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






2. Path where impulse travels from SA to AV node






3. Voltage - gated channels that stay open longer than Na channels and open later responsible for the plateau phase of cardiac muscle contraction






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






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






6. 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






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






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






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






10. Number of systole contractions per unit time






11. Body's mechanism of preventing bleeding






12. Blood clot or scab circulating in bloodstream






13. Where blood passes through 2 sets of capillaries before returning to the heart; Evolved as direct transport routes






14. 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)






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






16. Transportation of blood though the body and exchange of material btw blood and tissues






17. Tissue which the cytoplasm of different cells communicate via gap junctions






18. Pool of deoxygenated blood at low pressure - which collects blood from coronary veins - Only deoxygenated blood to not enter the right atrium via the vena cava






19. Breakdown product of the hemogloblin heme group






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






21. As low as pressure gets btw heart beats in arteries






22. Force per unit area exerted by blood on walls of arteries






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






24. Where are RBCs broken down?






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






26. Vessels that carry blood away from the heart at high pressure






27. 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






28. Resting membrane potential of -90mV and have long duration action potentials






29. Universal acceptor






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






31. Neutrophil - eosinophil - and basophil






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






33. Active form of fibrinogen - protein forms a mesh that holds platelet plug together to protect wound - ibrinogen is converted to (blank) by thrombin






34. AV valve between right atrium and right ventricle






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






36. Protein that maintains oncotic pressure in capillaries






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






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






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






40. Open when threshold is reached causing membrane potential to increase/depolarize; operate slower than Na channels






41. Highest blood pressure that occurs during ventricular contraction






42. 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






43. 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






44. Flow of blood from the heart to the lungs - pumped by the right side of the heart






45. Purpose of erythrocytes?






46. Heart rate *stroke volume= (units)






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






48. Inadequate blood flow - resulting in tissue damage due to shortage of O2 and nutrients - and increase of metabolic waste






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






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