Question

Which of the following is/are activated by an increase in mean arterial pressure (MAP) to 120 mmHg?

a. Myogenic autoregulation only
b. Tubuloglomerular feedback only
c. Both myogenic autoregulation and tubuloglomerular feedback
d. Neither myogenic autoregulation or tubuloglomerular feedback

Answer 1

When there is an increase in mean arterial pressure (MAP) to 120 mmHg, both myogenic autoregulation and tubuloglomerular feedback are activated.

Step-by-step explanation:

Myogenic autoregulation is the reflexive action which constricts the stretched smooth muscles in the blood vessels like arteries and arterioles when there is an increase in MAP.

Tubuloglomerular feedback is a mechanism which corrects the glomerular filtration rate based on the salt concentration in the renal tubules.

Both myogenic autoregulation (of preglomerular arterioles) and tubuloglomerular feedback (TGF) are the homeostatic mechanism used for autoregulation of renal blood flow (ARBF) and prevent renal arterial pressure elevation.

ARBF takes place which constricts the renal arterioles according to their salt content. TGF then acts along with myogenic autoregulation to control the elevation of MAP and renal arterial blood flow .

Answer 2

Both myogenic autoregulation and tubuloglomerular feedback are activated by an increase in mean arterial pressure (MAP) to 120 mmHg?

Step-by-step explanation:

Mean arterial pressure is the average blood pressure an individual has during a single cardiac cycle. It is considered normal when it is between 65 to 110 mmHg.

When there is an increase in MAP to 120 mmHg then the myogenic autoregulation helps in protecting the glomerular capillaries against the rapid elevation during arterial pressure. Whereas, tubuloglomerular feedback is involved in controlling the RBF and GFR has a response to sustained reduction MAP.