Cardiovascular physiology

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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 vessels ("vascular").

These subjects are sometimes addressed separately, under the names cardiac physiology and circulatory physiology.[1]

Although the different aspects of cardiovascular physiology are closely interrelated, the subject is still usually divided into several subtopics.

Heart[edit]

See Heart#Physiology for more details

Regulation of blood pressure[edit]

Hemodynamics[edit]

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 standing up), the body can increase the following:

In turn, this can have a significant impact upon several other variables:

Regional circulation[edit]

Name of circulation % of cardiac output Autoregulation Perfusion Comments
pulmonary circulation 100% (deoxygenated) Vasoconstriction in response to hypoxia
cerebral circulation 15%[2] 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%[3] Perfusion increases dramatically during exercise.
cutaneous circulation 2%[4] over-perfused Crucial in thermoregulation. Significant ability to use anaerobic respiration

References[edit]

  1. ^ Overview at Medical College of Georgia
  2. ^ Physiology at MCG 3/3ch11/s3c11_13
  3. ^ Physiology at MCG 3/3ch11/s3c11_2
  4. ^ Physiology at MCG 3/3ch11/s3c11_10

External links[edit]