BIOL 221 Lecture Notes - Lecture 1: Bone Marrow, Yolk Sac, Myeloid Tissue
10 Feb 2020
School
Department
Course
Professor
Document Summary
Erythropoiesis - locations: 1st 8 weeks of embryonic development, rbcs formed in yolk sac (topic 13, 2nd to 5th months in utero: liver (main supplier) and spleen, 5th month on: red bone marrow (myeloid tissue, post-natal formation in red bone marrow. Erythropoiesis is formation of red blood cells. It begins early in embryonic development with erythrocyte production by the yolk sac. From the second through the fifth month in utero (in the uterus), the liver becomes the main site of erythrocyte production; the spleen also produces erythrocytes during this period. Beginning in the fifth month, red bone marrow (also called myeloid tissue) becomes the main source of erythrocytes. Myeloid tissue becomes the sole site of erythropoiesis after birth. Some yellow marrow of medullary cavities can be converted back into red marrow, if needed. Have ribosomes & mitochondria leaves bone marrow after ~ 2 days. All blood cells including erythrocytes are formed from hemocytoblasts.
