Cardiovascular physiology
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2008-05-05T14:09:24Z
Avram
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'''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}}