Notes: The Integumentary System
Skin structure: Organs include: Hair, Skin, Nails and associated structures
I. Intro: know your skin diagrams & info: pages 5-7 of these notes
Skin color
I. Determined by combo of:
A.
B.
C.
II. Pigments
A. melanin - 3 types (black, brown, yellow)
1. melanocytes in stratum basale transfer pigment to keratinocytes
2. freckles & pigmented moles caused by: _______________________
3. Define: solar elastosis - ____________________________________
B. Carotene - yellow to orange
1. lipid soluble vitamin A precursor
2. accumulates in ___________________and ______________ cells
C. Hemoglobin
1. ______________________ color of oxygenated blood
2. more obviously detected in ____________ skin
II. Blood circulation
A. increase in flow - _________________________________________
B. decrease in flow - ________________________________________
IV. Diagnostics
A. skin color is often used as a first line diagnostic tool
B. Influenced by ______________ or _______________ states.
List color of skin AND possible causes for each of the following:
1. cyanosis
2. erythema
4. jaundice
5. bronzing
6. bruises (hematomas)
End of Worksheet #1 Material
Derivatives of skin
I. Hair Structure & Info
Split Ends
1
Hair shaft – above skin
Hair root – below skin
__________________________________
smooth muscle regulated by
cold/fright – contraction pulls hair
upright causing “goose bumps”
_________________________________
actively mitotic area in bulb – directly
surrounds papilla
_________________________________
capillary know in bulb for hair
nourishment
__________________________________
expanded deep end of follicule
a. Pigment
i. caused by proportions of 3 melanin types
ii. gray/white hair - melanin replaced by air bubbles in shaft
b. hair types
i. lanugo
ii. vellus
iii. terminal
c. hair growth
i. influenced by: (in this order)
1. nutrition - main influence
2. hormones
3. blood circulation
ii. cycles
1. growth phase: actively mitotic vs. resting phase: follicle atrophies
2. scalp - 4 year growth - eyebrows - 3 or 4 months growth
iii. baldness ( alopecia )
1. male pattern baldness - sex linked recessive genetic trait
2. minoxidil - know background, current use, & popularity
3. coarse repl. by vellus - progresses posteriorly
4. thinning – can be caused by medications, nutrition, stress, etc.
II. nails - know diagram
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III. Glands
Sebaceous (oil) glands
 waterproofing
 softens & lubricates skin and hair
 Open into ______________________
 bactericidal effect
 secretion stimulated by hormones
 List imbalance terms in ppt
sudoriferous (sweat) glands apocrine
glands
 duct opens into ________________
 axillary & anogenital region - begin to
function at puberty
 know sweat composition
ceruminous glands (not on diagram)
 modified apocrine gland
 external 1/3 of ear canal
sudoriferous (sweat) glands. eccrine
glands
 duct opens to __________________
 know sweat composition & pH
 regulated by sympathic NS to assist
in ______________________________
Integument functions
I. Protection
A. biological (cells)
macrophages(dermis) & Langerhan's cells (epidermis) engulf invaders
B. mechanical (physical)
1. continuity - special junctions (tight & desmosomes) form impermeable sheet
2. keratin - blocks diffusion of water & water soluble substances
C. chemical
1. skin secretions (acid mantle):
tears, sweats & oils lower pH and also contain lysozyme
2. melanin - pigment shield
II. Excretion - limited amounts of _________________ containing wastes and sodium chloride
III. Homeostasis of body temp.
A. Heat production - chief determinant - ________________________________
B. Heat loss/gain
1. 80% of heat transfer occurs through skin - rest through mucosa
2. regulated by regulating blood flow to skin (vasoconstriction/vasodilation)
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IV. Vitamin D production - imp. in _____________ uptake from stomach into blood
_________________ molecules - when exposed to UV light become inactive vitamin D
(precursor) - precursor is modified into active vitamin D in _________________
V. Sensation
End of Quiz #2 material
Skin cancer basic info
I. Incidence - ___________________________________ is main cause of all skin cancers
II. Risk factors
A. Clothing
B. Location
C. Skin type
D. types of UV
1. UV-A - falls evenly throughout day
a. resp. for aging, wrinkling, tanning, depletes collagen, burns
cornea
b. penetrates deeper - possible immune sys. damage
2. UV - B - falls during midday - resp. for burning – melanoma
III. Prevention
A. Wear sunscreen whenever outside or cover up
B. avoid midday sun between 10-2 and beware of reflected light
C. higher altitudes - every 1000 ft above sea level, radiation increases 4-5 %
D. Be cautious about tanning beds
E. Medications - tetracycline (antibiotics), Retin A, birth control, antidepressants,
diuretics, and anti-inflammatories cause photosensitivity
F. avoid sunburns
G. examine skin regularly - remember ABCD rule – have full body check
by dermatologist once a year
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