Читать книгу Manual of Equine Anesthesia and Analgesia - Группа авторов - Страница 98

 Blood in the middle of the vessel flows freely, whereas it flows slowly at the periphery because of the friction with the endothelium.In a small vessel, a large percentage of the blood is in contact with the vessel wall so the rapidly flowing central stream is absent.

 Although capillaries have the smallest vessel diameter, arterioles pose the highest resistance to blood flow (i.e., there is greater perfusion pressure drop across the arterioles than across any other segment of the systemic circulation).Due to the fact that each arteriole distributes blood to numerous capillaries, thus making the net resistance of the capillaries less than the resistance of the single arteriole delivering blood to them.Thus, dilation and constriction of the arterioles dictates organ and tissue blood flow.

 BP is dictated by the laws of Ohm and Poiseuille (see Table 3.1 and described below).