Biology

Vasopressin

Vasopressin (Antidiuretic Hormone)

Vector (biology)

Vein

Vein: structure, function, types, and clinical significance

A vein is a blood vessel that returns blood to the heart. This article explains vein anatomy, major types, physiological role, clinical importance and common disorders in concise,

Venom

Venom (animal-produced toxins and their roles)

Ventricles of brain

Ventricular fibrillation

Venule

Venule: small vessels of the microcirculation

Vertebra

Vertebra: structure, regions, development and clinical significance

Vertebrate

Vertebrate brain

Vertebrate brain: structure, function and evolutionary development

Vesicle

Vesicle (cellular membrane-bound sac)

Vespoidea

Vessel

Vestigial organ

Vestigial organs: remnants of ancestral anatomy

Vibrio

Vibrio (genus of aquatic bacteria)

Vibrio cholerae

Vibrio cholerae: bacterium that causes cholera

Vibrio vulnificus

Vibrio vulnificus: marine pathogen, disease, and prevention

Villi

Villi (small intestine): structure, function, and clinical relevance

Viral disease

Viral envelope

Viral envelope: structure, formation, and implications for infection

Viral life cycle

Viral life cycle: stages, variations, and biological significance

Viroid

Virology

Virus

Virus: structure, replication, and role in biology

A concise encyclopedia article on viruses: their structure, life cycle, interactions with hosts, historical discovery, medical importance, and notable examples.

Visual cortex

Vitamin

Vitamin: essential micronutrients — types, roles, sources, history, and safety

Overview of vitamins: what they are, classification, main functions, dietary sources, deficiency diseases, supplements, and safety considerations.

Vitamin B12

Vitamin B6

Vitamin B6 (pyridoxine): roles, sources, and clinical significance

Vitamin D

Vitamin D — overview, function, sources, deficiency and safety

Viviparity

Viviparity: internal development and live birth in animals

Vivisection

Vivisection: definition, history, practices, and ethical debate

Vomer bone

Vulva

Vulva (external female genitalia)

Warning colouration

Warning colouration (aposematism): signals, evolution and examples

Warning colouration, or aposematism, are conspicuous signals—often bright red, yellow, black or white—that advertise an animal's toxicity, unpalatability or defensive abilities to

Wastebasket taxon

Weaning

Weaning: the transition from milk to solid foods

Webbed feet

Weight loss

West Nile virus

West Nile virus (WNV): overview, transmission, history, and prevention

White blood cell

White blood cell (leukocyte): roles, types, and clinical significance

White matter

Wild type

Wild type (genetics): definition, history, and practical use

Wingspan

Wingspan: definition, measurement, and significance for birds and aircraft

Wood fibre

Wrinkle (skin)

Wrist

Wrist: structure, function, common conditions and care

Xenacoelomorpha

Xenotransplantation

Xenotransplantation: cross‑species transplantation of cells, tissues and organs