Question

For the regulatory systems below, describe the triggers for initiation of the system, what you would see on assessment of the patient, the physiologic process to restore homeostasis, and the outcomes on the system when homeostasis is restored.

• Renin Angiotensin-Aldosterone System:

  • Triggers for Initiation of the System:

  • Assessment of Patient:

  • Physiologic Process to Restore Homeostasis:

  • Outcomes on the System when Homeostasis is Restored:

• Naturetic peptides:

  • Triggers for Initiation of the System:

  • Assessment of Patient:

  • Physiologic Process to Restore Homeostasis:

  • Outcomes on the System when Homeostasis is Restored:

Answer 1

Renin is secreted in response to three stimuli

A decrease in arterial blood pressure (that could be related to a decrease in blood volume) as detected by baroreceptors (pressure-sensitive cells). This is the most direct causal link between blood pressure and renin secretion (the other two methods operate via longer pathways).

A decrease in sodium load delivered to the distal tubule. This load is measured by the macula densa of the juxtaglomerular apparatus.

Sympathetic nervous system activity, which also controls blood pressure, acting through the β1 adrenergic receptors.

Then the action will be as follows

Renin converts angiotensinogen, which is produced in the liver, to the hormone angiotensin I. An enzyme known as ACE or angiotensin-converting enzyme found in the lungs metabolizes angiotensin I into angiotensin II. Angiotensin II causes blood vessels to constrict and blood pressure to increase.