Vasoconstriction Mechanism
A Vasoconstriction Mechanism is an blood circulation sub-process that modifies the size of blood vessel passage.
- Context:
- It can create Constricted Blood Vessels, Normally-Sized Blood Vessels and Dilated Blood Vessels.
- It can be due to changes in Calcium (Ca2+ ions) concentration of within vascular smooth muscle cells.
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- Example(s):
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- Counter-Example(s):
- See: Intermittent Claudication, Endothelial Cell, Erythrocyte, Arteries, Arterioles, Blood Pressure, Vascular Resistance.
References
2022
- (Wikipedia, 2022) ⇒ https://en.wikipedia.org/wiki/Vasoconstriction#General_mechanism Retrieved:2022-11-17.
- The mechanism that leads to vasoconstriction results from the increased concentration of calcium (Ca2+ ions) within vascular smooth muscle cells. However, the specific mechanisms for generating an increased intracellular concentration of calcium depends on the vasoconstrictor. Smooth muscle cells are capable of generating action potentials, but this mechanism is rarely utilized for contraction in the vasculature. Hormonal or pharmacokinetic components are more physiologically relevant. Two common stimuli for eliciting smooth muscle contraction are circulating epinephrine and activation of the sympathetic nervous system (through release of norepinephrine) that directly innervates the muscle. These compounds interact with cell surface adrenergic receptors. Such stimuli result in a signal transduction cascade that leads to increased intracellular calcium from the sarcoplasmic reticulum through IP3-mediated calcium release, as well as enhanced calcium entry across the sarcolemma through calcium channels. The rise in intracellular calcium complexes with calmodulin, which in turn activates myosin light-chain kinase. This enzyme is responsible for phosphorylating the light chain of myosin to stimulate cross-bridge cycling. Once elevated, the intracellular calcium concentration is returned to its normal concentration through a variety of protein pumps and calcium exchangers located on the plasma membrane and sarcoplasmic reticulum. This reduction in calcium removes the stimulus necessary for contraction, allowing for a return to baseline.
2022
- https://psychonautwiki.org/wiki/Vasoconstriction
- QUOTE: Vasoconstriction can be described as a narrowing of the veins and blood vessels which results from a contraction of their muscular wall. It is particularly prevalent in the large arteries and small arterioles.
This effect typically results in feelings of tightness, achiness, and numbness within a person's arms and legs. It can range from mild in its effects to extremely uncomfortable.
Vasoconstriction is often accompanied by other coinciding effects such as stimulation. It is most commonly induced under the influence of moderate dosages of stimulating psychedelic compounds, such as LSD, 2C-E, and DOC. However, it can also occur under the influence of traditional stimulants such as methamphetamine, caffeine, and MDMA.
- QUOTE: Vasoconstriction can be described as a narrowing of the veins and blood vessels which results from a contraction of their muscular wall. It is particularly prevalent in the large arteries and small arterioles.
2018
- (Wikipedia, 2018) ⇒ https://en.wikipedia.org/wiki/vasoconstriction Retrieved:2018-3-21.
- 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 staunching hemorrhage and acute blood loss. When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular resistance. This makes the skin turn paler because less blood reaches the surface, reducing the radiation of heat. On a larger level, vasoconstriction is one mechanism by which the body regulates and maintains mean arterial pressure.
Medications causing vasoconstriction, also known as vasoconstrictors, are one type of medicine used to raise blood pressure. Generalized vasoconstriction usually results in an increase in systemic blood pressure, but it may also occur in specific tissues, causing a localized reduction in blood flow. The extent of vasoconstriction may be slight or severe depending on the substance or circumstance. Many vasoconstrictors also cause pupil dilation. Medications that cause vasoconstriction include: antihistamines, decongestants, and stimulants. Severe vasoconstriction may result in symptoms of intermittent claudication.
- 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 staunching hemorrhage and acute blood loss. When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular resistance. This makes the skin turn paler because less blood reaches the surface, reducing the radiation of heat. On a larger level, vasoconstriction is one mechanism by which the body regulates and maintains mean arterial pressure.