Studied by 2 peopleWhat is the order that nutrients and oxygen follow when diffusing from the blood?
blood → ISF → cells
What order does wastes move in?
cells → ISF → blood
What are erythrocytes?
red blood cells
What is plasma?
special cell fragments
What are leukocytes?
white blood cells
What are the granular leukocytes?
neutrophils, eosinophils, basophils
What are the agranular leukocytes?
lymphocytes and monocytes
What are thrombocytes?
platelets
What is the major function of platelets?
blood clotting
What is blood plasma’s composition?
90% water, ~7% proteins, and ~2% other solutes
Where are plasma proteins created?
the liver
What proteins are present in plasma?
albumin, immunoglobulins, and fibrinogen
What is albumin?
maintains blood osmotic pressure
What are immunoglobulins?
antibodies that bind antigens; form antigen-antibody complexes
What is fibrinogen?
for clotting; precursor to fibrin, the sticky protein to form clotting network
What other solutes are present in plasma?
electrolytes, nutrients, hormones, gases and waste products
What is the normal hematocrit range in females?
38-46%
What is the normal hematocrit range in males?
40-54%
What is anemia?
not enough RBCs (or hemoglobin) for proper O2 transfer
What is polycythemia?
having an excess of RBCs; can result in dehydration, tissue hypoxia, blood doping
What is hemoglobin?
a protein that carries oxygen
What is hemoglobin composed of?
-globins; 4 large protein chains (2 alpha 2 beta)
-a heme group (within each chain)
What is the heme group?
a porphyrin ring that surrounds a single iron molecule
How many O2 molecules can each hemoglobin carry?
4
What does CO2 bind to in hemoglobin?
amino acids in the globin portion
What is erythropoiesis?
RBC formation
Where does erythropoiesis occur?
in the red bone marrow
What are RBCs formed from after birth?
stem cells
Stem cells differentiate into:
proerythroblasts
Proerythroblasts then become _____ and then ________.
erythroblast; reticulocytes
When a reticulocyte reaches maturity, hemoglobin is produced and the nucleus is ejected, resulting in the formation of a mature __________.
erythrocyte
What is the role of hemopoietic growth factors?
regulation of differentiation and proliferation of blood cells
What are the 3 hemopoietic growth factors?
erythropoietin, thrombopoietin, and cytokines
What does erythropoietin do, and what produces it?
increases RBC precursors, produced by kidneys
What does thrombopoietin do, and what produces it?
stimulates platelet formation, produced by liver
What are cytokines and what do they do?
local hormones of bone marrow; stimulate proliferation in other marrow cells; colony-stimulating factors (CSFs) and interleukins stimulate WBC production
What is an example of a medical usage of erythropoietin?
treating decreased RBC production of end-stage kidney disease
What is an example of a medical usage of thrombopoietin?
helps prevent platelet depletion during chemotherapy
How long do RBCs live?
about 120 days
What causes RBCs to wear out?
bending to fit thru capillaries
What happens to worn out RBCs?
removed by macrophages in the spleen and liver; the globin portion is broken down into amino acids and recycled; the heme portion is split into iron and biliverdin
What happens to the iron portion of the heme of a worn down RBC?
it is transported in blood attached to protein transferrin; stored in liver, muscle, or spleen; attached to ferritin protein; transported to bone marrow for use in hemoglobin synthesis
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