Anatomy & Physiology

Integumentary System

Integumentary System

• Largest system in the body• Largest organ in the body

• System includes skin, glands, blood vessels, nerves, hair, & nails

Layers of the Skin

1. Epidermis – outermost layer2. Dermis – Contains blood vessels, nerves, glands, & hair

follicles– Covered with papillae (forms ridges & lines)

3. Hypodermis – Innermost layer; contains fatty tissue &

connective tissue;

Layers of the Skin

Glands in the Skin

• Sebaceous glands– Attached to hair follicles– Keeps skin & hair from becoming dry / brittle– If blocked with dirt/oil = pimple

• Sweat glands– Coiled tubes extending through the dermis (not

attached to hair follicles)– Sweat contains water, salts, sm amt of uric acid

Glands in the Skin

Additional Components

• Nails– Protect fingers & toes– Made of dead epidermal epithelial cells (has a

root)• Hair– Consists of root and hair shaft– Protects & covers body surface– Alopecia = permanent hair loss on the scalp

Additional Components

• Hair erector muscle– Muscle connected to each hair follicle– Contracts in response to cold, fear, etc.

(“Goosebumps”)

• Blood vessels – Carry blood & brings oxygen to cells

Additional Components

• Pacinian corpuscle– Nerve receptors; respond to pressure, pain,

vibration, temp.– Located in the hypodermis

• Melanocyte– Cell producing melanin (dark colored pigment that

protects skin from UV rays)

• Melanocyte• Oil gland• Sweat gland• Pacinian corpuscle• Hair erector muscle• Hair follicle• Hair shaft• Blood vessel (artery & vein)• Layers (Epidermis, Dermis, Hypodermis)