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MCAT Biology Circulatory System

Subjects : mcat, health-sciences
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Connected to SA node via internodal tract - and passes signal to Common bundle of His to contract ventricles






2. Site of exchange btw blood and tissues; smallest vessels that allow one RBC through at a time






3. Region that initiates start of cardiac cycle - which acts as a pacemaker of the heart; has unstable resting potential due to Na leak channels






4. 2 ways to increase venous return






5. Excessive bleeding that results from defective proteins






6. Vessels where deoxygenated blood from coronary sinus continue to flow into heart






7. Glycoproteins that are coded for by 3 alleles (A - B - i)






8. Filling of the ventricles by squeezing of the atria - marks the beginning of the 'dub' sound






9. Maximize entry of Ca into the cell by allowing entry of Ca extracellular environment; leads to contraction of actin - myosin fibers






10. Pump blood out of the heart at high pressures into arteries






11. Protein in RBC that transport O2 though the blood since O2 is too hydrophobic in plasma; protein has 4 subunits that change confirmation cooperatively depending on the concentration of O2






12. Muscular pump that forces blood through series of branching vessels






13. Receives deoxygenated blood from systemic circulation (superior and inferior vena cava)






14. CO2 is soluble in H2O - and thus some is dissolved and carried to lungs and tissues in plasma - O2 is not soluble in plasma at all






15. Reservoirs where blood collects from veins






16. Occurs when increased cardiac output is needed; the postganglionic nerve directly innervates the heart - releasing norepinephrine - increasing heart rate and force of contraction






17. Why is the SA node the primary pacemaker?






18. Buffer in blood. Keeps pH around 7.4






19. Return of blood to the heart by the vena cava - where increased venous return causes increased stretching of the muscle (increases stroke volume)






20. Amount of blood pumped w/ each systolic contraction






21. Heart rate *stroke volume= (units)






22. 2 portal systems to know






23. Destroy parasites and are involved in allergic rxns






24. When the valve of a vein fails and back flow occurs; blood not being moved toward the heart






25. Where are RBCs broken down?






26. Stretching to greater degree of heart muscle causes more forceful contraction; stretching increase occur by increasing fluid volume






27. What is the only process RBC use to generate ATP?






28. Flow of blood through a tissue






29. Purpose of erythrocytes?






30. Response by CNS when blood pressure is too low






31. Bone marrow cells that give rise to RBC and platelets






32. Adequate circulation - but O2 supply is reduced (no build up waste products or loss of nutrients)






33. First branches from the aorta that provide the heart's blood supply






34. Gap junctions in the cardiac muscle - where depolarization is communicated directly btw cytoplasm of neighboring cardiac cells






35. Fat storage cells of the body






36. What is the most important plasma protein in the body? Why?






37. Path where impulse travels from SA to AV node






38. 55% of whole blood that is composed of electrolytes - lipoproteins - sugars - buffer - and metabolic waste






39. Protein that maintains oncotic pressure in capillaries






40. Absorbed in the intestine and packaged in chylomicrons - which enter the lymphatic system - and dumped into the subclavian vein via the thoracic duct; the liver takes fats once in blood - converts them to another lipoprotein and sends them to adipocy






41. ABO blood group and Rh blood group






42. Is cardiac output the same or different btw the two ventricles?






43. Blood clot or scab circulating in bloodstream






44. Rh factor that follows dominant pattern (Rh+ in heterozygote)






45. Have single layer endothelial cells w/ spaces in between cells called intercellular cleft






46. Essentially 0 mmHg - which results b/c of branching of vessels dissipating pressure to overcome resistance






47. Ensure the one - way flow through the circulatory system






48. Peptide hormone secreted from the kidneys to increase RBC production in bone marrow






49. Osmotic pressure in capillaries due to plasma proteins






50. Valves between the ventricle and the atria to prevent back flow