Vaso Health Dictionary

An agent that narrows blood vessel openings, restricting the flow of blood through them... vasoconstrictor

An agent that expands blood vessels, allowing more blood to flow through them... vasodilator

Narrowing of blood vessels which results in the blood ?ow to a particular part of the body being reduced. Cold will cause vasoconstriction of the vessels under the skin, thus reducing heat loss. SHOCK due to injury or loss of blood will also provoke vasoconstriction.... vasoconstriction

The fraction isolated from extract of the posterior PITUITARY GLAND lobe which stimulates intestinal activity, constricts blood vessels, and inhibits the secretion of URINE. It is also known as the antidiuretic hormone (ADH) because of this last e?ect, and its only use in medicine is in the treatment of DIABETES INSIPIDUS.... vasopressin

The temporary loss of consciousness caused by an abrupt slowing of the heartbeat. This may happen following SHOCK, acute pain, fear, or stress. A common cause of fainting in normal people, a vasovagal attack may be a consequence of overstimulation of the VAGUS nerve which is involved in the control of breathing and the circulation.... vasovagal attack

The description ‘vasomotor’ refers to control of the muscular walls of blood vessels, particularly ARTERIES, dilating or constricting their diameters. The vasomotor centre is a group of neurons (see NEURON(E)) in the MEDULLA OBLONGATA of the BRAIN; they receive messages from sensory receptors in the circulatory system, and engineer re?ex alterations in the heart rate and blood-vessel diameters in order to adjust the blood pressure. The centre also receives transmission from other parts of the brain enabling emotions – fear or anger – to in?uence blood pressure. The vasomotor centre operates through the vasomotor nerves of the SYMPATHETIC NERVOUS SYSTEM and the PARASYMPATHETIC NERVOUS SYSTEM.... vasomotor centre

Like the previous, but less dangerous and more frequently caused by purely neurologic stimulus. The pain is more spasmodic and there is usually little actual blood vessel blockage.... angina, vasomotoria

An agent that stimulates blood flow to the viscera, and more closely mimicking the balance of circulation induced by parasympathetic states. This is one way to oppose excessive adrenergic circulatory states.... vasocholinergic

These drugs temporarily raise the BLOOD PRESSURE by constricting peripheral blood vessels. Sometimes they are used as a speedy way of raising blood pressure when other treatment has failed. EPHEDRINE and methoxamine hydrochloride are examples of this type of sympathomimetic.

Cardiopulmonary resuscitation ADRENALINE (epinephrine) is given intravenously in cardiac arrest, and other drugs used include ATROPINE and CALCIUM.... vasoconstrictor sympathomimetics

Vasoconstrictor sympathomimetic drugs, such as EPHEDRINE and NORADRENALINE, raise the BLOOD PRESSURE temporarily by acting on receptors that constrict peripheral blood vessels. They are occasionally used as a quick way of raising blood pressure when other measures have failed, but they have potentially serious side-effects on the kidney. Vasoconstrictors are also used with local anaesthetics (see under ANAESTHESIA) to counteract the latter’s vasodilator e?ect. Adrenaline will reduce local blood ?ow, slow the absorption of anaesthetic and prolong its e?ect.... vasoconstrictors

The increase of blood into the skin, resulting from the relaxation of the small arterioles that lead into the capillary beads at the edges of the body. This is a gentle way to lessen early high blood pressure, decreasing the difficulty of pushing columns of arterial blood through miles of capillaries.... vasodilation, peripheral

Substances that dilate blood vessels. Coronary vasodilators, such as NITRATES, CALCIUMCHANNEL BLOCKERS and POTASSIUM-CHANNEL ACTIVATORS, are used in heart failure to improve blood supply to the heart. Peripheral vasodilators affect the blood vessels in the limbs and are used to treat conditions due to poor circulation such as CHILBLAIN and RAYNAUD’S DISEASE.... vasodilators

Small nerve ?bres that lie upon the walls of blood vessels and connect the muscle ?bres of their middle coat with the NERVOUS SYSTEM. Through these nerves the blood vessels are retained in a state of moderate contraction. There are vasodilator nerves, through which are transmitted impulses that dilate the vessels, and, in the case of the skin vessels, produce the condition of blushing; there are also vasoconstrictor nerves which transmit impulses that constrict, or narrow, the blood vessels – as occurs on exposure to cold (see HYPOTHERMIA). Various drugs produce dilatation or contraction of the blood vessels, and several of the substances produced by ENDOCRINE GLANDS in the body have these effects: for example, ADRENALINE.... vasomotor nerves

Spasms and cramps of blood vessels that are caused by neurologic factors. Also called angioneurosis... vasoneurosis

Widening of blood vessels, causing increased blood flow to a part of the body.

Vasodilation under the skin occurs in response to hot weather and increases heat loss from the body.... vasodilation

A group of drugs that widen blood vessels.

Vasodilator drugs include ACE inhibitors, alphablockers, calcium channel blockers, nitrate drugs, and sympatholytic drugs.

They are used to treat disorders in which abnormal narrowing of blood vessels reduces blood flow through tissues, impairing the supply of oxygen.

Such disorders include angina pectoris and peripheral vascular disease.

Vasodilators are also used to treat hypertension and heart failure.

All vasodilator drugs may cause flushing, headaches, dizziness, fainting, and swollen ankles.... vasodilator drugs

see neurocardiogenic syncope.... malignant vasovagal syndrome

pl. n. the tiny arteries and veins that supply the walls of blood vessels.... vasa vasorum

adj. affecting the diameter of blood vessels, especially arteries. Examples of vasoactive agents are emotion, pressure, carbon dioxide, and temperature. Some exert their effect directly, others via the *vasomotor centre in the brain.... vasoactive

see VIP.... vasoactive intestinal peptide

n. an increase in the diameter of blood vessels, especially arteries. This results from local vasodilator hormones (e.g. *prostaglandins) or activation of the *vasomotor centre in the brain, which bring about relaxation of the arterial walls and a consequent lowering of blood pressure.... vasodilatation

n. the operation of joining the vas deferens to the epididymis in a side-to-side manner in order to bypass an obstruction to the passage of sperm from the testis. The obstruction, which may be congenital or acquired, is usually present in the mid-portion or tail of the epididymis. Vaso-epididymostomy is therefore usually performed by anastomosing the head of the epididymis to a longitudinal incision in the lumen of the adjacent vas.... vaso-epididymostomy

n. X-ray imaging of the *vas deferens. A contrast medium is injected either into the exposed vas deferens at surgery, using a fine needle, or into the ejaculatory duct (which discharges semen from the vesicle into the vas deferens) by inserting a catheter via an endoscope. The technique is used in the investigation of *azoospermia, to look for blockages in the vas.... vasography

n. the surgical tying of the vas deferens (the duct conveying sperm from the testis). This is performed to prevent infection spreading from the urinary tract and causing recurrent *epididymitis. It is sometimes performed at the same time as *prostatectomy to prevent the complication of epididymitis in the postoperative period.... vasoligation

n. an increase or decrease in the diameter of blood vessels, particularly the arteries. See vasoconstriction; vasodilatation.... vasomotion

adj. controlling the muscular walls of blood vessels, especially arteries, and therefore their diameter.... vasomotor

any nerve, usually belonging to the autonomic nervous system, that controls the circulation of blood through blood vessels by its action on the muscle fibres within their walls or its action on the heartbeat. The *vagus nerve slows the heart and reduces its output, but sympathetic nerves increase the rate and output of the heart and increase blood pressure by causing the constriction of small blood vessels at the same time.... vasomotor nerve

subjective sensations experienced by women around the time of the *menopause, often described as explosions of heat (hot flushes), mostly followed by profuse sweating and sometimes preceded by an undetermined sensation with waking at night. Objective signs are sudden reddening of the skin on the head, neck, and chest and profuse sweating. Physiological changes include peripheral vasodilatation, *tachycardia with normal blood pressure, and raised skin temperature with normal body temperature.... vasomotor symptoms

adj. stimulating the contraction of blood vessels and therefore bringing about an increase in blood pressure.... vasopressor

n. see Raynaud’s disease.... vasospasm

n. a surgical incision into the vas deferens (the duct conveying sperm from the testis). This is usually undertaken to allow catheterization of the vas and the injection of radiopaque contrast material for X-ray examination (see vasography), to test for patency of the duct in patients with *azoospermia.... vasotomy

adj. relating to the action of impulses in the *vagus nerve on the circulation. The vagus reduces the rate at which the heart beats, and so lowers its output.... vasovagal

n. the surgical operation of reanastomosing the vas deferens after previous vasectomy: the reversal of vasectomy, undertaken to restore fertility. It is ideally performed using microsurgical techniques. The success rates vary depending on the time between the vasectomy and its reversal.... vasovasostomy

n. inflammation of the *seminal vesicles and *vas deferens. This usually occurs in association with *prostatitis and causes pain in the perineum, groin, and scrotum and a high temperature. On examination the vasa and seminal vesicles are thickened and tender. Treatment includes administration of antibiotics.... vasovesiculitis