There is a hormone produced by the kidney called erythropoietin. That hormone makes the blood marrow produce more red blood cells.
When there isn’t enough oxygen reaching the kidney (because of the lost blood), it produces this hormone so more blood is made.
TL;DR: the kidney tells the blood marrow to make more blood
Your body has methods of measuring the actual amount of liquid blood in the vessels, as well as how much oxygen your organs are getting. This is done through a combination of chemoreceptors and pressure receptors. If your body senses it’s low on RBCs, it can release a chemical called Erythropoietin, which causes your bone marrow to up the production of red blood cells, and then it stops releasing that chemical once it detects the amounts are back to normal
I’ll add that there’s a part of your brain that can detect when the volume of blood is too low. When this happens, the pituitary secretes ADH that causes the kidneys to conserve more water instead of excreting it in urine. This helps maintain the volume of blood and blood pressure in addition to the actual amount of red blood cells which has been explained by others here (erythropoietin).
This is fascinating, can anyone speak to any disorders where your body can make too much blood?
I have a semi-rare disorder where my body makes too much spinal fluid! Lucky me it can be treated and it went smoothly. Funny thing about this condition (IIH/ pseudo-tumor cerebri) no one knows what causes it! Only how to fix it.
Latest Answers