Anatomy & Physiology Integumentary #3

Question

Which integumentary system structure is the first line of defense against microorganisms that are outside of the body in the external environment?

Answers

  1. Skin
    • Rationale:

      The skin is a barrier that serves as one of the body’s first lines of defense against harmful microorganisms. Specialized immune cells within skin tissue help to fight invading organisms.

  2. Hair
    • Rationale:

      Hair provides protection against mechanical trauma in addition to providing warmth. It is not the integumentary system’s first line of defense against microorganisms.

  3. Nails
    • Rationale:

      Nails protect the tips of the fingers and the toes from mechanical trauma. They are not the integumentary system’s first line of defense against microorganisms.

  4. Glands
    • Rationale:

      The sebaceous glands of the integumentary system lubricate and moisturize the skin while the sweat glands play a role in thermoregulation and excretion of bodily wastes. These structures are not the integumentary system’s first line of defense against microorganisms.

Overview

The skin is the body’s first line of defense against the threats in the environment that are external to the body.

Explanation

Learning Outcomes

The integumentary system protects the body for the external environment. The skin provides specific protections to the body. The skin helps protect the body from the following:
Dehydration
Mechanical trauma
Microorganisms
Ultraviolet (UV) radiation.

Test Taking Tip

Consider each answer option and ask yourself, “Does this integumentary structure provide the first line of defense against microorganism?” While all protect the body, only one protects specifically against pathogens.

Video Rationale