Blood moves into and then out of a heart chamber because
A. it moves along its pressure gradient, and that gradient depends on contraction and relaxation during the cardiac cycle.
B. it is under constant pressure, but its movement is dictated by the control of valve openings and closures.
C. the veins and arteries constrict and dilate to propel and attract blood.
D. All of the choices are correct.
A
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Reduced vitamin B12 absorption from the small intestine due to reduced intrinsic factor production in the stomach results in condition called
a) hemorrhagic anemia. b) aplastic anemia. c) megaloblastic anemia. d) pernicious anemia. e) iron deficiency anemia.
Which of the following agencies usually regulate exotic species?
a. Department of Wildlife c. Department of Treasury b. Department of Agriculture d. Department of State
An unmyelinated fiber with a large diameter can conduct action potentials more rapidly than an unmyelinated fiber with a smaller diameter
Indicate whether the statement is true or false
Replacement of dead and damaged cells with the same types of cells is called ________.
Fill in the blank(s) with the appropriate word(s).