Please Help me answer these objectives 2.GFR is held constant unless MAP is too
ID: 84028 • Letter: P
Question
Please Help me answer these objectives
2.GFR is held constant unless MAP is too low or too high.
3. The bulk of reabsorption takes place in the distal convoluted tubule
4. When systemic blood pressure (BP) rises, the vascular smooth muscle of the afferent arteriole in the kidneys constricts in response to being stretched. What is this called and what type of regulation is it?
a.) auto regulation, intrinsic regulation b.) myogenic mechanism, extrinsic regulation c.) auto regulation, myogenic mechanism d.) tubuloglomerular feedback, intrinsic regulation e.) myogenic mechanism, intrinsic regulation
5. In response to a decrease in mean arterial pressure (MAP), the kidneys will (select all that apply)
a. )Signal the SA node to increase its rate of action potentials in order to increase Heart Rate. b.) Signal the heart to contract with more force in order to increase Stroke Volume. c.) Conserve fluid in order to increase/maintain End Diastolic Volume and thus Stroke Volume d. )Release hormones that directly activates the sympathetic nervous system e. )Signal systemic vasoconstriction in order in increase Total Peripheral Resistance
6. Which of the following is not an example of extrinsic regulation of the nephron?
a. )sympathetic activation of granular cells b. )sympathetic activation of afferent arteriolar smooth muscle c.) renin release by granular cells stimulated by norepinephrine d. )tubuloglomerular feedback e. )Angiotensin II stimulation of aldosterone release
Explanation / Answer
Answer:
2. Renal autoregulation involves feedback mechanisms intrinsic to the kidney that cause either dilation or constriction in the afferent arteriole so as to counteract blood pressure changes and keep a steady GFR.
If blood pressure drops too low due to excessive fluid loss, then the sympathetic nervous system will override renal autoregulation. Sympathetic nerves innervate the afferent arteriole, causing smooth muscle contraction. The sequence of events is as follows: loss of ECF volume (due to hemorrhage, diarrhea or dehydration) causes a drop in mean arterial pressure (MAP).
Decreased MAP is detected by arterial baroreceptors, which leads to sympathetic nervous system activation, afferent arteriole constriction, and decreased GFR.
(Since there are more than 1 question, the first question have been answered according to the rules of Chegg)