There are two main systems that regulate the cardiovascular system:
1. Nervous
2. Humoral
Nervous control
Rapid responses occur via the autonomic nervous system, with changes being sensed by baroreceptors in the carotid sinus.
Question: What activates the carotid sinus baroreceptors?
Click here for answer.
|
|
Autonomic nervous system |
Humoral system |
|---|---|---|
|
Speed of response |
Seconds-minutes |
Minutes-hours |
|
Sensor |
Baroreceptors (carotid sinus) |
Juxtaglomerular apparatus (kidney) |
|
Effector |
Sympathetic outflow |
Renin-angiotensin (and subsequently aldosterone) |
|
Response |
Vasoconstriction + tachycardia |
Vasoconstriction + Na+/H2O retention |
Table 1 Response to hypotension
There are two main systems that regulate the cardiovascular system:
1. Nervous
2. Humoral
Nervous control
Rapid responses occur via the autonomic nervous system, with changes being sensed by baroreceptors in the carotid sinus.
Question: What activates the carotid sinus baroreceptors?
Answer: Stretch produced by a rise in blood pressure.
Because they respond to stretch, activation of the baroreceptors results in an inhibitory effect on the cardiovascular system, causing a fall in heart rate and vasodilatation.
Vasoconstriction and tachycardia result from a decrease in activity in the baroreceptors when the blood pressure falls.
|
|
Autonomic nervous system |
Humoral system |
|---|---|---|
|
Speed of response |
Seconds-minutes |
Minutes-hours |
|
Sensor |
Baroreceptors (carotid sinus) |
Juxtaglomerular apparatus (kidney) |
|
Effector |
Sympathetic outflow |
Renin-angiotensin (and subsequently aldosterone) |
|
Response |
Vasoconstriction + tachycardia |
Vasoconstriction + Na+/H2O retention |
Table 1 Response to hypotension