the anterior wall of the axillary sheath. (4) The pretrachial
fascia extends medially in front of the carotid vessels, and assists in
forming the carotid sheath. It is continued behind the depressor muscles of the
hyoid bone, and, after enveloping the thyroid gland, is prolonged in front of
the trachea to meet the corresponding layer of the opposite side.
Section of the neck at about the level of the sixth
cervical vertebra.
Showing the arrangement of the fascia
coli.
Above, it is fixed to the hyoid bone, while below it
is carried downward in front of the trachea and large vessels at the root of
the neck, and ultimately blends with the fibrous pericardium. This layer is
fused on either side with the prevertebral fascia, and with it completes the
compartment containing the larynx and trachea, the thyroid gland, and the
pharynx and esophagus.
Variations.—The
Sternocleidomastoideus varies much in the extent of its origin from the
clavicle: in some cases the clavicular head may be as narrow as the sternal; in
others it may be as much as
Triangles of the Neck.—This
muscle divides the quadrilateral area of the side of the neck into two
triangles, an anterior and a posterior. The boundaries of the anterior
triangle are, in front, the median line of the neck; above,
the lower border of the body of the mandible, and an imaginary line drawn from
the angle of the mandible to the Sternocleidomastoideus; behind, the
anterior border of the Sternocleidomastoideus. The apex of the triangle is at
the upper border of the sternum. The boundaries of the posterior triangle
are, in front, the posterior border of the Sternocleidomastoideus; below,
the middle third of the clavicle; behind, the anterior margin of the
Trapezius. The apex corresponds with the meeting of the Sternocleidomastoideus
and Trapezius on the occipital bone. The anatomy of these triangles will be
more fully described with that of the vessels of the neck (p. 562).
Nerves.—The
Sternocleidomastoideus is supplied by the accessory nerve and branches from the
anterior divisions of the second and third cervical nerves.
Actions.—When only one
Sternocleidomastoideus acts, it draws the head toward the shoulder of the same
side, assisted by the Splenius and the Obliquus capitis inferior of the
opposite side. At the same time it rotates the head so as to carry the face
toward the opposite side. Acting together from their sternoclavicular
attachments the muscles will flex the cervical part of the vertebral column. If
the head be fixed, the two muscles assist in elevating the thorax in forced
inspiration.
Sternocleidomastoid
region answers the projection of the same name muscle.
Lateral region of the neck is bordered by back
margin of the sternocleido-mastoid, anterior margin of the trapezius muscle and
upper margin of clavicle. There are follow areas in this region:
3.
Omo-trapezial trigone is bordered by
back margin of the sternocleidomastoid, lower belly of omohyoid and anterior
margin of the trapezius muscles.
4.
Omo-clavicular (greater
supraclavicular) trigone of neck is bordered by back margin of the
sternocleidomastoid, lower belly of omohyoid and upper margin of the clavicle.
Posterior
region answers the projection of the trapezius muscle.
Cervical
fascia
According V.M.Shevkunenko there are 5 cervical fasciae:
I - superficial cervical fascia envelops the platizma
Proper cervical fascia has two sheets:
II - superficial lamina of the proper cervical fasciae starts from
front surface of the sternum and clavicle, lower margin of mandible and
attaches the spinous processes of the cervical vertebrae. It forms the sheath
for sternocleidomastoid and trapezius muscles.
III - deep lamina of the proper cervical fasciae starts from back
surface of the sternum and clavicle and attaches to the hyoid bone from sides
bordered by omohyoid muscles. This fascia forms linea alba of neck and the
sheath for infrahyoid muscles.
Suprasternal interaponeurotic space made up
between superficial and deep lamina of the proper cervical fasciae. It contains
jugular venous arch and fat tissue. Suprasternal space connects with lateral
recesses located behind the lower part of sternocleidomastoid muscle.
s.
According international nomenclature (PNA)
there are 3 laminae of cervical fasciae:
IV - internal cervical fascia subdivides into parietal and visceral
sheets. Parietal lamina envelopes all organs of neck together and visceral –
each organ separately. Previsceral space positioned between
parietal and visceral laminae and contains adipose tissue, lymphatic nodes, and
nerves and communicates with anterior mediastinum. Pretracheal space located
before trachea between parietal and visceral sheet
V - prevertebral fascia envelops all deep cervical muscles forming
their sheathes. Retropharyngeal space made up between V fascia and parietal
lamina of IV fasciae. Retrovisceral space positioned
between internal cervical and prevertebral fasciae and contains adipose tissue
and continues into posterior mediastinum.
4.
Superficial lamina
meets the superficial lamina of the proper cervical fasciae according
V.M.Shevkunenko and contains the suprasternal
space.
5.
Pretracheal lamina meets
the deep lamina of the proper cervical fasciae according V.M.Shevkunenko and
forms carotid sheath.
6.
Prevertebral lamina meets
the same fasciae according V.M.Shevkunenko.