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48 Cards in this Set
- Front
- Back
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What does the electrocariogram do and what does it contain?
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-measures electronic impulses in heart
-contains P wave, QRS complex and T wave |
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What does the p-wave represent?
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-atrial depolarization and contraction (systole)
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What does the QRS compelx represent?
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-ventricular depolarization and contraction (systole)
-atria repolarizes |
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What does the T wave represent?
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-ventricular repolarization
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What is a systole?
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-muscle contraction
-p-wave/QRS= atricular systole |
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What is a diastole?
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-muscle relaxation
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What happens when blood fills in right atrium and what wave occurs here?
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-stretches right atrium
-depolarizes SA node cycle begins -p-wave |
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What happens when impulse reaches AV node?
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-both atriums contrast at the sametime
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What happens after atriums contract?
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-blood pours in ventricles
-impulse splits in branches to apex |
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What is early Ventricle contraction and what occurs?
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-pressure in ventricle excess pressure in atrium
-shuts AV valve -lub occures |
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What is late ventricle contraction and what occurs?
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-Pressure in ventricle exceed in vessels (pulmonary trunk and aorta)
-opens semi-lunar valves |
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What happens when ventricular contraction ends?
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-preesure in vessels exceed pressure in the ventricle
-creates back pressure |
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What happens when blood pour back?
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-catches flaps of semi-lunar valves and closes
-Dub occurs |
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What happens when heart cycle ends?
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-blood pours back into atrium and cycle restarts
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Where does blood pour in from in the right atrium?
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-from inferior and superior vena cava
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Where does blood pour out to in the right ventricle?
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-out to pulmonary trunk
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Where does blood collect from in the left atrium?
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-from lungs
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What is coronary bypass surgery?
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-To move blood past a clot using a piece of vein from the subclavian in the thigh
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What is the coronary circulation?
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-coronary arteries divide off of aorta directly after aortic semilunar valves
-coronary veins dump directly into right atrium |
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How do heart attacks occur?
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-caused by build-up of chorlesterol plaque in walls of coronary arteries
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What are capillaries made of?
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-one cell layer thick
-simple squamous -sometimes has basement membrane |
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What are tunica intima of vein and arteries made of, contain, and do?
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-endothemlium and loose connective tissue
-has elastic laminal tissue -keeps circulator smooth -lines heart also |
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What are tunica media of vein and arteries made of?
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-smooth muscle
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What are tunica externa of vein and arteries made of and contain?
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-elastic connective tissue
-contains blood supply from minature set of arteries and veins |
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How are arteries and veins the same?
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-same number of layers
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How are arteries different of veins?
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-arteries have more muscle to withstand blood pressure and to create back pressures to close semilunar valves
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How are veins different from arteries?
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-have valves every 4 inches (except vena cava)
-surrounded by skeletal muscles and bulging pushes against vein (muscular massage) -forces blood to flow up body to heart (same with lymphatic muscles) |
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What is the order of blood flow through the body based off of size of canals?
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-large arteries (aorta)-->small arteries--> capillarie bed--> small veins-->large veins (vena cava)
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Why do arteries have more muscle and elastic tissue?
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-For back pressure and so that blood can't go backwards
-so blood goes foreward -closes semi-luanr valves valves in heart |
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How do varicose veins form?
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-valves aren't workin
-from standing on feet and pregnacies |
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What are capillaries attached to, what do they do, and what is the advantage of having them?
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-attached on either side by arteriole and venule
-spreads oxygen and nutrients to cells of tissues -when a tissue is not in use, blood flow is reduced to lower stress on heart and increase longevity (120 years) |
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What are pre-capillary sphinchers adn what do they do?
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-circular muscle cells at beginning of capillaries
-biggest contributer to heart endurance -when not heavily metabolizing, spinchers close and reduce blood flow -vice-versa for metabolizing |
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What is normal blood pressure?
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-120mmHg / 80mmHg
-left number is systolic (contraction) measurement (blood flow stops) -right number is diastolic (blood flow restarts)(relaxation) measurement |
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What are they measuring?
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-the differential b/t systolic and diastolic is what it takes to get blood into tissue
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What is the normal blood pressure for blood flowing back to the heart?
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-1-2 mmHg
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Why is there a dramatic drop in blood pressure in capiilaries?
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-no pressure due to perforations
-blood pressure ends at capillaries |
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What is the common carotid artery?
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-comes up each side of neck
-at around the jaw-line, bifricates into internal and external carotid |
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What does the internal carotid artery provide blood for?
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-to brain
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What does the cternal carotid artery prvide blood for?
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-external parts of head
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What does the jugular vein bring blood to?
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-retunrs blood from head to the brachiocephalic vein to the heart
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Where does the brachiocephalic trunk provide blood for?
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-braches off to head and arms
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What is in the carotid sinus?
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-baro and chemo receptors
-measure blood pressure to brain and CO2 content |
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How much of the blood supply goes to the brain?
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-20%
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Where does the basular artery receive blood from?
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-vetebral arteries (parallel to vertebral column
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Why does the circle of willis exist in the brain?
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-so blood can go all over the brain
-superior to hypothalamus (how it monitors what's going on all around your body) |
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What major problem may occur with internal carotid arteries?
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-enough blockage can cause a stroke
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What's good about the internal carotid arties being near the surface?
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-can do surgery easily if necessary (only if above 70% blockage)
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Why are blockages not as important in other parts of the body other than the heart, brain and liver?
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-more than one branch of blood vessels
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