Hypertension and Heart Diseases (Chapter 12) Flashcards
most tissues in the body are connected to the sympathetic and parasympathetic NS. what tissue in the body is predominantly sympathetic?
adrenal gland
how does signal transmission occur in a parasympathetic nerve ?
pre-ganglionic nerve releases ach, detected by nicotinic receptors on post-ganglionic nerve.
then, post-ganglionic nerve releases ach, detected by cholinergic receptors on target tissue
what are the three types of cholinergic receptors on target tissue ?
muscarinic, nicotinic ganglionic, nicotinic neuromuscular
how does signal transmission occur in a sympathetic nerve ?
pre-ganglionic nerve releases ach, detected by nicotinic receptors on post-ganglionic nerve.
then, post-ganglionic nerve releases NE, detected by adrenergic receptors on target tissue
what are the five types of adrenergic receptors on target tissue ?
B1 B2 B3 A1 A2
what two NT’s do AR’s sense?
NE, and E released by adrenal medulla
which nerve signal transmission involve ach release- SNS or PNS?
both
PNS: released by pre and post- ganglionic nerve
SNS: released by pre-ganglionic nerve
explain what happens after NE binds to a B2 AR.
B2 AR acts as a G-Protein coupled receptor. Induces a second messenger pathway. It converts ATP to cAMP (second messenger)
what does cAMP do ?
causes vasodilation in blood vessel smooth muscle
bronchodilation in lungs
suppresses immune system
what is the difference between E and NE ?
NE comes from everywhere in the body and can specifically target tissues
E comes from adrenal medulla
which nerve decreases HR?
vagus nerve
which nerves increase HR and force of contraction ?
sympathetic cardiac nerves
which part of the ANS can control both HR and force of contraction ?
SNS
by how many bpm can the PNS decrease HR ?
10 bpm
by how many bpm can the SNS increase HR?
usually 10 bpm
in a strong SNS response, by more
what is the main adrenergic receptor that controls HR?
B1
what are the two main adrenergic receptors that control BP ?
A1
B2
what is the main role of A1 AR ?
causes vasoconstriction of blood vessel smooth muscle
therefore binding to it can cause BP increase
what is the main role of A2 AR ?
some vasoconstriction, also regulates NE by negative feedback
(not that important here)
what is the main role of B1 AR ?
increase HR and contractility
what is the main role of B2 AR?
increase BP, heart muscle contraction
what is the main role of B3 AR ?
thermogenesis
what NT is BP mostly controlled by ?
NE
termination of a neural signal can occur in two ways
1) promote reuptake of NT
2) promote destruction of NT by enzymes
which enzyme inactivates ach ?
cholinesterase
which enzyme inactivate NE ?
monoamine oxidase
what is the main mechanism of blood pressure increase ?
vasoconstriction via A1 AR on blood vessel walls.
what is the main mechanism of HR increase ?
B1 AR binding, increases rate and force of contraction
why don’t we use parasympathetic drugs to lower HR or to increase HR?
bc these drugs also modify the pre-ganglionic function in the SNS, leading to adverse effects.
what is the normal goal of the renin-angiotension-aldosterone system ?
to increase BP
what is renin ?
an enzyme which converts angiotensinogen to angiotensin I
what is angiotensin converting enzyme
ACE converts angiotensin I to angiotensin II
what does angiotensin II do ?
increase BP
what are the 2 ways in which angiotensin II increases BP ?
1) induce vasoconstriction by elevating epinephrine and inactivating bradykinin
2) increases sodium and water retention by causing release of aldosterone
what does bradykinin cause in the circulatory system ?
vasodilation
what is the role of aldosterone ?
it retains water and sodium, therefore increasing BP
what is renin release stimulated by (4) ?
decreased blood flow, drop in BP, diminished sodium and water retention, or increased SNS response on renal cells
what is renin released inhibited by ?
high blood pressure
indirect negative feedback
what is chronic high blood pressure called ?
hypertension
what is essential hypertension ?
if cause of high BP is unknown
what is secondary hypertension ?
high BP symptom that something else is wrong
what are the guidelines for high BP classification ?
normal: SBP <120 and DBP <80
prehypertension: SBP 120-139 OR DBP 80-89
stage 1 hypertension: SBP 140-159 OR DBP 90-99
stage 2 hypertension: SBP >160 OR DBP >100
what are the treatment options for prehypertension
lifestyle modifiction
drugs not typically given unless there is also kidney disease or diabetes
what are the treatment options for hypertension stage I
lifestyle modification
single drug prescribed
what are the treatment options for hypertension stage II
lifestyle modification
two drugs prescribed in combination
what are lifestyle modifications for hypertension that do not do much ? (3)
changing garlic, magnesium, caffeine intake
what are 5 lifestyle modification important in hypertension ?
- lose weight
- exercise aerobically
- no smoking
- less alcohol
- more potassium
why is it good to have more potassium in diet ?
eating potassium forces salt into urine. as potassium is absorbed, salt and water will go to kidney
what are foods really high in potassium ?
avocado, beans, dates, peanuts, baked potatoes with skin, raisins, plain yogurt
what are foods with intermediate potassium ?
apricots, banana, carrots, hamburger, salmon
what are foods low with potassium ?
apples, asparagus, blueberries, corn, hot dog, peach, peas, pizza
foods high in Na+ basicallt
what is angina ?
a chronic heart diease, where coronary arteries cannot supply adequate blood to heart muscles
what is ischemic heart disease ?
another word for angina pectoris
what are the three kinds of angina ?
chronic stable angina
variant angina
unstable angina
what kind of pain is in angina ?
sudden pain behind sternum, radiates to left shoulder and arm, may be in neck and jaw
what is the most common form of angina ?
chronic stable angina
what is the cause of chronic stable angina ?
atherosclerosis of coronary arteries- partial occlusion and restricted blood flow
what is chronic stable angina pain brought on by ?
exercise, can’t meet demand of myocardial muscles
what do drugs for chronic stable angina do ?
increase O2 to heart muscles, or reduce demand for oxygen
what are two other names for variant angina
vasospastic angina
Prinzmetal’s angina
what is the main difference between MI and angina ?
in MI the pain doesn’t go away
what is the main difference between variant and chronic stable angina ?
in variant, coronary artery spasm can happen at any time, not just during exertion
what kind of drugs treat variant angina ?
those that increase O2 to heart muscles
what is unstable angina ?
angina symptoms come and go regularly or at rest
changes in severity of pain or pattern of angina compared to normal
what is the most life threatening type of angina ?
unstable angina
what kind of drugs treat unstable angina ?
lower oxygen demand, increase oxygen delivery to heart muscle
what kind of occlusion occurs in myocardial infarction ?
partial or full occlusion
what is MI usually due to ?
atherosclerosis
plaque breaks off and closes off vessels
how does exercise reduce risk of MI ?
more branching, more blood vessels therefore less probability that it will get blocked off
what symptoms in MI differ from angina ?
vomiting, chest pressure, numbness/tingling in arm, shortness of breath
what are 4 risk factors for MI ?
hyperlipidemia
hypertension
smoking
history of angina
what medication would be involved in emergency treating MI ?
aspirin to inhibit clotting
morphine to reduce pain and reduce oxygen demand in heart
are heart disease and heart failure the same ?
no
what subset of the population has heart failure more
old people
what is the mechanism in heart failure
ventricles fail to eject enough blood for body tissues, which means diastolic filling increases
heart gets 2-3 times larger
heart stretched, therefore enlarged. as a compensation, contractility is increased.
constriction of blood vessels to maintain blood pressure.