NationMaster - Encyclopedia: Vasoconstrictor

A vasoconstrictor, also vasopressor or simply pressor, is any substance that acts to cause vasoconstriction (narrowing of the lumena of blood vessels) and usually results in an increase of the blood pressure. (The opposite process, vasodilation, is the opening of blood vessels. ) artery anatomy, showing lumen The lumen (pl. ... f you all The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... A sphygmomanometer, a device used for measuring arterial pressure. ... Vasodilation is where blood vessels in the body become wider following the relaxation of the smooth muscle in the vessel wall. ...

Many vasoconstrictors also cause pupil dilation. Categories: Medicine stubs | Sign (medicine) ...

Uses

Vasoconstrictors are used in medicine to treat hypotension and as topical decongestants. In physiology and medicine, hypotension refers to an abnormally low blood pressure. ... Topical decongestants are decongestants applied directly to the nasal cavity. ...

Mechanism

Many vasoconstrictors act on specific receptors, such as vasopressin receptors or adrenoreceptors. Antidiuretic hormone (ADH), or arginine vasopressin (AVP), is a peptide hormone produced by the hypothalamus, and stored in the posterior part of the pituitary gland. ... tyrosine is the precursor of catecholamines epinephrine norepinephrine dopamine Synthesis Catecholamines are chemical compounds derived from the amino acid tyrosine containing catechol and amine groups. ...

Causes

Vasoconstrictors are also used clinically to increase blood pressure or to reduce local blood flow. Exposure to moderately high levels of stress also induces vasoconstriction. A sphygmomanometer, a device used for measuring arterial pressure. ... In medical terms, stress is the disruption of homeostasis through physical or psychological stimuli. ...

Vasoconstriction also occurs in superficial blood vessels of warm-blooded animals when their ambient environment is cold; this process diverts the flow of heated blood to the center of the animal, preventing the loss of heat. A warm-blooded (homeothermic) animal is one that can keep its core body temperature at a nearly constant level regardless of the temperature of the surrounding environment (that is, to maintain thermal homeostasis) . This can involve not only the ability to generate heat, but also the ability to cool down...

Examples of vasoconstrictors

Vasoconstrictors include systemic and topical. For example, pseudoephedrine is available systemic (i.e. orally ingested tablets like Sudafed), and topical (such as nose sprays like phenylephrine Neo-synephrine, and eye drops for pupil dilation purposes) Pseudoephedrine (commonly abbreviated as PSE) is a sympathomimetic amine commonly used as a decongestant. ... Sudafed is a brand name and registered trademark for a family of over-the-counter (OTC) decongestants based on pseudoephedrine hydrochloride and manufactured by Pfizer Inc. ... Phenylephrine or Neo-Synephrine is an Î±-adrenergic receptor agonist used primarily as a decongestant, as an agent to dilate the pupil and to increase blood pressure. ... Categories: Medicine stubs | Sign (medicine) ...

Amphetamine or Amfetamine(Alpha-Methyl-PHenEThylAMINE), also known as beta-phenyl-isopropylamine and benzedrine, is a prescription stimulant commonly used to treat Attention-deficit hyperactivity disorder (ADHD) in adults and children. ... An H1 antihistamine is a histamine antagonist which serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions, through action at the H1 receptor. ... Molecular structure of ADMA Asymmetric dimethylarginine (ADMA) is a naturally occurring chemical found in blood plasma. ... This cosmetics store has lighting levels over twice recommended levels and sufficient to trigger headaches and other health effects Over-illumination is the presence of lighting intensity (illuminance) beyond that required for a specified activity. ... tyrosine is the precursor of catecholamines epinephrine norepinephrine dopamine Synthesis Catecholamines are chemical compounds derived from the amino acid tyrosine containing catechol and amine groups. ... Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. ... A decongestant is a broad class of drugs designed to symptomatically treat ailments affecting the respiratory system. ... Roadway noise is the main source of exposure Noise health effects, the collection of health consequences of elevated sound levels, constitute one of the most widespread public health threats in industrialized countries. ... Endothelin is a 21-amino acid vasoconstricting peptide that plays a key part in vascular homeostasis. ... LSA, also known as d-lysergic acid amide, d-lysergamide, ergine, and LA-111, is an alkaloid of the ergoline family that occurs in various species of vines of the Convolvulaceae and some species of fungi. ... Lysergic acid diethylamide, commonly called LSD, LSD-25, or acid. ... Vitamin R redirects here. ... Neuropeptide Y (NPY) is a 36 amino acid peptide neurotransmitter found in the brain and autonomic nervous system. ... Norepinephrine (INN)(abbr. ... Phenylephrine or Neo-Synephrine is an Î±-adrenergic receptor agonist used primarily as a decongestant, as an agent to dilate the pupil and to increase blood pressure. ... Pseudoephedrine (commonly abbreviated as PSE) is a sympathomimetic amine commonly used as a decongestant. ... Psilocybin (also known as psilocybine) is a psychedelic alkaloid of the tryptamine family, found in psilocybin mushrooms. ... Stimulants are drugs that temporarily increase alertness and wakefulness. ... Tetrahydrozoline is a derivative of imidazoline, which is found in over-the-counter eyedrops and nasal sprays. ... Thromboxane A2 Thromboxane B2 Thromboxane is a member of the family of lipids known as eicosanoids. ...

See also

Addisons disease(also known as chronic adrenal insufficiency, hypocortisolism or hypocorticism) is a rare endocrine disorder in which the adrenal gland produces insufficient amounts of steroid hormones (glucocorticoids and often mineralocorticoids). ... An inotrope is an agent which increases or decreases the force or energy of muscular contractions. ... In physiology and medicine, hypotension refers to an abnormally low blood pressure. ... R-phrases , , , , S-phrases , , , Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Nitric oxide or Nitrogen monoxide is a chemical compound with chemical formula NO. This gas is an important signaling molecule in the body of... A phaeochromocytoma (pheochromocytoma in the US) is a neuroendocrine tumor of the medulla of the adrenal glands originating in the chromaffin cells, which secretes excessive amounts of catecholamines, usually adrenaline and noradrenaline (epinephrine and norepinephrine in the US). ... This article is about the medical condition. ... The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... Postural orthostatic tachycardia syndrome (or POTS) is a condition of orthostatic intolerance in which a change from the supine position to an upright position causes an abnormally large increase in heart rate, often, but not always accompanied by a fall in blood pressure. ...

External links

Categories: Cardiovascular system | Drugs For transport in plants, see Vascular tissue. ... Human Physiology is the science of the mechanical, physical, and biochemical functions of humans in good health, their organs, and the cells of which they are composed. ... A circulatory system (sometimes cardiovascular system) is an organ system that moves substances to and from cells; it can also help stabilize body temperature and pH (part of homeostasis). ... Heart during ventricular diastole. ... In cardiac physiology, afterload is the tension produced by a chamber of the heart in order to contract. ... End-systolic volume is the volume of blood in the ventricles just after systole. ... End-diastolic volume is the volume of blood in the ventricles just before systole. ... The Frank-Starling law of the heart (also known as Starlings law) states that the more the ventricle is filled with blood during diastole (end-diastolic volume), the greater the volume of ejected blood will be during the resulting systolic contraction (stroke volume). ... Cardiac output (CO) is the volume of blood being pumped by the heart, in particular by a ventricle in a minute. ... Wiggers diagram. ... Generalized PV diagram A pressure volume diagram (or P-V diagram, or volume-pressure loop)[1]) is used to describe a thermal cycle involving the following two variables: Volume (on the X axis) Pressure (on the Y axis) This is in fact enough information to fully describe a simple system... Chronotropic effects (from chrono-, meaning time) are those that change the heart rate. ... A dromotropic agent is one which affects the conduction velocity of the AV node, and subsequently the rate of electrical impulses in the heart. ... An inotrope is an agent which increases or decreases the force or energy of muscular contractions. ... Hemodynamics is concerned with the forces generated by the heart and the motion of blood through the cardiovascular system. ... Special nerve cells called baroreceptors are located in the wall of the heart auricles, vena cava, aortic arch and carotid sinuses, and are specialized to monitor changes in blood pressure. ... The kinin-kallikrein system or simply kinin system is a poorly delineated system of blood proteins that plays a role in inflammation, blood pressure control, coagulation and pain. ... Schematic depicting how the RAAS works. ... Vasodilation is where blood vessels in the body become wider following the relaxation of the smooth muscle in the vessel wall. ... Compliance is a measure of the tendency of a hollow organ to resist recoil toward its original dimensions upon removal of a distending or compressing force. ... Vascular resistance is a term used to define the resistance to flow that must be overcome to push blood through the circulatory system. ... The normal electrical conduction in the heart allows the impulse that is generated by the sinoatrial node (SA node) of the heart to be propagated to (and stimulate) the myocardium (Cardiac muscle). ... The cardiac action potential is a specialized action potential in the heart, with unique properties necessary for function of the electrical conduction system of the heart. ...

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