Terms V-Z

Vagotomy: The cutting of certain branches of the vagus nerve, performed with gastric surgery, to reduce the amount of gastric acid secreted and lessen the chance of recurrence of a gastric ulcer.

Vagus Nerve: Either of the longest pair of cranial nerves mainly responsible for parasympathetic control over the heart and many other internal organs, including thoracic and abdominal viscera.

Varicose Vein: A tortuous, dilated vein with incompetent valves. Causes include congenitally defective valves, thrombophlebitis, pregnancy, and obesity.

Vascular: Pertaining to a blood vessel.

Vasculitis: Inflammation of the blood vessels.

Vasodilation: An increase in the diameter of a blood vessel.

Vasodilator: A nerve or agent that causes dilation of blood vessels by promoting the relaxation of vascular smooth muscle. Chemical vasodilators include hydralazine, nitroglycerin, nitroprusside, and trimethaphan. They have been useful in the treatment of acute heart failure in myocardial infarction, in cases associated with severe mitral regurgitation, and in failure resulting from myocardial disease.

Venous Insufficiency: An abnormal circulatory condition characterized by decreased return of venous blood from the legs to the trunk o the body. Edema is usually the first sign of the condition.

Ventricle: A small cavity, such as the right and the left ventricles of the heart or one of the cavities filled with cerebrospinal fluid in the brain.

Ventricular Dysfunction: An abnormality in the contraction of the ventricles or the motion of the walls.

Ventricular Hypertrophy: Abnormal enlargement of the heart ventricles. It is often caused by hypertension, a valvular disease, or heart failure.

Ventriculography: The radiographic examination of a ventricle of the heart after injection of a radiopaque contrast medium.

Vertebra: Any one of the 33 bones (26 in the adult) of the spinal column, comprising the 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (1 in adult), and 4 coccygeal vertebrae (1 in adult).

Vertigo: A sensation of instability, giddiness, loss of equilibrium, or rotation, caused by a disturbance in the semicircular canal of the inner ear or the vestibular nuclei of the brainstem.

Viral infection: Any of the diseases caused by one of approximately 200 viruses pathogenic to humans. If cells are damaged by the viral attack, disease exists. Viruses are introduced into the body through nonintact skin or mucous membranes or through a transfusion into the bloodstream or transplantation, by droplet infection through the respiratory tract, or by ingestion through the digestive tract into the GI system.

Visual field defect: One or more spots or defects in the vision that remains constant in position, unlike a floater.

Visual Pathway: A pathway over which a visual sensation is transmitted from the retina to the brain.

Vitamin: An organic compound essential in small quantities for normal physiologic and metabolic functioning of the body.

Volvulus: A twisting of the bowel on itself, causing intestinal obstruction. The condition is frequently the result of a prolapsed segment of mesentery and occurs most often in the ileum, the cecum, or the sigmoid parts of the bowel. If it is not corrected, the obstructed bowel becomes necrotic, peritonitis and rupture of the bowel occur, and death may result.

Wandering: The diagnosis is defined as meandering, aimless or repetitive locomotion that exposes the individual to harm. It is frequently incongruent with boundaries, limits, or obstacles. Related factors include cognitive impairment, specifically memory and recall deficits, disorientation, poor visuoconstructive ability, and language defects.

Wasting: A process of deterioration marked by weight loss and decreased physical vigor, appetite, and mental activity.

Whiplash Injury: An injury to the cervical vertebrae or their supporting ligaments and muscles marked by pain and stiffness. It usually results from sudden acceleration or deceleration, such as in a rear-end car collision that causes violent back-and-forth movement of the head and neck.

White Blood Cell: A white blood cell, one of the formed elements of the circulating blood system.

World Health Organization (WHO): An intergovernmental organization within the United Nations system whose purpose is to aid in the attainment of the highest possible level of health by all people.

Wound: Any physical injury involving a break in the skin, usually caused by an act or accident rather than by a disease, such as a chest wound, gunshot wound, or puncture wound. To cause an injury, especially one that breaks the skin.

Wound Care: A nursing intervention from the Nursing Interventions Classification (NIC) defined as prevention of wound complications and promotion of wound healing.

Xanax: Trademark for a benzodiazepine antianxiety agent (alprazolam).

X-ray: Electromagnetic radiation with wavelengths between about 0.005 and 10 mm. X-rays are produced when electrons traveling at high speed strike certain materials, particularly heavy metals such as tungsten.

X-ray Dermatitis: A skin inflammation caused by exposure to x-rays. Excessive exposure to x-rays can lead to skin cancer.

Yeast: Any unicellular, usually oval, nucleated fungus that reproduces by budding.

Yellow Fever: An acute arbovirus infection transmitted by mosquitoes.

Zinc: An essential nutrient in the body and is used in numerous pharmaceutics, such as zinc acetate, zinc oxide, zinc permanganate, and zinc stearate.

Zinc deficiency: A condition resulting from insufficient amounts of zinc in the diet. It is characterized by abnormal fatigue, decreased alertness, a decrease in taste and odor sensitivity and poor appetite.

Zinc Oxide: A topical protectant used for a wide range of minor skin irritations.