Anatomy and Physiology 1 The Integumentary System chapter 6.docx

Anatomy and Physiology 1
Chapter 6: The Integumentary System
October 4 2018
The integumentary system
 Skin- cutaneous membrane
o Accessory organs: hair, nails, sweat and oil glands
 Skin structure
o 2 primary layers
 *Epidermis
 *Dermis
 Hypodermis
 Hypodermis:
o Areolar and adipose
o Anchors skin in place
o Allows skin to move
o Fatty composition
 Shock absorber
 Insulator
 Dermis:
o Deep layer of skin
o Strong but flexible
o Loose and dense irregular connective tissue
 Mostly collagen
 Some elastic fibers
 Some reticular fibers
o Contains blood vessels
o Contains nerves
o Reticular layer
 Dense irregular CT
o Dermis: 2 layer structure
o Papillary layer
 Superficial layer of dermis
 Areolar tissue, many blood vessels
 Upper surface has projections called Dermal
Papillae
 Temp regulation
 Contain free nerve endings and touch
receptors
 Push epidermis into epidermal ridges =
fingertips

 Ridges also help us hold objects - prevent
slipping
o Epidermis
 composed of keratinized stratified squamous
epithelium
 not all cells keratinized but do contain
keratin
 thick skin- 5 layers
 palms and feet
 thin skin- 4 layers
 avascular
Cells of epidermis
 stem cells
o undifferentiated cells