1. The Veins Dr.Pardeep kumar

2. Introduction: Introduction: The veins convey the blood from the different parts of the body to the heart. The veins convey the blood from the different parts of the body to the heart. The capillaries converge into very small vessels called venules, which, in turn, join to form larger vessels called veins. The major veins return blood to the atria of the heart. The capillaries converge into very small vessels called venules, which, in turn, join to form larger vessels called veins. The major veins return blood to the atria of the heart.

3. After the blood leaves the capillaries, its pressure continues to drop; it is lowest near the right atrium of the heart in the superior and inferior venae cavae. With the progressive change from capillaries to venules to veins, the diameters of individual vessels and the thickness of their walls steadily increase, whereas the total cross- sectional area of parallel vessels decreases. Venous pressure is always lower than arterial pressure, and the walls of the veins are never as thick as the walls of the corresponding arteries. After the blood leaves the capillaries, its pressure continues to drop; it is lowest near the right atrium of the heart in the superior and inferior venae cavae. With the progressive change from capillaries to venules to veins, the diameters of individual vessels and the thickness of their walls steadily increase, whereas the total cross- sectional area of parallel vessels decreases. Venous pressure is always lower than arterial pressure, and the walls of the veins are never as thick as the walls of the corresponding arteries. The veins consist of the pulmonary and systemic ones. The veins consist of the pulmonary and systemic ones.

4. The characteristics of the veins are as follows: The characteristics of the veins are as follows: 1) The rate of flow of the blood in veins being slower than in the arteries. 1) The rate of flow of the blood in veins being slower than in the arteries. 2) Veins are larger and more numerous than the corresponding arteries so that the blood delivered to tissues can be adequately returned to the heart. 2) Veins are larger and more numerous than the corresponding arteries so that the blood delivered to tissues can be adequately returned to the heart.

5. 3) Venous valve: Most veins are provided with valves which serve to prevent the reflux of the blood. The valves are very numerous in the veins of the extremities, especially in the veins of lower limbs, these veins having to conduct the blood against the force of gravity in addition to being subjected to intermittent pressure due to muscular contractions 3) Venous valve: Most veins are provided with valves which serve to prevent the reflux of the blood. The valves are very numerous in the veins of the extremities, especially in the veins of lower limbs, these veins having to conduct the blood against the force of gravity in addition to being subjected to intermittent pressure due to muscular contractions

6. 4) The systemic veins can be divided into the superficial and deep veins. 4) The systemic veins can be divided into the superficial and deep veins. The superficial veins, which lie just beneath the skin (in the superficial fascia, in the hypodermis, immediately under the skin), return blood from the skin and the subcutaneous regions to the deep veins.They freely anastomose with one another, and they also communicate with the deep veins. The superficial veins, which lie just beneath the skin (in the superficial fascia, in the hypodermis, immediately under the skin), return blood from the skin and the subcutaneous regions to the deep veins.They freely anastomose with one another, and they also communicate with the deep veins.

7. The deep veins accompany the arteries. Most of the deep veins travel alongside an artery and have the same name as the artery. Accompanying the smaller arteries, as the radial, ulnar, brachial, tibial, or peroneal, the deep veins exist generally in pairs, one lying on each side of the artery, and are called venae comitantes. In certain regions, however, the deep veins do not accompany the arteries. The deep veins accompany the arteries. Most of the deep veins travel alongside an artery and have the same name as the artery. Accompanying the smaller arteries, as the radial, ulnar, brachial, tibial, or peroneal, the deep veins exist generally in pairs, one lying on each side of the artery, and are called venae comitantes. In certain regions, however, the deep veins do not accompany the arteries.

8. 5) The anastomoses between veins are more numerous. 5) The anastomoses between veins are more numerous. 6) Specific structural veins includes sinus of dura mater and diploic vein. 6) Specific structural veins includes sinus of dura mater and diploic vein. Venous sinuses are not actually vessels, but are spaces that collect blood in certain regions and return it to the veins. The walls of venous sinuses are composed of connective tissue, with no muscle present, and they are lined with endothelium that is continuous with the endothelium of the capillaries and veins. Venous sinuses are not actually vessels, but are spaces that collect blood in certain regions and return it to the veins. The walls of venous sinuses are composed of connective tissue, with no muscle present, and they are lined with endothelium that is continuous with the endothelium of the capillaries and veins. Larger venous sinuses are located in the dura mater, the outer meningeal covering of the brain. Larger venous sinuses are located in the dura mater, the outer meningeal covering of the brain.

9. Ⅰ. The Veins of Pulmonary Circulation The pulmonary veins are four in number, two from each lung, and are devoid of valves. The pulmonary veins are four in number, two from each lung, and are devoid of valves. They return the oxygenated blood from the lungs, perforate the fibrous layer of the pericardium and open separately into the upper and posterior part of the left atrium of the heart. They return the oxygenated blood from the lungs, perforate the fibrous layer of the pericardium and open separately into the upper and posterior part of the left atrium of the heart.

10. Ⅱ. The Veins of Systemic Circulation They may be arranged into three groups, They may be arranged into three groups, The superior vena cava and its tributaries The superior vena cava and its tributaries The inferior vena cava and its tributaries The inferior vena cava and its tributaries The veins of the heart. The veins of the heart.

11. Ⅰ ) The System of Superior Vena Cava It includes the superior vena cava and its tributaries. It collects the blood from the head and neck, the upper limbs, the wall and some organs (with the exception of heart and lungs) of the thorax, and a portion of the upper part of the wall of the abdomen. It includes the superior vena cava and its tributaries. It collects the blood from the head and neck, the upper limbs, the wall and some organs (with the exception of heart and lungs) of the thorax, and a portion of the upper part of the wall of the abdomen.

12. The superior vena cava The superior vena cava It is formed by the junction of two brachiocephalic (innominate) veins behind the lower border of the first right costal cartilage close to the sternum, and has no valves. It descends vertically on the right of the ascending aorta, and ends in the upper part of the right atrium opposite the third costal cartilage. It is formed by the junction of two brachiocephalic (innominate) veins behind the lower border of the first right costal cartilage close to the sternum, and has no valves. It descends vertically on the right of the ascending aorta, and ends in the upper part of the right atrium opposite the third costal cartilage.

14. Brachiocephalic (innominate) veins They are two large trunks. Each is formed, behind the sternal end of the clavicle, by the union of the internal jugular and subclavian veins of its side. They are two large trunks. Each is formed, behind the sternal end of the clavicle, by the union of the internal jugular and subclavian veins of its side. The angle of the union is termed the venous angle. The angle of the union is termed the venous angle. The tributaries of the brachiocephalic veins are The tributaries of the brachiocephalic veins are the vertebral the vertebral internal thoracic internal thoracic inferior thyroid veins. inferior thyroid veins.

15. The internal jugular vein It collects the blood from the brain, superficial parts of the face and neck. It begins at the skull in the jugular foramen, as a direct continuation of the sigmoid sinus, runs downwards through the neck within the carotid sheath, and behind the sternoclavicular joint, unites with the subclavian vein to form the brachiocephalic vein. It collects the blood from the brain, superficial parts of the face and neck. It begins at the skull in the jugular foramen, as a direct continuation of the sigmoid sinus, runs downwards through the neck within the carotid sheath, and behind the sternoclavicular joint, unites with the subclavian vein to form the brachiocephalic vein.

17. The chief extracranial tributaries of the internal jugular vein are: The chief extracranial tributaries of the internal jugular vein are: ① The facial vein ① The facial vein It begins at the medial angle of the eye, and runs obliquely downwards and backwards behind the facial artery. A little below the angle of the mandible it is joined by the anterior branch of retromandibular vein. It begins at the medial angle of the eye, and runs obliquely downwards and backwards behind the facial artery. A little below the angle of the mandible it is joined by the anterior branch of retromandibular vein.

18. The communication with cavernous sinus: The communication with cavernous sinus: The facial vein has no valves and it communicates with the cavernous sinus by two routes: The facial vein has no valves and it communicates with the cavernous sinus by two routes: a. firstly, through connections directly with the ophthalmic vein, a. firstly, through connections directly with the ophthalmic vein, b. secondly, by the deep facial vein, which links it to pterygoid plexus and hence also to the cavernous sinus. b. secondly, by the deep facial vein, which links it to pterygoid plexus and hence also to the cavernous sinus.

19. Thus infective thrombosis of the facial vein may extend into the intracranial venous sinuses. Thus infective thrombosis of the facial vein may extend into the intracranial venous sinuses. hence, the territory of the facial veins around the nose and the upper lip is frequently termed the “ danger area ” of the face. hence, the territory of the facial veins around the nose and the upper lip is frequently termed the “ danger area ” of the face.

20. ② Retromandibular vein ② Retromandibular vein It is formed by the union of the superficial temporal vein and maxillary vein. It is formed by the union of the superficial temporal vein and maxillary vein. It descends in the substance of the parotid gland, and divides into two branches: It descends in the substance of the parotid gland, and divides into two branches: an anterior which passes forwards and unites the facial vein, an anterior which passes forwards and unites the facial vein, a posterior which is joined by posterior auricular vein to form the external jugular vein. a posterior which is joined by posterior auricular vein to form the external jugular vein.

21. Pterygoid plexus: Pterygoid plexus: The pterygoid plexus is placed between the temporalis and pterygoid muscles. The pterygoid plexus is placed between the temporalis and pterygoid muscles. It anastomoses with the facial vein through the deep facial vein; it is also connected with the cavernous sinus by veins which pass through the emissary foramen. It anastomoses with the facial vein through the deep facial vein; it is also connected with the cavernous sinus by veins which pass through the emissary foramen. The maxillary vein begins in the pterygoid plexus. The maxillary vein begins in the pterygoid plexus. In addition, the internal jugular vein receives the veins of the tongue, the superior and middle thyroid veins, and the pharyngeal veins. In addition, the internal jugular vein receives the veins of the tongue, the superior and middle thyroid veins, and the pharyngeal veins.

22. 2) The subclavian vein It is the continuation of the axillary vein. It is the continuation of the axillary vein. Its tributaries are the external jugular vein, and sometimes the anterior jugular vein. Its tributaries are the external jugular vein, and sometimes the anterior jugular vein. The external jugular vein: The external jugular vein: The external jugular vein is formed by the union of the posterior division of the retromandibular vein with the posterior auricular vein. It runs down the neck, crosses the sternocleidomastoid obliquely, and in the supraclavicular triangle perforates the deep fascia to end in the subclavian vein. The external jugular vein is formed by the union of the posterior division of the retromandibular vein with the posterior auricular vein. It runs down the neck, crosses the sternocleidomastoid obliquely, and in the supraclavicular triangle perforates the deep fascia to end in the subclavian vein.

24. 3) The veins of upper limb They are divided into two sets, superficial and deep, which anastomose freely with each other. They are divided into two sets, superficial and deep, which anastomose freely with each other.

25. ① The superficial veins of upper limb ① The superficial veins of upper limb They are placed immediately under the skin, in the superficial fascia. They are placed immediately under the skin, in the superficial fascia. They are the They are the Cephalic Cephalic Basilic Basilic median cubital veins, median cubital veins, and their tributaries. and their tributaries.

26. The cephalic vein begins in the radial part of the dorsal venous rete of hand and winds upwards round the radial border of the forearm to its anterior surface; it then ascends subcutaneously along the lateral side of the forearm and arm to the upper one-third of the arm, where it lies in the groove between the pectoralis major and deltoid, and pierces the deep fascia to end in the axillary vein or subclavian vein. The cephalic vein begins in the radial part of the dorsal venous rete of hand and winds upwards round the radial border of the forearm to its anterior surface; it then ascends subcutaneously along the lateral side of the forearm and arm to the upper one-third of the arm, where it lies in the groove between the pectoralis major and deltoid, and pierces the deep fascia to end in the axillary vein or subclavian vein. The basilic vein begins in the ulnar part of the dorsal venous rete of hand. The basilic vein begins in the ulnar part of the dorsal venous rete of hand.

28. It runs up for some distance on the posterior surface of the ulnar side of the forearm but inclines forwards to the anterior surface below the elbow; it then ascends medial to biceps, and perforates the deep fascia a little below the middle of the arm to end in the brachial vein. It runs up for some distance on the posterior surface of the ulnar side of the forearm but inclines forwards to the anterior surface below the elbow; it then ascends medial to biceps, and perforates the deep fascia a little below the middle of the arm to end in the brachial vein. The median cubital vein is given off from the cephalic vein below the front of the elbow, and passes medially to join the basilic vein. The median cubital vein is given off from the cephalic vein below the front of the elbow, and passes medially to join the basilic vein.

29. Significance: Significance: Blood sampling and transfusion, and intravenous injection in general, are often performed at the bend of the elbow, the largest vein, usually the median cubital vein, is commonly selected. Blood sampling and transfusion, and intravenous injection in general, are often performed at the bend of the elbow, the largest vein, usually the median cubital vein, is commonly selected.

30. 3. The azygos vein It begins as the continuation of the right ascending lumbar vein. It ascends along the right side of the thoracic vertebrae to the fourth thoracic vertebra, where it arches forwards over the root of the right lung to end in the superior vena cava. It begins as the continuation of the right ascending lumbar vein. It ascends along the right side of the thoracic vertebrae to the fourth thoracic vertebra, where it arches forwards over the root of the right lung to end in the superior vena cava. The azygos vein receives the posterior intercostal veins of the right side, the hemiazygos and accessory hemiazygos and the right bronchial veins. The azygos vein receives the posterior intercostal veins of the right side, the hemiazygos and accessory hemiazygos and the right bronchial veins.

32. 1) The hemiazygos vein It begins as the continuation of the left ascending lumbar vein. It ascends on the left of the thoracic vertebrae as high as the eighth thoracic vertebra, then passes across the column to end in the azygos vein. It begins as the continuation of the left ascending lumbar vein. It ascends on the left of the thoracic vertebrae as high as the eighth thoracic vertebra, then passes across the column to end in the azygos vein. The hemiazygos vein receives the lower posterior intercostal and subcostal veins of the left side, the accessory hemiazygos vein and some esophageal veins. The hemiazygos vein receives the lower posterior intercostal and subcostal veins of the left side, the accessory hemiazygos vein and some esophageal veins.

33. 2) The accessory hemiazygos vein It descends on the left side of the vertebral column, corsses the body of the seventh thoracic vertebra and joins the azygos vein, sometimes joins the hemiazygos veins. It descends on the left side of the vertebral column, corsses the body of the seventh thoracic vertebra and joins the azygos vein, sometimes joins the hemiazygos veins. The accessory hemiazygos vein receives the left fourth to eighth posterior intercostal veins. The accessory hemiazygos vein receives the left fourth to eighth posterior intercostal veins.

35. 3) The veins of spinal column The external vertebral plexus. The external vertebral plexus. The internal vertebral plexus. The internal vertebral plexus.

36. Ⅱ ) The System of Inferior Vena Cava It includes the inferior vena cava and its tributaries. It collects the venous blood from the lower part of the body. It includes the inferior vena cava and its tributaries. It collects the venous blood from the lower part of the body.

37. 1. The inferior vena cava It is the largest venous trunk which conveys blood to the right atrium of the heart from all the body below the diaphragm. It is the largest venous trunk which conveys blood to the right atrium of the heart from all the body below the diaphragm. It is formed by junction of the two common iliac veins anterior to the fifth lumbar vertebra, a little to the right. It is formed by junction of the two common iliac veins anterior to the fifth lumbar vertebra, a little to the right.

38. It ascends in front of the vertebral column, on the right side of the abdominal aorta. Reaching the liver it is contained in the sulcus for inferior vena cava on its posterior surface. It then passes the vena caval foramen of the diaphragm, and pierces the fibrous pericardium to open into the lower posterior part of the right atrium. It ascends in front of the vertebral column, on the right side of the abdominal aorta. Reaching the liver it is contained in the sulcus for inferior vena cava on its posterior surface. It then passes the vena caval foramen of the diaphragm, and pierces the fibrous pericardium to open into the lower posterior part of the right atrium.

39. 2. The common iliac vein It is formed by the union of the external and internal iliac veins, in front of the sacroiliac joint; passing obliquely upwards, it ends on the right side of the fifth lumbar vertebra by uniting with opposite one at an acute angle to form the inferior vena cava. It is formed by the union of the external and internal iliac veins, in front of the sacroiliac joint; passing obliquely upwards, it ends on the right side of the fifth lumbar vertebra by uniting with opposite one at an acute angle to form the inferior vena cava.

41. 1) The internal iliac vein Like arteries, the tributaries of the internal iliac vein can be divided into parietal and visceral. Like arteries, the tributaries of the internal iliac vein can be divided into parietal and visceral. The visceral tributaries begin in the venous plexuses which surround the rectum, bladder, prostate, uterus and vagina. The visceral tributaries begin in the venous plexuses which surround the rectum, bladder, prostate, uterus and vagina.

43. The rectal plexus consists of two parts, an internal in the submucosa and an external outside the muscular coat of the rectum and anal canal. The two parts communicate freely with each other. The rectal plexus consists of two parts, an internal in the submucosa and an external outside the muscular coat of the rectum and anal canal. The two parts communicate freely with each other. The external plexus is drained by the anal veins into the internal pudendal vein, the inferior rectal vein into the internal iliac vein, and the superior rectal into the inferior mesenteric vein. The external plexus is drained by the anal veins into the internal pudendal vein, the inferior rectal vein into the internal iliac vein, and the superior rectal into the inferior mesenteric vein.

44. 2) The external iliac vein It is the upward continuation of the femoral vein, and begins behind the inguinal ligament. It is the upward continuation of the femoral vein, and begins behind the inguinal ligament. It collects the blood from the lower limb and the lower portion of the abdominal wall. It collects the blood from the lower limb and the lower portion of the abdominal wall.

45. 3) The veins of lower limb They can be divided, like those of the upper limb, into two sets, superficial and deep; the superficial veins are immediately under the skin in superficial fascia, the deep veins accompany the arteries. They can be divided, like those of the upper limb, into two sets, superficial and deep; the superficial veins are immediately under the skin in superficial fascia, the deep veins accompany the arteries.

46. ① The superficial veins of lower limb ① The superficial veins of lower limb They are the great and small saphenous veins and their tributaries. They are the great and small saphenous veins and their tributaries. The small saphenous vein The small saphenous vein It begins in the dorsal venous arch of foot, at the lateral margin of the foot, passes behind the lateral malleolus, ascends along the midline of the back of the leg, perforates the deep fascial in the lower part of the popliteal fossa, and ends in the popliteal vein. It begins in the dorsal venous arch of foot, at the lateral margin of the foot, passes behind the lateral malleolus, ascends along the midline of the back of the leg, perforates the deep fascial in the lower part of the popliteal fossa, and ends in the popliteal vein.

48. The great saphenous vein The great saphenous vein It begins in the dorsal venous arch of foot, at the medial margin of the foot, passes in front of the medial malleolus, and ascends along the medial side of the leg to the knee. It begins in the dorsal venous arch of foot, at the medial margin of the foot, passes in front of the medial malleolus, and ascends along the medial side of the leg to the knee. It runs upwards posteromedial to the medial condyle of the femur and along the medial side of the thigh to the saphenous hiatus, where it drains into the femoral vein. It runs upwards posteromedial to the medial condyle of the femur and along the medial side of the thigh to the saphenous hiatus, where it drains into the femoral vein.

49. Before perforating the cribriform fascia of the saphenous hiatus it receives the flowing superficial: Before perforating the cribriform fascia of the saphenous hiatus it receives the flowing superficial: The superficial epigastric vein, The superficial epigastric vein, The superficial iliac circumflex vein, The superficial iliac circumflex vein, The external pudendal vein, The external pudendal vein, The superficial medial femoral vein, The superficial medial femoral vein, The superficial lateral femoral vein. The superficial lateral femoral vein.

50. The saphenous veins frequently become dilated and tortuous, called the varicose vein. The saphenous veins frequently become dilated and tortuous, called the varicose vein. In operating upon varicose vein all the tributaries at the groin have to be ligated as well as the main saphenous trunk; if one tributary escapes, it in turn becomes dilated and produces recurrence of the varicose. In operating upon varicose vein all the tributaries at the groin have to be ligated as well as the main saphenous trunk; if one tributary escapes, it in turn becomes dilated and produces recurrence of the varicose.

51. ② The deep veins of lower limb ② The deep veins of lower limb They accompany the arteries and their branches and are similarly named. The veins of the foot and leg are generally in pairs. They accompany the arteries and their branches and are similarly named. The veins of the foot and leg are generally in pairs.

52. 3. The tribuaries of the inferior vena cava They are also divided into parietal and visceral. They are also divided into parietal and visceral. 1) The parietal tributaries 1) The parietal tributaries They are the inferior phrenic and lumbar veins, which accompany the corresponding arteries. They are the inferior phrenic and lumbar veins, which accompany the corresponding arteries. The lumbar veins are connected by a longitudinal vessel which is termed the ascending lumbar vein. The lumbar veins are connected by a longitudinal vessel which is termed the ascending lumbar vein.

53. 2) The visceral tributaries 2) The visceral tributaries ① The testicular veins ① The testicular veins They issue from the testis and epididymis and form a convoluted plexus, called the pampiniform plexus, the chief constituents of the spermatic cord. They issue from the testis and epididymis and form a convoluted plexus, called the pampiniform plexus, the chief constituents of the spermatic cord. The right testicular vein opens into the inferior vena cave, and the left testicular veins opens into the left renal vein at a right angle. The right testicular vein opens into the inferior vena cave, and the left testicular veins opens into the left renal vein at a right angle. The ovarian veins in the female correspond with the testicular veins in the male. The ovarian veins in the female correspond with the testicular veins in the male.

54. ② The renal veins ② The renal veins They issue from the hilum of each kidney, and open into the inferior vena cava almost at a right angle. The left is thrice the length of the right. They issue from the hilum of each kidney, and open into the inferior vena cava almost at a right angle. The left is thrice the length of the right. ③ The suprarenal veins ③ The suprarenal veins They accompany the middle suprarenal arteries. The right opens into the inferior vena cava, and the left into the left renal vein. They accompany the middle suprarenal arteries. The right opens into the inferior vena cava, and the left into the left renal vein.

56. ④ The hepatic veins ④ The hepatic veins They are usually three in number, the right, middle and left, collect the blood which has passed through the liver from the hepatic portal vein and hepatic artery. They are usually three in number, the right, middle and left, collect the blood which has passed through the liver from the hepatic portal vein and hepatic artery. They emerge from the posterior surface of the liver and open immediately into the inferior vena cava as it lies in the groove on the posterior surface of the liver. They emerge from the posterior surface of the liver and open immediately into the inferior vena cava as it lies in the groove on the posterior surface of the liver.

57. Hepatic portal venous system It constitutes the hepatic portal vein and its tributaries. It includes all the veins collecting the blood from the abdominal part of the alimentary tract (with the exception of the lower part of the anal canal) and from the spleen, pancreas and gallbladder. It constitutes the hepatic portal vein and its tributaries. It includes all the veins collecting the blood from the abdominal part of the alimentary tract (with the exception of the lower part of the anal canal) and from the spleen, pancreas and gallbladder. From these viscera the blood is conveyed into the liver by the hepatic portal vein. In the liver this vein ramifies like an artery and ends in capillary- like vessels termed sinusoids. From these viscera the blood is conveyed into the liver by the hepatic portal vein. In the liver this vein ramifies like an artery and ends in capillary- like vessels termed sinusoids.

58. 1)The characteristics of the hepatic portal venous system 1)The characteristics of the hepatic portal venous system ① The blood of the portal system passes through two sets of “ exchange ” vessels: the capillaries of the alimentary tract, spleen, pancreas and gallbladder; and the sinusoids of the liver. ① The blood of the portal system passes through two sets of “ exchange ” vessels: the capillaries of the alimentary tract, spleen, pancreas and gallbladder; and the sinusoids of the liver. ② The hepatic portal vein and its tributaries have no valves. ② The hepatic portal vein and its tributaries have no valves.

59. 2) The formation of the hepatic portal vein 2) The formation of the hepatic portal vein The hepatic portal vein is formed by the junction of the superior mesenteric and splenic veins, behind the neck of pancreas. The hepatic portal vein is formed by the junction of the superior mesenteric and splenic veins, behind the neck of pancreas. It is about 6 — 8 cm long, passes upwards behind the first part of the duodenum, then ascends in the right border of the lesser omentum to reach the right end of the porta hepatis where it divides into right and left stems, which accompany the corresponding branches of the proper hepatic artery into the substance of the liver. It is about 6 — 8 cm long, passes upwards behind the first part of the duodenum, then ascends in the right border of the lesser omentum to reach the right end of the porta hepatis where it divides into right and left stems, which accompany the corresponding branches of the proper hepatic artery into the substance of the liver. In the lesser omentum it is placed behind the common bile duct and the proper hepatic artery, the former lying to the right of the latter. In the lesser omentum it is placed behind the common bile duct and the proper hepatic artery, the former lying to the right of the latter.

60. 3) The tributaries of the hepatic portal vein 3) The tributaries of the hepatic portal vein ① The superior mesenteric vein ① The superior mesenteric vein It receives the veins from the organs supplied by the branches of the superior mesenteric and gastroduodenal arteries. It receives the veins from the organs supplied by the branches of the superior mesenteric and gastroduodenal arteries. ② The splenic vein ② The splenic vein It drains the short gastric, left gastroepiploic, the pancreatic and the inferior mesenteric veins. It drains the short gastric, left gastroepiploic, the pancreatic and the inferior mesenteric veins.

62. ③ The inferior mesenteric vein ③ The inferior mesenteric vein Its tributaries correspond to the branches of the inferior mesenteric artery. Its tributaries correspond to the branches of the inferior mesenteric artery. ④ The left gastric vein ④ The left gastric vein ⑤ The right gastric vein ⑤ The right gastric vein ⑥ The cystic vein ⑥ The cystic vein ⑦ The paraumbilical veins ⑦ The paraumbilical veins

63. 4) The anastomoses between the hepatic portal venous system and vena caval system 4) The anastomoses between the hepatic portal venous system and vena caval system These anastomoses, which may collectively offer an effective collateral circulation in case of obstruction of the hepatic portal vein, are as follows: These anastomoses, which may collectively offer an effective collateral circulation in case of obstruction of the hepatic portal vein, are as follows:

64. ① The esophageal venous plexus ① The esophageal venous plexus In the abdominal part of the esophagus, tributaries of the left gastric vein (portal drainage) anastomose with the esophageal tributaries of the azygos veins (superior vena caval drainage), viz. In the abdominal part of the esophagus, tributaries of the left gastric vein (portal drainage) anastomose with the esophageal tributaries of the azygos veins (superior vena caval drainage), viz. Hepatic portal v. → Left gastric v. → Esophageal venous plexus → esophageal tributaries → azygos v. → Superior vena cava. Hepatic portal v. → Left gastric v. → Esophageal venous plexus → esophageal tributaries → azygos v. → Superior vena cava.

66. ② The rectal venous plexus ② The rectal venous plexus In the wall of the anal canal, the superior rectal vein (portal drainage) anastomoses with the inferior rectal vein (inferior vena caval drainage), viz. In the wall of the anal canal, the superior rectal vein (portal drainage) anastomoses with the inferior rectal vein (inferior vena caval drainage), viz. Hepatic portal v. → Splenic v. → Inferior mesenteric v. → Superior rectal v. → Rectal venous plexus → inferior rectal and anal v. → Internal iliac v. → Common iliac v. → Inferior vena cava. Hepatic portal v. → Splenic v. → Inferior mesenteric v. → Superior rectal v. → Rectal venous plexus → inferior rectal and anal v. → Internal iliac v. → Common iliac v. → Inferior vena cava.

67. ③ The periumbilical venous network ③ The periumbilical venous network At the umbilicus, the fine paraumbilical veins (portal drainage) anastomose with the superificial and deep epigastric vein (caval drainage). Viz. At the umbilicus, the fine paraumbilical veins (portal drainage) anastomose with the superificial and deep epigastric vein (caval drainage). Viz. Hepatic portal v. → Paraumbilical v. → Periumbilical venous network → the following routes: Hepatic portal v. → Paraumbilical v. → Periumbilical venous network → the following routes:

68. a) Superficial epigastric v. → Great saphenous v. → Femoral v. → External iliac v. Common iliac v. → inferior vena cava. a) Superficial epigastric v. → Great saphenous v. → Femoral v. → External iliac v. Common iliac v. → inferior vena cava. b) Thoracoepigastric v. → Lateral thoracic v. → Axillary v. → Subclavian v. Brachiocephalic v. → Superior vena cava. b) Thoracoepigastric v. → Lateral thoracic v. → Axillary v. → Subclavian v. Brachiocephalic v. → Superior vena cava. C) Superior epigastric v. → Internal thoracic v. → Brachiocephalic v. → Superior vena cava. C) Superior epigastric v. → Internal thoracic v. → Brachiocephalic v. → Superior vena cava. d) Inferior epigastric v. → External iliac v. → Common iliac v. → Inferior vena cava. d) Inferior epigastric v. → External iliac v. → Common iliac v. → Inferior vena cava.

69. ④ The internal and external vertebral plexus ④ The internal and external vertebral plexus Hepatic portal v. → superior and inferior mesenteric veins → small veins of the posterior abdominal wall → internal and external vertebral plexus → posterior intercostal veins and lumbar veins → inferior vena cava. Hepatic portal v. → superior and inferior mesenteric veins → small veins of the posterior abdominal wall → internal and external vertebral plexus → posterior intercostal veins and lumbar veins → inferior vena cava.

70. 5) The clinical significance 5) The clinical significance Normally, the hepatic portal venous blood traverses the liver and empties into the inferior vena cava. Normally, the hepatic portal venous blood traverses the liver and empties into the inferior vena cava.

71. This pathway may be obstructed by various causes, e.g., the pressure of a tumor on the hepatic portal vein, the cirrhosis of liver, the valvular disease of the heart. This pathway may be obstructed by various causes, e.g., the pressure of a tumor on the hepatic portal vein, the cirrhosis of liver, the valvular disease of the heart. In this condition, the portal venous pressure rises and collateral pathways open up between the portal and caval venous systems. The anastomotic veins then become dilated and varicose and they may even rupture to lead to a fatal hematemesis or hematochezia. In this condition, the portal venous pressure rises and collateral pathways open up between the portal and caval venous systems. The anastomotic veins then become dilated and varicose and they may even rupture to lead to a fatal hematemesis or hematochezia.

72. The varicose veins are called the esophageal varices in the esophagus, the hemorrhoids in the rectum, and the “ caput meusae ” around the umbilicus. The varicose veins are called the esophageal varices in the esophagus, the hemorrhoids in the rectum, and the “ caput meusae ” around the umbilicus. Some success has been achieved in case of portal obstruction by anastomosis of the portal vein to the inferior vena cava, of the splenic vein to the left renal vein, after removal of the spleen. Some success has been achieved in case of portal obstruction by anastomosis of the portal vein to the inferior vena cava, of the splenic vein to the left renal vein, after removal of the spleen.