Cardiovascular physiology 4156844 210326390 2008-05-05T14:09:24Z Avram 199307 /* External links */ fixing typo in link and adding link description '''Cardiovascular physiology''' is the study of the [[circulatory system]]. More specifically, it addresses the [[physiology]] of the [[heart]] ("cardio") and [[blood vessel]]s ("vascular"). These subjects are sometimes addressed separately, under the names '''cardiac physiology''' and '''circulatory physiology'''.<ref>[http://www.lib.mcg.edu/edu/eshuphysio/program/section3/3outline.htm Overview] at [[Medical College of Georgia]]</ref> Although the different aspects of cardiovascular physiology are closely interrelated, the subject is still usually divided into several subtopics. ==Heart== :''See [[Heart#Physiology]] for more details'' * [[Cardiac output]] (= [[heart rate]] * [[stroke volume]]. Can also be calculated with [[Fick principle]].) ** [[Stroke volume]] (= [[end-diastolic volume]] - [[end-systolic volume]]) ** [[Ejection fraction]] (= stroke volume / end-diastolic volume) ** ((Cardiac Output)) is mathematically ` to ((Systole)) ** [[Inotropic]], [[chronotropic]], and [[dromotropic]] states ** [[Cardiac input]] (= [[heart rate]] * [[suction volume]] Can be calculated by inverting terms in [[Fick principle]] ** [[Suction volume]] (= [[end-systolic volume]] + [[end-diastolic volume]]) ** [[Injection Fraction]] (=suction volume / end-systolic volume) ** [[Cardiac Input]] is mathematically ` to (Diastole)) * [[Electrical conduction system of the heart]] ** [[Electrocardiogram]] ** [[Cardiac maker]] ** [[Cardiac action potential]] * [[Frank-Starling law of the heart]] * [[Wiggers diagram]] * [[Pressure volume diagram]] ==Blood vessels== :''See [[Blood vessel#Physiology]] for more details'' * [[Compliance (physiology)|Compliance]] * [[Microcirculation]] * [[Starling equation]] * [[Fick's law of diffusion]] * [[Poiseuille's law]] * [[Skeletal-muscle pump]] ==Regulation of blood pressure== * [[Baroreceptor]] * [[Baroreflex]] * [[Renin-angiotensin system]] ** [[Renin]] ** [[Angiotensin]] * [[Juxtaglomerular apparatus]] * [[Aortic body]] and [[carotid body]] * [[Autoregulation]] ===Hemodynamics=== Under most circumstances, the body attempts to maintain a steady [[mean arterial pressure]]. When there is a major and immediate decrease (such as that due to [[hemorrhage]] or [[Orthostatic hypotension|standing up]]), the body can increase the following: * [[Heart rate]] * [[Total peripheral resistance]] (primarily due to [[Vasoconstrictor|vasoconstriction]] of [[arteries]]) * [[Inotrope|Inotropic state]] In turn, this can have a significant impact upon several other variables: * [[Stroke volume]] * [[Cardiac output]] * Pressure ** [[Pulse pressure]] ([[Systole (medicine)|systolic pressure]] - [[Diastole|diastolic pressure]]) ** [[Mean arterial pressure]] (usually approximated with diastolic pressure + 1/3 pulse pressure) ** [[Central venous pressure]] ==Regional circulation== {| class="wikitable" | '''Name of circulation''' || '''% of [[cardiac output]]''' || '''[[Autoregulation]]''' || '''[[Perfusion]]''' || '''Comments''' |- | [[pulmonary circulation]] || 100% (deoxygenated) || || || [[Vasoconstriction]] in response to [[Hypoxia (medical)|hypoxia]] |- | [[cerebral circulation]] || 15%<ref>{{GeorgiaPhysiology|3/3ch11/s3c11_13}}</ref> || high || under-perfused || Fixed volume means intolerance of high pressure. Minimal ability to use [[anaerobic respiration]] |- | [[coronary circulation]] || 5% || high || under-perfused || Minimal ability to use [[anaerobic respiration]]. Blood flow through the [[left coronary artery]] is at a maximum during [[diastole]] (in contrast to the rest of [[systemic circulation]], which has a maximum blood flow during [[systole]].) |- | [[splanchnic]] circulation || 15% || low || || Flow increases during [[digestion]]. |- | [[hepatic circulation]] || 15% || || || Part of [[portal venous system]], so [[oncotic pressure]] is very low |- | [[renal circulation]] || 25% || high || over-perfused || Maintains [[glomerular filtration rate]] |- | [[skeletal muscular]] circulation || 17%<ref>{{GeorgiaPhysiology|3/3ch11/s3c11_2}}</ref> || || || Perfusion increases dramatically during [[exercise]]. |- | [[cutaneous]] circulation || 2%<ref>{{GeorgiaPhysiology|3/3ch11/s3c11_10}}</ref> || || over-perfused || Crucial in [[thermoregulation]]. Significant ability to use [[anaerobic respiration]] |} ==References== <references/> ==External links== * {{MeshName|Cardiovascular+physiology}} * [http://www.cvphysiology.com/ ''Cardiovascular Physiology Concepts''] - Comprehensive explanation of basic cardiovascular concepts, based on a textbook of the same name. {{Cardiovascular physiology}} {{circulatory-stub}}