Webster's New World Medical Dictionary

Velpeau hernia
See 
hernia, Velpeau.
velvet ant
A parasitic wasp that is common in
most parts of the world, including the southern and
southwestern US. Velvet ant stings can trigger aller-
gic reactions that vary greatly in severity. Avoidance
and prompt treatment are essential. In selected
cases, allergy injection therapy is highly effective.
vena cava, inferior
The large vein that receives
blood from the lower extremities, pelvis, and
abdomen and then empties that blood into the right
atrium of the heart.
vena cava, superior
The large vein that returns
blood to the right atrium of the heart from the head,
neck, and both upper limbs. The superior vena cava
is located in the middle of the chest and is sur-
rounded by rigid structures and lymph nodes.
Structures bordering the superior vena cava include
the trachea, aorta, thymus, right bronchus of the
lung, and pulmonary artery. Compression of the
superior vena cava by disease of any of the struc-
tures or lymph nodes surrounding it can cause
superior vena cava syndrome. See also 
superior
vena cava syndrome.
vena cava syndrome, superior
See 
superior
vena cava syndrome.
venereal
Having to do with sexual contact. For
example, a venereal disease is a sexually transmitted
disease.
venereal disease
See 
sexually transmitted 
disease.
venereal warts
See 
genital warts.
venlafaxine
A unique antidepressant drug
(brand name: Effexor) that is prescribed to treat
depression. Venlafaxine is believed to affect the 
neurotransmitters serotonin, norepinephrine, and
dopamine, but not monoamine oxidase (MAO).
Venlafaxine is not usually indicated for use by peo-
ple with kidney or liver disease, or by those with
high blood pressure. Common side effects include
sleepiness, insomnia, dry mouth, nervousness, nau-
sea, and sexual dysfunction.
venom
A poison, particularly one secreted by an
animal. Examples are bee venom, snake venom,
scorpion venom, and spider venom. Snake venom is
also called venin.
venous aneurysm
A localized widening and
bulging of a vein. At the area of a venous aneurysm,
the vein wall is weakened and may rupture.