How will the baroreceptor reflex function to help maintain mean arterial pressure after a blood donation?
What will be an ideal response?
Answer: The baroreceptor reflex is triggered by baroreceptors, which are stretch-sensitive mechanoreceptors located in the walls of many of the major blood vessels. The most important of these are located in the carotid artery and aorta, although there are also some in the walls of pulmonary arteries and in the heart. These baroreceptors, under normal conditions send a steady stream of action potentials to the CNS. The cardiovascular control center in the medulla oblongata integrates these inputs, and sends out efferent signals via autonomic neurons that control heart rate, stroke volume, and vasomotor and venomotor tone, thus influencing blood pressure. Increased blood pressure causes arterial walls to stretch, increasing baroreceptor firing frequency which, through the integrating activity of the medulla oblongata, decreases output of sympathetic fibers resulting in vasodilation. In combination with an increase in parasympathetic output, this will additionally result in decreased cardiac contraction force and rate. This lowers blood pressure.
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The study of the relationships of the body's structures by examining cross sections of tissues or organs is called ________ anatomy
A) gross B) surface C) systemic D) regional E) sectional
The radial structures in contact with the ulna include the
A) head. B) radial tuberosity. C) antebrachial joint. D) ulnar notch and head. E) ulnar notch
Inappropriate relaxation of the ________ muscles during sleep contributes to ________, a sleep disorder associated with snoring.
Fill in the blank(s) with the appropriate word(s).
Which of the following is a unique mechanism of exchange used by sinusoidal capillaries?
A) vesicular transport from the lumen to the interstitium B) diffusion through endothelial cells C) filtration through gaps between endothelial cells D) active transport from the interstitium to the lumen E) diffusion through pores