Hemoglobin Recycling and Metabolism

This set covers the vocabulary and physiological processes involved in the breakdown and recycling of hemoglobin, including clinical markers and waste product pathways.

Aged Red Blood Cell

A red blood cell that has reached the end of its lifespan, typically lasting approximately $120$ days.

Hemolysis

The process of rupturing red blood cells, which accounts for about $10\%$ of red blood cell breakdown.

Macrophages

Phagocytic cells located in the spleen, liver, and red bone marrow that engulf aged red blood cells and break hemoglobin into components.

Iron

The specific component of the heme unit that is recycled by the body to synthesize new hemoglobin.

Hemoglobinuria

A condition resulting in brown-colored urine due to abnormally high levels of hemolysis or breakdown of red blood cells in the bloodstream.

Hematuria

The presence of whole red blood cells in the urine, usually indicating kidney problems or blood vessel damage.

Biliverdin

A green organic compound formed after iron is removed from the heme unit during the recycling process.

Bilirubin

An orangish-yellow substance converted from biliverdin that binds to albumin for transport to the liver.

Jaundice

A yellow appearance of the skin and eyes caused by the buildup of bilirubin in the body.

Albumin

The protein in the bloodstream to which bilirubin binds to be transported to the liver for excretion.

Urobilins and Stercobilins

Substances formed by intestinal bacteria and oxygen from bilirubin that provide color to feces.

Urobilin

A derivative of hemoglobin breakdown excreted by the kidneys that gives urine its characteristic yellow color.

Transferrin

A transport protein that carries iron through the bloodstream to the red bone marrow for the production of new red blood cells.

Ferritin and Hemosiderin

Specific proteins used to store excess iron in the liver and spleen.

Anemia

A clinical condition that occurs when there is insufficient iron to produce enough hemoglobin for red blood cells to function properly.