How does the spleen....?

Question

get rid of old and damaged blood cells? does it use enzymes and secrete them outside of the body through the rectum? Any help is appreciated.

Answer 1

Erythrocytes (red blood cells) generated in the bone marrow are destroyed in the spleen when they get old or damaged. This releases hemoglobin, which is broken down to heme, as the globin parts are turned into amino acids. The heme is then turned into unconjugated bilirubin in the macrophages of the spleen. It is then bound to albumin and sent to the liver.

In the liver it is conjugated with glucuronic acid, making it water soluble. Much of it goes into the bile and thus out into the small intestine. Some of the conjugated bilirubin remains in the large intestine and is metabolised by colonic bacteria to stercobilinogen and then oxidised to stercobilin.

Some is reabsorbed, and excreted in the urine as urobilinogen and the oxidised form, urobilin. If the liver’s function is impaired, there is a hemolytic anemia (increased destruction of red blood cells), or biliary drainage blocked, some of the conjugated bilirubin appears in the urine, turning it dark amber.

Answer 2

Splenic macrophages phagocytose damaged cells.