Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
An allergy is an exaggerated or hypersensitive response of the immune system to certain substances in the environment that are normally harmless to most people.
The substances that trigger an allergic reaction are called allergens. Examples include pollen, dust mites, mold spores, and certain proteins in food like or .
When an allergen enters the body, the immune system produces a specific class of antibodies known as (Immunoglobulin E).
These antibodies bind to specialized cells called mast cells. Upon subsequent exposure to the allergen, these cells release a chemical called histamine (), which causes symptoms like inflammation, sneezing, and itching.
Entry routes for allergens include Inhalation (e.g., ), Ingestion (e.g., ), Injection (e.g., ), and Contact (e.g., or ).
A severe, life-threatening allergic reaction is known as anaphylaxis, which requires immediate medical attention.
📐Formulae
💡Examples
Problem 1:
During the spring season, a student experiences continuous sneezing, watery eyes, and a runny nose. Identify the likely allergen and the biological mediator causing these symptoms.
Solution:
The likely allergen is , and the biological mediator is .
Explanation:
In spring, flowering plants release grains into the air. When inhaled by a sensitive individual, the immune system identifies them as threats and releases from mast cells, leading to the symptoms of hay fever.
Problem 2:
Explain why a person might react to a bee sting with sudden swelling and redness using scientific terminology.
Solution:
The reaction is caused by acting as an allergen, triggering antibodies and release.
Explanation:
Bee venom is injected into the skin. The body’s immune system produces specific to the venom proteins. This triggers a localized inflammatory response where increases the permeability of blood vessels, causing and at the site of the .