Immunoglobulin A

Definition

Immunoglobulin A (IgA) is an antibody that plays a crucial role in the immune function of mucous membranes. It is found in high concentrations in areas such as the respiratory and gastrointestinal tracts.

5 Must Know Facts For Your Next Test

1. IgA helps protect mucosal surfaces by neutralizing pathogens and toxins.
2. It is the most abundant immunoglobulin in secretions like saliva, tears, and mucus.
3. Nutritional status can influence IgA levels, particularly deficiencies in vitamins A and D.
4. Inadequate IgA levels can increase susceptibility to respiratory infections.
5. Breast milk contains significant amounts of IgA, providing passive immunity to infants.

Review Questions

• What role does IgA play in protecting mucosal surfaces?
• How can nutritional status affect IgA levels?
• Why is IgA important for infants, particularly those who are breastfed?

Related terms

Mucosal Immunity: The immune response that protects the body's mucous membranes from infection.

Passive Immunity: The transfer of active humoral immunity in the form of ready-made antibodies from one individual to another.

Vitamins A and D: Essential nutrients that support various bodily functions including immune response modulation.