Module 13: Blood and Blood Vessels Flashcards
3 functions of blood
distribution (oxygen, CO2, nutrients, waste, hormones)
regulation (body temp, pH, volume of fluid)
protection (controls bleeding, defends infection)
Characteristics of blood
Fluid connective tissue Stickly Salty Scarlet/dark red color 8% of body's weight 4-6L pH 7.35-7.45 Higher than body temp
Blood is formed of 2 things
plasma and formed elements
formed elements
rbc, wbc, platelets
Hematocrit
percentage of erythrocytes in whole blood
Males: 40-54%
Females: 38-46%
Buffy coat of centrifuged blood
leukocytes and platelets
Erythrocytes
120 day lifespan
Produced at rate of 2mi/second
Hemoglobin ranges
Adult male: 135-180g/L
Adult female: 120-160g/L
infants: 140-200g/L
Leukocytes
lifespan of a few days to 15 years
contain granulocytes or may be agranulocytes
Granulocytes
neutrophils
eosinophils
basophils
Agranulocytes
lymphocytes
monocytes
Thrombocytes
platelets
fragments of megakaryocytes
Lifespan of 7 days
Plasma
intercellular matrix in blood
Straw color
55% of blood volume
90% water and 10% ions, proteins, fats, glucose, vitamins, nutrients, hormones, oxygen, co2, antibodies, waste
vessels are lined with
endothelium (single layer of squamous epithelial cells)
5 components of hemostasis
Form a clot: vasoconstriction, platelet plug formation, coagulation
Braking system: Fibrinolysis, Natural inhibitors/anticoagulants
vasoconstriction
smooth muscle in vessel walls constrict
platelets move toward injury site
Platelet plug formation
contact with collagen
platelet plug fills gap to prevent further blood loss
coagulation
only if injury is severe and requires actual clot
coagulation factors activated
prothrombin to thrombin
Fibrin threads form mesh that adheres to the damaged tissue and traps blood cells and platelets to form the clot
Fibrinolysis
after healing, clot is dissolved by enzymes