Question

9.   The hepatic portal system drains venous blood from

              a. capillaries in the intestines, spleen, pancreas, stomach and gallbladder into sinusoids in the liver

              b. the lower extremities and stomach into the spleen, from there into the inferior vena cava

              c. the stomach and kidneys into the liver and then on into the inferior vena cava

              d. the brachia into the liver, then into the inferior vena cava

              e. liver into the inferior vena cava

13. The main branches of the human aortic arch include all of the following EXCEPT

              a. right brachiocephalic artery

              b. right subclavian artery

              c. left subclavian artery

              d. left common carotid artery

              e. all of the above are direct branches of the aortic arch in humans (cats differ)

14. Lymph is drained from the thoracic duct into the

              a. cisterna chyli

              b. right jugular or subclavian vein

              c. left lymphatic duct

              d. right lymphatic duct

              e. left jugular or subclavian vein

Answer 1

9. (a)Capillaries in the intestines, spleen, pancreas, stomach, and gallbladder into sinusoids in the liver.

The portal venous system is responsible for 80% of total blood to the liver. It basically drains the abdominal part of the GI tract. Portal vein is contributed by splenic vein (which is contributed by inferior mesenteric vein) and superior mesenteric vein. Superior mesenteric vein drains blood from the small intestine. Inferior mesenteric vein drains blood from the large intestine. Splenic vein drains from spleen and pancreas. For gall bladder, we have a cystic vein that drains directly into the portal vein. Portal vein then drains to inferior vena cava through the hepatic veins.

Hence all other statements are wrong. The portal vein does not drain the kidneys.

13.(b)Right subclavian artery.

The right subclavian artery is not a direct branch of the arch of the aorta. It is derived from the right brachiocephalic artery. The right brachiocephalic artery divides into branches known as the right subclavian artery and the right common carotid artery.

Arch of the aorta in humans gives out three main branches. These are left subclavian artery, left common carotid artery, and right brachiocephalic artery ( or simply brachiocephalic vein because there is no left brachiocephalic artery, there are two left brachiocephalic veins).

14.(e)Left jugular or subclavian vein.

Lymph from the thoracic duct is drained into the left jugular vein or left subclavian vein. Thoracic duct is basically the largest lymphatic vessel of the body. It receives lymph from almost all the parts of the body except from those parts which are received from the right lymphatic duct.

Cisterna chyli is a sac-like structure found at the thoracic duct lower end that drains into the thoracic duct collecting lymph from lower extremities and intestinal tract.

The right lymphatic duct drains into the right jugular vein to the right subclavian vein.

Right lymphatic duct gets lymph from the right thoracic cavity, right arms, and right side of the head and neck.