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91 Cards in this Set
- Front
- Back
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Which way is the heart tilted?
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The apex is directed to the left
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What is the majority of the heart composed of?
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myocardium
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What makes up the wall of the heart?
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myocardium
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How does blood supply get to the heart?
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coronary arteries and cardiac veins
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What can blockage of the coronary arteries lead to?
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Infarction
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What is an infarction?
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sudden insufficiency of blood supply due to an obstruction or narrowing of a BV that produces an area of dead tissue in a part of the body
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What is an infarct?
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The area of dead tissue that results from sudden insufficiency of blood supply due to an obstruction or narrowing of a BV that produces an area of dead tissue in a part of the body.
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What can be used to circumvent the blockage of a BV?
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Coronary bypass
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What are the muscle fibers of myocardium branched and tightly joined to one another by?
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intercalated discs
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Why would a bypass be done?
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To save NEARBY blod cells, you can't repair the damaged part.
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How come the heart is able to pump blood without creating friction?
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the inside of the pericardium secretes a lubrication fluid and the pericardium slides smoothly over the surface
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What divides the heart into l and r halves?
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the septum
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What serves the heart muslce itself?
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coronary arteries (which means the heart is not directly nourished by the blood in the chambers)
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What are the first branches off the aorta?
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Coronary arteries
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What exists at the initial portion of aorta?
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2 vessels L and R coronary arteries
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Because the coronary arteries have a very small diameter, what could happen to them?
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They may become clogged MI
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CS: What is the gadget used to measure blood oxygen?
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pulse oximeter
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What is the pulmonary pump?
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Right side of the heart
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Where is BP highest in the heart?
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in aorta
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The right side of the heart has a lower BP, why?
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It's slower so that gas exchange can occur.
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As the total cross sectional area of arteries increases, what decreases?
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Blood pressure decreases
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What is the word to refer to how the heart beats on its own?
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Intrinsic rhythmicity
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What can heart sounds be heard with?
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stethoscope
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What can cause heart murmurs?
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Valvular regurgitation from defective valves caused by streptococcal bacteria which also leads to rheumatic fever.
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How can heart valves be damaged?
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Streptococcal sore throat and tonsillitis can trigger rheumatic fever and autoimmune damage to the valves of the heart
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What causes the "lub" sound?
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atrioventricular valves close at the beginning of ventricular systole.
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What causes the "dup" sound?
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ventricular diastole closes pulmonary and aortic semilunar valves
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What would a wave of depolarization caused by the SA node do to the atria?
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Contract
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If the atria were not contracting at all, can a person still live?
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You betcha
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What does ventricular systole do?
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cause L & R AV valves to close, causes the lub sound, among other stuff
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What is responsible for Atrial systole?
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SA node
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What is the medical term for when the SA node is doing well?
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"normal sinus rhythm
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What is the full name for the SA node?
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sinoatrial node
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What is at the upper back portion of the right atrium, and what does it do?
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a specialized group of myocardial cells which spontaneously generates electrical impulses (appx 70/minute or once every .85) sec
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What separates the atria and why is this separation important?
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a band of non-conductive tissue so the wave of excitation can't spread directly to the ventricles
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The AV node is assoicated with what?
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L and R bundle branches, perkinje fibers, a delay in electrical impulse
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If the SA node fails to work properly, does the heart beat? If so, how?
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due to impulses generated by the AV node, however the beat is slower (40-60 beats per minute)
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What nerve would be responsible for slowing the heart down?
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vagus nerve
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how did Elvis Presley die?
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barbiturates depressed the heart and contributed to constipation,
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What is Valsalva's maneuver?
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When you close off airway and bear down
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How did Valsalva's maneuver contribute to Elvis' death/
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Elvis had been taking barbiturates which depress the heart rate, when Elvis did Valsalva's maneuver, it contributed to additional depression by stimulating the vagus nerve to slow down the SA node and without the strong signal from the SA node, the heart developed disorganized contractions (fibrillation)
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What contributed to Elvis' death?
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ventricular fibrillation, barbiturates, valsalva's maneuver, a slow heart rate, not enough oxygen to blood
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What is a potent stimulator of the SA node and where is it produced?
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epinephrine (a hormone) which is produced by the adrenal glands that sit on top of the kidneys
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What would the sympathetic stimulation be responsible for in the heart?
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stimulates the SA and AV nodes, increases adrenaline,
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What is responsible for an increasing atrial systolic response?
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SA node, epinephrine (aka adrenaline), sympathetic nerve fibers, exercise, excitement, stress, etc.
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Why would they put someone with a weak heart on laxatives?
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Avoid having the patient use valsalva's maneuver which can stimulate the vagus nerve to additionally depress the SA node
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What is naturally produced by the adrenal glands during stress?
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epinephrine or adrenaline
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What can be injected directly into the heart to promote heart activity? Why?
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adrenaline or epinephrine, they use it to stimulate the SA and AV node to contract the chambers to keep blood moving through the body
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What sets the rhythm for the muscular contractions of the heartbeat?
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atria
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what can cause atrial fibrilation?
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many infections to heart attacks
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How is the AV node a responsible gatekeeper when it comes to fibrillation?
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It doesn't respond to every erratic atrial discharge, or the ventricles would quiver into life-ending impotence.
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Why would failure of the AV node to act as a gatekeeper lead to death?
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BP drops and blood starts eddying back into the lungs, cutting off oxygen flow to the body.
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What is digitalis?
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The active principle in foxglove leaf which is used to boost the AV node's damping action and thus slowing the ventricular rate.
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specifically, what creates the electrical charge of the heart?
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potassium ions in, sodium ions out (by active transport) segregation of these ions creates a small electrical potential within cells.
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what type of channels contribute to the electrical impulse of the heart?
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ion channels in the cell membrane allowing sodium ions to pour in, when it reaches its threshold, it triggers the release of electrons from the cell--this is the electrical impulse. Ion channels in a neighboring cell sense the electron discharge and this, in turn, changes the charge within that cell DOMINO!
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How does the cell get restored to its original state of affairs in the electrical impulse of the heart?
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The first cell's pumps drive sodium ions out and suck potassium ions back in
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what 3 ions trigger a discharge in the heart?
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calcium, sodium, and potassium
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How it the intricacy of the ions passing through and triggering discharge a wak point in the heart?
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When the timing mechanism is off, normally obedient cells start firing on their own, sparking mayhem.
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What is used for damage control when cells within the heart start randomly firing and causing mahem? how does it control it?
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MAGNESIUM SULFATE, it makes firing less random
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What are arrhythmias? 2 of them?
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Abnormal heart rate, bradycardia slows it down, tachycardia speeds it up
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Why would you want a calcium blocker to help restore heart rate after fibrillation? What is the name for a calcium channel blocker?
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Calcium is one of the ions that triggers a discharge and causes electrical impulses to fire in the heart. DILTIAZEM
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What can ventricular tachycardia lead to?
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ventricular fibrillation aka sudden death
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What is a bypass tract?
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An anamalous ribbon of heart tissue that can conduct some of the chaotic atrial impulses directly into the ventricles w/o passing through the AV node, but digoxin and diltiazem, both accelerate conduction through the aberrant pathway, thus allowing atrial chaos to pass unhindered into the ventricles.
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What do digoxin and diltiazem do?
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standard treatment for A-fib, they boht accelerate conduction through the aberrant pathway, thus allowing atrial chaos to pass unhindered into ventricles.
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What does a defibrillator do?
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stills all unruly cells and allows the natrual pacemaker to regain control
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What are epsom salts?
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magnesium sulfate.
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What records the heartbeat?
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Electrocardiogram
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The sequence of electrical events in the heart can be measured by a?
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electrocardiograph
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Who was the first person to use an ECG, who and what was his patients name?
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Augustus Waller, used it on his dog Jimmie
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What measures electrical events in the heart, and what produces?
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graph produces gram
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What would be seen on an electrocardiogram as the electrical excitation of the atria? What node is responsible for it, what valves are open and closed, and what sound will it produce?
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P wave, SA node responsible for it, semilunar valves closed, produces the "dup" sound
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What produces the "dup" sound? what wave would be responsible for it?
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the closure of the L and R semilunar valves P and T waves
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What indicates the atria are about to contract?
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P waves
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What is associated with QRs wave?
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L & R ventricular systole, L & R AV valves closed, semilunars open, "lub" sound
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What causes the T wave?
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recovery and repolarization by myocardia, ventricles relax, semilunars closed, AV valve open "dub" sound
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What is associated with the "lub" sound?
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AV valves close, semilunars open
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What is the T-wave caused by?
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recovery and repolarization of myocardia, ventricles relaxing, semilunars closed, AV open, Dup sound
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What is associated with the dup sound?
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P wave, T wave, semilunars closed, AV's open,
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Is a person completely fine if they have a normal EKG?
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could be, but it can't tellyou if there is blood in the heart
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Why would you die by electrocution?
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It causes disruption of the cardiac conduction system and leads to v-fib
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What can causes V-fib?
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heart disease, electrocution, or drug abuse (i.e. cocaine)
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Why doesn't the electrocardiogram show the qtria recovering?
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it's covered up by the QRS wave.
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A person may have a normal EKG, but why would they not be ok?
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because blood could not be in heart
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What does a defibrillator do?
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MIGHT stop the erratic contractions by causing simultaneous depolarization of the entire myocardium and allow the SA node to resume control.
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What would take over the role of the SA node?
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An artificial pacemaker
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Why does an artificial pacemaker have two leads?
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one picks up weak SA node, strengthens it, and shoots it to the ventricles.
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If you compress the ventricles during CPR what is closed and what is open?
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AV closed, semilunars are open, lub sound
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How effective is CPR?
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about 1/3 as effective
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What does AED stand for?
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Automatic External Defibrillator
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What does CPR stand for?
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Cardiopulmonary resuscitation
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What is an AEd?
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a computer that analyzes heart activity to determine if a shock is needed. Strong electrical current is applied for a short time to defibrillate the heart.
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