5.1 Layers of the Skin

Integumentary System

Integumentary System

​Function:

• Protect the inside of the body from elements in the environment

  • ​Examples: bacteria, pollution, and UV

• Retain bodily fluids

• Eliminate waste products

• Regulate the body temperature​

​

Integumentary System

Integumentary System

​Structures:

• Skin

• ​Hair

• ​Nail

• ​Exocrine Glands

  • ​sudoriferous glands (sweat glands)

  • ​Sebaceous Glands

  • ​Ceruminous Glands

  • ​Mammary Gland

SKIN: Epidermis

• Most superficial layer of the skin

• Protects the deeper and thicker dermis layer of the skin

• ​about 4- to 50 rows of stacked squamous epithelial cells

• ​An avascular region (does not contain blood or blood vessels

SKIN:Epidermis

​Layers

• Stratum Corneum

• ​Stratum Lucidum

• ​Stratum Granulosum

• ​Stratum Spinosum

• ​Stratum Basale

SKIN:Epidermis

​Cell Types

• Keratinocytes: (90%) of epidermal cells contains keratin, protects and waterproofs the skin

• Melanocytes: (8%) produces melanin, skin color and absorbs UV light

• ​Langerhans: (1%) Participate in immune response

• ​Merkel Cells: (.5%) sensation of touch

SKIN:Dermis

​Layers (connective tissue)

• Papillary Layer

  • ​contain nerves and blood vessels

• ​Reticular Layer

  • ​tough collagen and stretchy elastin fibers running in all direction to provide strength and elasticity

  • ​contains blood vessels

SKIN:

Below the Dermis: HYPODERMIS

• Below the Dermis:

  • ​Loose connective tissues called hypodermis subcutis

  • ​Serves as the flexible connection between the skin and the underlying (muscles, bones, fat..)