Details Title: Cardiovascular System Description: A&P Total Flash Cards: 55 Created: 04/15/2009 16:37:24		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Physiology Flashcards
Cards in this set: Term Intercalated discs of cardiac muscle tissue.... Definition join adjacent cardiac muscle cells Term Gap Junctions of the cardiac muscle tissue... Definition provide electrical connections between cells Term autorhythmic fibers Definition 1% of heart muscle that spontaneously depolarize, setting the pace for beating of heart Term Contractile fibers of the heart Definition 99% of heart muscle responsible for pumping Term The order the electrical signals travel in the cardiac conductive system... Definition SA node, AV node, AV bundle, bundle branches, purkinje fibers Term SA node Definition sinoatrial node; group on contractile autorythmic muscle cells located in right atrium; controls heart rate Term Pace maker potential in SA node Definition ability to depolarize spontaneously, resulting in a pacemaker potential Term What produces the refractory period in myocardium? Definition surge in Ca+ Term What does the stimulus cause in the depolarization of myocardium? Definition voltage regulated Na+ gates to open and Na+ rushes in Term myocytes are? Definition muscle cells of the heart Term What happens during depolarization of myocardium? Definition K+ channels open, and K+ leaves the cell Term Refractory period Definition when cells cannot generate an action potential Term P wave Definition produced when a signal from the SA node spreads through the atria and depolarizes them causing atrial systole Term QRS comlex Definition occurs when AV node fires, ventricles depolarize causing ventricular systole Term atrial distole in QRS complex caused by... Definition atrial repolarization Term T wave Definition ventricles repolarize causing ventricular diastole Term systole Definition contraction of a chamber Term diastole Definition relaxation of a chamber Term Systolic blood pressure Definition peak pressure in arterial system, due to ventricular systole Term Diastolic blood pressure Definition lowest pressure in the arterial system, due to ventricular diastole Term where is blood pressure lowest? Definition in right atrium Term Where is blood pressure highest? Definition in aorta Term What are the 3 main factors that influence blood pressure? Definition cardiac output, peripheral resistance, blood volume Term What is peripheral resistance? Definition resistance to blood flow as blood travels away from the heart Term What does peripheral resistance result from? Definition friction of blood against the walls of the vessels Term What three ways are peripheral resistance affected? Definition buy the vessels diameter, length of the vessel/how far the blood has to travel, and the blood viscosity Term Cardiac output definition Definition amount of blood ejected per ventricle per min Term Stroke volume Definition amount of blood ejected per ventricle per beat Term Cardiac output = ______x______ Definition heart rate x stroke volume Term Is cardiac output increased or decreased by exercise? Definition increased Term Short term blood pressure regulation Definition counteracts fluctuations in BP by altering peripheral resistance Term what mediates short term blood pressure regulation? Definition the nervous system Term Long term BP regulation Definition hormonal control and renal mechanisms that change blood volume Term BP regulation that alters blood volume? Definition long term BP regulation Term BP regulation that alters peripheral resistance? Definition short term BP regulation Term baroreceptors Definition pressure sensors in blood vessels Term chemoreceptors Definition chemical receptors in blood vessels that send messages to vasomotor center in the medulla oblongata Term How does vasomotor center regulate blood vessels diameter? Definition by impulses sent to vascular smooth muscle to cause either vasoconstriction or vasodialation Term What keeps the blood vessels partially contracted? Definition sympathetic nervous system Term where is the vasomotor system? Definition in the brain stem under ANS Term What is angiotensinogen produced by? Definition liver Term ACE inhibitors Definition block ACE-lower BP Term Angiotensin II Definition potent vasoconstrictor, increases blood volume and pressure by secretion of aldosterone which causes a retention of Na and H2O Term aldosterone is secreted by... Definition adrenal gland Term where does the exchange of nutrition take place in the organization of the blood vessels? Definition in the capillary bed Term what controls blood flow to capillaries of the capillary bed? Definition precapillary sphincters Term Baroreflex Definition changes in BP detected by stretch receptors(baroreceptors) in large arteries above the heart Term where are chemoreceptors located? Definition aortic arch, subclavian arteries, external carotid arteries Term Chemoreflex Definition autonomic response to chemical changes in the blood Term Primary and secondary role of chemoreflex? Definition adjust respiration, vasodialation or constriction Term Chemoreflex Definition autonomic response to chemical changes in the blood Term Mechanisms involved in capillary exchange? Definition diffusion, pino and exocytosis, filtration and reabsorption Term where does capillary filtration occur? Definition at arterial end Term where does capillary reabsorption occur? Definition at venous end Term venous return/inhalation Definition thoracic cavity expands-pressure goes down.abdominal pressure goes up forcing blood up