Hematopoiesis

Hematopoiesis stem cells

what is the precursor for all blood cells

bone marrow

What is the site of synthesis of all formed elements of the blood

produces all blood cells and contains adipose and connective tissue

red bone marrow

mostly stores adipose tissue but can produce blood cells in case of emergencies

yellow bone marrow

capillaries that allow newly formed blood cells to pass through them and enter the circulation

what are sinusoids

develops from epithelial reticular cells

T lymphocytes mature

Thymus

surrounded by connective tissue - capsules

trabeculaea - extensions of the capsules that form lobules

Cortex - dark and contains immature T cells

Medulla - lighter and contains mature T cells

anatomy of the Thymus

epithelial reticular cells

what is this (darker spots)

hassalls corpuscles

what is this

Erythrocyte destruction

Filter blood and removes RBC that are old or dysfunctional

Stores activates lymphocytes, RBC, and Platelets

Spleen

1. Outer capsule - dense connective tissue with trabeculae

2. Red Pulp - occupies most of the spleen, filled with RBC, WBC and sinusoidal capillaries

3. White Pulp - restricted to around the central arterioles. Rich in lymphocytes and macrophages. Where T and B cells get activated

Layers of the spleen