Iron Storage, RBC Lifecycle, and Leukocytes

This deck covers iron metabolism, the lifecycle and destruction of red blood cells, the bilirubin pathway, and the characteristics and types of white blood cells (leukocytes).

Hemoglobin Iron Storage

The primary location of body iron, containing approximately $65\%$ of total iron or about $4000\,mg$.

Ferritin and Hemosiderin

Protein-iron complexes that safely store iron inside cells to prevent toxicity.

Transferrin

A transport protein that iron loosely binds to for movement through the blood.

Daily Iron Loss

The amount of iron lost via sweat, feces, and urine, estimated at $1.7\,mg/day$ for females and $0.9\,mg/day$ for males.

Erythropoiesis Vitamins

Vitamin $B_{12}$ and folic acid, which are essential for DNA synthesis during red blood cell production.

RBC Lifespan

The functional duration of a mature erythrocyte, typically lasting $100-120$ days.

Spleen

Known as the "RBC graveyard" because it is the primary site where old, rigid erythrocytes are trapped and destroyed.

Macrophages

Cells that engulf and break down dying erythrocytes.

Globin Recycling

The process where the protein portion of hemoglobin is broken down into amino acids and reused.

Biliverdin

A green pigment formed as the initial conversion product of heme after iron is removed.

Bilirubin

A yellow pigment converted from biliverdin that is released into the blood in an unconjugated form.

Albumin

The protein used to transport unconjugated bilirubin through the bloodstream to the liver.

Conjugated Bilirubin

Bilirubin that has been processed by the liver and secreted into the small intestine as part of bile.

Urobilins

Yellow pigments produced from the breakdown of bilirubin and excreted by the kidneys in urine.

Stercobilins

Brown pigments produced from the breakdown of bilirubin that provide feces with its characteristic color.

Leukocytes

White blood cells (WBCs) which are complete cells containing a nucleus and organelles, functioning in body defense.

Total WBC Count

The total number of all white blood cells in the blood, normally ranging from $4,000-11,000\,WBCs/mm^3$.

Differential WBC Count

An assessment of the number or percentage of each of the five specific types of white blood cells.

Diapedesis

The movement of leukocytes as they exit the blood vessel walls to enter surrounding tissues.

Amoeboid Motion

The self-propelled movement used by WBCs, particularly neutrophils and monocytes, to navigate through tissues.

Positive Chemotaxis

The mechanism where WBCs follow a trail of chemical signals to locate areas of infection or tissue damage.

Granulocytes

A category of spherical WBCs with lobed nuclei and membrane-bound cytoplasmic granules; includes neutrophils, eosinophils, and basophils.

Agranulocytes

WBCs that lack visible cytoplasmic granules and typically have longer lifespans; includes lymphocytes and monocytes.