Lecture 13 Flashcards
hematopoiesis or hemopoiesis
process of blood cell production
Erythropoietin (EPO)
hormone released by the kidneys that stimulates red blood cell developemnt
stem cells
all formed elements are derived from a single population of hemocytoblasts
what happens when hemocytoblasts divide
one daughter cell remains a hemocytoblast while the other differentiates into either a myeloid stem cell or a lymphoid stem cell
Stem cells
all formed elements derived form single population of hemocytoblasts
Myeloid stem cell becomes
proerythroblasts, myeloblasts, monoblasts, megakaryoblasts
proerythroblasts
develop into red blood cells
myeloblasts
develop into basophils, neutrophils and eosinophils
monoblasts
develop into monocytes
megakaryoblasts
develop into platelts
what do lymphoblasts
lymphoid stem cells
Lymphoblasts
develop into lymphocytes
Red blood cells
-biconcave disc shape
-7.5 um in diameter
- no nucleus
- flexible and capable of bending allowing passing through
- contain hemoglobin, lipids, ATP, carbonic anhydrase
RBC functions
- transport oxygen from lungs to tissues
- carbondioxide transported from tissues to lungs
hemoglobin
protein consisting of four subunits
Globin
each subunit composed of a single polypeptide
Three typed of hemoglobin
oxyhemoglobin, deoxyhemoglobin, and carbaminohemoglobin
embryonic and featal
have greater attraction for oxygen than adult
Oxyhemoglobin
iron in
hemoglobin bound to oxygen; 4 per
molecule of hemoglobin; bright red in color
Deoxyhemoglobin
hemoglobin not bound to oxygen dark red
Carbaminohemoglobin
globin of
hemoglobin bound to carbon
dioxide.
Erythropoiesis
- formation rbc, takes 4 days
production of rbc
Myeloid stem cells → proerythroblasts → early erythroblasts
→ intermediate erythroblasts → late erythroblasts →
reticulocytes (released into the blood) → erythrocytes.
Erythropoietin
hormone stimulates RBC production; produced
by kidneys in response to low blood O2 levels (hypoxia).
