Integumentary System

• Made up of skin and hair, nails, sebaceous glands, and sweat glands

• AKA cutaneous membrane

Functions of the Skin

• Covers underlying tissues. Protects them from dehydration, injury, and infection.

• Helps regulate body temperature (controls size of blood vessels in dermal layer of skin)

• Makes vitamin D

• Protects body from UV radiation from the sun

Structure of the Skin

• Epidermis: outermost covering. made of epithelial cells. contains no blood vessels.

  • thickness varies (thinner on eyelids, thicker on palms/soles of hands/feet

  • surface layer (stratum corneum) has dead skin cells rich in keratin (protein that makes skin dry and provides waterproof covering)

• Dermis: made of connective tissue and is vascular.

  • thicker inner layer of skin directly below epidermis (thickness also varies here — thinner on shoulders/abdomen, thicker on palms/soles)

  • made of dense connective tissues

  • contains nerve receptors

Appendages of the skin: hair, nails, sweat glands, oil glands