9. Damage to the sinoatrial node in humans
a) would block conductance between the bundle branches and the Purkinje fibers
b) would have a negative effect on peripheral resistance
c) would disrupt the rate and timing of cardiac muscle contractions
d) would have a direct effect on blood pressure monitors in the aorta
11. You breathe in a molecule of oxygen, which is then bound to a molecule of hemoglobin and transported in your blood. For the oxygen to reach the hemoglobin, at a minimum, how many membranes did it have to cross?
a) 1, in the lining in the lungs- and then it can bind directly to hemoglobin.
b) 2, in the cell lining the lungs- and then it can bind directly to hemoglobin.
c) 4, including the cells lining the lung, the endothelial cells lining an alveolar capillary- and then it can bind directly to hemoglobin.
d) 5, including the cells lining the lung, the endothelial cells lining an alveolar capillary, the red blood cell- and then it can bind with hemoglobin.
e) we cannot really tell how many membranes the oxygen was transported across.
13. If we compare veins and arteries, we can say they:
a) both consist of exactly the same tissues- the difference is only the way blood flows
b) consist of the same basic tissues but in different proportions
c) have at least some different tissues between them
d) both have valves to prevent back flow
e) both have basically the same size lumen but differ in amount of muscle
14. An inflammatory response typically includes:
a) increased activity of phagocytes in an inflamed area
b) reduced permeability of blood vessels to conserve plasma
c) release of substances to decrease the blood supply to an inflamed area
d) inhibiting the release of white blood cells from bone marrow
15. Mammals have toll-like receptors (TLRs) that typically recognize
a) specific species of pathogen
b) MHC
c) macromolecules absent from vertebrates but present in certain groups of pathogens
d) cytokines