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45 Cards in this Set
- Front
- Back
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vascular system:
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-consist of arterial system, venous system and capillaries
-delivers O2 and nutrients -removes waste from the tissues |
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arterial system:
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-high pressure system that delivers blood to the tissues
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venous system:
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-low pressure system that collects blood from the capillaries
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Layers of the heart:
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1. epicardium (outer)
2. myocardium (muscle) 3. endocardium (inner) |
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Layers of pericardium and heart wall:
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1. parietal pericardium (fibrous/serous)
2. parietal cavity 3. visceral pericardium (epicardium) 4. myocardium 5. endocardium |
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What coronary artery feeds the right side of the heart?
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posterior descending branch
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What 2 coronary arteries feed the left side of the heart?
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anterior descending branch and the circumflex
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How do the veins of the body enter the heart?
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thru the coronary sinus which goes into the right atrium
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What 2 conditions are caused by valvular stenosis or blockage?
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left pulmonary edema and right peripheral edema (less severe)
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Causes of myocardial ischemia:
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1. decrease in aortic pressure or RV pressure
2. reduced vessel diameter (blockage) 3. reduced perfusion time 4. increased metabolic demands (fever, sepsis) |
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What can cause reduced perfusion time of vessels?
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fast heart rate
arrhythmias |
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What molecule is necessary for muscle contraction?
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Calcium ions
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What happens during a contraction?
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-all cells shorten simultaneously to produce a forceful contraction
-action potential travels down the conduction system |
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What is the fastest way to determine myocardial damage?
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-enzymes leak into extracellular fluid
-test cardiac enzymes (CK levels are elevated) |
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List the ECG pathway.
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1. SA node
2. AV node 3. Bundle of His (intra-atrial septum) 4. Bundle branches (septum) 5. Purkinje fibers (from apex upward) |
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SA node:
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-pacemaker of the RA
-impulses sent to atria |
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AV node:
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-posterior spetal wall of RA
-pacemaker if SA node fails -delay here to complete atria contraction |
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Electrocardiography components:
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-P-wave (atrial depolarization)
-QRS (ventricular depolarization) -T wave (repolarization of ventricles) |
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Components of QRS:
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Q=depolarization from left septum to right
R=down septum to apex S=depolarization of base |
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cardiac output:
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= SV x HR
-amount of blood pumped in one minute -norm: 5-6 lpm (70 ml/min) -one factor may offset the other |
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List the 8 determinants of heart rate.
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1. sympthetics
2. parasympathetics 3. baroreceptors 4. chemoreceptors 5. sensory receptors in heart chambers 6. drugs 7. CNS (anxiety, fear) 8. excess tachycardia |
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How does excess tachycardia affect heart rate?
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decreases cardiac output
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How do sympathetics affect HR?
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-causes inadequate BP, lack of O2 and buildup of metabolic end products
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baroreceptors:
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Ex: aortic and carotid SINUSES
-found in the wall of the artery -if stretched too much, CV center vasodilates to compensate |
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chemorecptors:
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Ex: aortic and carotid BODIES and hypothalamus
-monitors O2 levels (mostly), CO2 levels and pH |
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3 Determinants of stroke volume:
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1. venous return (BV in the heart)
2. contractility 3. ventricular ejection |
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positive ionotropes:
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-increases Ca levels for contractility
Exs: epiepherine, norepinepherine, thyroid hormone, caffeine, digitalis |
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Bad conditions in the body cause the blood to become more ___.
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acidic
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digitalis:
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-increases contractility and better utilization of O2
-given to pts with heart conditions |
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negative inotropes:
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-decreases Ca levels
Exs: calcium channel blockers, parasympathomimetics, sympathetic blockers |
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List the 3 contractile capabilities of the heart.
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1. positive inotropes
2. negative inotropes 3. baroreceptor reflex |
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What valvular condition is most common?
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aortic
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Who mainly has aortic valve trouble?
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more common in older people
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atrial natriuretic factor:
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-diuretic reaction
-released from atrial stretch -causes an increase in excretion of Na and water -decreases BV and BP |
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Which heart valve is the most dangerous to have damaged?
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tricuspid valve
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Which heart valve is the least dangerous to have damaged?
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pulmonary valve
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4 tests of cardiac function:
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1. ECG
2. Echocardiogram (ultrasound) 3. nucluear cardiography 4. cardiac catheterization |
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6 ECG leads:
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1 (btn RA and LA)
2 (btn RA and LL) 3 (btn LA and LL) AVR (btn RA and heart) AVL (btn LA and heart) AVF (btn LL and heart) |
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holter monitoring:
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24 hr EKG used on pts with premature beats or irregularities
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3 measurements of ECG:
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1. heart enlargement
2. conduction (rate and rhythm) 3. damage |
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3 measurements of echocardiogram:
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1. valve function
2. heart size 3. contractility |
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3 Reasons for cardiac catheterizations:
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1. pressures in vessels and chambers
2. coronary patency 3. O2 content in various areas |
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Tx for pts needing a cardiac cath:
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thrombolytics, balloon angioplasty or stents
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stents:
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-vessels that do not remain dilated
-can also be used with stenosis of the ureter |
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thrombolytics:
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-dissolves clots
-used within 2 hrs of incident -expensive |
