1. The Integumentary System Chapter 6

2. Membranes All derived from epithelial or connective tissue
Epithelial membranes
Line exposed cavities
Line organs
Secrete serous fluid
lubricate

3. Mucous Membranes Line cavities and tubes exposed to outside
Secrete mucus
Line respiratory, digestive, urinary and reproductive tracts

4. Serous Membranes Line joint cavities and covers organs
Secrete serous fluid (synovial fluid in joint cavities)

5. Cutaneous Membranes
Covers body surfaces exposed to external environment
Dry membrane
Skin

6. Protects from water loss, foreign invasion Maintains body temp.
Integumentary System
Function
Protects from water loss, foreign invasion
Maintains body temp.
Excretes water, salt, nitrogenous wastes

7. Sensory organ
Produces vitamin D
Limited absorption
regenerative

8. Structure – 2 major layers; Epidermis & Dermis
Epidermis – 5 layers named for their appearance; produce melanin and carotene to give skin color
Stratum corneum – top layer; as cells die they become keratinized (“cornified”); scalelike with no nucleus

9. Stratum lucidum – several rows of clear flat cells; found only on skin of palms and soles
Stratum granulosum – 3 – 5 layers of flattened cells; transition layer

12. Stratum spinosum – 8-10 layers of polyhedral cells
Stratum basale (germinativum) – single layer of cuboidal or columnar cells that are constantly dividing; accelerated by friction or pressure

16. Dermis – below epidermis; thicker
Has many upward projections (dermal papillae)
Binds epidermis to underlying tissue
Composed of collagen and elastic fibers in a gooey matrix

17. Provides strength and elasticity
Vascular; bed sores are a problem here. Innervated (sensory and motor – for arrector pili muscles)
Divided into regions
Papillary – upper
Reticular lower

18. Reticular layer contains accessory organs:
Hair follicles
Sebaceous glands
Arrector pili muscles
Sudoriferous glands

19. Blood vessels
Nerves
Attaches dermis to bone & muscle by way of subcutanous layer (adipose tissue)

20. Hair
Formed by epidermal cells at base of follicle; growth due to division of cells in base of follicle = root
As cells die; they keratinize

21. Glands A) Merocrine – fluid B) Apocrine – pts of cells & fluid
C) Holocrine – whole cell rlsd & disintegrates

22. Sebaceous glands
Sebum – produced in cytoplasm of cell and is discharged when cell dies (holocrine gland)
Secreted into hair follicles; helps keep hair and skin soft and pliable.

23. Sudoriferous glands
Armpits/hair; triggered by stress (apocrine glands)
Forehead, neck, back; triggered by temp. (merocrine glands)

24. Nails
Produced by epithelial cells at root
Nail bed
Lanula – highly mitotic
Keratinization – harder than other keratin

25. Skin Pathology
Burns –
evaluated by degree; each degree is deeper into the skin
Danger of burns is infection and dehydration
Rule of nines – body is broken into 9 sections; % of burned area is determined by how many of these parts are affected.

27. 1o burn
Erythema of the skin
Top layers of epidermis affected

28. 2o burn
Erythema and blistering
Epidermis and dermis affected

29. 3o burn – most serious
Charred, or white appearance
Epidermis, dermis and subcutaneous tissue burned
Skin grafts needed
Critical
Pain is minimal after burn until nerves begin to regenerate
Hair usually does not grow back

31. Skin Colorations Albinism Vitiligo Freckles Mongolian spots Cyanosis
Jaundice
Hemangioma
Erythema
nevi

39. Skin Eruptions (contact dermatitis)
Urticaria - hives
Insect bites
blisters

40. Lesions
Viral – cold sores, “pox”, genital warts
Bacterial – chankers, Impetigo, boils, carbuncles
Fungal – moniliasis, Tinea pedis, ringworm
Ulcerative - bedsores

42. Growths
Warts - viral
Corns – pressure on skin of feet
Callus – pressure on skin

43. Sebacceous Glands
Whiteheads
Acne
Seborrhea
Blackheads
Psoriasis
eczema

44. Seborrhea
Eczema
Psoriasis

45. Alopecia – nongenetic hair loss
Wrinkles – loss of collagen and elastic fibers
Scarring – growth of connective tissue above epithelial tissue; genetically determined

46. Stretch marks – growth of connective tissue due to rapid stretching of skin; genetically determined