1. Skin and the Integumentary System Chapter 6
Objectives:
Identify anatomical structures and functions of the integumentary system.
Identify accessory organs of the integumentary system.
Recognize diseases and disorders of the integumentary system.

2. Integumentary System Def.: the skin and its accessory organs
Skin is called the cutaneous membrane.
Other membranes and their locations:
Serous membranes – line cavities not open to the outside of the body
Mucous membranes - ?
Synovial membranes – form the inner linings of synovial joints (between freely movable bones)
Mucous membranes line cavities and tubes that open to the outside of the body 2

3. 2 Distinct Layers of the Skin
Epidermis = ?
Dermis = ?
Separated by an undulating (???) basement membrane (???).
Epidermis is made of stratified squamous epithelium (???).
Dermis is thicker and contains collagenous (???) and elastic (???) fibers, epithelial tissue, smooth muscle tissue, nervous tissue, and blood(???).
Subcutaneous layer (“hypodermis”) = ?; made up of loose connective and adipose tissue.
Epidermis = upon skin (outer layer of the skin)
“undulating” = moving in a wave-like pattern
Basement membranes anchor epithelial tissue to underlying connective tissue.
Label 1-3 of Diagram A 3

4. A. Epidermis Characteristics
Cells
Keratinocytes - outer cells fill with a tough, fibrous, waterproof keratin protein
Melanocytes – produce melanin, providing dark pigmentation
Layers (details on next slide)
Growth (details on following slides)
What purpose would keratinization serve for the epidermis? 4

5. 2. Layers (top to bottom):
Stratum corneum
25-30 layers of flat, dead, keratinocytes
Continuously shed and replaced
Stratum lucidum
3-5 layers of flat, dead keratinocytes
Only present in thick skin of palms and soles
Stratum granulosum
3-5 layers of flattened, dying keratinocytes
Dividing line between living and dead layers
Stratum spinosum
8-10 layers of keratinocytes
Some can still undergo cell division
Cells are tightly joined together
Provides skin with strength and flexibility
Stratum basale
Stratum germinatum – where new cells are produced
Single row of cuboidal or columnar keratinocytes
Basement membrane
Add these layers to Diagram A (4-6). 5

6. Growth process New cells form in the stratum _______________.
Cells keratinize and die as they are push toward the surface.
They eventually slough off at the surface.
Total process ≅ 4 weeks
germinatum 6

7. B. Dermis Contains: Collagen fibers (70%) – strength
Elastic fibers – elasticity
Capillaries
Tactile (touch) receptors
Hair follicles
Nerve cell processes
Sebaceous glands
Sweat glands 7

8. B. Dermis
Epidermal ridges project into the dermis + dermal papillae (conical projections of the dermis) passing into the spaces between the ridges cause the boundary between dermis and epidermis to be uneven (undulating).
This undulation continues all the way to the outer layer, forming valleys and ridges known as fingerprints.
Draw this on the board for students.
Add labeling to Drawing A.
Fingerprinting activity 8

9. Skin Color 3 Pigments: Melanin – dark Carotene – yellow-orange
Hemoglobin –
red (bright red) if well oxygenated
Blue (dark red) if not
What dark marks on the skin are caused by an accumulation of melanin?
Discuss vitamin A problems, albinism, cyanosis, jaundice, erythema 9