Venous system

Venous system

 

SYSTEM of SUPERIOR VENA CAVA

Superior vena cava is generated by reason of confluence of right and left brachiocephalic veins behind joint of cartilage of first right rib with sternum. Superior vena cava on level of third right cartilage empties into right atrium. Azygos vein empties into superior vena cava from right side.

Brachiocephalic veins form by the confluence of subclavian vein, internal jugular and sometimes External jugular vein. This place is called as venous angle, where thoracic lymphatic duct empties (left side), and right lymphatic duct (right side). Inferior thyroid veins from thyroid plexus, inferior laryngeal vein and thymic vein, pericardial veins from pericardium, bronchic veins and esophageal veins from esophagus fall into brachiocephalic veins.

Azygos vein continues into thoracic cavity from right ascending lumbar vein. Azygos vein receives posterior intercostal veins, esophageal veins, bronchic veins, pericardial veins and mediastinal veins, also hemizygos vein.

Venous system of the heart carries largest part of deoxygenated blood into coronal sinus. Some veins empty in it:

-         greater cardiac vein [vena cordis magna], which passes in anterior interventricular sulcus and coronal sulcus;

-         lesser cardiac vein [vena cordis parva], which passes in right part of coronal sulcus;

-         middle cardiac vein [vena cordis media] passes in posterior interventricular sulcus;

-         posterior vein of left ventricle;

-         oblique vein of left atrium.

There are venae minimae (Tebezia) and anterior venae, positioned in myocardium of right atrium.

Internal jugular vein is a largest vessel, which drainage blood from area of head and neck. Internal jugular vein originates from sygmoid sinus of dura mater encephali, where it begins on level of jugular foramen by superior bulb and lies behind internal carotid artery and vagus nerve. Inferior jugular bulb is situated near the confluence with subclavian vein.

Internal jugular has the following extracranial influxes:

pharyngeal veins;

lingual vein;

superior thyroid vein;

facial vein, which receives retromandibular vein

retromandibular vein empties into facial vein, or into internal jugular vein.

Follow vessels belong to intracranial tributaries of internal jugular vein:

venous sinuses of dura mater encephali and veins of brain;

diploic veins from skull bones;

meningeal veins are from cranial dura mater;

superior ophthalmic vein and inferior ophtalmic vein is from sight organ;

labyrinthic veins - from internal ear;

emissary veins from intracranial veins and sinuses of dura mater and communicate with extracranial veins.

External jugular vein is generated by the confluence of occipital vein and posterior auricular vein, which accompany same name arteries. External jugular vein receives anterior jugular vein, which collect blood from anterior neck area and, anastomosing each other, form jugular venous arc.

Subclavian vein continues from axillary vein, lies in same name sulcus of first rib and collects blood from thoracic veins and dorsal scapular vein.

  The superior vena cava (v. cava superior) drains the blood from the upper half of the body. It measures about 7 cm. in length, and is formed by the junction of the two innominate veins. Itbegins immediately below the cartilage of the right first rib close to the sternum, and, descending vertically behind the first and second intercostal spaces, ends in the upper part of the right atrium opposite the upper border of the third right costal cartilage: the lower half of the vessel is within the pericardium. In its course it describes a slight curve, the convexity of which is to the right side.

 

Relations.In front are the anterior margins of the right lung and pleura with the pericardium intervening below; these separate it from the first and second intercostal spaces and from the second and third right costal cartilages; behind it are the root of the right lung and the right vagus nerve. On its right side are the phrenic nerve and right pleura; on its left side, the commencement of the innominate artery and the ascending aorta, the latter overlapping it. Just before it pierces the pericardium, it receives the azygos vein and several small veins from the pericardium and other contents of the mediastinal cavity. The portion contained within the pericardium is covered, in front and laterally, by the serous layer of the membrane. The superior vena cava has no valves.

  The azygos vein (v. azygos; vena azygos major) begins opposite the first or second lumbar vertebra, by a branch, the ascending lumbar vein (page 678); sometimes by a branch from the right renal vein, or from the inferior vena cava. It enters the thorax through the aortic hiatus in the diaphragm, and passes along the right side of the vertebral column to the fourth thoracic vertebra, where it arches forward over the root of the right lung, and ends in the superior vena cava, just before that vessel pierces the pericardium. In the aortic hiatus, it lies with the thoracic duct on the right side of the aorta; in the thorax it lies upon the intercostal arteries, on the right side of the aorta and thoracic duct, and is partly covered by pleura.

 Tributaries.It receives the right subcostal and intercostal veins, the upper three or four of these latter opening by a common stem, the highest superior intercostal vein. It receives the hemiazygos veins, several esophageal, mediastinal, and pericardial veins, and, near its termination, the right bronchial vein. A few imperfect valves are found in the azygos vein; but its tributaries are provided with complete valves.

  The intercostal veins on the left side, below the upper three intercostal spaces, usually form two trunks, named the hemiazygos and accessory hemiazygos veins.

  The Hemiazygos Vein (v. hemiazygos; vena azygos minor inferior) begins in the left ascending lumbar or renal vein. It enters the thorax, through the left crus of the diaphragm, and, ascending on the left side of the vertebral column, as high as the ninth thoracic vertebra, passes across the column, behind the aorta, esophagus, and thoracic duct, to end in the azygos vein. It receives the lower four or five intercostal veins and the subcostal vein of the left side, and some esophageal and mediastinal veins.

  The Accessory Hemiazygos Vein (v. hemiazygos accessoria; vena azygos minor superior) descends on the left side of the vertebral column, and varies inversely in size with the highest left intercostal vein. It receives veins from the three or four intercostal spaces between the highest left intercostal vein and highest tributary of the hemiazygos; the left bronchial vein sometimes opens into it. It either crosses the body of the eighth thoracic vertebra to join the azygos vein or ends in the hemiazygos. When this vein is small, or altogether wanting, the left highest intercostal vein may extend as low as the fifth or sixth intercostal space.

  In obstruction of the superior vena cava, the azygos and hemiazygos veins are one of the principal means by which the venous circulation is carried on, connecting as they do the superior and inferior venæ cavæ, and communicating with the common iliac veins by the ascending lumbar veins and with many of the tributaries of the inferior vena cava.

  The Bronchial Veins (vv. bronchiales) return the blood from the larger bronchi, and from the structures at the roots of the lungs; that of the right side opens into the azygos vein, near its termination; that of the left side, into the highest left intercostal or the accessory hemiazygos vein. A considerable quantity of the blood which is carried to the lungs through the bronchial arteries is returned to the left side of the heart through the pulmonary veins.

 The Veins of the Vertebral Column

  The veins which drain the blood from the vertebral column, the neighboring muscles, and the meninges of the medulla spinalis form intricate plexuses extending along the entire length of the column; these plexuses may be divided into two groups, external and internal, according to their positions inside or outside the vertebral canal. The plexuses of the two groups anastomose freely with each other and end in the intervertebral veins.

  The external vertebral venous plexuses (plexus venosi vertebrales externi; extraspinal veins) best marked in the cervical region, consist of anterior and posterior plexuses which anastomose freely with each other. The anterior external plexuses lie in front of the bodies of the vertebræ, communicate with the basivertebral and intervertebral veins, and receive tributaries from the vertebral bodies. The posterior external plexuses are placed partly on the posterior surfaces of the vertebral arches and their processes, and partly between the deep dorsal muscles. They are best developed in the cervical region, and there anastomose with the vertebral, occipital, and deep cervical veins.

 

  The internal vertebral venous plexuses (plexus venosi vertebrales interni; intraspinal veins) lie within the vertebral canal between the dura mater and the vertebræ, and receive tributaries from the bones and from the medulla spinalis. They form a closer net-work than the external plexuses, and, running mainly in a vertical direction, form four longitudinal veins, two in front and two behind; they therefore may be divided into anterior and posterior groups. Theanterior internal plexuses consist of large veins which lie on the posterior surfaces of the vertebral bodies and intervertebral fibrocartilages on either side of the posterior longitudinal ligament; under cover of this ligament they are connected by transverse branches into which the basivertebral veins open. The posterior internal plexuses are placed, one on either side of the middle line in front of the vertebral arches and ligamenta flava, and anastomose by veins passing through those ligaments with the posterior external plexuses. The anterior and posterior plexuses communicate freely with one another by a series of venous rings (retia venosa vertebrarum), one opposite each vertebra. Around the foramen magnum they form an intricate net-work which opens into the vertebral veins and is connected above with the occipital sinus, the basilar plexus, the condyloid emissary vein, and the rete canalis hypoglossi.

  The basivertebral veins (vv. basivertebrales) emerge from the foramina on the posterior surfaces of the vertebral bodies. They are contained in large, tortuous channels in the substance of the bones, similar in every respect to those found in the diploë of the cranial bones. They communicate through small openings on the front and sides of the bodies of the vertebræ with the anterior external vertebral plexuses, and converge behind to the principal canal, which is sometimes double toward its posterior part, and open by valved orifices into the transverse branches which unite the anterior internal vertebral plexuses. They become greatly enlarged in advanced age.

  The intervertebral veins (vv. intervertebrales) accompany the spinal nerves through the intervertebral foramina; they receive the veins from the medulla spinalis, drain the internal and external vertebral plexuses and end in the vertebral, intercostal, lumbar, and lateral sacral veins, their orifices being provided with valves.

  The veins of the medulla spinalis (vv. spinales; veins of the spinal cord) are situated in the pia mater and form a minute, tortuous, venous plexus. They emerge chiefly from the median fissures of the medulla spinalis and are largest in the lumbar region. In this plexus there are (1) two median longitudinal veins, one in front of the anterior fissure, and the other behind the posterior sulcus of the cord, and (2) four lateral longitudinal veins which run behind the nerve roots. They end in the intervertebral veins. Near the base of the skull they unite, and form two or three small trunks, which communicate with the vertebral veins, and then end in the inferior cerebellar veins, or in the inferior petrosal sinuses.

  Brachiocephalic veins are two large trunks, placed one on either side of the root of the neck, and formed by the union of the internal jugular and subclavian veins of the corresponding side; they are devoid of valves. The right brachiocephalic vein is a short vessel, about 2.5 cm. in length, which begins behind the sternal end of the clavicle, and, passing almost vertically downward, joins with the left innominate vein just below the cartilage of the first rib, close to the right border of the sternum, to form the superior vena cava. It lies in front and to the right of the innominate artery; on its right side are the phrenic nerve and the pleura, which are interposed between it and the apex of the lung. This vein, at its commencement, receives the right vertebral vein; and,lower down, the right internal mammary and right inferior thyroid veins, and sometimes the vein from the first intercostal space.

Veins of upper limb are subdivided into superficial and deep. They are communicated by numerous anastomoses and have valves.

  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 andabove, 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 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.

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.

 

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 receivesthe 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 obliqueintercapitular veins. They drain into a venous plexus which is situated over the thenar and hypothenar eminences and across the front of the wrist.

  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 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 anddeep 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 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.

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 axillar 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.

 

SYSTEM of INFERIOR VENA CAVA

Inferior vena cava starts on level IV-V lumbar vertebrae by the confluence of left common iliac vein and right common iliac vein, to the right and beneath from bifurcation of aorta. It passes through special foramen in centrum tendineum of diaphragm into mediastinum and empties into right atrium.

There are parietal and visceral influxes of inferior vena cava.

Parietal tributaries of inferior vena cava:

          lumbar veins are 3-4 pairs, which collect blood from areas according with ramification of lumbar arteries, they anastomose by right and left ascending lumbar veins;

          inferior phrenic veins collect blood from areas according with ramification same name arteries.

Follow veins are the visceral tributaries of inferior vena cava:

          in male - right testicular vein starts from posterior testicle margin. Testicular vein forms pampiniform plexus which enters to composition of spermatic cord. Left testicular vein (also left ovaric vein in famile) empties by right angle into left renal vein;

          in famile - right ovaric vein begins from ovary hilus;

          renal veins, pair, pass from kidney hilus and, anastomosing with lumbar veins, emptiy into inferior vena cava between lumbar vertebrae first and second;

          right suprarenal vein, exits from hilus of adrenal gland. Left suprarenal vein falls into left renal vein;

          hepatic veins (3-4) veins fall into inferior vena cava in area of same name sulcus in liver.

 

Vena portae hepatis is situated in thickness of hepatoduodenal ligament between ductus choledochus and proper hepatic artery (formula of their position DVA from right to left). It originates behind head of pancreas by the confluence of superior, inferior mesenteric veinc and splenic vein. It collects venous blood from odd organs of abdominal cavity, except liver. Vena portae receives cystic vein, right and left gastric veins and prepyloric vein closely to liver hilus. Paraumbilical veins fall into portal vein in liver hilus.

There are cava-caval and porto-caval anastomoses between systems of portal vein, superior and inferior vanea cavae (see table on the next page).

 

Anastomoses between the superior and inferior venae cavae systems

 

System

Veins

Veins

Position of anastomose

V. cava superior

And

v. cava inferior

v. epigastrica superior (tributary of the internal thoracic vein) and v. Thoracoepigastrica (tributary of the subclavian vein)

v. epigastrica inferior (tributary of the external iliac vein) and v. Epigastrica superficialis (tributary of the femoral vein)

In anterior abdominal wall round the navel

V. cava superior

And v. Cava inferior

vv. azygos and hemiazygos

vv. lumbales

On posterior abdominal wall

V. cava superior

And v. Cava inferior

Rr. spinales (tributary of the vv. Intercostales posteriores)

Rr. spinales (tributary of the vv. Lumbales)

Form internal and external vertebral plexus

 

Anastomoses between the superior and inferior venae cavae

and portal vein systems

 

V. cava superior and v. Portae

v. epigastrica superior (tributary of the internal thoracic vein)

Vv. paraumbilicales

In anterior abdominal wall round the navel

V. cava superior and v. Portae

Vv. esophageales (tributary of the azygos vein)

v. gastrica sinistra

Near gastric cardia

V. cava inferior and v. Portae

v. epigastrica inferior (tributary of the external iliac vein)

Vv. paraumbilicales

In anterior abdominal wall

V. cava inferior and v. Portae

V. rectalis media (tributary of the internal iliac vein)

V. rectalis superior (tributary of the inferior mesenteric vein)

Plexus venosus rectalis

V. cava inferior and v. Portae

Vv. lumbales

Vv. mesenterica superior and inferior

In thickness of ascending and descending colon

 

 

VEINS of PELVIS and LOWER LIMB

The common iliac veins arose on level of sacroiliac joint by the confluence of internal iliac vein and external iliac vein.

Internal iliac vein has parietal and visceral influxes according to ramification of same name arteries.

Visceral tributaries of internal iliac vein form from such venous plexuses:

          sacral venous plexus;

          vesical venous plexus;

          rectal venous plexus.

External iliac vein is continuation of femoral vein and receives blood from all veins of lower limb. Inferior epigastric vein and deep circumflex ilei vein empties into external iliac vein under inguinal ligament.

The veins of lower limb subdivide into superficial and deep. Deep veins are double and accompany same name artery (only a popliteal vein and femoral vein are odd).

Follow veins belong to superficial veins of lower limb:

1.     Vena saphena magna has numerous valves, starts in front of medial malleolus, where receives influxes from plantar surface of foot, passes along saphenus nerve on medial leg surface upward, than on medial surface on thigh to saphaenus hiatus, where transfixes cribriform fascia and empties into femoral vein. Vena saphena magna has the numerous subcutaneous tributaries from anteromedial surface of leg, thigh and external genitals.

2.     Vena saphena parva has the numerous valves and collects blood from dorsal venous arch of foot, passes behind lateral malleolus, lies into sulcus between lateral and medial heads of gastrocnemius muscle and in popliteal fossa empties into popliteal vein.

Follow vessels belong to deep veins of lower limb:

          femoral vein;

          deep femoral vein;

          popliteal vein;

          anterior tibial veins;

          posterior tibial veins;

          fibular veins.

Circulatory system of the foetus has a row of peculiarities that differ from adult one:

-         arterial blood reaches the foetus through umbilical vein from placenta;

-         exclusive of umbilical vein, a blood in vessels is mixed;

-         venous (ranti) duct functions between umbilical and inferior vena cava by veins;

-         blood from inferior vena cava gets from right atrium through the ovale foramen into left atrium;

-         pulmonary circulation does not function;

-         arterial (Botalova) duct functions between aortic arch and pulmonary trunk, through the which blood from pulmonary blood circle passes in systemic circulation;

-         more oxygenated blood supplies head, neck, upper limbs and superior part of torso. Inferior part of trunk and lower limbs supplied by mixed blood, which is insufficiently saturated by oxygen, that's why these body portions of foetus fall behind in development in compare of head and upper part of torso.

After birth breath starts and pulmonary circulation begins to function. Umbilical vessels overgrow in 6-7 days, Botali duct - in 9-10 days and oval foramen in interatrial wall in 30 days after birth.