3.31.25 lecture: RBC life cycle

how long does an erythrocyte live?

3-4 months

the _____________ secrete ________________ to stimulate erythropoiesis

kidneys; EPO

the RBCs get damaged in circulation and are eventually cleared out in the ______ by __________________________

liver; macrophages

what do the macrophages actually do to the damaged erythrocytes?

they break down the membrane to be recycled

what happens to the hemoglobin when the RBC membrane is broken down?

the protein portion (globin) is recycled, and the heme group is broken down into bilirubin to be excreted

what do we do with the bilirubin once it's created?

it's transported to the gallbladder where it will become a component of bile

pop quiz: what does bile do?

it's a substance that helps emulsify fats in the small intestine

what role does bilirubin play in the function of bile?

none! it just gives bile its color. bile is just how we get rid of bilirubin

what is the toxic portion of the heme?

the iron, it can't travel freely in the bloodstream

If Fe can't travel freely in the bloodstream, then what do we do with it? (2 things)

1. bind to ferritin to transport in blood

2. store in liver

So when we transport Fe in the bloodstream via ferritin proteins, where do we take it?

the bone marrow to be recycled into more heme