Medical terms - Letter V (page 8) | MedicalVocabulary.org

Visual nerve pathways

The optic nerves serving the eyes join behind the eyes just in front of the pituitary gland to form a cross-shaped structure called the optic chiasma. Within the optic chiasma some of the nerve fibers cross. The fibers…
Visual pathway glioma

A slow-growing benign tumor of the eye
Visual receptor

The layer of rods and cones that are the visual cells of the retina
Vital

Necessary to maintain life. Breathing is a vital function
Vital bodily function

1. An essential bodily function. 2. A key function for life. 3. A function required by most, if not all, people. The definition of vital bodily functions is prerequisite to the determination of death. But what are the…
Vitamin A

>Beta carotene: An antioxidant which protects cells against oxidation damage that can lead to cancer. Beta carotene is converted, as needed, to vitamin A. Food sources of beta carotene include vegetables such as…
Vitamin A deficiency

Deficiency of niacin, one of the B-complex vitamins, causes pellagra. See: Pellagra.
Vitamin B -- niacin

Deficiency of niacin, one of the B-complex vitamins, causes pellagra. See: Pellagra
Vitamin B -- nicotinic acid

Deficiency of nicotinic acid (also known as niacin), one of the B-complex vitamins, causes pellagra. Pellagra was known as the 'disease of the four D's' -- dermatitis, diarrhea, dementia and death. The disease is…
Vitamin B -- pantothenic acid

This is one of the less well known B vitamins, perhaps because it is widely distributed in nature. Pantothenic acid is virtually ubiquitous. It is present in foods as diverse as poultry, soybeans, yogurt, and sweet…
Vitamin B1

Thiamine. Vitamin B1 (thiamine) acts as a coenzyme in the metabolism of the body. Deficiency of thiamine leads to the disease beriberi, a disease affecting the heart and nervous system. The word 'vitamin' was coined in…
Vitamin B1 deficiency, infantile

See: Infantile beriberi
Vitamin B12

A vitamin important for the normal formation of red blood cells and the health of the nerve tissues. Undetected and untreated vitamin B12 deficiency can lead to anemia and permanent nerve and brain damage. Pernicious…
Vitamin B12-responsive methylmalonicaciduria

An inherited metabolic (biochemical) disease that, unless effectively treated, causes young children to become mentally retarded. The defect in some (but not all) of these children has to do with an inability to use the…
Vitamin B15

An old name for dimethylglycine (DMG, pangamic acid), which is no longer considered to be a vitamin by the strict definition of that word
Vitamin B2

An essential nutrient found in meat, dairy foods, plant foods and grain products. The body requires vitamin B2 to break down food components, maintain tissue, and absorb other nutrients. Like other vitamins, vitamin B2…
Vitamin B3

Vitamin B3 is niacin. Deficiency of niacin causes pellagra. Pellagra was known as the 'disease of the four D's' -- dermatitis, diarrhea, dementia and death. The disease is specifically characterized by: > >Dermatitis: A…
Vitamin B5

Vitamin B5 is pantothenic acid, one of the less well known B vitamins, perhaps because it is widely distributed in nature. Pantothenic acid is virtually ubiquitous. It is present in foods as diverse as poultry…
Vitamin B6

A group of closely related chemical compounds with related names -- pyridoxine, pyridoxal and pyridoxamine -- that are transformed within the body to yet another form of vitamin B6, pyridoxal phosphate, that acts as a…
Vitamin C

An essential nutrient found mainly in fruits and vegetables. The body requires vitamin C to form and maintain bones, blood vessels, and skin. Like other vitamins, vitamin C is an organic compound. An organic compound is…
Vitamin D

A steroid vitamin which promotes the intestinal absorption and metabolism of calcium and phosphorus. Under normal conditions of sunlight exposure, no dietary supplementation is necessary because sunlight promotes…
Vitamin D requirement

The amount of vitamin D recommended per day, which varies according to the age of the individual. Recommendations are as follows: > >For Children: The National Academy of Sciences and American Academy of Pediatrics have…
Vitamin D3

A vitamin produced by the body when exposed to ultraviolet light or obtained from dietary sources. Vitamin D3 is a hormone that has an important role in calcium and phosphorus metabolism. Technically, vitamin D3 is not…
Vitamin E

Alpha-tocopherol, an antioxidant vitamin which binds oxygen free radicals that can cause tissue damage. Deficiency of vitamin E can lead to anemia. Vitamin E may play a possible role in preventing heart disease and…
Vitamin K

One of two naturally occurring fat-soluble vitamins (vitamin K1 and vitamin K2) needed for the clotting of blood because of an essential role in the production of prothrombin (a clotting factor). The term vitamin A may…
Vitamin O

Not a true vitamin but rather a pricey health supplement that is composed largely of salt water (plus some germanium, a trace element dangerous to health). The US Federal Trade Commission (FTC) charged the manufacturer…
Vitamin P

An old name for substances now known as bioflavinoids. They are no longer considered to be vitamins by the strict definition of that word
Vitamin Q10

See: Coenzyme Q10
Vitamin requirements, infant

Vitamins are organic substances that are essential in minute quantities for the proper growth, maintenance, and functioning of the baby. Vitamins must be obtained from food because the body cannot produce them. The…
Vitamin therapy

The use of vitamins to prevent or cure disease. Many physicians are now recognizing the beneficial uses of anti-oxidant and other vitamins for a wide variety of conditions, often as a complementary therapy to accompany…
Vitamins

>Vitamin A: Retinol. Carotene compounds responsible for transmitting light sensation in the retina of the eye. Deficiency leads to night blindness. >Beta carotene: An antioxidant which protects cells against oxidation…
Vitiligo

Vitiligo: Pronounced vit-uh-LIE- go. A condition in which the skin turns white due to the loss of melanocytes. These cells produce melanin, the pigment that gives the skin its characteristic color. (Melanocytes also…
Vitrectomy

Removal of the gel (called the vitreous) from within the eyeball. This may be done because it has blood and scar tissue in it that blocks sight. An eye surgeon then replaces the clouded gel with a clear fluid
Vitreous

A clear, jelly-like substance that fills the middle of the eye. Also called the vitreous humor, 'humor' in medicine referring to a fluid (or semifluid) substance
Vitreous type 2 Stickler syndrome

Stickler syndrome, type II. See: Stickler syndrome
Vitreous type Stickler syndrome

Stickler syndrome, type I. See: Stickler syndrome
Vocal cord

One of two small bands of muscle within the larynx. These muscles vibrate to produce the voice. The vocal cords form a 'V' inside the larynx, a 2-inch-long, tube-shaped organ in the neck: NTER>We use the larynx when we…
Vocal cord paralysis

Vocal cord paralysis:bility of one or both vocal folds (vocal cords) to move. The paralysis is usually due to damage to the nerves going to the vocal cords or due to damage to the brain itself. In more technical terms…
Vocal cord, false

See: False vocal cord
Vocal tremor

Tremor: Trembling or shaking of one or more of the muscles of the larynx (the voice box), resulting in an unsteady sounding voice
Vohwinkel syndrome

A genetic disorder characterized by hearing loss and thickened skin, particularly on the knuckles. The sensorineural hearing is mild-to-moderate in degree. The thickening of the skin (hyperkeratosis) can be 'mutilating'…
Voice box

The voice box, or larynx, is the portion of the respiratory (breathing) tract containing the vocal cords which produce sound. It is located between the pharynx and the trachea. The larynx, also called the voice box, is…
Voice disorder

One of a group of problems involving abnormal pitch, loudness, or quality of the sounds produced by the larynx (the voice box)
Void

To urinate. Just as we can void a check and empty it of value, so can we void our bladder and empty it of urine
Voiding cystourethrogram

A test done to examine the bladder and urethra while the bladder fills and empties. A radiopaque liquid (that can be seen on x-ray) is placed in the bladder through a catheter. The bladder is filled until the patient…
Voiding cystourethrography

A procedure done to examine the bladder and urethra while the bladder fills and empties. A radiopaque liquid (that can be seen on x-ray) is placed in the bladder through a catheter. The bladder is filled until the…
Volar

Pertaining to both the palm and sole. It comes from word 'vola' which the ancient Romans used for 'the palm of the hand and the sole of the foot.' By comparison, the term 'palm' applies to only the palm (the grasping…
Volume, stroke

Stroke: The amount of blood pumped by the left ventricle of the heart in one contraction. The stroke volume is not all of the blood contained in the left ventricle. The heart does not pump all the blood out of the…
Voluntary

Done in accordance with the conscious will of the individual. The opposite of involuntary. The terms 'voluntary' and 'involuntary' apply to the human nervous system and its control over muscles. The nervous system is…
Voluntary Euthanasia Society (VES)

The first society of its kind in the world -- its founders included doctors, lawyers and churchmen -- the VES was set up in England in 1935. The announced aim of the VES is to make it legal for a competent adult…