Composition and Functions Blood Composition and Functions

Composition of Blood 55% plasma nonliving fluid matrix 45% erythrocytes RBC = red blood cell Remainder 1% leukocytes WBC = white blood cell platelets cell fragments function in blood clotting

Blood is sticky, opaque, and salty. bright to dark red 5x more viscous than water pH 7.35 to 7.45 slightly alkaline 8% of body weight males 5-6L and females 4-5L connective tissue because of its substance distribution functions

Functions of Blood

Distribution Functions Transports O2 from lungs to all body cells Transports nutrients Transport metabolic wastes from cells to kidneys or lungs Transport hormones Maintains body temperature - absorb and distribute heat

Protective Functions maintain normal pH maintain adequate fluid volume prevent blood loss prevent infection

Hematopoiesis

Blood Formation called hematopoiesis occurs mainly in red bone marrow flat and lg. long bones cell numbers increase in response to need all derive from stem cells called hemocytoblasts maturation differs according to cell type note degeneration of nuclei in RBC After degeneration, nucleus is ejected and space where it was collapses to form concave region.

Erythrocytes Red Blood Cells

O2 transportation due to hemoglobin

mature cells lack a nucleus shape is biconcave which allows greatest surface area to volume flexible so can fit through smallest capillaries

RBC : WBC 800 : 1

RBC formation triggered by: hemorrhage which decreases the number of RBC decreased availability of O2 ex. high altitudes or pneumonia increased tissue demand for O2 ex. aerobic exercise

iron and B vitamins are needed for hemoglobin synthesis

RBC life span 100 - 120 days broken down by phagocytes in spleen hemoglobin is broken down to bilirubin iron is saved, rest secreted in bile

Reduced oxygen carrying capacity of blood Anemia

Symptoms: Fatigue Pale Shortness of breath Chills Know these Headache Cold hands or feet Pale or yellow skin Chest pain Weakness Shortness of breath Dizziness Fast or irregular heartbeat Pounding or "whooshing" in your ears

Common causes: not enough RBC’s due to: Hemorrhage damage due to parasites Infections decrease hemoglobin due to lack of iron in diet abnormal hemoglobin formation sickle cell etc...

Anemia: Abnormal Hemoglobin

Genetics of Sickle Cell Anemia 25