Definition

Noun: 1. A minute, hair-like projection: A very small, finger-shaped or hair-like structure that projects from the surface of a mucous membrane, especially in the small intestine, to increase the surface area for absorption. 2. A specific anatomical structure: Refers to one of the numerous tiny projections lining the inner surface of the small intestine (intestinal villus) or found on other mucous membranes, such as in the chorion of the placenta (chorionic villus).

Examples

• General Noun:
  • Each villus contains a network of blood capillaries and a lymphatic vessel called a lacteal.
  • The damage to the intestinal lining caused the villus to become flattened and ineffective.
• Plural Form (villi):
  • The inner wall of the small intestine is covered with millions of microscopic villi.
  • The villi greatly increase the surface area available for nutrient absorption.

Advanced Usage

• "Villus atrophy": A medical condition where the villi in the small intestine become damaged, flattened, or shortened, often leading to malabsorption (e.g., in celiac disease).
  • The biopsy confirmed severe villus atrophy, consistent with a diagnosis of celiac disease.
• "Chorionic villus": Refers to the villi that are part of the chorion (the outermost fetal membrane), which form part of the placenta and are involved in nutrient and gas exchange between mother and fetus.
  • Chorionic villus sampling (CVS) is a prenatal test that examines genetic material from these structures.

Variants and Related Words

• Villi (n., plural): The standard plural form of "villus".
• Villous (adj.): Having, covered with, or resembling villi. Describes a surface texture.
  • The villous surface of the mucosa is essential for efficient digestion.
• Microvillus (n.): An even smaller, microscopic cellular membrane projection found on the surface of villi and other cells, further increasing surface area.
  • Each epithelial cell on a villus has its own brush border made of thousands of microvilli.

Synonyms

• Projection: A general term for something that extends out from a surface.
• Process: In anatomy, a natural outgrowth or projection from a part of an organism.
• Papilla: A small, nipple-shaped projection, often used in different anatomical contexts (e.g., tongue, skin).

Notes on Meaning

• The primary and most common usage of "villus" is in human and animal anatomy, specifically related to the digestive system (intestinal villus).
• A secondary, specialized usage is in embryology and gynecology (chorionic villus), relating to pregnancy and fetal development.
• The term is almost exclusively used in scientific, medical, and biological contexts.

Noun

1. a minute hairlike projection on mucous membrane