Kapillärtonus

Kapillärtonus refers to the state of contraction or relaxation of the smooth muscle in the walls of capillaries. Capillaries are the smallest blood vessels in the circulatory system and are responsible for the exchange of oxygen, nutrients, and waste products between the blood and the body's tissues. The tone of the capillaries is a crucial factor in regulating blood flow and pressure within these tiny vessels.

This muscle tone is influenced by various factors, including the autonomic nervous system, local chemical signals, and hormones. For instance, sympathetic nerve stimulation can cause vasoconstriction, increasing capillary tone and reducing blood flow. Conversely, certain metabolic byproducts like carbon dioxide or lactic acid can lead to vasodilation, decreasing capillary tone and increasing blood flow to meet the metabolic demands of the tissues.

Changes in kapillärtonus play a significant role in maintaining overall cardiovascular homeostasis. They are essential for distributing blood flow appropriately to different parts of the body according to physiological needs, such as during exercise or in response to injury. Dysregulation of kapillärtonus can contribute to various pathological conditions, including hypertension, shock, and inflammatory responses. Understanding kapillärtonus is therefore vital in the study of vascular physiology and pathophysiology.