Final Exam Flashcards
what is the structure and function of platelets?
flattened cell fragments, no nucleus, contain some granules. live about 10 days. participate in blood clotting.
what is the structure and function of erythrocytes?
biconcave disc, anucleate and no organelles, contains hemoglobin. Life span of 100-120 days. Binds and transports O2 and some CO2
what is the structure and function of hemoglobin (Hb)?
globin made of 4 polypeptide chains. each chain contains 1 heme group with 1 iron atom. binds to oxygen.
what is the difference between erythrocytes and leukocytes?
erythrocytes are red blood cells while leukocytes are white blood cells. RBCs transport gases and nutrients while WBCs fight infection primarily.
what are the types of leukocytes?
-neutrophils, eosinophils, basophils (granulocytes)
-monocytes and lymphocytes (agranulocytes)
what is the structure and function of neutrophils?
granulocyte, multilobed nucleus, bacteria slayers, kill by respiratory bursts or defensins.
what is the structure and function of eosinophils?
granulocyte, bilobed nucleus. important responders in asthma, allergies, attack parasitic worms.
what is the structure and function of basophils?
granulocyte, bilobed hidden nucleus, contain histamines. histamine is vasodilator and attractant for other WBCs.
what is the structure and function of monocytes?
agranulocyte, kidney u-shaped nucleus, largest leukocyte. Become phagocytic macrophages, activate the immune system.
what is the structure and function of lymphocytes?
agranulocyte, large round nucleus.
T lymphocytes: act on infected cells or tumor cells.
B lymphocytes: become plasma cells and release antibodies.
what are the 3 steps of hemostasis?
vascular spasms, platelet plug formation, coagulation
what happens in vascular spasms?
the vessels constrict.
what happens in platelet plug formation?
positive feedback loop. platelets swell, form spikes, stick to each other and collagen fibers in the wall. platelets release chemical messengers that increase platelets and vascular spasms.
what happens in coagulation?
both intrinsic and extrinsic pathways are triggered. Inactive clotting factors become activate. Each clotting factor activates the next.
what happens in the 3 phases of coagulation?
- extrinsic and intrinsic factors both activate clotting factor X, which activates prothrombin activator.
- prothrombin activator activates prothrombin. prothrombin activates thrombin.
- thrombin activates fibrinogen which activates fibrin. fibrin forms strands and the strands form a fibrin net.
compare and contrast the extrinsic versus intrinsic pathways of coagulation.
intrinsic pathway: activated by factors in the blood, slower.
extrinsic pathway: activated by tissue factor, less clotting factor to activate, faster pathway.
how are ABO blood groups determined?
The blood can have either an A or a B antigen (Ag). If the blood has the A Ag, the blood type is A. If the blood has the B Ag, the blood type is B. If the blood contains both Ags then the blood type is AB, and if the blood type does not contain either Ag the blood type is O.
How is a positive or negative blood type determined?
With the presence or absence of the Rh Ag. The presence of this indicates a positive blood type, while the absence indicates negative.
What is the microscopic anatomy of cardiac muscle tissue?
striated muscle, light I and dark A bands, uninucleate with many mitochondria. gap junctions, desmosomes.
Name the components of the conduction (heart) system
SA node begins polarization wave, both atria contact. Depolarization spreads to AV node, spreads to AV bundle. Spreads to right and left bundle branches, spreads to purkinje fibers, both ventricles contract.
What is the pathway of blood in the heart?
SVC/IVC, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary artery, pulmonary veins, left atrium, bicuspid valve, left ventricle, aorta
What event does systole represent?
contraction of chamber, blood empties
What event does diastole represent?
relaxation of chamber, blood fills
what is the relationship of heart rate, cardiac output, and stroke volume?
CO=HRxSV
What happens in capillary exchange?
filtration. hydrostatic and osmotic pressures cause fluid to leave capillaries (arterial end) and enter capillaries (venous end). diffusion with gradients. O2 and nutrients enter tissues, CO2, and metabolic wastes enter blood.
What are the pressures involved in capillary exchange?
Hydrostatic pressures-> pushing out
Osmotic pressures-> pulling in
NFP= outward pressures-inward pressures