- describes the distensibility of blood vessels.
- is inversely related to elastance. The greater the amount of elastic tissue in a blood vessel, the higher the elastance, but the lower the compliance.
- can be expressed by the following equation:
C = capacitance or compliance (ml/mm Hg) V = volume (ml) P = pressure (mm Hg)
- is directly proportional to volume and inversely proportional to pressure.
- describes how volume changes in response to a change in pressure.
- is much greater for veins than for arteries. As a result, more blood volume is contained in the veins (unstressed volume) than in the arteries (stressed volume).
- Changes in the capacitance of the veins produce changes in unstressed volume. For example, a decrease in venous capacitance decreases unstressed volume and increases stressed volume by shifting blood from the veins to the arteries.
- Capacitance of the arteries decreases with age; as a person ages, the arteries become stiffer and less distensible.
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