CHAPTER 5 - INTEGUMENTARY SYSTEM
I. SKIN & ITS DERIVATIVES
A. HAIR, NAILS & GLANDS
B. LARGEST ORGAN SYSTEM
C. FUNCTION: "PAST DR."
1. PROTECTION
a. PHYSICAL
b. CHEMICAL
c. BIOLOGICAL
d. UV LIGHT
2. ANTIDESICCANT
3. SENSATION - pain, pressure, temperature, position
4. THERMOREGULATION - Temp. control
a. EXCRETION - SWEAT & OILS
b. FAT STORAGE
5. VITAMIN D PRODUCTION - Ca2+ & P uptake & regulation
6. REPRODUCTION
a. MAMMARY GLANDS
b. PHEROMONES - sex attractants
c. BOYFRIEND/HUSBAND TOUCHES, wants more . . . X X X !
II. 2 PORTIONS = CUTANEOUS MEMBRANE/LAYER (Fig 5.1, p. 150)
A. EPIDERMIS - STRATIFIED, KERATINIZED, SQUAMOUS EPITH. (p. 152)
1. STRATUM CORNEUM - KERATINIZED
2. " LUCIDUM
3. " GRANULOSUM
4. " SPINOSUM
5. " BASALE S. GERMINATIVUM = SPIN. + BAS.
40-60 days from S. Basale to S. Corneum (p. 150)
B. DERMIS - DENSE, IRREGULAR C.T. w/ ADIPOSE, NERVES & BLOOD
1. PAPILLARY - closest to epidermis
2. RETICULAR – deeper
3. STRETCH MARKS - Striae
C. HYPODERMIS – SUBCUTANEOUS, SUPERFICIAL FASCIA (p. 150)
1. NOT part of skin
2. LOOSE, IRREGULAR C.T. w/ ADIPOSE
D. CLEAVAGE/TENSION LINES (p. 156) – parallel to collagen fiber orientation
III. SKIN TYPES - refers to EPIDERMIS STRUCTURE ONLY
A. THICK - ALL 5 STRATA
1. NO HAIR
2. PALMS, SOLES OF FEET
3. FINGERPRINTS - é grip
B. THIN - S. LUCIDUM ABSENT
1. HAIR PRESENT
2. EVERYWHERE ELSE !
C. TOTAL THICKNESS = EPIDERMIS + DERMIS, BACK is thickest
IV. SKIN COLOR
A. MELANIN (p. 156)
1. MELANOCYTES produce
2. MELANOSOMES store
3. RACES have same # MELANOCYTES, PRODUCTION varies
4. TAN = RESPONSE TO é UV
5. STRATUM BASALE
6. PREGNANCY é melanin @ aerolae & nipples
B. CAROTENE - from plants, imparts yellowish/orange tint to skin
C. BLOOD 1. REDDISH/PINKISH tint - VASODILATION
2. PALE - SHOCK - VASOCONSTRICTION
3. BLUE - CYANOSIS - ê in blood O2
V. ACCESSORY SKIN STRUCTURES (Fig. 5.6, p. 158)
A. HAIR - vascularized
1. EPITHELIAL DERIVATIVE
2. STRUCTURE
a. SHAFT- above skin
- species specific
b. ROOT - beneath surface
c. BULB - base of root, growth
d. FOLLICLE - surrounds root & bulb
i. DERMAL SHEATH
ii. EPITHELIAL SHEATHS
3. GROWTH - scalp
a. 90% GROWING
b. 10% RESTING
B. MUSCLE - ARRECTOR PILI
1. "GOOSE" flesh
2. RESPONSE TO COLD/FEAR
C. GLANDS - EPITHELIAL DERIVATIVES, NON-VASCULAR (p. 162)
1. SEBACEOUS
a. ACINAR - shape & HOLOCRINE - cells + oil
b. SEBUM - oil to lubricate hair
c. Opens to HAIR FOLLICLE, not skin
2. SWEAT-SUDORIFEROUS
a. MEROCRINE - open to skin
- most common
- H2O, salts, NH3, urea
b. APOCRINE - open to follicles, axillae, genitalia
- organic acids & fats
- B.O.=bacteria in glands, not secretions
3. CERUMINOUS - CERUMEN = ear wax
4. MAMMARY - milk
D. NAILS - non-vascularized (Fig. 5.8, p. 162)
1. BODY - exposed, S. corneum, hard keratin
a. EPONYCHIUM - cuticle, "quick"
b. HYPONYCHIUM - under free edge
2. ROOT - covered
a. S. germinativum = MATRIX
b. LUNULA = white crescent - thick MATRIX
c. Irregular nail deposition = disease indicator