Blood volume

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The total amount of blood in an organism is called blood volume . It is the sum of the liquid (total plasma volume ) and cellular (total blood cell volume ) blood components. In adults, this is about 4.5 to 6.0 liters (about 8 percent of body weight (body weight); 77 ± 10 ml / kg body weight in men and 65 ± 10 ml / kg body weight in women). In children, the blood volume, decreasing from newborns to adolescents, is 85 to 72 ml / kg body weight. The volume in the pulmonary circulation and on the left side of the heart is called the central blood volume .

Since the blood plasma exchanges with the interstitial fluid through capillary filtration , an increase in the extracellular space ( hyperhydration ) is usually accompanied by an increase in blood volume ( hypervolemia ). An increased blood volume increases the central venous pressure and thus also the arterial blood pressure via the Frank Starling mechanism (see cardiovascular diagram ). The long-term regulation of blood pressure therefore consists in volume regulation ; Most antihypertensive drugs also intervene here.

If there is a deficiency in plasma proteins , the balance between intravascular and extravascular volume is shifted in the direction of extravascular volume due to the decreased colloid osmotic pressure . The body's own control circuits for maintaining a normal blood volume then lead to a pathological increase in the extracellular fluid, which is expressed in edema .

With severe blood loss, the lack of volume leads to circulatory shock .

Model organisms

In colored mice ( Mus musculus ) the blood volume is in the range of 60 to 75 ml / kg body weight, in colored rats ( Rattus norvegicus forma domestica) it is 54 to 70 ml / kg body weight and in guinea pigs ( Cavia porcellus ) it is 69 to 75 ml / kg KG.

Individual evidence

  1. ↑ Robert F. Schmidt: Physiology of humans. Springer-Verlag, 2013, ISBN 978-3-662-09340-5 , p. 515 ( limited preview in Google book search).
  2. ↑ Reinhard Larsen: Anesthesia and intensive medicine in cardiac, thoracic and vascular surgery. (1st edition 1986) 5th edition. Springer, Berlin / Heidelberg / New York et al. 1999, ISBN 3-540-65024-5 , p. 320.
  3. ^ Sarah Wolfensohn, Maggie Lloyd: Handbook of Laboratory Animal - Management and Welfare. 3rd edition, Blackwell Publishing, 2003.