Biochem 3 test Cardio

What happens if Sinoatrial (SA) node fails to provide action potentials?

Atrioventricular (AV) node can independently generate action potentials at 40-60/min

What causes a decrease in SA node rate and force of contraction?

Sympathetic nerves

What causes a increase in SA node rate and force of contraction?

Parasympathetic nerves

What does muscle contraction rely on?

Voltage-Dependent Calcium Channels (VDCCs)

What channel opens to induce extracellular Ca+ on the sarcolemma/T-tubules?

L-type calcium channels/dihydropyridine receptor (a VDCC)

During contraction and relaxation Ca+ is taken back into the SR through what?

Sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA)

What type of receptors does the heart mainly have?

Beta 1 receptors

The calcium channel blocker with an affinity for smooth muscle calcium channels that is predominately used for BP control/hypertension is?

Dihydropyridines
-Example: amlodipine, felodipine, and nifedipine

What is the CCB that is relatively cardiac selective and less likely to cause reflex tachycardia; also Decreased rate and force of cardiac contraction?

Phenylalkylamine/Non-Dihydropyridines

Intermediate CCB that decreases rate and force of cardiac contraction & dilation of blood vessels is?

Benzothiazipines

What is vasoconstriction regulated by?

vasopressin, angiotensin II, and endothelin (peptide hormones) or via chatacholamines

What activates guanylyl cyclase in vasodilation?

Nitrous Oxide (NO)

Endothelial permeability is induced by what?

-Histamine via H1 receptor
-Prostaglandins (Gs/adenylyl cyclase/cAMP)
-Interleukin-1 (IL-1) via a Janus kinase (JAK) receptor

What are the two ways to metabolize and transport cholesterol and lipoproteins?

-Endogenous pathway
-Exogenous pathway

Which pathway involves processing of cholesterol and triacylglycerols synthesized by the liver beginning with secretion of nascent very-low-density lipoprotein (VLDL) and high-density lipoprotein (HDL)

Endogenous pathway

Which pathway processing of ingested cholesterol and triacylglycerols beginning with secretion of chylomicrons after eating by intestinal epithelial cells initially into the lymphatic system (from the diet)?

Exogenous pathway

Exogenous/dietary lipids carried into the body via

chylomicrons

What is the cofactor for lipoprotein lipase?

APO-II

What protein made in the liver and is the first protein that is made in the endogenous pathway?

Very Low Density Lipoprotein (vLDL)

What is LDL packed with?

packed just w/ mainly cholesteryl esters

What is the genetic disorder caused by a defective LDL receptors or apo B?

Familial Hypercholesterolemia AKA hyperlipoproteinemia type IIa

What are the 7 causes that affect the LDL receptor?

-LDL receptor completely absent
-LDL receptor not on plama membrane (improper transport from ER)
-LDL receptor does not bind LDL due to mutation in receptor Apo B
-LDL receptor/LDL complex does not endocytose in clathrin-coated pits
-LDL receptor does not

In atherosclerosis accumulation of oxidized LDL, cholesterol deposits and leukocytes (esp. macrophages) is known as?

fatty streak

What can partially or completely occlude the artery that can lead to myocardial infarction?

Thrombus

Blockage of artery can also cause irreversible dilation known as an?

Aneurysm

In Atherosclerosis, what lowers levels of LDL and other harmful lipids/lipoproteins?

Statins

Statins inhibit what enzyme?

HMG-CoA reductase
-responsible for the conversion of HMG-CoA into mevalonate

In addition to statins, other drugs such as fibrates (gemfibrozil, fenofibrate), and clofibrate, lower cholesterol by activating what?

peroxisome proliferator-activated receptor alpha (PPAR-?)

What does activation of peroxisome proliferator-activated receptor alpha (PPAR-?) lead to?

? liver ?-oxidation of lipids
? LPL lipolysis of TGs from CM and VLDL
? HDL (reverse cholesterol transport)
? secretion of TG from liver into blood

What reduces GI cholesterol absorption?

Exetimibe (Zetia)

Complete blockage of blood vessels that feed the heart muscle produces a state of what?

Anoxia

Many MIs are categorized as what?

an ST elevation MI (STEMI) or non-STEMI

What may happen when Myocardial Infarction (MI) blockage is suddenly relieved?

reperfusion injury

What is causes by Failure to produce or diffuse NO can lead to vasoconstriction from the acetylcholine effect?

Prinzmetal's Angina

Is a breakdown of a thrombus or embolus whose treatment replies on plasminogen activators is?

Thrombolytics

Binds to atrial receptors to relax blood vessels via cGMP is what?

B-type Natriuretic Peptide (BNP)

What disease causes BNP to rise?

congestive heart failure (CHF)