MDCAT XI Biology Circulation Online Test-2

1. Which feature of capillary walls primarily facilitates the diffusion of dissolved substances between blood and tissues?

2. Why are larger plasma proteins generally unable to pass through capillary walls?

3. What is the main reason veins are described as a ‘low resistance pathway’ for blood return?

4. Read the following statements about the role of arterioles in vasodilation and vasoconstriction, then choose the correct combination:

I. The muscular walls of arterioles respond only to neural signals and are unaffected by hormones or local chemicals.

II. On a hot summer day, arterioles in the skin dilate, which increases blood flow to the skin capillaries, helping the body lose excess heat.

III. In extremely cold weather, arterioles supplying the extremities constrict, which helps reduce heat loss but can lead to frostbite in fingers and toes.

IV. Vasoconstriction of skin arterioles during cold conditions helps maintain internal body temperature by minimizing heat dissipation through the skin.

Which of the following options is correct?

5. Read the following sequence describing the circulation of blood in a healthy adult human. For each step, identify the correct structure or vessel involved in that step.

I. Blood that has delivered oxygen to the body returns back and enters the first chamber of the heart.
II. From there, it moves into another chamber that pumps it to an organ for oxygen exchange.
III. After picking up oxygen, the blood returns to the heart again but enters a different chamber than before.
IV. The blood then moves into a powerful pumping chamber that sends it out to the entire body.
V. The blood reaches tiny vessels where nutrients and gases are exchanged with tissues.
VI. After this exchange, the blood returns to the heart through larger vessels.

Which of the following correctly matches each step with the structure or vessel involved? 

6. Below are given some statements, choose the correct set of statement for the characteristics of Tunica Media.

I)Tunica Media has collagen fibres.

II)Tunica Media has only smooth muscles.

III) Tunica Media has elastic fibers

IV)Tunica Media consists of squamous endothelium.

7. What is the composition of Tunica externa?

I)Fibrous Connective tissue

II)Elastic Fibers

III)Collagen Fibers.

IV)Squamous endotheliun.

8. Similarity between capillary and lymph vessel is ______.

9. About ______ percent of tissue fluid drains into blindly ending lymphatic capillaries as lymph.

10. Lymph capillary walls are composed of cells with opening between them that act as _____ valves.

11. Spleen is locked in the _____ side of abdominal cavity between _____ and _______.

12. Which cells are produced in the lymph nodes ______.

13. Tissue fluid is formed when _____ passes through capillaries.

14. Numerous small lymph nodes and____ additional organs although not strictly part of circulatory system.

15. The lymphatic system consists of ____ vessels , that drains____ from all over the body back to circulation.

16. Lymph closely resembles which of the following :

17. Heart activities are controlled by

18. Why bicuspid or tricuspid is closed

19. The tricuspid valve is present between

20. Bundle of His is a network of

21. Which of the following has the thickest wall?

22. What provides the main force that moves lymph through larger lymph vessels?

23. SA node is located in _____.

24. Blood enters into the heart because of muscles of ______.

25. Bicuspid valve is also called mitral valve because of

26. Left ventricle of human heart opens into

27. Heart is the smooth muscle consist of

28. Which of the following is Pacemaker of heart?

29. More CO₂ blood enter into

30. What us the resting period of heart during heart beat

31. The two atria of human heart are separated by

32. Pick the best which exerts max pressure.

33. Left atrium receive deoxygenated blood by

34. The layer of serous membrane that covers the heart and lies closest to the sternum is the:

35. The group of modified cardiac muscle cells that delays action potentials between the atria and the atrioventricular bundle is called the:

36. Fibrous connective tissue with collagen fibre

37. Veins have valve to force blood into heart while artieries do not have then which have greater pressure

38. AV-node is located in:

39. Lumph node provide immunity by

40. In human heart, SAN is:

41. Sinoatrial node consists of:

42. Left ventricle of human heart opens into

43. Capillary wall consists of

44. Blood enters the right atrium from the body through the venae cavae in

45. The two ventricles of human heart are separated

46. Dr Feroz who is well known cardiologist surgeon, when he operated his patient , he saw that his av valves are open at which phase of heart beat cycle it beats

47. Select the correct statement.

48. Which of the following is correct statement for Lymph?

49. Approximately what percentage of the lymphatic fluid may be made up of fat globules absorbed from the small intestine?

50. Where do intestinal cells release the fat globules after absorbing digested fats?