KAAP310 LP1 Blood Typing, Hematocrit, and Blood Pressure

principal functions of RBCs

carry oxygen and CO2, contain hemoglobin

hematocrit percentage for men

42-52%

hematocrit percentage for women

37-47%

hemoglobin concentration for men

13-18 g/dL

hemoglobin concentration for women

12-16 g/dL

rbc count for men

4.6-6.2 million/uL

rbc count for women

4.2-5.4 million/uL

why are clinical values lower for females?

androgens stimulate RBC production, periodic menstrual losses, hematocrit inversely proportional to body fat percentage

erythrocyte production

kidneys release EPO due to low O2, EPO stimulates immature-RBCs to mature in bone marrow, released into bloodstream

hypoxemia via negative feedback loop

1. Hypoxemia

2. Sensed by liver and kidneys

3. secretion of EPO

4. stimulation of red bone marrow

5. accelerated erythropoiesis

6. increased RBC count

7. increased O2 transport

polycythemia

excess of RBCs

primary polycythemia

cancer of erythropoietic cell line in red bone marrow

RBC count as high as 11 million RBCs/uL; hematocrit 80%

Secondary polycythemia

polycythemia from other causes (dehydration, emphysema, high altitude, physical conditioning)

RBC count up to 8 million RBCs/uL

dangers of polycythemia

increased blood volume, pressure, viscosity

can lead to embolism, renal damage, hypertension, stroke, or heart failure

anemia

low levels of circulating RBCs or hemoglobin

three categories of anemia

hemorrhagic anemias from bleeding, hemolytic anemias from RBC destruction, inadequate erythropoiesis or hemoglobin synthesis

inadequate erythropoiesis or hemoglobin synthesis anemia

kidney failure, iron-deficiency anemia, pernicious anemia, hypoplastic anemia, aplastic anemia

pernicious anemia

autoimmune attack of stomach tissue leads to inadequate b12 absorption

hypoplastic anemia

slowing of erythropoiesis

aplastic anemia

cessation of erythropoiesis

three consequences of anemia

tissue hypoxia and necrosis

-patient is lethargic, short of breath, and necrotic

reduced blood osmolarity, producing tissue edema

low blood viscosity

blood types are determined by presence or absence of ____ on the plasma membranes of erythrocytes.

antigens

When surface antigens, agglutinogens, are exposed to corresponding antibodies _____ occurs.

agglutination

agglutination

dangerous clumps of rbcs that can block small blood vessels, blocking blood supply and causing damage to tissues. hemolysis may also occur.

A blood type

anti-B, A antigen

B blood type

anti-A, B antigen

AB blood type

no antibody, A and B antigens

O blood type

anti-A and anti-B, no antigens

hemolytic disease of the newborn

This disease occurs in the fetus if the fetus is Rh+ while the mother is Rh-.

RhoGAM

Used to prevent an immune response to Rh positive blood in people with an Rh negative blood type

Erythroblastosis fetalis

hemolytic anemia in the fetus

blood pressure

the pressure that is exerted by the blood against the walls of blood vessels

systolic pressure

Blood pressure in the arteries during contraction of the ventricles.

diastolic pressure

occurs when the ventricles are relaxed; the lowest pressure against the walls of an artery

what changes bp supine vs. seated vs. standing

increases

how exercise changes blood pressure

increases it, then baroreceptor reflex kicks in and returns it to normal