Step 1: The body detects low blood volume, which can happen due to dehydration or blood loss.
Step 2: The kidneys sense the low blood volume and release an enzyme called renin.
Step 3: Renin starts a process called the renin-angiotensin-aldosterone system (RAAS).
Step 4: Renin converts a protein in the blood (angiotensinogen) into angiotensin I.
Step 5: Angiotensin I is then converted into angiotensin II, which has several effects.
Step 6: Angiotensin II causes blood vessels to narrow, increasing blood pressure.
Step 7: Angiotensin II also stimulates the adrenal glands to release aldosterone.
Step 8: Aldosterone helps the kidneys retain sodium and water, which increases blood volume.
Step 9: As blood volume increases, blood pressure stabilizes and returns to normal.
Renin-Angiotensin-Aldosterone System (RAAS) – The physiological mechanism activated in response to low blood volume, involving the release of renin, which leads to increased blood pressure and volume.
Hormonal Response to Low Blood Volume – The body's endocrine response involving hormones like aldosterone that promote sodium and water retention to increase blood volume.
