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Below are several examples of differing types of local blood flow regulation by specific organ type or organ system. In each case, there is a specific type of intrinsic regulation occurring in order to maintain or alter blood flow to that given organ alone, instead of creating a systemic change that would affect the entire body.
Often expressed in cm/s. This value is inversely related to the total cross-sectional area of the blood vessel and also differs per cross-section, because in normal condition the blood flow has laminar characteristics. For this reason, the blood flow velocity is the fastest in the middle of the vessel and slowest at the vessel wall.
To summarize, vasoconstriction is a physiological process that involves the narrowing of blood vessels, particularly arteries and arterioles, resulting in a reduction of blood flow to specific tissues or organs. This phenomenon is primarily regulated by the contraction of smooth muscle cells within the vessel walls.
Blood typically exits the wound in spurts, rather than in a steady flow; the blood spurts out in time with the heartbeat. The amount of blood loss can be copious, and can occur very rapidly. [10] Venous bleeding: This blood is flowing from a damaged vein. As a result, it is blackish in colour (due to the lack of oxygen it transports) and flows ...
Through the processes of vasoconstriction and vasodilation, these cells can actively control the rate of blood flow by means of: Contraction of cellular processes that encircle capillaries as in pericytes, which possess contractile proteins such as α-actin , tropomyosin , and myosin enabling them to contract and relax.
Most vessels of the microcirculation are lined by flattened cells of the endothelium and many of them are surrounded by contractile cells called pericytes.The endothelium provides a smooth surface for the flow of blood and regulates the movement of water and dissolved materials in the interstitial plasma between the blood and the tissues.
This part of coronary circulatory regulation is known as auto regulation and it occurs over a plateau, reflecting the constant blood flow at varying CPP & resistance. The slope of a CBF (coronary blood flow) vs. CPP graph gives 1/Resistance. Autoregulation maintains a normal blood flow within the pressure range of 70–110 mm Hg.
An electronic device called a rheoencephalograph [from Greek rheos 'stream, anything flowing', from rhein 'to flow'] is utilized in brain blood flow biofeedback. Electrodes are attached to the skin at certain points on the head and permit the device to measure continuously the electrical conductivity of the tissues of structures located between ...