Integumentary System Dermis

2 layers of skin Epidermis – Surface layer of skin

2 layers of skin Dermis – Underlying layer of skin

Skin Layers Strength of skin in Dermis –Collagen fibers Greek for ‘glue producing’ –Elastic fibers

Skin Layers Storage area for water

Dermis Layers 2 Layers – –Papillary –Reticular

Dermis – 2 Layers 1. Papillary layer  Thinner layer

Dermis – 2 Layers 1. Papillary layer  Has Dermal papillae – finger-like projections into epidermis

Dermal Papillae 1. Papillary layer  Papillae ridges– result in fingerprints  Responsible for grip

Dermal Papillae Dermal papillae

Dermal Papillae

Dermal Layer 2. Reticular layer  Network of fibers or reticulum  Thicker layer  Used for leather

Dermal Layer

 Muscles attach  Result: Facial expression

Dermal Layer  Arrector pili muscle Attach to hair follicle

Dermal Layer  During fright – hair stands up  Called “skin crawl”

Dermal Layer

 Dermal layer doesn’t shed

Dermal Layer  Contains sensory receptors Pain Pressure (touch) Heat

Dermal Layer  Contains appendages Hair Nail Sweat Sebaceous gland (oil)