iphy 3430 10-04-11

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