Human Anatomy and Physiology Chapter 18: Skin Structure and Functions

Skin Composition

• The epidermis is composed of stratified squamous epithelial cells.

Dermis

• The dermis contains projections called dermal papillae.

Subcutaneous Tissue

• The main function of the subcutaneous tissue is to attach the skin to underlying muscles and bones.

Epidermal Derivatives

• Epidermal derivatives include hair, nails, and sweat glands.

Integument

• The integument is also known as the skin.

Skin in Adults

• The skin typically accounts for around 15% of total body weight in adults.

Protective Function

• The skin protects the body by providing a barrier against external damage, such as ultraviolet radiation and physical injury.

UV Protection

• Melanin protects cell nuclei from ultraviolet radiation.

Sensory Function

• One of the sensory functions of the skin is to detect changes in temperature.

Metabolic Function

• One example of a metabolic function of the skin is the synthesis of vitamin D when exposed to sunlight.

Attraction

• The skin serves as a visual indicator of health, which plays a role in attraction between sexes.

Thick Skin Patterns

• Unique patterns, such as fingerprints, are formed by distinctive ridges and grooves in thick skin.

Elasticity

• The subcutaneous layer of the skin allows for rapid expansion to cover swollen areas.

Dermal Papillae

• Dermal papillae increase the surface area of the dermis, allowing for more efficient exchange of oxygen and nutrients.

Sensory Receptors

• The main role of sensory receptors in the skin is to detect various sensations, such as pressure, temperature, and pain.

Subcutaneous Layer

• A key function of the subcutaneous layer of the skin is to store energy in the form of fat.