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






2. The principle sugar in blood that maintains a relatively constant concentration for adequate nutrition






3. Crosses septum and connects to Purkinje fibers to allow coordinated contraction of ventricles. Key is that is slows transmission across septum to allow ventricles to fully fill before contraction






4. 2 ways to increase venous return






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






6. Aggregate at site of damage to a blood vessel and form a platelet plug to stop bleeding






7. Why is the SA node the primary pacemaker?






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






9. Which is longer - diastole or systole?






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






11. Connects the two capillary beds of the intestine and the liver






12. Connected to SA node via internodal tract - and passes signal to Common bundle of His to contract ventricles






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






14. At position 6 - missense mutation substitutes valine for glutamate. valine is hydrophobic - where glutamate was charged. It is an autosomal recessive disease where RBCs accumulated in small vessels - heterozygote for (blank) shows resistance to malar






15. Flow from the heart to the rest of the body; pumped by the left side of the heart






16. 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






17. Phagocytose bacteria resulting in pus; amoeboid motility and chemotaxis






18. The difference btw systolic and diastolic blood pressures






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






20. Highest blood pressure that occurs during ventricular contraction






21. Protein that maintains oncotic pressure in capillaries






22. 55% of whole blood that is composed of electrolytes - lipoproteins - sugars - buffer - and metabolic waste






23. Where do all components of the blood develop from?






24. Amount of blood pumped w/ each systolic contraction






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






26. Breakdown product of the hemogloblin heme group






27. Request by tissues to increase blood flow - where build up of metabolic waste causes arterioles to dialate






28. 3 substances that can diffuse through intercellular cleft






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






30. The difference in pressure divided blood flow; controlled by the sympathetic nervous system generating adrenergic tone






31. 73% of CO2 converted to carbonic acid by carbonic anhydrase - and carbonic acid is converted to bicarbonate - which acts a buffer






32. Glucose - amino acids - and fats






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






34. Allow Na to leak across membrane - causing cell potential to get closer to threshold potential; allow threshold to be reached for Ca channels to open let Ca into the cell






35. Caused by closure of Ca channels and opening of K channels






36. Heart rate *stroke volume= (units)






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






38. What is the direct cause of edema?






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






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






41. 2 lymphocytes






42. Hematocrit or RBC those compose 35-45% of the blood; cells are non - nucleated and have no organelles. Acquire ATP through glycolysis have biconcave shape to maximize surface area for binding O2






43. Voltage - gated channels that open quickly; open at threshold potential






44. Produced during cell metabolism and diffuses through the endothelial cells into the blood stream - where it is picked up by the liver and converted to forms that can be excreted (all other wastes are picked up by the kidneys)






45. Receptors in the carotid arteries and aortic arch that notify CNS if blood pressure is high or low






46. Vessels that carry blood back to the heart at low pressure






47. Purpose of erythrocytes?






48. Buffer in blood. Keeps pH around 7.4






49. 1. depolarization caused by fast Na channels - where action potential through intercalated discs reaches threshold potential - opening Na channels 2. initial depolarization with Na channels closing and k channels opening - but Ca channels also open 3






50. Plasma that lacks clotting proteins