EKG: Cardiac A&P Flashcards
The heart varies in size depending on the person’s body size, but it is roughly the size of the person’s _____.
fist
Compared to the average person, an athlete’s heart usually weights _____ and an elderly’s person heart weights _____.
more; less
From in to outwards, the heart wall layers are as follows: endocardium –> _____ –> epicardium –> _____ space –> parietal pericardium –> fibrous pericardium
myocardium; pericardial
What is the function of the pericardium?
It surrounds the heart and acts as a tough, protective sac.
Which layer makes up the largest portion of the heart’s wall and of which muscle tissue contracts w/ each heartbeat?
Myocardium
The heart is located between the lungs and in front of the spine. The top of the heart or its _____, lies just below the 2nd rib; and the bottom of the heart or its _____ rests on the diaphragm.
base; apex
Which two chambers serve as volume reservoirs for blood being sent into the ventricles?
Atria (Right and Left)
The right atrium receives deoxygenated blood from which two blood vessels?
Vena Cava (Inferior and Superior)
The left atrium receives O2 rich blood from what type of vein?
4 pulmonary veins
Which heart chambers serve as pumping chambers of the heart?
Ventricles (Right and Left)
Arteries direct O2 rich blood _____ from the heart whereas veins vacuum deoxygenated blood back _____ the heart.
away; toward
The right ventricle receives blood from the right _____ and pumps it through the _____ arteries to the lungs which it picks up O2 and drops off CO2.
atrium; pulmonary
The left ventricle receives O2 rich blood from the _____ atrium and pump it through the _____ and then out to the rest of the body.
left; aorta
Arteries transport O2 rich blood from the heart to the rest of the body, then veins return the deoxygenated blood back to the heart. TRUE or FALSE.
TRUE
In _____ circulation, arteries transport O2 rich blood from the heart out to the tissues and veins vacuum deoxygenated blood back to the heart.
Systemic
Why is that the atria walls are much thinner compared to ventricle walls?
The chamber wall’s thickness depends on the amount of high-pressure work the chamber does. Because the atria collect blood for the ventricles and don’t need to pump it far, their walls are considerably thinner.
Why does the left ventricle has a much thicker wall than the right ventricle?
The left ventricle pumps blood against the higher pressures in the body’s arterial circulation whereas the right ventricle pumps blood against the lower pressures in the lungs.
The two AV values located between the atria and ventricles are called the _____ and _____ valves. How do they differ?
tricuspid; mitral.
The mitral valve has 2 cusps and the tricuspid has 3.
What happens to the blood flow if the AV valves are damaged?
The blood can flow backward into a chamber resulting in a heart murmur
The semilunar valves are the _____ valve and the _____ valve. They are called semilunar because the cusps resemble three half-moons.
pulmonic; aortic
The pulmonic valve located where the pulmonary artery meets the _____ ventricle, permits blood flow from the right ventricle to the _____ artery and prevents blood backflow into that ventricle.
right; pulmonary
The aortic valve, located where the _____ ventricle meets the aorta; allows blood to flow from the left ventricle to the aorta and prevents blood backflow into the left _____.
left; ventricle
The right ventricle pumps blood through the pulmonic valve into the pulmonary arteries and then into the lungs. From here the blood flows through the pulmonary veins and empties into the left atrium which completes the _____ circulation.
pulmonary
How would understanding the coronary blood flow can help you provide better care for a pt w/ a MI?
Help predict which areas of the heart would be affected by a blockage in a particular coronary artery
Cardiac veins collect blood from the capillaries of the _____ and via the _____ sinus returned to the right atrium.
myocardium; coronary sinus
Complete the circulation of the blood flow: Vena Cava (superior/inferior) –> right atrium –> tricuspid valve –> right _____ –> _____ valve –> pulmonary arteries–> lungs –> pulmonary _____–> left atrium –> _____ valve –> left ventricle –> aortic valve –> _____ –> rest of the body
ventricle; pulmonic; veins; mitral; aorta
_____ coronary artery: Supplies blood to the right atrium and ventricle and part of the left ventricle
Right
Left anterior _____ artery: Supplies blood to the anterior wall of the left ventricle, interventricular septum, right bundle branch, and left posterior fasciculus of the left bundle branch
descending
_____ artery: Supplies blood to the lateral walls of the left ventricle, left atrium, and left posterior fasciculus of the left bundle branch
Circumflex
During _____, the ventricles relax, and the atria _____, and blood is forced through the open tricuspid and mitral valves. The aortic and pulmonic valves are closed.
diastole; contract
During _____, the atria relax and fill w/ blood. The mitral and tricuspid valves are closed. The aortic and pulmonic valves are _____.
systole; opened.
The atrial contraction that contributes about 30% of the CO is also called the _____ _____
atrial kick
Stroke volume (SV) refers to the amount of blood pumped by the _____ ventricle of the heart in 1 heart contraction.
left
The # of times the heart beats (Normal: 60-100 bpm) refers to the _____ _____ (HR).
heart rate
What is cardiac output (CO)?
The amount of blood the heart pumps in 1 minute. Normal is 4-8 L/minute
Name the 3 factors that affect stroke volume (SV)
- Preload
- Afterload
- Myocardial contractility
Preload is the stretching of muscle fibers in the _____ and is determined by the pressure and amount of blood remaining in teh left ventricle at the end of _____.
ventricles; diastole
Afterload is the amount of pressure that the _____ ventricle must work against to pump blood into the circulation. The greater this resistance, the more the heart works to pump out blood.
left
The sympathetic nervous system is also known as _____ and the parasympathetic nervous system is also known as _____.
adrenergic; cholinergic
Which branch of the ANS releases norepinephrine and epinephrine to ↑ HR, automaticity, AV conduction, and contractility?
Sympathetic
Parasympathetic nervous system serves as the heart’s brakes via the stimulation of the _____ nerve it ↓ HR and via release of _____ ↓ AV conduction
vagus; acetylcholine
The automaticity refers to the ability of a cell to _____ an impulse on its own.
initiate
Excitability refers to how well a cell responds to an electrical _____
stimulus
The ability of a cell to transmit an electrical impulse to another cardiac cell is called?
Conductivity
Contractility refers to how well the cell _____ after receiving a stimulus
contracts
Name the 4 phases that cardiac cells undergo (depolarization and repolarization).
- Phase 0: Rapid depolarization – the cell receives an impulse from a nearby cell and is depolarized
- Phase 1: Early repolarization – early rapid repolarization occurs
- Phase 2: Plateau phase– a period of slow repolarization occurs
- Phase 3: Rapid repolarization – the cell returns to its original state
- Phase 4: Resting phase – the cell rests and readies itself for another stimulus
Complete the cardiac conduction pathway: SA node –> internodal tracts –> Bachmann’s bundle –> _____ node –> bundle of _____ –> bundle branches –> _____ fibers
AV; His; Purkinje
Why is that when impulses are initiated they follow a specific path through the heart and usually do not flow backward?
Cardiac cells can’t respond to a stimulus immediately after depolarization – refractory period.
What is the difference between depolarization and repolarization?
**Memory trick: ** R in repolarization stands for REST. Remember that repolarization is the resting phase of the cardiac cycle.
ECG/EKG represents the electrical activity of the heart and not the actual pumping. TRUE or FALSE.
TRUE
Automaticity (↑ or ↓), retrograde conduction and reentry are examples of normal impulses. TRUE or FALSE.
FALSE.
Complete the following formula:
CO = _____ x HR
SV
Memory Trick: Cardiac OUTput refers to O2 blood _____ to the body
OUT
Intrinsic pacemaker order: SA node (60-100/minute) –> _____ (40-60/minute) –> Purkinje fiber (20-40/minute)
AV node
The normal pacemaker of the heart is the:
1. SA node
2. AV node
3. Bundle of His
4. Purkinje fibers
The SA node is the normal pacemaker of the heart, firing @ an intrinsic rate of 60-100 times/min.
In what case, would Purkinje fibers take over for the intrinsic pace making?
They initiate only when they don’t receive one from above (SA node, AV junction) i.e. when SA the node is damaged from a MI
Parasympathetic stimulation of the heart results in:
1. ↑ HR and ↓ contractility
2. ↑ HR and faster AV conduction
3. ↓ HR and slower AV conduction
4. ↓ HR and ↑ contractility
Parasympathetic stimulation of the vagus nerve causes a ↓ in HR and slowed AV conduction.
The impulse delay produced by the AV node allows the atria to:
1. repolarize simultaneously
2. contract before the ventricles
3. send impulses to the bundle of His
4. complete their filling
The 0.04 second delay allows the atria to contract and the ventricles to completely fill, which optimizes CO.
The coronary arteries fill w/ blood during:
1. atrial systole
2. atrial diastole
3. ventricular systole
4. ventricular diastole
The coronary arteries and the ventricles fill w/ blood during diastole. The aortic valve is closed @ that time, so it no longer blocks blood flow through the coronary ostium into the coronary arteries.
The nurse is caring for a pt w/ suspected congestive heart failure (CHF). Which test result offers the best indication that the pt is experiencing severe CHF?
1. BNP of 950 pg/mL
2. Ejection fraction of 58%
3. Creatinine of 2.5 mg/dL
4. Albumin of 2.7 g/dL
Normal BNP levels are values < 100 pg/mL. Values over 900 pg/mL, like the result of 950 pg/mL indicate severe CHF.
Which statement accurately describes components of a ROMI panel?
1. ROMI panels measure levels of troponin, myoglobin, and C-reactive protein (CRP)
2. Troponin is a nonspecific indicator of muscle injury that aids in the early detection of MI
3. ROMI panels should be drawn hourly for the first 6-8 hours after presentation w/ MI
4. A troponin level > 0.5 is considered a positive indicator of MI
Troponin is the most specific indicator of trauma to the heart muscle, and levels > 0.5 indicate a heart attack. Troponin is released into the circulation 3-4 hours after the onset of a heart attack. Peak levels occur within 24-48 hours and resolve within 1-2 weeks.
Which pt’s medical history predisposes the pt to developing problems w/ afterload? Select all that apply:
1. Hypertension
2. Diabetes
3. Aortic stenosis
4. Glaucoma
5. Raynaud’s syndrome
1, 2, 3.
Afterload is the amount of resistance the heart must work against to eject blood out from the ventricles and into systemic circulation. The heart must work harder in the cases of hypertension (to overcome arterial peripheral resistance), diabetes (uncontrolled blood sugar can ↑ blood viscosity and osmolality), and aortic stenosis (overcome the pressure gradient created by the narrowed opening).
