Dictionary

vasopressin See antidiuretic hormone.

vasomotor rhinitis Inflammation of the nose (rhinitis) due to abnormal nerve control of the blood vessels in the nose. Vasomotor rhinitis is not allergic rhinitis. Decongestant medications are used to temporarily reduce swelling of sinus and nasal tissues leading to an improvement of breathing and a decrease in obstruction.

vasomotor Relating to the nerves and muscles that cause blood vessels to constrict or dilate.

vasodilator An agent that acts as a blood vessel dilator, opening blood vessels by relaxing their muscular walls. For example, nitroglycerin is a vasodilator, as are the angiotensin converting enzyme (ACE) inhibitors.

vasodilation Widening of blood vessels that results from relaxation of the muscular walls of the vessels. What widens in vasodilation is actually the diameter of the interior (lumen) of the vessel. The opposite of vasodilation is vasoconstriction.

vasodepressor syncope See syncope, situational.

vasoconstriction Narrowing of the blood vessels that results from contraction of the muscular walls of the vessels. The opposite of vasoconstriction is vasodilation.

vasectomy A surgical procedure designed to make a man sterile by cutting or blocking both the right and left vas deferens, the tubes through which sperm pass into the ejaculate.

vasculitis, allergic See Churg-Strauss syndrome.

vasculitis A general term for a group of uncommon diseases that feature inflammation of the blood vessels. Each of the vasculitis diseases is defined by characteristic distributions of blood vessel involvement, patterns of organ involvement, and laboratory test abnormalities. The actual causes of these vasculitis diseases are usually not known, but immune system abnormality is…

vascular endothelial growth factor A gene that is responsible for the growth of blood vessels. Abbreviated VEG-F.

vascular dementia A common form of dementia in older persons that is due to cerebrovascular disease, usually with stepwise deterioration from a series of small strokes and a patchy distribution of neurologic deficits affecting some functions and not others. Risk factors include high blood pressure and advanced age. Symptoms include confusion, problems with recent memory,…