Why Are Some Tissues Damaged by Diphtheria Toxin While Others

question 78

Multiple Choice

Why are some tissues damaged by diphtheria toxin while others are unaffected by it?

• A) Diphtheria toxin is a superantigen. Only TH cells are affected by this type of toxin, so tissues lacking TH cells are unaffected.
• B) The causative agent is inhaled into the lungs, so only lung tissue is affected by the toxin released by the organism.
• C) Diphtheria toxin is an A-B toxin. Cells that do not have a receptor for the toxin are unaffected by it.
• D) The causative agent is ingested, so only gastrointestinal tissue is affected by the toxin released by the organism.
• E) Diphtheria is a localized infection. Only tissues in the immediate area of the bacteria are affected by the toxin.

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Definitions:

Teratogen

From the Greek word tera, meaning “monster,” this term refers to any agent that causes a birth defect. Teratology is the field of study that investigates the causes of birth defects.

Prescription Drug

Medications that are legally dispensed only by a prescription from a licensed healthcare provider.

Some Depressants

Substances that decrease or slow down central nervous system activities, affecting mental and physical functions.

Teratology

The study of abnormalities of physiological development, focusing on the causes and biological processes behind birth defects.