Ch. 6 Skin
I.
Integumentary System - Skin and its appendages
II.
A.
Hair, nails, and _____________ ________________
B.
Integument = "____________"
C.
Relatively flat organ; classified as a cutaneous
membrane
Structure of the Skin (Figs. 6-1, 6-2)
A.
Outer, thinner layer or strata - _________________
B.
Inner, thicker layer of vascular c.t. - ______________
C.
Beneath dermis lies loose subcutaneous layer; rich in
fat and ________________ tissue - _________________ (not considered
layer of skin)
D.
E.
Thin and thick skin- refers to the epidermal layer
1.
Thin - most covering body surface
2.
Thick - palms of hands, soles of feet
a.
All ______ layers of epidermis present
b.
raised dermal papillae(_____________ or _____________)
c.
no ______________
Epidermis
1.
Cell types
a. Keratinocytes - filled with tough, ______________
protein = ______________; 90% of ep. Cells
b. Melanocytes - synthesizes pigment melanin (color to
skin); protects deeper layers from ________________ light
c. Langerhan cells- (immune cells)
macrophage like; arise from bone
marrow; migrate to epidermis
2.
Cell layers (Fig. 6-1) - 5 strata (layers)
a.
Stratum __________________ (horny layer)
1) most ______________________ layer
2) Shingle like dead cell
3) cytoplasm replaced by ____________________
4) held together by desmosomes
5) Keratinization - process of cells
formed from deeper layers, filled
with keratin, and pushed to
surface
b.
Stratum lucidum (____________ layer)
1) _____________________ are anucleated and
clear
2) Cytoplasm filled w/Eleidin protein-bound lipid that will
eventually be turned into keratin
3) Blocks water penetration
4) Occurs only in thick skin
c.
Stratum ___________________ (granular
layer)
1) ____________________ begins here
2) 2-4 layers of flattened cells
3) cells filled w/ granules =
______________________
d.
Stratum spinosum (______________ layer)
1) ___________ layers of irregularly shaped
cells w/ prominent intercellular
desmosomes
2) AKA prickle cells
3) Cells rich with ___________ for Protein
synthesis- required for (keratin)
e.
Stratum _____________ (base layer)
1) Single layer of _______________ cells
2) mitosis only occurs here
3) cells originate here => migrate to
different layer => shed
f.
Stratum ______________________ (growth layer)
1) used to describe the stratum ________________
and stratum ________________ together
F.
G.
H.
Epidermal growth and repair (p. 163)
1.
____________________ time - time period required for
population of cells to mature & reproduce
2.
time for new cell formation = rate old keratinized cells
flake off
3.
cells push upward => into each layer => die =>
become keratinized => ___________________ (fall away)
4.
Regeneration time ~ 35 days
Dermal-epidermal junction (p. 164)
1.
Composed of ____________________ membrane
2.
Also contains specialized fibrous elements &
_______________________ gel that cement epidermis to
dermis
3.
partial barrier to the passage of some cells and large molecules
Dermis or _______________________
1.
thicker than _______________________
2.
protective function against ____________________
injury
3.
reservoir storage area for water &
________________________
4.
____________________ sensory receptors (nerves & nerve
endings)
5.
muscle fibers, hair follicles, sweat &
sebaceous glands & blood vessels
6.
the rich vascular supply of the dermis plays a critical role in
regulation of body temperature
7.
Two layers:
a.
_________________ layer (Fig. 6-1) -thin
1) Loose, areolar CT with fibers
2) dermal papillae - bumps that project
into epidermis
3) creates distinct ridges on epidermis
finger and toes (fingerprints)
4) ___________ surfaces
b.
Reticular layer (Fig. 6-1) -thick
1) dense irregular c.t.
2. network of fibers - _________________ &
elastic (when commercially processed = leather)
3) contains muscle - __________________ &
smooth(allows for a point of attachment for mm)
4) __________________ - scalp movement &
facial expressions
5) _________________ __________ muscles small bundle of smooth muscle that causes hair to
"stand on end"- which causes the skin around it to
raise = “goose bumps”
6) somatic sensory receptors for pain,
_________________, touch, and ____________
I.
Blisters (Box 6-3)
1.
injury of epidermal cells or separation of
dermal-epidermal jxn
2.
damages __________________ - skin fall apart/away
from body
3.
causes of blisters- burns, friction, exposure to primary
irritants
III.
Skin Color (p. 168)
A.
Pigments
1.
Melanin (Fig. 6-5)- brown pigment
a. quantity determines skin ________
b. melanocytes convert a.a. _____________
melanin w/ help from enzyme
___________________
c. melanocytes mostly found in stratum _____________
d. amt of melanin produced depends upon
__________________, sun exposure, age, and
hormones
e. ________________ - enzyme tryrosinase is absent
from birth; can not make melanin
2.
_______________ - yellow pigment
a. stratum corneum mostly
b. palms and soles
3.
Change in ____________ volume through the skin’s
_______________ causes a temporary change in skin color
a. skin blood vessels constrict => ____________
b. skin blood vessels dilate => ______________
c. ___________________ - when an excess of poorly
oxygenated blood exists; skin appears bluish
IV.
Functions of the Skin (Table 6-1)
A.
Protection (p. 170)
1.
barrier against _________________,
harmful chemicals and mechanical _____________ to
tissues
2.
prevents _________________
3.
________________ protects from harmful UV light
4.
_______________ - flexible; waterproofing proteins
5.
Surface film - ep.cells + secretions from sebaceous & sweat
glands => functions=> ______________ and antifungal
activity, lubrication, hydration of the skins surface
B.
Sensation (Fig. 6-3; Chapter 15)
1.
_______________ ________________ serve as antennas that
detect stimuli, ex. Pressure, ___________, temperature,
__________ and vibration
C.
Movement and growth without injury d/t elastic fibers
D.
Excretion
1
regulates total fluid __________________ and ______________
products
2.
waste products include uric acid, ammonia, ___________
E.
Vitamin D production (endocrine function)
F.
Immunity - specialized cells are present in skin
Ex. _______________ cells with help of helper _____ cells
G.
Homeostasis of body temperature
1.
Heat production - ________________ of food and
________________ activity & glands (especially the liver)
2.
To prevent heat loss, dermal blood vessels
_________________ => more warm blood circulating
deeper in body
3.
To increase heat loss, dermal blood vessels
___________________ => inc. skin supply of warm blood
=> lost to external environment by physical process
evaporation, radiation, conduction, and convection
4.
Homeostatic regulation of heat loss Fig. 6-7
a. _______________ _____________ loop - affects sweat
glands and blood vessels to return
temperature back to set point 37 degrees C
b. __________________ is control center
V.
Burns (p. 174)
A. Tissue damage (Proteins denature) and cell death caused by heat, _________,
UV radiation, or _____________
B.
Estimating body surface area (Figs. 6-8, 6-9)
1. "Rule of _____________" - palm size = _____% if body surface
2. "Rule of _____________"
C.
body surface divided into _______ areas of 9%
b.
area around genitals 1% - perineum
Severity of burns
1.
2.
3.
VI.
a.
_____________ degree burns - typical ______________
a.
only epidermis is damaged
b.
skin is red and swollen, no blistering
Second degree burns
a.
Epidermis and ____________ are damaged
b.
damage to _____________ glands, ___________ follicles,
and sebaceous glands
c.
__________________, severe pain, _______________ and
scarring common
Third degree burns (______________ thickness burns)
a.
destruction of __________________ and dermis
b.
tissue death extends below ___________ glands and
_____________ follicles
c.
burning may involve fascia, ______________, and
____________
d.
Insensitive to pain immediately after due to
destruction of ________________ endings
Appendages of the Skin (p. 176)
A.
Hair (Figs. 6-10, 6-11)
B.
Nails (Figs. 6-12, 6-13) - heavy _______________ epidermal cells
C.
Skin glands (Fig. 6-14)
1.
Sweat glands (_______________)- most common
2.
Sebaceous glands (Box 6-10)- oil for hair &
skin
3.
VII.
________________ glands
Mechanisms of Disease: Skin Disorders (p. 181)
A.
Dermatosis - "skin condition"
1.
Skin infections (viruses, bacteria, & fungi)
a.
Impetigo - bacteria (___________________)
infection in young children; reddish
discoloration that develops into
vesicles (blisters) and ________________ crusts
b.
Tinea (Fig. 6-15) -______________ infection;
Ringworm, jock itch, and _____________ _______
1) s/sx - erythema (________________), scaling, &
crusting
c.
Warts – ________________ viruses
1) usually _____________, can become malignant
2) transmitted by _____________ contact
3) Tx - ________________, drying, laser therapy
d.
Boils (furuncles) - local ____________________
1) infection of hair follicles
2) Lg, inflamed pus-filled lesions
2.
Vascular and inflammatory skin disorders
a.
Decubitus ulcers (_________________) (Fig. 6-16)
1) lesion caused by ______________ blood flow to
skin area
2) ulcer forms
3) Tx -frequent changing positions
and soft surfaces
b.
Urticaria (_______________)- raised red lesions =
-wheals
1) causes - leakage of fluid from __________
blood vessels
2) severe _____________
3) _______________ rxn, physical irritant, &
systemic disease
c.
Scleroderma - autoimmune dz
affecting ________________ vessels and c.t of skin
1) patches of _________________, hardened skin
d.
Psoriasis (Fig. 6-17) - _________________
inflammatory dz
1) ________________ basis
2) cutaneous inflammation, followed
by ____________________ lesions
e.
Eczema – most common _________________
disorder of skin
1) inflammation, ______________, blisters, &
crusts
2) usu. s/sx of underlying cond'n
3) allergic rxn or poison ivy
B.
VIII.
Abnormal body temperature (Fig. 6-18)
1.
Fever
2.
Malignant hyperthermia (MH)
3.
_______________ exhaustion
4.
Heat stroke
5.
_________________
6.
Frostbite
Skin Cancer (Box 6-4)
A.
m/c form of CA in humans
B.
Basal cell carcinoma
C.
1.
most common type of _______________ cancer
2.
arises from stratum basale
3.
nose and ________________
4.
patient usually > _____________ years old
5.
least _____________________ and rarely metastasize
___________________ cell carcinoma
1.
slow growing and arises from st. __________________
2.
middle-aged and ________________
3.
sun-exposed areas (_______________, forehead, backs of
hands
4.
D.
some forms may metastasize
Malignant ____________________
1.
Most ________________ of all skin CA
2.
older individuals (~53 y/o), light skin, eyes, and
hair
3.
may develop from pigmented mole (_________________)
4.
Use ABCD rule for detection
a.
____________________
1) benign moles symmetrical
2) malignant moles ___________________
b.
Border
1) B9 - distinct border
2) malignant - border irregular/indistinct
c.
________________
1) B9 - even color of brown
2) malignant - unevenly ______________, mixture of
shades
d.
Diameter
1) malignant usually larger than ______ mm