Human Anatomy & Physiology
Chapter 4-SKIN & BODY MEMBRANES notes
_________________________cover surfaces,line body
cavities and forms protective-sometimes lubricating –sheets
around organs
I.
Classification of Body Membranes
A. EPITHELIAL MEMBRANES
Covering and lining membranes
All have an underlying sheet of connective tissue
1. Cutaneous Membranes= skin
 Superficial epidermis
is____________________________________
 Underlying dermis is dense(fibrous)
connective tissue.The superficial tissue is
exposed to air and is a
________________________________
2. Mucous Membranes-made of varying types of epithelial tissue
resting on a loose connective tissue called
_______________________________ and lines all membranes
that open to the exterior(hallow organs of respiratory
tract,digestive,urinary and reproductive…
 Mucosa refers to location,not cellular
makeup….But most mucosa are stratified
squamous (mouth and esophagus) epithelium
or simple columnar (rest of digestive tract)---all wet and bathed in secretions)
3. Serous membranes(serosa) Has a layer of simple squamous epithelium on
a thin layer of
________________________________
 Serosa are closed to the exterior(except for
dorsal body cavities and joint cavities)
 Occur in pairs…The
______________________________lines a
specific portion of the ventral body cavity
 Parietal layer folds in itself to form
______________________________-covers
outside of the organs in that cavity
 Serous layers separated
by______________________________secreted by both membranes
 Serous fluid allows organs to slide
against ea. other and cavity w/o
friction
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 SEROUS NAMES RELATED TO
LOCATION
 ______________________covers
abdominal cavity
 ____________________-surrounds
lungs
 _______________________surrounds
heart
B.Connective Tissue membranes
Composed of
_____________________________and has
NO epithelial cells-line capsules
surrounding joints
Line small sacs of connective tissue called
bursae and the tubelike tendon sheath----all
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cushioning organs against each other and
tendon across bone
II.The Integumentary Sysyem(skin)-cutaneous membrane
A. functions –most importantly protective….against mechanical
damage,chemical damage,
bacterial damage,
UV effects,thermal effects and dessication(drying out)
---also aids in controlling body heat
---aids in excretion of urea and uric acid
----synthesizes Vitamin D
The uppermost layer is full of _________________-and is
cornified or hardened-help prevent water loss
Capillaries and sweat glands work on thermal control
____________________________sense
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touch,pressure,temperature and pain
B. Structure of skin
Epidermis-stratified squamous epithelial capable of
keratinizing(hardening
_________-underneath-mostly dense connective tissue
Epidermis and dermis strongly connected,but some abuse can cause them
to separate—interstitial fluid comes between layers making a
_____________
________________________________is below dermis and mostly
adipose----not actually considered part of skin,but attaches skin to organs
beneath---works as “shock absorber” and insulates from extreme
temperatures
1. Epidermis has 5 layers or _______________.From
inside out they are stratum basale,
spinosum ,granulosum, lucidum and
corneum
 avascular
 most cells are
______________________________which
make keratin
 Stratum basale-closest to dermis and
connected along a wavy borderline.Contains
epidermal cells that that get the most
nourishment by diffusion from
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dermis;constant cell division-MILLIONS OF
NEW CELLS DAILY(also called stratum
germanitivum),daughter cells pushed upward
Stratum Spinosum and stratum granulosum
become flatter and increasingly full of
keratin
When the previous cells die,they form the
clear
_________________________________-not
in all skin regions-only where skin is hairless
and extra thick-ie.palms and soles;it secretes
a water repellent glycolipid into extracellular
space;distant from blood supply,so little
nutrients-doomed cells
OUTERMOST Stratum corneum—20-30
cells layers thick and is ¾ of epidermal
thickness;cornified,shinglelike dead
cells,filled w/ keratin;protects lower
cells;dandruff sloughs off from here
We have a totally new epidermis every 25-45
days
___________________pigment that ranges
in color from yellow to brown to black
produced by melanocytes(in stratum
basale).When skin is exposed to sun,this
stimulates these cells to make more of the
pigment---THUS tanning
Melanin accumulates in membrane bound
granules called __________________.They
move to the end of the melanocytes and
taken up by keratinocytes .THERE,melanin
forms a pigment umbrella over superficial
side of nuclei-shielding DNA from UV
_______________and moles are where
melanin are concentrated in one spot
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2. dermis-‘hide”
strong,stretchy
dense fibrous connective tissue
1. _____________________upper
dermal
region;_______________________peglike projections from superior
surface-many containing capillary
loops-thus nutrients;some have pain
receptors______________________________
or touch receptors_______________________________
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Has whorled rings on soles and
palms,increasing friction and
gripping ability----genetically
determined…..sweat pores
provide for fingerprints
2. _______________________________
deepest skin layer w/blood
vessels,sweat and oil glands and
_______________________________
deep pressure receptors;phagocytes act
here at reticular layer
o Collagen and elastic fibers
found in dermis.collagen
gives toughness and attract
water for hydration.Elasisic
fibers give elasticity that
declines w/age
o Many blood vessels help w/
body
temp.,homeostasis.skin is
red when hot due to
engorging of blood
o ______________________
_____________ happen in
bedridden patients not
turned regularly -pressure
restricts blood supply and
redness when pressure is
released
o Rich nerve supply
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C. Skin Color-3 pigments:
1. melanin in epidermis
2. carotene in stratum corneum and subcutaneous tissue
3. O2-rich hemoglobin in dermis
----varying amounts of the above create the numerous skin colors.Which
is showing up more in Caucasians?_________________________
 ________________________hemoglobin is poorly
oxygenated---can happen during heart failure and
severe bleeding
a.
b.
c.
d.
e.
What else affects skin color?:
Emotions and various disease states:
___________________-redness-blushing, hypertension,
inflammation ,allergy
___________________-blanching-pale—fear ,anger also
anemia ,low blood pressure ,impaired blood flow
___________________-yellowness-liver disorder
____________-sites where blood has escaped and clotted in
tissue spaces;can happen w/disease or vitamin C deficiency
_________________-clotted blood mass
D. Appendages of the Skin
1. __________________________________-exocrine glandsrelease secretions to skin’s surface via ducts
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a)Sebaceous glands-oil glands-excepts on palms and soles—some
open into hair follicle and some to surface
________________-is product-clump of oil and cells;keeps skin
moist and prevents hair from drying out
2. _____________________________(sudoriferous glands)-many
in the skin-2 types:1)eccrine glands-all over body and make
sweat(mostly water,NaCl,vitamin C and traces of metabolic
wastes(ammonia, urea,uric acid and lactic acid.It is acidic and
inhibits bacteria….sweat comes through a pore(not same as
facial pores);helps regulate temp.(37 C)
2)_____________________________-mostly
at axillary and genital areas;ducts empty into hair follicles;contains
fatty acids and proteins—giving milky/yellowish color.It is
odorless,but that changes when bacteria use it as food:function at
onset of puberty regulated by androgens(male sex hormones---have been connected to sexual foreplay
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3. Hair and Hair Follicles
 1)Hairs made by hair follicles and is flexible
epithelial structure;root in
________________and shaft protrudes It is
formed by mitosis of stratum basale
epithelial cells in matrix(growth zone)become keratinized and die as pushed
forward---mostly hair contains protein
 Hair has central core called a medulla
surrounded by a cortex.This is covered by a
cuticle(most keratinized region)-gives
strength
 Hair pigments made by melanocytes in hair
bulb
 Variety of shapes and sizes(eyebrows v. head
then skin hair).If shaft is flat and ribbonlikehair curly or kinky.If shaft is round-straight
or coarse hair
 Hair all over except soles,palms,nipples and
lips
 Fastest growing tissue in body
 Have hormonal control
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2) hair follicles-contain inner epidermal
sheath that forms hair/outer dermal sheath is
connective tissue/papilla yield blood supply
to matrix in hair bulb
______________________________smooth
muscle that raise hair in resonse to temp
3) Nails-scalelike product of
dermis(corresponds to hoof or nail)
Each nail has a _______________,a
body(visible and a root(imbedded in skin)
Nail bed in stratum basale and inner
____________________,responsible for
growth-cells become keratinized and die
Part appears pink due to vascularization in
dermis
___________________ appears white
E. Homeostatic imbalances of skin
1. Infections and Allergies
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___________________________-fungal,itchy red ,peeling skin(tinea
pedis)
Boils and Carbuncles-inflammation of hair follicles and sebaceous
glands—often dorsal neck.Carbuncles are caused by bacteria-esp.
Staphylococcus aureus
_____________________-small fluid filled(fever blisters)-itch and sting
–caused by a herpes simplex virus-can be activated from dormancy from
emotions,fever,UV light-usually around lips or oral mucosa
_____________________________-itchy,red,swelling and turns into
blisters-exposure to chemicals like poison ivy
___________________-pink,water-filled raised lesions around nose and
mouth;w/yellow crust;caused by Staphylococcus
_____________________-chronic overproduction of cells w/ red
epidermal lesions—probably autoimmune
2. burns-tissue damage and cell death caused intense
heat,electricity,UV light or certain chemicals--This can have a domino effect on several organ
systems
destroys cells
Life threatening from 1) loss of
fluids as they seep from burned
surface-dehydrating and fluid
imbance-could shut down
kidneys and cause circulatory
shock
___________________________
-divides body into 11 areas,ea.
9% of total body surface area+
area around genitals-determines
5 burned
2) infection later is a leading
cause of death-after 24
hrs.,pathogens invade the area
and multiply quickly
Classification:
1st degree-only epidermis is
damaged-red and swollen
2nd degree injury to epidermis
and upper dermis-regrowth will
occur
1st and 2nd degree are
___________________________
burns
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3rd degree-destroys entire
thickness of skin(full-thickness
burns)
Critical if a) over 25% covered
w/ 2nd degree b) over 10% 3rd
degree OR c) 3rd on face ,hands
or feet
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BURNS
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3. Skin Cancero Most neoplasms benign(ex-wart)
o Affect 1/5 americans
o ________________________________
_-least malignant and most commonaffects stratum basal so cannot form
keratin;boundary between epidermis
and dermis lost;fairly slow growing
o _______________________________from stratum spinosumscalp,ears,hands-grows rapidly,but if
caught early,prognosis is good
o ___________________________cancer of melanocytes(5%of skin
cancers)-happen where ever there is
pigment and often deadly-50% survival
w/early detection
o ABCD RULE_
a)asymmetry
b)border irregularity
c)color-areas of different color
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d)diameter-larger than 6 mm
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III. Take notes p. 127 on developmental aspects:
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