I. Membranes

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I. Membranes Classified by tissue
types. 1. Epithelial Membranes (layer of
epithelia and connective tissue) Simple
organ a. Cutaneous Membrane (skin) composed
of stratified squamous and dense
connective tissue. Unique because it
is primarily a dry membrane.
b. Mucous Membrane (mucosa) composed
of epithelia and loose connective tissue. i.
Membrane lines body cavities that open to the
exterior (digestive, respiratory, urinary and
reproductive) ii. A wet membrane continuously
bathed in secretions (mucus or urine).
iii. Cell types vary (squamous or columnar)
typically specialized for secretion (mucus)
or absorption (digestive tract).
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c. Serous Membranes (serosa) composed of simple
squamous and aerolar connective tissue. i.
Line body cavities that are closed to the
exterior (except dorsal cavity and joints) ii.
Occurs in pairs 1. Layer that lines the
body cavity is known as the parietal
layer 2. Layer that lines the body
organ is the visceral layer 3. Fluid
between layers
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iii. Function of membrane is to decrease
friction between organs. Ex. Heart and
lungs, stomach and intestine. iv. Location of
membrane can dictate name. Ex. Pleura around
lungs pericardium around heart, peritoneum in
abdominal cavity.
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2. Connective Tissue Membranes/Synovial Membranes
(composed of soft aerolar tissue) a. Lines i.
fibrous capsules of your joints, ii. bursa
(sacs of connective tissue at some
joints), iii. tendon sheaths b. Protects
against friction between moving parts of the body.
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• Friction is the force resisting the relative
  motion of solid surfaces, fluid layers, and
  material elements sliding against each other.

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Cool Skin Facts

• Your skin weighs around 9 pounds
• You lose 30-40 thousand skin cells each minute
  (around a billion in a day)
• These mites live in your
• Eyelash follicles!

Hi! I live in your eyelashes!
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II The Integument System Structure (skin and its
derivatives) A. Epidermis top most superficial
layer 1. Composed of stratified squamous
epithelial 2. Avascular and not innervated (no
nerves) 3. Different cell types a.
Keratinocytes produce keratin helps with
waterproofing of the skin these cells are lost
through friction. b. Melanocytes produce
melanin (primary skin pigment), found in the
lowest level of epidermis. Function is to
protect the DNA in the nucleus from the UV
radiation of the sun. Amount and kind of
melanin determine skin color. c. Immune
system cells in lower layers for early
detection (called Langerhans cells)
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4. Layers of epidermis a. Stratum corneum most
superficial layer, numerous cell layers (20 to
30) cells are dead (cornified) and flake off
easily. Major protective layer. b. Stratum
Lucidum Only present on palms and soles of your
feet. Cells are clear and dead (too far to
receive nutrients and oxygen) c. Stratum
Granulosum d. Stratum Spinosum e. Stratum
Basale/Germinativum layer of rapid cell
division How tatoos work.
"Come, Let's Get Sun Burned" From superficial
to deepCorneumLucidumGranulosumSpinosumBasal
e Germinativum
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2. Dermis Intermediate layer and the thickest
your hide 1. Composed of dense fibrous
connective tissue 2. Primary function is to hold
the body together therefore it is very strong and
stretchy 3. Composed of two layers a. Papillary
layer upper/superficial layer i. Contains
dermal papillae (ridges that extend up into the
dermis) these are the ridges of your
fingerprints. Increase friction. ii. Capillaries
extend into the ridges to provide nutrients to
stratum basal layer by diffusion. iii. Location
of pain receptors (Meissners corpuscles)
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b. Reticular layer thicker layer of the
dermis i. Contains blood vessels, sweat and oil
glands, pressure receptors (Pacinian corpuscles),
phagocytes (immune cells) and collagen and
elastic fibers. a. Collagen help keep skin
hydrated b. Elastic help with skin
stretchyness c. Hypodermis Deepest layer of
skin 1. Composed of adipose tissue 2. Anchors
the two other layers to underlying organs also
insulate and act as a shock absorber.
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Skin Layer Review
"Come, Let's Get Sun Burned" From superficial
to deepCorneumLucidumGranulosumSpinosumBasal
e Germinativum
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III Appendages of the Skin Arise from the
epidermis (stratum basal) A. Cutaneous
Exocrine (have a duct) glands 1. Sebaceous
Gland / Oil Glands a. Found everywhere
except palms of hands and feet. b.
Duct empties into a hair follicle. c.
Sebum is the product excreted composed
of oils, chemicals that kill bacteria and
fragmented cells. d. Function to lubricate
the skin and hair and protection against
microbial invasion.
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2. Sudoriferous / Sweat Glands a. 2.5
million per person b. Two types i.
Eccrine Glands more numerous and found
everywhere primary excretion is sweat (water,
salts, vitamin C, metabolic wastes, and lactic
acid) Secretion empties out onto the skin
through a pore ii. Apocrine Glands Only
found in axillary and genital areas empty into
hair follicle secretions contain fatty acids and
proteins (causes body odor when microbes digest)
function not yet clear.
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The lovely mites that live in our eyelash
follicles!
B. Hair and Hair Follicle 1. Layers of hair
cuticle (outer most, looks like shingles on a
roof), cortex (area of color) and medulla (core,
different pattern in each species) 2. Types of
hair a. Vellus hair peach fuzz covers the
entire body. b. Terminal hair darker hair on
head, eye lashes, eye brows, pubic area, etc
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c. Function of the hair protection (eye lashes,
nose hairs, etc..) d. Hair follicle
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IV Function of the integument (the best coat
youll ever wear) A. Thermoregulation
maintaining proper body temperature 1.
Capillaries in the dermis can dilate (get bigger)
releasing heat from the skin (red and swollen)
causing a flushed appearance or become
restricted and redirect blood flow away
from skin to more vital parts of the body (why
your skin feels cold) 2. Sweat glands
-release of water from sweat results in
evaporative cooling. B. Physical and Chemical
Damage - bumps, cuts, scrapes, burns. a.
Keratinized cells in upper epidermis b. Nerve
receptors that alert central nervous system to a
problem
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C. Microbe damage bacteria 1. acid mantle
secretions of epidermis slow/prevent bacterial
growth 2. Phagocytes in dermis that engulf
pathogen (disease causing microbes) D.
Desiccation drying out 1. Keratinized
epidermal cells- waterproof E. Excretion 1.
Sweat uric acid, heat, other toxins and
chemicals. 2. Pheromones through apocrine
sweat glands 3. Oil through sebaceous
glands F. Synthesis 1. Vitamin D (modified
cholesterol and sunlight) helps with calcium
absorption in the digestive tract. 2. Proteins
necessary for immunity. G. UV radiation 1.
Melanin protecting DNA in nucleus from mutations.
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Fingerprints

• Arch
• Whorl Double loop

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Eccrine vs. Apocrine Glands Use your notes to
explain their location, secretion, functions
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Question of the Week Why do we have
fingernails?

• We have fingernails because we're primates,"
  said John Hawks, a biological anthropologist at
  the University of Wisconsin-Madison.
• Fingernails distinguish primates, they are
  essentially flattened forms of claws to grab onto
  things, to climb things, to scratch things, and
  to dig holes."
• While claws would have provided excellent grip as
  our mammalian ancestors clambered up large tree
  trunks, they would have been a nuisance for
  larger-bodied primates trying to grasp smaller
  branches while scrambling across tree canopies
  for fruits. Rather, primates developed broader
  fingertips made for grasping.
• Nails serve as a visual advertisement of a
  person's health, he said. For instance,
  malnutrition can change the coloring of nails.
• small pits in fingernails can signal the skin
  condition psoriasis.
• Spoon-shaped--- anemia
• A healthy nail has a specific shapeslightly
  raised in the middle, then curving down a bit at
  the tip.
• Dry and brittle its possible for an under-active
  thyroid to cause both dry skin and brittle nails
• Yellow-When all of the nails turn yellow it can
  be a sign of lung disease or diabetes,
• White spots- nail injury or can be ZINC
  defeciency, or air spaces in nail plate

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V Development of the Integument System A.
Fetal Development and Birth 1. Lanugo downy
hair that covers the fetuss body and is
typically shed by birth. 2. Vernix caseosa
white secretion by the sebaceous glands which
protects the babys skin in the uterus. 3.
Milia accumulation of sebaceous glands on nose
and forehead, typically disappear by 3rd week.
4. Seborrhea cradle cap formed from
overactive sebaceous glands forming raised
lesions that crust over and slough off. 5.
As baby developed skin becomes thicker and moist
and more subcutaneous fat is deposited.
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B. Adolescence 1. Sebaceous glands increase
their activity and acne (infection of sebaceous
gland) can appear. a. White head sebaceous
gland blocked by sebum b. Black head
when accumulated material oxidizes and
dries c. 20s and 30s your skin is the best it
will ever look! C. Old Age 1. Subcutaneous fat
deposits decrease (intolerance of cold due to
lack of insulation and thinness of skin can
lead to increase in bruising) 2. Decrease oil
production and fewer collagen fibers contribute
to overall decrease in moisture level of skin.
3. Sagging is caused by the loss of elasticity
of the elastic fibers in the skin. 4.
Overexposure to sun can lead to increase
incidence of skin cancer (accumulation of
mutations over the years) 5. Hair follicle
numbers decrease by 1/3 by the age of 50
resulting in hair loss (alopecia) and
melanocytes can stop producing melanin in the
follicle and the hair appears gray (due to a
delayed action gene)
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D. How can we reverse this aging trend? 1. Stay
out of the sun /use sunscreen 2. Good balanced
diet (antiaging foods- blueberries, nuts,
brocolli, green leafy veggies, garlic, tomatoes,
soy beans, prunes, etc.) 3. Plenty of water 4.
Cleanliness / good hygiene
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VI Homeostatic Imbalances of the Skin (there are
over 1000) A. Changes in color 1. Redness
/Erythema dilation of capillaries in the skin
2. Blanching/Pallor pale skin can be
indicative of anemia, emotional stress, low
blood pressure. 3. Jaundice yellowing of
skin from a liver disorder (not breaking down
bile properly and the pigments are circulated
through the blood) 4. Bruises blood has
escaped the vessels and clotted in the tissues
(hematoma)
In Raynaud's disease, smaller arteries that
supply blood to your skin narrow, limiting blood
circulation to affected areas.
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B. Blockage in circulation results in cell death
and therefore tissue death. Ex. Bed sores
(decubitis ulcer) result when patients are
bedridden, weight of the body puts pressure on
the skin and circulation is impaired in that
area. C. Blisters - skin is exposed to
constant friction causing the dermis and
epidermis to separate D. Attack by bacteria,
virus and/or fungus or allergy. Symptoms and
effects to skin vary with cause. (read over pg.
107 for specific types) Ringworm, caused by a
fungus in middle picture and impetigo caused by
bacteria in third picture.
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E. Burns tissue damage and cell death caused by
radiation, electricity, chemicals or heat 1.
Dangerous because a. Loss of fluids
(dehydration and electrolyte imbalance) b.
Exposure to pathogens and risk of infection
(exposed area and depressed immune system) 2.
Three types (classified by severity) a.
Partial Thickness Burns 1)First Degree Burn
Only epidermis is damaged symptoms are redness
and swelling in the area. Heals usually within
2 to 3 days. 2) Second Degree Burn
Epidermis and upper layer of dermis affected
blisters will appear regeneration can occur
(little scarring)
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2. Full Thickness Burns Third Degree Burn
entire thickness of skin is burned area is
charred (black) or blanched nerve endings
destroyed (not initially painful) regeneration
not possible, skin must be grafted. Burns are
considered critical if the following criteria are
met 25 of body has 2nd degree burn 10 of body
has 3rd degree burn 3rd degree burns on face and
hands (loss of mobility due to lack of
regeneration and proximity to respiratory
system) Look over the Rule of 9s on page 108.
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F. Skin Cancer 1.Cells divide uncontrollably and
the cancer can metastasize (move to other areas
of the body) growth can also be benign such as
warts. 2. Factors that can predispose a
person to skin cancer exposure to UV radiation
(sun), frequent irritations, genetics. 3.Types
Basal Cell Carcinoma least malignant most
common cells stop producing keratin and invade
the dermis. Relatively slow growing and 99 full
cure if lesions removed surgically. Sun
induced! Squamous Cell Carcinoma Arise from
stratum spinosum layer lesion is scaly in
appearance appears on scalp, ears, tops of hands
and lower lips grows more rapidly and can
metastize. Malignant melanoma Cancer of
melanocytes often deadly metastases quickly
survival 50 with early detection.
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• Rule for detection ABCD Rule
• Asymmetry of the lesion
• Border irregularity (not smooth)
• Color changes and different colors in same area
• Diameter is larger than 6mm (pencil eraser

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Skin Disease Assignment

• Choose a skin disease from the list provided and
  research with a partner.
• Research and create a presentation in KEYNOTE on
  the iPads. KEYNOTE is so user-friendly! Let me
  know if you need help getting started.
• You will be doing a 5 min. presentation to the
  class tomorrow! See rubric for grading
  information.
• Name of skin disease 1 points
• Skin structures/ layers affected 5 points
• Cause(s) 5 points
• Signs and symptoms 5 points
• Treatments, cures, prevention 5 points
• Illustrations, pictures 5 points
• Bibliography (min.2 sources) 4 points