Red Blood cells = rbc’s =erythrocytes

I. Structure = function Biconcave discs, no nucleus*, 4-5 million

per uL of blood

II. Erythropoiesis = erythrocyte formation -Hypoxia and/or low red blood cell count

stimulates the release of erythropoietin(EPO)

- Erythropoietin ( from the kidneys) - It stimulates the red bone marrow, calledMyeloid tissue, to increase erythropoiesis -Necessary raw materials iron, amino acids, vit B12, copper, cobalt

III. Reticulocytes = immature red blood cells -make up about 1-2% of circulating rbc’s - are larger (why?) still contain many organelles like endoplasmic

reticulum

IV. Hematocrit – 42-45 ml rbc’s per 100ml blood(normal)

-affected by altitude, etc - written as just a number, e.g. 45

V. Destruction – after approx. 100-120 days -Three organs to remove old rbc’s liver, spleen, bone marrow -The liver receives all components of rbc

breakdown. - Iron is recycled, rest of heme secreted as

bilirubin in bile -proteins returned to amino acids -100 million rbc’s formed/destroyed per

minute

VI. Hemoglobin (33% wet weight) -300 million molecules per rbc -4 iron atoms per molecule - each iron can bind/carry 1 oxygen molecule - Therefore, each hemoglobin can carry 4

oxygen molecules as oxyhemoglobin -hemoglobin can also bind up to 20% of CO2

forming carbaminohemoglobin

VII. Abnormal erythrocytes a)crenated – shriveled -may be due to anticoagulants or

dehydration b) codocytes – target appearance -indicators of iron deficiency c) sickle cells – sickled when low in O2 -genetic- recessive d) schizocytes – rbc fragments -artificial heart valves, atherosclerosis

Crenated

CODOCYTES

Sickle Cells

Schizocytes

VIII. Anemia = Less than 10g hemoglobin / 100ml blood

a) pernicious anemia- due to a lack of vit B12. Large, brittle, pale rbc’s

b) iron deficiency anemia – codocytes c) hemorrhagic anemia - bleeding d) hemolytic anemia- improper blood

transfusion e) aplastic anemia – loss of red bone

marrow

f) Normocytic – normal size Microcytic- smaller than normal

Macrocytic – larger than normalg) Normochromic – normal color Hyperchromic – darker than normal Hypochromic – paler than normal

IX. Polycythemia -elevated rbc count - elevated hematocrit normal causes – altitude, anemia induced causes – blood doping -- EPO injections