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Biology LibreTexts

25.22: Glossary: V

  • Page ID
  • vaccine

    substance containing a modified pathogen that does not cause disease but provokes an adaptive immune response, resulting in immunity to the pathogen


    large sac-like organelle that stores and transports materials inside a cell


    female reproductive organ that receives sperm during sexual intercourse and provides a passageway for a baby to leave the mother’s body during birth


    inflammation of the vagina usually caused by an infection with microbes

    variability-selection hypothesis

    idea that hominins evolved greater adaptability in response to climate change rather than evolving specializations for a particular climate

    vas deferens

    one of a pair of thin tubes that transports sperm from an epididymis to an ejaculatory duct during ejaculation; also called sperm duct


    surgical sterilization procedure in males in which the vas deferens are blocked so sperm cannot be ejaculated


    narrowing of blood vessels so less blood can flow through them


    widening of blood vessels so more blood can flow through them


    organisms such as an insect that spreads pathogens from host to host


    type of blood vessel that carries blood toward the heart from the lungs or body


    process of moving air into and out of the lungs; also called breathing

    ventral cavity

    major human body cavity at the anterior (front) of the trunk that contains such organs as the lungs, heart, stomach, intestines, and internal reproductive organs


    one of two lower chambers of the heart that pumps blood out of the heart


    thick waxy coating that forms on a fetus to protect the skin and that mostly disappears by birth

    vertebra (plural, vertebrae)

    one of 33 small bones that make up the vertebral column

    vertebral column

    flexible column of vertebrae that connects the trunk to the skull and encloses the spinal cord; also called spine or backbone


    small sac-like organelle that stores and transports materials inside a cell

    vesicle transport

    type of active transport in which substances are carried across a cell membrane by vesicles

    vestigial structure

    structure such as the human tailbone or appendix that evolution has reduced in size because it is no longer needed

    villi (singular, villus)

    microscopic, finger-like projections in a mucous membrane that form a large surface area for absorption

    viral load

    amount of virus in a sample of an infected individual’s blood


    tiny, nonliving particle that contains DNA but lacks other characteristics of living cells and may cause human disease


    ability to sense light and see; also called sight


    organic compound needed in small amounts for proper body functioning

    vitamin D

    micronutrient synthesized in the skin and needed to absorb calcium for strong bones


    external female reproductive structures, including the clitoris, labia, and vaginal and urethral openings