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37 Cards in this Set
- Front
- Back
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Ions involved in cardiac muscle contraction... |
Na+
Ca2+ K+ |
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Na+ job in cardiac muscle contraction...
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influx of Na+ ions triggers rapid depolarization once threshold is reached, stimulates the cardiac muscle to contract
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Ca2+ job in cardiac muscle contraction..
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influx of calcium ions triggers the plateau, maintains strength of contraction and prevents heart from entering tetany
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K+ job in cardiac muscle contraction...
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outflux of K+ ions triggers repolarization, inside of cardiac fiber becomes negative D/T outflux of positive K ions, causes muscle to relax
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Job of the conduction system of the heart...
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coordinates the contraction/relaxation of the chambers
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Conduction system of heart follows what parts?
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SA node
AV node AV bundle R&L bundle branches Purkinje fibers |
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Job of SA node...
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spontaneously depolorizes down the atria, pushes blood toward ventricles, depolarization reaches the AV node
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Job of the AV node...
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slows down the depolarization, allows the atria time to contract and the ventricle time to fill up
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Job of the AV bundle...
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specialized cells that convey depolarization toward the bottom(apex) of heart
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Job of the R and L bundle branches...
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specialized cells that convey depolarization toward apex of heart
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Job of purkinje fibers...
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spreads depolarization through apex to push blood up toward the aorta and pulmonary trunk
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ECG does what?
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measures the electrical activity of the heart
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P wave...
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corresponds to the excitation of ventricles, followed by the contraction of ventricles
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QRS wave...
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corresponds to the excitation of ventricles, followed by contraction of ventricles
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T wave...
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corresponds to the repolarization of ventricles, followed by relaxation of ventricles
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PR interval...
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corresponds to the conduction time from the SA node to the AV node
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Normal Sinus Rhythm...
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normal EKG HR 60-100
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Sinus bradycardia...
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normal EKG with HR below 60
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Sinus tachycardia...
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normal EKG with HR above 100
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Atrial flutter...
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abnormal EKG, atrial rate above 150 bpm, lots of P waves present
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Atrial fibrillation...
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abnormal EKG, atria are quivering, no P wave present
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Ventricular flutter...
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abnormal EKG with a ventricular rate above 150 bpm, lots of QRS complexes present
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Ventricular fibrillation...
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abnormal EKG where the ventricles are quivering, no QRS present
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Systole...
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flat line
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Heart block...
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abnormal EKG with increased length of the PR interval, indicates a conduction system problem
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Cardiac output is...
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heart rate x stroke volume
the amount of blood ejected from the left ventricle per minute |
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Stroke volume is...
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the amount of blood ejected from the left ventricle per beat
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Normal cardiac output at rest?
Normal cardiac output during exercise? |
4-6L per min
20-25L per min |
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How does the Sympathetic NS affect HR?
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increases it by increasing the depolarization of the SA node, controlled by the cardio accelerator nerve
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How does the Parasympathetic NS affect HR?
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decreases it by decreasing the depolarization rate of the SA node, control led by the vegas nerve
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How does NE and E affect the heart rate?
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increase it
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How do thyroid hormones affect the HR?
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T3 &T4 increase the metabolic rate of the body..increasing the HR and the cardiac output
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Three tunics to an artery are?
Arteries carry blood____the heart. |
tunica externa
tunica media tunica interna away from the heart |
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Capillaries have one tunic called?
Are also the site of what? |
tunica interna
site of ALL exchange between blood and tissues |
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Three types of capillaries...
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tight capillaries-very few pores
"normal" capillaries-a few pores leaky capillary-lots of pores, significant amt of leakage |
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Veins carry blood___the heart.
Veins have 3 tunics |
toward the heart
tunica externa tunica media tunica interna |
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Veins carry blood low in ____ and high in ____.
Arteries carry blood low in ____ and high in _____. |
Veins are low in O2 and high in CO2
Arteries and low in CO2 and high in O2 |
