BIOL 115 Lecture Notes - Lecture 21: Red Pulp, White Pulp, Abdominal Cavity
Document Summary
In children, most bones have red marrow; only a few do in adults. Bilobed; in the thoracic cavity superior to the heart. It is largest in children and shrinks as we age. Produces thymosin, a hormone that induces the maturation of t cells (t lymphocytes) Immature t cells move from the marrow to the thymus, where they mature. In the upper left region of the abdominal cavity. Connective tissue divides it into white pulp and red pulp. Macrophages in red pulp remove pathogens, debris, and worn out red blood cells from the blood. Has a thin outer capsule, so can rupture from trauma. Connective tissue forms a capsule around it and divides it into compartments. Filled with macrophages that engulf pathogens and debris. Also houses lymphocytes, which fight infections and cancer cells. Named for their location: common in the neck, armpit, and groin regions. Concentrations of lymphoid tissue that don"t have a capsule.
