Blood and shock Flashcards
1
Q
Why does blood loss make you thirsty
A
When someone is injured and loses a lot of blood volume (known as hypovolaemia), less blood reaches the kidneys. This causes the kidneys to secrete an enzyme called renin, which enters the blood and catalyzes a hormone called angiotensinogen to convert it into a hormone called angiotensin. One form of angiotensin (angiotensin II) causes the pituitary gland and adrenal cortex to secrete hormones that prompt the kidneys to conserve water as a protective measure. Angiotensin II also affects the subfornical organ (SFO), an organ that lies just outside the blood-brain barrier. Through the SFO angiotensin II stimulates thirst.
