IPHY 3430 10-04-11
Circulatory System
Purposes:Delivery of O2, energy containing
substrates, vitamins and other nutrients to cells;
Removal of CO2, secretory products, and waste products from cells.
Topicsa. blood constituentsb. transport of gasesc. heart functiond. blood pressuree. blood volume and lymphatic system
Additional components of the circulatory system:
Medulla vasomotor centerSNS, PNS
And, blood...
Components of Blood:Cells: red blood cells, white blood cells, and plateletsPlasma: water
proteinsa. Albuminb. globulins (,,) c. Fibrinogen
ionsglucose, amino acids
wastes (creatinine, urea, ammonia)
Transport of Oxygen
3% transported dissolved in plasma97% transported in red blood cell in
association with hemoglobin
Red blood cells
Men: 5 million/ml bloodWomen: 4.5 million/ml blood
25-30 trillion rbc’s in total blood volume
120 day life spanno nucleus, mitochondria nor ribosomes
4 heme groups (Fe plus pyrroles) + 4 globin molecules
Hemoglobin binding on heme groups 1. O2
2. CO on globin chains3. CO2
4. H+5. Nitric oxide (NO)6. 2,3 biphosphoglycerate
Regulation of red blood cell production
RBCs (O2 delivery) ---> Kidney (both sensor and integrator)---> secretion of erythropoietin --> stimulation of bone marrow to produce RBCs --> RBCs (O2 delivery)
RBCs (O2 delivery) ---> Kidney (both sensor and integrator)---> secretion of erythropoietin --> stimulation of bone marrow to produce RBCs --> RBCs (O2 delivery)
Pathological variation in RBCs
Anemias (30% and below)1. Iron deficiency2. Lack of folic acid in diet3. Pernicious4. Hemorrhagic5. Aplastic6. Hemolytic7. Renal
Regulation of red blood cell production
RBCs (blood PO2) ---> Kidney (both sensor and integrator)---> secretion of erythropoietin --> stimulation of bone marrow to produce RBCs --> RBCs (PO2)
RBCs (blood PO2) ---> Kidney (both sensor and integrator)---> secretion of erythropoietin --> stimulation of bone marrow to produce RBCs --> RBCs (PO2)
Pathological variation in RBCs
Polycythemia (70% and above)1. Polycythemia vera2. Chronic high altitude mountain sickness
Relation between hematocrit and oxygen transport
Hematocrit
O2 transport
Normal hematocrit
Blood doping
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