Blood Flashcards
characteristics of blood
normal temperature of 100.4 F
pH of 7.4
five times greater viscosity than water
blood constitutes approximately 8% of adult body weight
adult males: 5-6 liters of blood
adult females: 4-5 liters of blood
plasma
transports nutrients, hormones, and proteins
a yellow liquid that makes up about 55% of the body’s blood volume
platelets
form clots to stop bleeding
make up less than 1% of blood
red blood cells
carry fresh oxygen through the body and remove carbon dioxide
make up about 40 to 45% of blood
white blood cells
part of the body’s immune system
detect and fight viruses and bacteria
5 major types
make up less than 1% of blood
transportation
deliver oxygen and nutrients to as well as remove wastes from body cells
defense
white blood cells
platelets
regulates
body temperature
red blood cells
more than 25 trillion
every second, 2-3 million are produced in bone marrow and released into circulation
diameter of 6 um
small enough to squeeze through the smallest blood vessels
circulate around the body for up to 120
hemoglobin
an iron-containing globular protein which is composed of four subunit polypeptide chain
greater amount of Hb
greater oxygen carrying capacity in the body
steps of RBC formation
- kidneys detect reduced O2- carrying capacity of blood
- kidneys respond by secreting erythropoietin into the blood stream
- erythropoietin stimulates erythropoiesis by the bone marrow
- addition of circulation erythrocytes increase O2- carrying capacity in blood
- increase O2- carrying capacity relieves the initial stimulus that triggered EPO secretion
anemia
hemoglobin levels of <=12.0 g/dl for women and <=13.0 g/dl for men
5.6% of US population has it
the prevalence of anemia increases with age with 8-44% of elderly individuals being diagnosed
caused by iron deficiency, vitamin deficiency, chronic inflammation, bone marrow disease, blood diseases, sickle cell disease
endurance exercise
stimulates increased red blood cell synthesis due to exercise induced arterial hypoxia
increase in RBC by 5% over several months
increased plasma volume with endurance exercise directly relates to
increased synthesis and retention of plasma albumin
there is a 12-20% increase in plasma volume after 3-6 aerobic training sessions
increase to end diastolic volume
increase to cardiac output
improves temperature regulating ability during exercise
blood doping
the use of substances or techniques that increase the number of circulating red blood cells (erythrocytes) or the oxygen-carrying capacity of blood to improve human performance
increases maximal aerobic fitness and endurance performance
banned by internal Olympic committee since 1984
banned by NCAA, world anti doping agency, union cyclist international
blood withdrawal and reinfusion
autologous transfusion
withdrawal of 1-4 units of whole blood and immediately reinfuse the plasma
1 unit = 450 mL
place packed red blood cells in frozen storage for later refusion
homologous transfusion: infuses a type-matched donor’s blood
infuse stored blood 1-7 days before endurance event
results in an 8-20% increase in RBC count and hemoglobin & increases blood volume
epoetin
synthetic form or erythropoietin that stimulates the formation of new RBCs by the bone marrow
6 weeks results in a 12% increase in hemoglobin and RBC
self-administration in an unregulated and unmonitored manner can increase hematocrit more than 60% (no effect on overall blood volume)
increases blood viscosity which increases likelihood of stroke, heart attack, heart failure, and pulmonary edema
safety considerations for blood doping
high levels of hematocrit increase risk for heart attack, stroke, pulmonary, or cerebral embolism
even more common after dehydration as a result of strenuous exercise
homologous transfusion
transfer of virus or other blood-borne pathogens
autologous transfusion
significant health risks if the procedure is not done properly or if the blood is not handled or stored in a proper manner
