Glossary 605
V
vaccination the introduction of a foreign substance to the
body for the purpose of inducing immunity
vacuum-assisted closure treatment for a bedsore that
involves a vacuum drawing moisture from the ulcer
vagina a thin-walled, tubular structure below the uterus;
birth canal
vagus nerve (VAY-gus) one of three cranial nerves that is
responsible for transmitting taste sensations to the brain
valvular stenosis a narrowing of the heart valve due to
stiff or fused valve cusps
vas deferens (vas DEHF-eh-rehnz) see ductus deferens
vasa recta thin-walled blood vessels that begin and end
near the boundary between the renal cortex and the
renal medulla, and which extend deep into the renal
medulla, running parallel to the nephron loops; play a
role in the formation of concentrated urine
vasoconstrict (VA-soh-KUN-strikt) to decrease the
opening of the lumen
vasoconstriction (VA-soh-kun-STRIK-shun) narrowing
of the lumen of the blood vessels, which decreases blood
fl ow
vasodilate (VA-soh-DIGH-layt) to increase the opening of
the lumen
vasodilation (VA-soh-digh-LAY-shun) widening of the
lumen of blood vessels, which increases blood fl ow
vasopressin see antidiuretic hormone (ADH)
veins vessels that carry blood to the heart
ventral ramus (VEHN-tral RAY-mus) the anterior division
of spinal nerves that communicate with the muscle and
skin of the anterior and lateral trunk
ventricular fi brillation a life-threatening condition in
which the heart ventricles quiver at a rate greater than
350 bpm
ventricular tachycardia
(ven-TRIK-yoo-lar tak-i-KARD-ee-a)
a life-threatening arrhythmia in which the ventricles,
rather than the SA node, initiate the heartbeat; the heart
rate is between 150 and 250 bpm, requiring swift medical
attention
venules (VEN-yools) the smallest veins that connect the
capillaries with the larger systemic veins
vertebra (VER-teh-bra) one of the bones making up the
spinal column
vertebral arch (VER-teh-bral) round projection of bone
on the posterior aspect of the vertebra which surrounds a
hole known as the vertebral foramen, through which the
spinal cord passes
vertebral body (VER-teh-bral) solid, disc-shaped portion
on the anterior side of a vertebra, which bears most of
the weight positioned above it
vertebral foramen (VER-teh-bral foh-RAY-mehn) hole in
the center of the vertebral arch, through which the spinal
cord passes
vertex presentation normal position of the fetus in which
the head exits the mother’s body fi rst
vertigo severe dizziness
vesicular follicle a mature ovarian follicle that contains
a fl uid-fi lled cavity and that ruptures during ovulation to
release an egg
vestibular region the area at the front of the nasal cavity,
just inside the naris
vestibule (VEHS-ti-byool) (1) a chamber in the inner
ear that contains the three semicircular canals; (2) the
recessed area in which the vaginal and urethral openings
lie
vestibulocochlear nerve (vehs-TIB-yoo-loh-KAHK-lee-ar)
a cranial nerve comprised of the cochlear nerve and the
vestibular nerve
visceral layer membrane covering each organ within a
body cavity
visceral pleura (PLOO-ra) the membrane that lines the
lungs and dips into the fi ssures
vital capacity (VC) the total amount of air that can
be forcibly expired from the lungs after a maximum
inspiration
vital signs measurements of pulse and blood pressure
vitamin defi ciency the long-term lack of a particular
vitamin in one’s diet; may result in certain health
problems
vitamins organic chemicals needed by the body for
normal functioning and good health
vitreous fl oaters small, irregularly shaped specks that
appear to drift within the fi eld of vision
vocal cords a pair of folds in the mucous membrane of
the larynx
vomer (VOH-mer) plow–shaped bone, comprising most
of the bony nasal septum
vulva the external female genitalia; includes the labia,
mons pubis, clitoris, and vestibule
W
weight force equal to the gravitational acceleration
exerted on the mass of an object
wet macular degeneration a condition that involves
leakage of small blood vessels within the eye
white blood cells formed elements present in blood;
fi ght infection and protect the body through various
mechanisms; leukocytes
white matter the term that describes tracts of myelinated
fi bers within the central nervous system
womb see uterus
Z
zona pellucida (peh-LOO-si-da) a clear, extracellular
glycoprotein coat that develops on the oocyte
zygomatic bones (ZIGH-goh-MAT-ik) cheek bones,
which also form much of the sides of the orbits, or eye
sockets
zygote (ZIGH-goht) a diploid cell produced by the fusion
of a sperm with an egg; a fertilized egg