Dictionary

Body systems

Anatomy and the conditions of each body system, from the heart and lungs to the skin.

vaginaThe muscular tube that leads from the cervix of the uterus to the outside of the body; the birth canal.

vaginalRelating to the vagina.

vagus nerveThe 10th cranial nerve, which runs from the brain stem to the chest and belly and slows the heart and helps digestion.

variable decelerationAn abrupt drop in the fetal heart rate of at least 15 beats per minute that lasts at least 15 seconds and less than 2 minutes.

varicellaA very contagious infection caused by the varicella-zoster virus; also called chickenpox.

varicesSwollen, twisted veins, most often in the lower esophagus or the stomach, or in the legs.

varicose veinA swollen, twisted vein just under the skin, most often in the legs, in which the valves do not work well.

vascularRelating to blood vessels.

vasculitisInflammation of blood vessels.

vasoconstrictionThe narrowing of blood vessels when the muscle in their walls tightens.

vasodilationThe widening of blood vessels as the muscle in their walls relaxes, which lets more blood flow through.

veinA blood vessel that carries blood back toward the heart.

venaThe Latin word for vein, used in names such as vena cava.

vena cavaOne of the two large veins that return oxygen-poor blood from the body to the right atrium of the heart.

venous bloodBlood in the veins, returning to the heart after it has given up oxygen to the tissues.

venous insufficiencyA long-term condition in which the leg veins cannot carry blood back to the heart well.

venous returnThe flow of blood back to the heart through the veins.

venous stasisSlow or pooled blood flow in the veins, most often in the legs.

ventilationAir moving in and out of the lungs as a person breathes.

ventilator-associated pneumoniaA lung infection that starts 48 hours or more after a client has been put on a breathing machine through a tube.

ventralOn or toward the front, belly side of the body.

ventricleOne of the two lower chambers of the heart, or one of the fluid-filled spaces inside the brain.

ventricular fibrillationA heart rhythm in which the lower chambers quiver in a fast, chaotic way instead of pumping.

ventricular septal defectA hole in the wall between the heart's two lower chambers, present from birth.

ventricular tachycardiaA fast heart rhythm that starts in the lower chambers of the heart (the ventricles), usually over 100 beats per minute.

venuleA very small vein that collects blood from the capillaries.

vernix caseosaThe white, creamy, cheese-like coating on a newborn's skin.

vertebraOne of the bones that stack together to form the spine.

vertebral columnThe spine: the column of small bones (vertebrae) that runs down the back and surrounds the spinal cord.

vertigoA false feeling that you or the room around you is spinning or moving.

vesicalRelating to the urinary bladder.

vesicoureteral refluxThe backward flow of urine from the bladder up into the ureters and toward the kidneys.

villusOne of the tiny, finger-like folds that line the small intestine and take in nutrients.

viral gastroenteritisAn infection of the stomach and intestines caused by a virus, such as norovirus or rotavirus.

viral infectionAn illness caused by a virus, a very small germ that can multiply only inside living cells.

Virchow triadThree conditions that together promote blood clots in vessels: slowed blood flow, damage to the vessel wall, and blood that clots too easily.

visceralHaving to do with the internal organs, especially those in the chest and belly.

visual acuityHow clearly and sharply a person can see.

vitamin AA fat-soluble vitamin needed for vision, especially in dim light, healthy skin and a working immune system.

vitamin B12A vitamin from animal foods that the body needs to make red blood cells and keep nerves healthy; also called cobalamin.

vitamin CA water-soluble vitamin in fruits and vegetables that the body needs to make collagen, heal wounds and absorb iron; also called ascorbic acid.

vitamin DA fat-soluble vitamin that the skin makes in sunlight and that helps the body absorb calcium for strong bones.

vitiligoA long-term skin condition in which patches of skin lose their color.

voidingPassing urine; emptying the bladder.

voluntary muscleMuscle that a person can move by choice, such as the muscles of the arms and legs.

vomitingForcefully bringing up the contents of the stomach through the mouth.