Blood Flow
Where are most DVTs commonly found?
Veins in the lower legs (great saphenous)
After how many minutes of ischemia, does infarction occur?
20 minutes
What is the criteria for Stage 1 HTN?
130-139/80-89
What is the main type of collateral circulation in the brain?
Circle of Willis
What does the mitral valve do?
Prevent backflow of blood from LV back into RA
What are clinical manifestations of an arterial occlusion?
Distal to the occlusion:
Pallor, Polar (cold), Pulselessness, Pain, Paresthesia, Paralysis
Define stable angina and unstable angina
Stable: predictable onset, elicited by similar stimuli each time, relieved by rest and nitroglycerin tabs
Unstable: unpredictable and represents a medical emergency, occurs at rest, new in onset, worsens over time
What is the criteria for Stage 2 HTN?
140+/90+
Compare and contrast ischemic stroke versus hemorrhagic
Ischemic: blood clot blocks a cerebral artery, reducing blood flow and oxygen to brain tissue, leading to neuronal death
Hemorrhagic: results from a ruptured blood vessel in the brain, causing bleeding that increases intracranial pressure and damages brain tissue
What is ejection fraction measuring?
With each heartbeat, the ventricles eject much of their blood volume, and the amount ejected (LV) per beat is called the ejection fraction
What are the clinical manifestations of a venous occlusion?
Distal to the occlusion:
Redness, swelling, pain
What happens to BP and HR during an MI
Initially, ↑ HR and BP, then ↓ BP (secondary to ↓ in CO)
The amount of work/force needed to move blood into aorta
Explain contralateral hemiplegia
paralysis on one side of the body caused by damage to the opposite side of the brain
What is systolic failure?
Impaired myocardial contraction defined by low ejection fraction <40% (HFrEF)
Compare and contrast a true aneurysm versus a false aneurysm!
True aneurysm: involves all 3 layers of vessel wall
False aneurysm: extravascular hematomas
What is troponin?
cardiac enzyme important in detecting MI
Define preload
Amount of ventricular stretch at end of diastole
What is broca aphasia vs. wernicke's aphasia
Broca's aphasia: Trouble speaking, but understanding is mostly intact.
Wernicke's aphasia: Speech is fluent but makes little sense; understanding is impaired.
What are the compensatory mechanisms activated in HF that also contribute to worsening of the disease?
1. SNS activation
2. Increased preload
3. Remodeling
What is Virchow's Triad?
Tells us triad of risk factors for DVT: stasis of blood flow, endothelial injury, hypercoagulability
Explain in stepwise fashion the process of atherosclerosis
1. Injury to endothelial cells
2. Leaking of LDLs into intima and oxidation of LDLs attract monocytes
3. Macrophages transform into foam cells and trigger inflammatory response
4. Foam cells attract LDLs and turn into fatty streak and then plaque formation
5. Plaque rupture
Explain in stepwise fashion the RAAS System
1. Kidneys secrete renin in response to low blood pressure or reduced renal perfusion.
2. Renin converts angiotensinogen (from the liver) into angiotensin I, which is then converted by ACE (in the lungs) to angiotensin II.
3. Angiotensin II causes vasoconstriction and aldosterone secretion
What are TIAs?
Episodes of neurologic dysfunction lasting no more than 1 hour and resulting from temporary obstruction of brain blood flow
Explain backward failure clinical manifestations in right sided HF?
JVD, peripheral edema, hepatomegaly, splenomegaly