Youel: Cardio
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- what triggers coronary artery vasodilation?
- AHA: anoxemia, hyperkalemia, adenosine increased
- what is the calcium-binding protein in myocardium? smooth muscle?
- troponin; calmodulin
- what nerves are involved in the carotid sinus reaction?
- glossopharyngeal IX and vagus X
- how many nuclei are in each myocardial cell?
- 1 (for "1 heart and many skeletal muscles")
- why is long action potential in myocardium important?
- prevents tetany
- length of action potentials in each muscle type?
-
cardiac: 200ms
smooth: 20ms
skeletal: 2ms
- cardiac and smooth have slow Ca++ channels; skeletal uses internal Ca++ - how does digitalis work on the cardiac AP?
- poisons the Na/K/Ca pump to increase intracellular Ca and increase contractility
- what is McArdle's disease?
- a glycogen storage disease which is due to a deficiency of muscle phosphorylase
- what is the "TIC triplet"?
-
- troponin T: Tightly binds to tropomyosin to block attraction to myosin
- troponin I: Inhibits ATPase
- troponin C: Calcium binds it to trigger Contraction - what does ATP do in the cross-bridging of muscle fibers?
- it binds to myosin head and releases actin filament
- what is the Bowditch or Treppe effect?
- Chronotropism: Cardiac rate increased, Calcium increased intracellularly, Contractility increased
- what are the 7 big etiologies of edema?
- CHARRED: Cardiac failure, Hepatic failure, Albumin deficit, Renal failure, Restricted return, Endocrine excess (cortisol, ADH), Drug effect (vasodilation)
- what causes non-pitting edema?
- myxedema and mucopolysaccharide deposits in severe hypothyroidism
- what is the Bainbridge reflex?
- stretching the right heart and the great veins causes an adrenergic response: increased contractility of the heart
- how can you increase atrial natriuretic peptide release in the heart? what does increased ANP lead to?
- increased preload; sodium diuresis
- what does lower preload lead to?
- increased ADH, an antidiuretic factor
- what effect does HYPOcalcemia and HYPOkalemia have on the QRS potential?
- lengthens the QRS complex, the time it takes for ventricles to depolarize and repolarize
- what are the effects of HYPERcalcemia and HYPERkalemia?
- coma and heart block, respectively
- how are tension, pressure, resistance and wall thickness (h) related?
- T = P * R * 1/2h
- what happens if a patient with atrial flutter is given quinidine?
- the heart block is overcome, putting the patient in danger
- at what heart rate is there fetal distress?
- <100 bpm
- what are the effects of preload and afterload on the PV loop?
- preload shifts loop to the right and afterload shifts upwards
- what is the avg resting cardiac output? maximum cardiac output?
- 5-6 l/min; 30 l/min
- what is the difference between S3 and S4 heart sounds?
- S3 is early diastole (ventricular) and S4 is late diastole (atrial); "Kentucky" vs "Tennessee"
- what is the cardiac 70-70-70 rule?
- for a 70kg man, stroke volume is about 70ml and ejection fraction is about 70%
- effect of angiotensin II? what does aldosterone do?
- VAST: Vasoconstrictor, Aldosterone releaser, Sympathetic sensitizer, Thirst & salt craving; triggers absorption of Na+ and release of K+ (exchanger)
- name 8 local natural hypertensives
- CV STEALTH: Catecholamines, Vasopressin, Serotonin (can dilate), Thyroxine, Endothelin, Angiotensin II, Leukotriene and some prostaglandins, THromboxine (TV CLEATS)
- name 4 natural vasodilators
- NAPKIN ring: Nitrous oxide, Adenosine, Prostaglandins, KINins
- 3 mechanisms of shock
- cardiogenic, hypovolemic, vasodilation
- what are some effects of forward heart failure? backward heart failure?
- hypoxic encephalopathy & uremia; hepatosplenomegaly & ascites
- what can you do besides drugs to treat hypertension?
- SAWER: Salt restriction, Alcohol avoidance, Weight control, Exercise, Relaxation
- which of the left fascicles is bigger?
- posterior
- with sympathetic stimulation, how is the heart affected?
- +chronotropism, +bathmotropism, +dromotropism, +inotropism