Module 7: Cardiology Flashcards
what 2 systems are intrinsic regulators of the heart and blood vessels?
Nervous system and endocrine system
what is the right side of the heart’s action and what is it associated with?
pumps blood through the lungs ; pulmonary circulation
what is the left side of the heart’s action and what is it associated with?
pumps blood throughout the body; systemic circulation
what action do arteries do?
they carry blood from the heart to the rest of the body
what action do capillaries have?
contact and exchange between the blood and the interstitial space
what action do veins have?
carry blood from the capillaries back to the heart
what are the 3 layers of the heart?
epicardium, myocardium, and endocardium
what is the thickest layer of the heart?
myocardium
The right side of the heart has what kind of pressure?
low pressure system
the left side of the heart has what kind of pressure?
high pressure system
what is the opening between the left and right aria before birth called?
the foramen ovale
what is another name for the right AV valve?
tricuspid valve
what is another name for the left AV valve?
mitral valve
The right side of the heart receives what kind of blood?
deoxygenate blood
the left side of the heart pumps what kind of blood to the circulatory system?
oxygenated blood
what is diastole and what happens?
period of relaxation during cardiac cycle; blood fills the ventricles
what is systole and what happens?
ventricular contraction during cardiac cycle; propels blood out of the ventricles into the pulmonary and systemic circulation
what are collateral arteries?
connections or anastomoses between coronary artery branches
what are two ways for collateral vessel formation?
arteriogenesis and angiogenesis
what is arteriogenesis?
new artery growth from pre-existing arteries
what is angiogeneis?
growth of new capillaries within a tissue
what stimulates collateral growth?
shear stress–could be stenosis, inflammation caused by cytokines.
fiber shortening is in relation to what?
muscle contraction or systole
fiber relaxing and returning to their resting length is associated with what?
diastole
what are the 2 pacemakers of the heart?
sinoatrial node and atrioventricular node
what ANS system increases heart rate and conduction through nodes?
sympathetic nervous system
what ANS system slows heart rate and prolongs intranodal conduction time?
parasympathetic nervous system
where is the sa node located?
it is located near right atrium of the heart near the SVC and above the tricuspid valve
where is the AV node located?
it is in the right atria WALL, superior to the tricuspid valve
what innervates the AV node?
it is innervated from the autonomic parasympathetic ganglia that serve as receptors for the Vagus nerve
what is depolarization?
electrical activation of the muscle cells
what is repolarization?
electrical deactivation of the muscle cells
what occurs in phase 0?
depolarization, rapid sodium enters into the cell
what occurs in phase 1?
early repolarization, calcium slowly enters the cell
what occurs in phase 2?
plateau, continuation of repolarization . sodium and calcium enter the cell
what occurs in phase 3?
potassium is moved out of the cell
what occurs in phase 4?
return to resting membrane potential
what does the p wave represent?
atrial depolarization; atrial contraction
what does the PR interval represent?
the difference in time from the onset atrial activation (contraction/depolarization) to the onset of ventricular activation (contraction/depolarization)
what is the normal time frame during the PR interval?
0.12–0.20
what does the QRS complex represent?
sum of all ventricular muscle depolarization
what is the ST interval?
the entire ventricular myocardium depolarized
what is the QT interval?
the electrical systole of the ventricles
what is the normal rate for the SA node to depolarize?
60–100 bpm
if the SA node is damaged, what node will take over next?
The AV node
what is the normal rate for the AV node to depolarize?
40–60 bpm
sympathetic stimulation causes calcium to do what?
The increased influx of calcium cause increased contractile strength, heart rate goes up or electrical impulses are faster
where do the efferent sympathetic fibers originate from?
they originate from the thoracic spinal cord and branch into the superior middle and inferior cardiac nerves
parasympathetic (Vagus) activity causes the release of what?
acetylcholine
what effect does acetylcholine have on the heart?
decreases heart rate, slows conduction through the AV node, reduces strength of contraction
beta 1 receptors are found where?
in the heart/conduction system
beta 2 receptor are found where?
in the heart and smooth muscle
stimulation of beta 2 receptors causes what?
vasodilation and increases coronary blood flow (because of the location of receptors over smooth muscle)
stimulation of beta 3 receptors causes what?
opposes the effects of beta 1 and beta 2 receptors and decreases myocardial contractility (negative inotropic effect)
what is a negative inotropic effect?
decrease in cardiac contractility
stimulation of alpha 1 adrenergic receptors causes what?
smooth muscle contraction and vasoconstriction
stimulation of alpha 2 adrenergic receptor causes what?
promotes vasodilation
chronotropic (chronotropy) refers to what?
heart rate
inotropy refers to what?
heart contractility
name 3 calcium channel blockers
nifedipine, verapamil, diltiazem
what channel is affected by the calcium channel blockers?
The L-type or long-lasting channels are predominant and are blocked by calcium channel blocking drugs
what is the action of calcium channel blockers?
DECREASES STRENGTH OF CARDIAC CONTRACTILIY
what is cardiac output?
HR multiplied by stroke volume
what is a normal cardiac output?
5 L/min
what is ejection fraction?
the amount of blood the ventricles eject per beat
what are 4 factors that affect cardiac output directly?
Preload, afterload, myocardial contractility, and heart rate
what is afterload?
the resistance to eject blood from the ventricle
low aortic pressures , do what to the heart and afterload?
decrease afterload and enable the heart to contract more rapidly
high aortic pressure do what to the heart and afterload?
increase afterload and slow contraction and cause high workload against the heart
increased aortic pressure is usually the result of increased what?
systemic vascular resistance
what is stroke volume?
the volume of blood ejected per beat during systole
Excessive increase in preload has what affect on stroke volume?
decreased stroke volume
what are the two most important endogenous inotropic agents?
norepinephrine and epinephrine
what do inotropic agents affect?
contractility of the heart
what is the most important negative inotropic agent?
acetylcholine which is released from the Vagus nerve
lack of oxygen (hypoxia) has what effect on contractility?
leads to decreased contractility
low temperature has what affect on the heart?
bradycardia
increase temperature has what affect on the heart?
can increase heart rate
In respiratory inspiration, what happens with the heart rate?
the heart rate goes up
in respiratory expiration, what happens with the heart?
the heart rate goes down
what area of the brain regulates temperature in CV response?
hypothalamus (hypothalamic)
what are of the brain regulates/adjust CV reaction to emotional states?
the cerebral cortex
what area of the brain regulates heart rate and blood pressure?
medulla oblongata
the resting heart rate is under the control of what ANS?
parasympathetic (Vagus) stimulation
what are the 2 baroreceptors located?
aortic arch and carotid arteries
dysfunction in baroreceptors can result in what?
postural hypotension which is associated with aging
baroreflex can reduce high blood pressure through neural impulses from what 2 cranial nerves?
glossopharyngeal nerve from the carotid and Vagus nerve from the aorta
atrial natriuretic peptide has what affect?
has a diuretic and natriuretic (salt excretion) prosperities which decrease blood volume and pressure
Norepinephrine does what to heart, contractility, and blood vessels?
increases heart rate, enhances contractility, and constricts blood vessels
epinephrine dilates vessels of the liver and skeletal muscles and does what to myocardial contractility?
increases myocardial contractility
which thyroid hormone increases heart rate and contractility resulting in an increase in cardiac output and decreases systemic vascular resistance?``
triiodothyronine (T3)
the key vasoconstrictor hormones include: (4)
angiotensin II, vasopressin (ADH), epinephrine, and norepinephrine
what is ADM?
adrenomedullin; a VASODILATING peptide
Vasopressin and Aldosterone affect BP by
increasing blood volume through the influence on fluid reabsorption of water from the tubular fluid in the kidney
what is the end product of the RAAS?
aldosterone
what are the vasodilator hormones?
ANP, BNP, CNP, urodilatin
what are the functions of the vasodilator homrones?
they function as both vasodilators and regulators of sodium and water excretion
increased BNP level predicts what?
a poor outcome in Heart failure (also PE, valvular disease, and chronic CAD)
what is flow-mediated dilation (FMD) test used for?
to evaluate endothelial function and predict risk for CV disease
nitric oxide (NO) has what kind of properties?
maintains vascular homeostasis, vascular dilator tone, regulation of local cell growth, and protects the vessel
describe prostacylcin
it is a vasodilator; has antithrombotic properties (opposes clot formation)
what is Nattokinase?
it is an enzyme found in natoo–traditional food made of soybeans fermented with bacillus subtilis
Nattokinsae intake can reduce the risk of what in humans?
thrombosis
what is cardiac output?
amount of blood moved by the heart in 1 minute
what is the normal range for cardiac output?
normal range is 4 to 8 liters
what is stroke volume?
the amount of blood ejected by the LEFT VENTRICLE during systole
