1. Chapter 4 – Skin and Body Membranes
Anatomy
Chapter 4 – Skin and Body Membranes

2. Introduction – Integumentary System
Body membranes cover the surface, line body cavities, form protective sheets around organs
Two major groups:
Epithelial membranes – cutaneous (skin or integumentary system), mucous, and serous membranes
Connective tissue membranes – synovial membranes

3. Classification of Body Membranes
Epithelial membranes – covering or lining membranes
Skin
Mucosa

4. Serous membranes line ventral body cavities closed to interior; occur in pairs

5. Connective tissue membranes
Synovial membranes
No epithelial cells
Bursae – lubricating sacs that reduce movement – related friction
Tendon sheath – tube-like covering over a tendon
Both cushion organs moving against each other during muscle activity

6. Integumentary System (skin) – Cutaneous membrane
Structure of the skin:
Stratum basale (stratum germinativum)
Stratum spinosum
Stratum granulosum
Stratum lucidum
Stratum corneum
Melanin - pigment

7. Skin structure
Dermis – underlying layer
Hypodermis – adipose

8. Skin color Pigments - three contribute to color
Melanin – in epidermis; yellow, reddish brown, black
Carotene – in stratum corneum and subcutaneous tissue ; orange-yellow
Hemoglobin – dermal blood vessels; pigment in red blood cells
Influenced by emotional stimuli
Redness or erythema
Pallor or blanching
Jaundice or yellow cast
Bruises
Cyanosis

9. Appendages of the skin Sebaceous Sudoriferous Eccrine apocrine
Cutaneous glands - exocrine glands that release secretions onto skin surface via
ducts
Sebaceous
Sudoriferous
Eccrine
apocrine

10. Hair and Hair Follicles – scattered all over body; protection
Shaft
Matrix
arrector pili
Electron micrograph of hair shaft emerging from a follicle on the skin

11. Nails – scale-like modification of dermis; hoof or claw

12. Infections and allergies
Homeostatic imbalances of the skin
Infections and allergies
Boils and carbuncles
Athlete’s Foot
Cold Sore
Impetigo
Psoriasis

13. Decubitus ulcers – restriction of normal blood supply to skin resulting in cell death
Bed sores occur in bedridden patients not turned regularly or are dragged across the bed repeatedly
Deep (stage III) ulcer

14. Burns
Burns - tissue damage and cell death; intense heat, electricity, UV radiation, chemicals.
Rules of Nines - 11 body areas account for approximately 9% of body surface area; 1% genital area
Infection is most important threat and is leading cause of death in burn victims; skin is sterile for 24 hours after a burn
Critical burns
25% of body has 2nd degree burns
10% of body has 3rd degree burns
3rd degree burns on face, hands, or
feet

15. First Degree Burn - only epidermis is damaged
Sunburn:
Red
Swollen
Heal in 3 days

16. Second Degree Burn - injury to epidermis and upper region of dermis; red and painful; blisters appear; regrowth can occur; no permanent scars
2nd degree burns on the hand
2nd degree burns on the leg

17. Third Degree Burns - destroy entire thickness of skin; area blanched or blackened; nerve endings destroyed; regeneration not possible
Third degree burn on the neck

18. Squamous Cell Carcinoma
Skin Cancer - neoplasm in the skin; single most common type of cancer in humans; 1 in 5 Americans develop cancer
American Cancer Society ABCD Rule:
Asymmetry
Border
Color
Diameter
Basal Cell Carcinoma
Squamous Cell Carcinoma
Melanoma
A typical mole developing into cancer.

19. Developmental Aspects of skin and Body Membranes
Lanugo - downy type of hair on fetus; shed by birth; premature babies may still have it.
Vernix caseosa - white, cheesy-looking substance produced by sebaceous glands; protects babies skin while floating in amniotic fluid.