Definition

Noun: A mast cell is a type of white blood cell found in connective tissues throughout the body. It contains granules filled with potent chemical substances, such as histamine, heparin, and serotonin. These substances are released when the cell is activated, typically during an allergic reaction, in response to injury, or as part of an inflammatory process.

Usage

The term mast cell is used specifically in biological, medical, and immunological contexts to describe this particular cell type and its functions. - It functions as a central player in the body's immune and inflammatory responses. - It is often discussed in relation to allergies, asthma, anaphylaxis, and other hypersensitivity disorders.

Examples

• In a biological explanation:
  • Mast cells are strategically located near blood vessels and nerves in the skin, lungs, and digestive tract.
• In a medical context:
  • The doctor explained that the hives were caused by the release of histamine from activated mast cells.
  • Research focuses on how to stabilize mast cells to prevent severe allergic reactions.

Advanced Usage

• Mast cell activation: Refers to the process by which a mast cell is triggered to release its granular contents. This can be initiated by allergens, physical injury, or certain drugs.
  • Mast cell activation syndrome (MCAS) is a condition where these cells are overly reactive and release mediators too frequently.
• Mast cell degranulation: The specific event where the granules inside the mast cell fuse with the cell membrane and release their contents into the surrounding tissue.
  • The rapid onset of symptoms in anaphylaxis is due to widespread mast cell degranulation.

Variants and Related Words

• Mastocyte: A less common synonym for mast cell.
• Basophil: A different type of white blood cell that also contains histamine and plays a role in allergic reactions, but it circulates in the blood rather than residing in tissues.
• Connective tissue: The type of tissue where mast cells are predominantly found.

Synonyms

• Mastocyte (technical synonym)
• Labrocyte (an obsolete term rarely used in modern contexts)

Related Phrases and Concepts

• Mast cell stabilizer: A type of medication (e.g., cromolyn sodium) that helps prevent mast cells from releasing their inflammatory substances.
  • She uses a mast cell stabilizer nasal spray to control her allergy symptoms.
• Mast cell mediator: Refers to any of the chemical substances (like histamine, leukotrienes) stored and released by mast cells.
  • The itching and swelling are caused by various mast cell mediators.

Noun

1. a large connective tissue cell that contains histamine and heparin and serotonin which are released in allergic reactions or in response to injury or inflammation