BMS130 Lecture Notes - Lecture 3: Anemia, Heart Failure, Viscosity
CARDIOVASCULAR SYSTEM
Lecture 1 - Erythrocytes and Hemoglobin
Describe the life cycle of RBCs including their production and disposal
120 day cycle
2.5 million per second
Erythropoiesis
3-5 days
RBC produced in red bone marrow
(a soft network of connective tissue
bordering on wide capillaries called
sinusoids)
Results in the loss of the nucleus and
most organelles and the synthesis of
hemoglobin loss of nucleus and no
ribosomes means the RBC cannot
repair itself
1. Pluripotent stem cell
2. Colony-forming unit (erythrocyte CFU)
- First committed cell
3. Precursor cell (erythroblast)
4. Precursor cell (reticulocyte)
- Discarded nucleus
- Named for fine network of endoplasmic reticulum
- 0.5 to 1.5% of circulating RBCs
5. Mature cell (erythrocyte)
Document Summary
Describe the life cycle of rbcs including their production and disposal. Rbc produced in red bone marrow (a soft network of connective tissue bordering on wide capillaries called sinusoids) Results in the loss of the nucleus and most organelles and the synthesis of hemoglobin loss of nucleus and no ribosomes means the rbc cannot repair itself: pluripotent stem cell, colony-forming unit (erythrocyte cfu) First committed cell: precursor cell (erythroblast, precursor cell (reticulocyte) Named for fine network of endoplasmic reticulum. 0. 5 to 1. 5% of circulating rbcs: mature cell (erythrocyte) Negative feedback control: inadequate o2 transport, drop in rbc count, hypoxemia, sensed by liver and kidneys, increased erythropoietin (epo) output from kidneys, stimulates red bone marrow, accelerated erythropoiesis. Increase in exercise: increased rbc count in 3-4 days, increased o2 transport. Polycythemia: a blood condition in which there is an abnormally high rbc count and/or hematocrit.
