Flashcards in CVD, BONE METABOLISM, DIABETES, HERBALS Deck (33)
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1
what are pacemaker cells of the heart
they have instable membrane potentials that allow them to reach threshold and generate action pot spontaneously
2
what movements maintain cardiac cell (3)
1. constant diffusion of na and k down their gradiants
2. 3 Na out for 2 k in
3. ca out 3 NA in
3
what are the 5 (0+4) phases of ventricular action pot
0-depolarization (NA open)
1-rapid repolarization (na close k open n close)
2-plataue (ca open)
3-final repolarization (ca close, k open)
4-spontaneous depolarization (sod permeability increases)
4
What effect do catecholamines have on the heart
positive chronotropic effect
(increase levels of cAMP)
5
what effect does parasympathetic stim have on the heart
stim of muscarinic receptors cause reduced level of cAMP that produces an increase in outward K current (hyperpolarization)= decrease in pacemaker activity
6
what effect that ca have on non pacemaker cells
increase in intracellular ca= increase contraction strength
7
what is peripheral edema indicative of
heart failure
8
what are the cardiovascular consequenses of heart failure
increase venous pressure
increase sympathetic activity
increased renin, aldosterone etc
9
what is digitalis glycosides and how does it work
used for heart failure to have positive iontropic effect
inhibits na/k atpase pump with results in increase of intrcellular sodium conc= greater activation of contractile pros and less ca leaving
10
does digoxin affect skeletal mm
no just increases force and velocity of myocardial contraction
11
what is the cardiac side effects of digitalis glycosides
dose related arrhythmias
-premature atrial and ventricular contractions
12
what are the extracardiac toxicity of digitalis glycosides
most GIT
-vommiting due to stim of chemoreceptor trigger zone
13
What is the antidote for digitalis toxicity
administer potassium iv to decrease the slope of phase 4
or lidocaine
(the spontaneous depolarization portion)
14
What do class I anti arrhythmic drugs do
slow down rate of phase 0 (and 4) by blocking membrane sodium channels
--cause decrease in excitability + conduction velocity
15
What do class II anti arrhythic drugs do
B-adrenergic receptor antagonists- depress phase 4 depolarization by competing w catecholamine stim
16
what do class III anti arrhythmic durgs do
prolong the action potential with a consequent increase in the absolute and effective refractory period
17
What do call IV anti arrhytmic drugs do
Decrease inward current carried by calcium (in sa node decreases rate of phase 4 spontaneous depolarization)
18
what is the net calcium absorbtion when taken orally
15-40%
19
what is essential for calcium absorbtion
bile
20
effects of calcitonin
inhibits rate of bone turnover, increases exretion of sodium, pot and phosphate
21
what is raloxifene and what are its effects and the bioavailability
Selective estrogen receptor modulator (produces agonist effects)
only 2% oral bioavailability
22
How do bisphosphonates work and what is the oral bioavailability
10% bioavailability
-inhibit bone resorption by cellular effects on osteoclasts (inhibis recruitment, differentiation and activity)
23
what does flouride do
incorporated into bone as hydroxyfluroapatite which is resistant to resorption
24
What receptors do insulin bind to
binds to specific tyrosine kinase receptors to initatiate a series of enzyme reactions that impact on glucose homeostasis
25
What do sulfonylureas do
oral hypoglycemic drug
-act by binding to ATP dependent potassium channels in pancreatic B cells which accumulates calcium stimming release of insulin
26
what do glitinides do
oral hypoglucemic drug
same mechanism of sulfonylureas but quicker and shorter action
27
What do thiazolidinediones do
oral hypoglycermic drug
act as insulin sensitizers to regulate the expression of specific genes in adipocytes improving insulin sensitivity of mm and liver
28
what doe biguanides do
oral hypoglycermic drug
they act directly on mm to increase glucose uptake and utalization
29
what doe sglt2 inhibitors do
inhibit glucose resorbtion in prox tubule
30
what % of diabetics get diabetic neuropathy
50% of pts w type 1/2 DM
31
What is diabetic retinopathy
leading cause of new blindness in persons 25-74
32
what is diabetic nephropathy
persistent albuminuria, progressive decline in GFR and elevated BP
33
