answers latest update 2024
MI
Death of myocardium from sudden blockage of coronary artery blood flow
What causes cell death in MI?
unstable plaque breaks off, triggering platelet aggregation, coagulation cascade and thrombus
formation. continued no blood flow in 10 seconds ischemia, 20 minutes cell die
What consequence of cell death leads to CP?
hypoxia as cannot meet cell demand for oxygen
How is MI diagnosed
EKG (STEMI) or elevated Troponin (non-STEMI)
What might you find in blood consistent with MI?
elevated CK MB, Troponin
Where does CK MB and Troponin come from?
Release of lysosomal enzymes; CK MB detected after myocardial necrosis, Troponin released from
damaged heart muscle
3 mechanism of cell injury related to reperfussion injury
ischemia, necrosis, reperfussion l/t RAS
define reperfussion injury
injury that occurs after oxygen is reintroduced to tissue perfusion
how does inflammatory process contribute to reperfussion injury?
as oxygen is reintroduced it comes in contact with damaged proteins triggering inflammatory
response
how does oxidative process contribute to RI?
RAS causes impairment of cell membrane and pro-apotptoic cells release. making cell unstable
what is primary Hypertension?
Essential or idiopathic, elevated BP without an identified cause, accounts for 90 - 95% of all cases of
hypertension?
what is secondary hypertension?
Elevated BP, labile BP; related to conditions ie kidney dz; resistant to BP meds
what is significance of Ventricular hypertrophy and HTN?
persistent hypertension leads to ventricular hypertrophy; decrease CO
, what comorbidities/conditions does HTN cause?
stroke, ischemia, heart failure, aneurysm, hemorrhage
what is preload?
volume of blood in ventricles at end of diastole
what is afterload?
peripheral resistance against which the left ventricle must pump
hoe does HTN l/t CHF?
overwork left ventricle due to increase pressure; decreased pumping ability of heart and decreases
CO.
identify pathological process of gangrene?
form of coagulative necrosis; interruption of blood flow l/t denaturing cells enzymes and bacterial
invasion
three types of gangrene
dry, wet & gas
what is the major treatment approach for gangrene?
removing affective tissue to prevent infection; treating problem that led to gangrene
why use antibiotic for gangrene?
to slow bacterial damage
What are the two major necrotic processes?
Coagulative and liquifactive
What is coagulative necrosis?
necrosis caused y interruption of blood flow l/t desrease Ph, and bacterial growth
what is liquifactive necrosis?
Caustic enzymes dissolve and liquify necrotic cell; cottage cheese like appearance.
Describe dry gangrene
hypoxia l/t ischemia l/t last of blood flow l/t coagulative necrosis
Describe wet gangrene
extensive damage from bacteria with WBC's that have invaided site produces a liquid wound
describe gas gangrene