V–Z

VACTERL The acronym for a constellation of
BIRTH DEFECTSthat tend to occur in coincidence
with each other. Doctors consider a baby who has
three or more of the defects to have the VACTERL
association, and will examine the baby closely for
the other defects in the constellation. These
defects include

• V: vertebral (spinal) anomalies


• A: ANAL ATRESIA(also called imperforate ANUS)


• C: cardiac (HEART) anomalies


• T/E: tracheoesophageal fistula (may also occur
  as tracheal fistula and ESOPHAGEAL ATRESIA)


• R: renal (kidney) anomalies


• L: limb anomalies

Occurring often enough that some doctors
believe it, too, is part of the constellation, is a sin-
gle-ARTERY UMBILICAL CORD(the normal umbilical
cord has two arteries), which sometimes appears
in the acronym as a final S(VACTERLS). VAC-
TERL occurs sporadically (in a nonhereditary pat-
tern); researchers do not know what causes it, nor
do they understand the connections among the
various defects. Some of the birth defects can be
life threatening, such as the HEARTmalformation
tetralogy of Fallot (a complex of four serious heart
defects). Treatment, often surgery, attempts to cor-
rect the congenital anomalies.
See also CONGENITAL ANOMALY; CONGENITAL HEART
DISEASE.

vagina The muscular passageway between the
CERVIXand the VULVA(outside of the body). The
vagina serves as the portal through which the
menstrual flow leaves the body with
MENSTRUATION, the erect PENISenters during SEXUAL

INTERCOURSE, and the FETUS passes during

CHILDBIRTH.

The outer structures of the vagina are strong

muscles that have the ability to vary the inner

diameter of the vagina from its normal state in

which the vaginal walls touch each other to four

or five inches to accommodate the birth of a child.

Deep folds of mucous membrane (the vaginal

mucosa) line the vagina. The folds, called rugae,

give the vagina its ability to expand. The vaginal

muscles also relax to extend the depth (length) of

the vagina, facilitating SEXUAL INTERCOURSE.

The vaginal tissue near the opening of the

vagina (the vaginal introitus) has an abundance of

sensory NERVEendings though the rest of the vagi-

nal mucosa has few sensory nerve endings. A

small ring of vaginal mucosa, called the hymen,

extends partially across the opening of the vagina.

The degree to which the hymen restricts access to

the vagina varies widely among women. Though

conventional wisdom purports that penetration of

the erect penis with a woman’s first experience of

sexual intercourse tears or ruptures the hymen,

this may or may not be the case. A hymen that

does not extend very far across the vaginal open-

ing may not impede the entry of the erect penis.

The hymen may also rupture or tear as a result of

other factors such as insertion of tampons or activ-

ities such as horseback riding.

The Bartholin’s glands and Skene’s ducts near

the entrance to the vagina and the nabothian

glands (cervical glands) that cover the cervix pro-

vide secretions to moisten and lubricate the inte-

rior of the vagina. These secretions diminish with

the loss of ESTROGENSthat characterizes MENOPAUSE.

As a result the vaginal mucosa becomes thin and

fragile and the vagina less flexible after

menopause.

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