Which of the following factors assists in the return of venous blood to the heart? (1) arterial dilation (2) valves in the veins (3) sympathetic stimulation (4) compression of veins by muscular movements
A. 1 and 2
B. 1, 2, 3
C. 1, 2, 3, 4
D. 2, 3, 4
E. 1, 3, 4
D
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The sympathetic and parasympathetic systems have ________ effects on heart rate.
A. synergistic B. negligible C. antagonistic D. cooperative
All human cells have cell membranes.
Answer the following statement true (T) or false (F)
Describe the pyramids of the medulla oblongata and a decussation
A) The pyramids contains tracts of sensory fibers that originate at the cerebral cortex. Some of the sensory fibers cross to the opposite sides of the medulla oblongata and that crossing over is called a decussation. B) The pyramids contains tracts of sensory fibers that originate at the spinal cord. Some of the sensory fibers cross to the opposite sides of the medulla oblongata and that crossing over is called a decussation. C) The pyramids contains tracts of motor fibers that originate at the cerebral cortex. Some of the motor fibers cross to the opposite sides of the medulla oblongata and that crossing over is called a decussation. D) The pyramids contains tracts of motor fibers that originate at the spinal cord. Some of the motor fibers cross to the opposite sides of the medulla oblongata and that crossing over is called a decussation. E) The pyramids contains tracts of motor fibers that originate at the spinal cord. All of the motor fibers stay on the same side of the medulla oblongata and that is called a decussation.
Which muscle cells have the greatest ability to regenerate?
A) no muscle can regenerate B) smooth C) skeletal D) cardiac