Exam 3: Blood Flashcards
Functions of blood
Transport of oxygen and carbon dioxide, nutrients, hormones, waste products
Regulation of body temp., blood pH, and osmolality of body fluids
Hemostasis
Immunity
Blood elements
Plasma, Erythrocytes (RBC), Leukocytes, Platelets (thrombocytes)
Hematocrit
RBC
45% of blood in males
40% of blood in females
55% of blood in newborns, decreases to 35% at 2 months, then elevates to adult values by puberty
Buffy coat
leukocytes and platelets
Serum
plasma without fibrinogen
Plasma
yellowish fluid, 90% water
Contains albumin, globulins, clotting proteins, complement proteins, lipoproteins, hormones, electrolytes, and dissolved gases
Albumin
maintains colloid osmotic pressure and transports
Pulls water into blood from tissues
Loss of albumin leads to edema
Erythrocytes
bioconcave disc - increases surface area to volume ration facilitating gas exchange
Small in diameter
4.2 to 6.1 million RBC per cubic mm
Only organelles are cytoskeletal components
Polycythemia
elevated erythrocyte count
Anemia
below normal erythrocyte count
Decrease in packed volume of erythrocytes or reduction in hemoglobin concentration
Erythrocyte transmembrane proteins
Glycophorin (A,B, & C) - unique to RBC
Band 3 - transports bicarbonate and chloride across plasmalemma (increases CO2 in blood) - antiporter
Band 4.1
proteins anchor cytoskeletal components by complexing with spectrin, glycophorin, and actin
Band 4.2
binds with Band 3 - forms a complex with ankyrin and spectrin
Adducin
promotes actin-spectrin association
Hereditary spherocytosis
mutations in ankyrin, band 3, spectrin, or band 4.2 that disrupt tethering interactions
Causes spherical shaped RBC - destroyed by spleen
Leads to anemia, jaundice, and splenomegaly
Elliptocytosis
caused by mutations in spectrin, protein 4.1, or glycophorin C
Antigens on surface of plasmalemma
determine blood type
A, B, AB, O
Rh - positive or negative
Erythroblastosis fetalis
Rh- mother forms antibodies against Rh antigen after birth of first Rh+ baby.
2nd Rh+ baby, mother’s antibodies will cross placenta and attach to erythrocytes of fetus
Mother receives Rho-GAM just before and after birth of first Rh+ baby to prevent disorder - contains antibodies against Rh antigen and will destroy Rh+ before mother can develop antibodies
Kell, Duffy, and Lewis antigens
immunogenic antigens
Can cause problems if not matched properly in transplants
Lewis only one don’t have to worry about matching