Mast cells

Definition

Mast cells are a type of white blood cell that play a crucial role in the immune system, particularly in allergic reactions and defense against pathogens. These cells are found in connective tissues throughout the body and contain granules filled with histamine and other chemicals that are released during an immune response. Their activation can lead to disruptions in the immune system, contributing to conditions like allergies and asthma.

5 Must Know Facts For Your Next Test

1. Mast cells originate from bone marrow but migrate to various tissues, including the skin, lungs, and digestive tract, where they reside long-term.
2. They are key players in type I hypersensitivity reactions, which include common allergies such as hay fever and food allergies.
3. Mast cells can be activated by various stimuli, including allergens, certain medications, and physical factors like temperature changes.
4. The release of histamine from mast cells causes symptoms like itching, swelling, and redness in allergic reactions.
5. Mast cell disorders can lead to conditions such as mastocytosis, where excessive numbers of mast cells accumulate in the body.

Review Questions

• How do mast cells contribute to the body's response during an allergic reaction?
  • Mast cells play a central role in allergic reactions by releasing histamine and other inflammatory mediators upon activation. When an allergen enters the body, it binds to antibodies on mast cells, triggering their degranulation. This release leads to increased blood flow and inflammation at the site of exposure, resulting in symptoms such as itching, swelling, and redness.
• Discuss the implications of mast cell activation in chronic inflammatory conditions.
  • Mast cell activation can have significant implications in chronic inflammatory conditions. In diseases like asthma or chronic urticaria, persistent mast cell activation leads to ongoing inflammation and tissue damage. The continued release of mediators from mast cells can exacerbate symptoms and contribute to the pathophysiology of these conditions, making management more challenging.
• Evaluate the potential therapeutic approaches targeting mast cells in allergy treatment and management.
  • Targeting mast cells presents several potential therapeutic approaches for allergy treatment. Medications such as antihistamines block the action of histamine released by mast cells, alleviating allergy symptoms. Other therapies might include mast cell stabilizers that prevent degranulation or newer biologic therapies designed to modulate mast cell activity. Evaluating these strategies could lead to more effective treatments for individuals with severe allergies or mast cell disorders.

Related terms

Histamine:

A chemical released by mast cells during an allergic reaction, causing inflammation and other symptoms associated with allergies.

Allergies: An abnormal immune response to typically harmless substances, which can be triggered by the release of substances from mast cells.

Anaphylaxis:

A severe, potentially life-threatening allergic reaction that can occur rapidly, often involving mast cell degranulation and massive histamine release.