Search results
Results From The WOW.Com Content Network
The enzyme histidine decarboxylase (EC 4.1.1.22, HDC) is transcribed on chromosome 15, region q21.1-21.2, and catalyzes the decarboxylation of histidine to form histamine.In mammals, histamine is an important biogenic amine with regulatory roles in neurotransmission, gastric acid secretion and immune response.
Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in controlling hemorrhage and reducing
As the needs of the neuronal activity are met, blood flow returns to homeostatic levels. In haemodynamics , the body must respond to physical activities, external temperature, and other factors by homeostatically adjusting its blood flow to deliver nutrients such as oxygen and glucose to stressed tissues and allow them to function.
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.
Hypoxic pulmonary vasoconstriction (HPV), also known as the Euler–Liljestrand mechanism, is a physiological phenomenon in which small pulmonary arteries constrict in the presence of alveolar hypoxia (low oxygen levels). By redirecting blood flow from poorly-ventilated lung regions to well-ventilated lung regions, HPV is thought to be the ...
The Pringle manoeuvre is used during liver surgery and in some cases of severe liver trauma to minimize blood loss. [1] For short durations of use, it is very effective at reducing intraoperative blood loss. [2] The Pringle manoeuvre is applied during closure of a vena cava injury when an atriocaval shunt is placed. [citation needed]
Histamine N-methyltransferase is encoded by a single gene, called HNMT, which has been mapped to chromosome 2 in humans. [5]Three transcript variants have been identified for this gene in humans, which produce different protein isoforms [6] [5] due to alternative splicing, which allows a single gene to code for multiple proteins by including or excluding particular exons of a gene in the final ...
When a blood vessel is damaged, there is an immediate reflex, initiated by local sympathetic pain receptors, which helps promote vasoconstriction. The damaged vessels will constrict (vasoconstrict) which reduces the amount of blood flow through the area and limits the amount of blood loss.