Integumentary System & Body
First for the QUIZ!
Please Turn to Page 93 in Your
• 2 types of body membranes: Epithelial and
• A membrane= a very thin strong pliable
tissue which covers, lines or connects parts
of an organism
• Simple organs which contain epithelial and
connective tissue there are 4 types:
– Cutaneous Membrane: Skin
– Mucous Membranes: (Mucosa) Epithelium
on loose connective tissue. Lines body cavities
that open to the outside. Ex.Most form
– Serous Membrane (Serosa): Simple
Squamous epithelium on areolar connective
tissue. Line closed body cavities
– Synovial Membranes: Only connective tissue,
They line joints and tendons.
What do all membranes have in
• 1) They all have layers
• 2) Serous and Mucous Membranes have
parietal layers forming the outside wall and
visceral layers that cover the organs
• The Serous Membrane secretes a fluid like
the mucosal membranes which decrease
Serous Membranes To Know:
– Peritoneum- Lining of the abdominal cavity
and its organs
– Pleura- Lining of the lungs and thoracic cavity
– Pericardium- Membrane around the heart
• All have visceral and parietal layers.
How did this pimple happen to
• What is acne?-Acne is a disorder resulting from the action of hormones and other
substances on the skin's oil glands (sebaceous glands) and hair follicles
• What causes it? The hair, sebum, and keratinocytes that fill the narrow follicle may
produce a plug, which is an early sign of acne. The plug prevents sebum from reaching the surface of
the skin through a pore. The mixture of oil and cells allows bacteria Propionibacterium acnes (P.
acnes) that normally live on the skin to grow in the plugged follicles. These bacteria produce attract
white blood cells that cause inflammation. When the wall of the plugged follicle breaks down, it
spills everything into the nearby skin – sebum, shed skin cells, and bacteria – leading to lesions or
pimples. Hormonal changes , heredity, and some medications.
• How is it treated? Benzoyl peroxide – destroys P. acnes, and may also
reduce oil production
Resorcinol – can help break down blackheads and whiteheads
Salicylic acid – helps break down blackheads and whiteheads. Also helps cut
down the shedding of cells lining the hair follicles
Sulfur – helps break down blackheads and whiteheads
• What doesn’t cause it? Chocolate, caffeine, greasy foods, dirt, stress- no effect
• Who gets it? (Hint its not nobody) yup, anybody, slows down after
40 or 50.
In order to find out how we all get
pimples, we need to know the parts of
Review parts of the skin
So here is how it happens…
What is skin?
• Its an organ
• Made of cutaneous membrane. Superficial
epidermis made of stratified squamous
epithelium and dense connective tissue.
Is skin the same thing as the
• Skin is a cutaneous membrane
• Integumentary system includes sweat and
oil glands, hair, and nails.
• Integument= covering
What is the jobs of the skin?
• Regulates heat loss.
• Excretory functions for urea, salts, and
• Water Retention
• Manufactures proteins
• Synthesizes vitamin D
• Integrate with the nervous system for touch
But don’t get too much sun!
What are the three layers of the
What is the job of the epidermis?
• Keratinizes: becomes hard for protection
• Avascular: only the lowest level of the
epidermis is close enough to capillaries to
gain nutrients. That means: the skin you see
is all dead! Shedding skin doesn’t hurt!!!
• Contains Melanin: pigment produced by
new every 30 days!
What is an appendage of the
• Append= to hang on
• These are things that “hang on” or are
attached to the skin.
• Appendages include: Glands, Hair, and
• All appendages are part of the epidermis
What is the job of hair and hair
• Guards the head and eyes as well as
respiratory tract from particles & impact.
• Head Hair retains body heat. All other body
hair is a vestigial feature.
• Hair Follicles grow hair
Hair grows for three
of four years, than rests
for a few weeks. Each
hair is on its own cycle.
What are the parts of the hair follicle?
• Root of hair is enclosed in the hair follicle
(The hair bulb matrix= zone of growth
which contains melanin).
• Hair grows up the shaft to the surface of the
• The bulk of hair is dead. There are 3 layers
to hair: 1) Medulla, 2) Cortex, 3) Cuticle
(Protection against abrasion, Damage=Split
What makes hair look different?
• The amount of melanin secreted
• The shape of the hair folicle
– Straight Hair= Straight hair follicle
– Wavy and Smooth Hair= Slightly hooked
– Curley Hair= Hooked hair follicle
What are the parts of the nail?
• Used for protection
• The root of the nail is embedded in the
skin. Grows from the nail matrix. The
cells, heavily Keratinized die.
• Extends along the nail bed.
• Lunula – moon shaped beginning of nail
Nails grow faster
in the summer than
the winter. Fingernails
grow 3-4X faster
than toe nails.
What do Melanocytes do?
• Produces pigment to protect the cells DNA.
What are the three layers of the
What is the job of the dermis?
• Its leather. Protective, strong, living, and
houses many other tissues.
• Sweat Glands: maintain body temp.
• Hair follicles/bulbs: for warmth
• Nerves: pain, pressure, temperature
• Blood vessels: maintain body temp
What do the cutaneous glands
• Exocrine glands that secrete onto the
surface of the skin. Sebaceous & Sweat
• Sebaceous Glands- Produce oil all over the
body. Sebum used for softening, water
retention, killing bacteria. Increases when
testosterone is produced= Oily skin.
• Sweat Glands- helps maintain homeostasis
What are the two types of sweat
• Eccrine Glands: Cover Body, Contain
H2O, Salt, Vit. C, Wastes, Lactic Acid
• pH 4-6: antibacterial
• Sweat pores are not easily visible, Contain
nerve endings for regulation
• Develop 4th month gestation
And the Other One? .
• Apocrine glands- auxiliary and genital
areas. Ducts empty into hair follicles.
• Milky-yellowish in color, odorless. Body
odor occurs when bacteria eat it. *Thought
to be used in excreting pheromones*
• Develop 6th month gestation.
Why do you not have wrinkles
when your young?
• Collagen fibers: Strong and keep the skin
hydrated (attract H2O).
• Elastic fibers: Keep skin elastic. Like all
elastic its less so after time.
• Loose fat in the hypodermis. = sagging
• Decrease in subcutaneous tissue, causes
dryness, cold sensitivity, and bruising in the
What happens when the
epidermis and dermis separate?
• A blister
• Caused by friction or burns.
What causes goose bumps?
• Smooth muscles called Arrector pili that
attach to hair follicles contract.
What is the job of the
• Anchors the skin
• Shock absorber
• Insulates from temperature change
• Gives shape to fatty areas of the body
Diseases of the Skin and Aging
Problems of the skin
• Bedsores or Decubitus Ulcers- Caused by
pinching off of the blood supply to the skin.
Occurs over bony areas of the body. See
figure 4.4 on Pg. 98
Cyanosis or Turning Blue
• Not a problem with the skin, but a problem
that can be seen in the skin.
• Mostly visible in Causasions
• In people of color cyanosis can be seen in
the mucous membrane and the nail bed
• Typical of a heart attack
• Jaundice-Yellow cast to the skin caused by
bile from the liver being absorbed by the
blood. Indicative of liver disease
• Hematoma and Bruises- caused by blood,
escaping from damaged blood vessels,
clotting under the skin.
• Fancy word for balding
• By age 50, 1/3 of your hair follicles may be
• Severe alopecia can happen to anyone at
any age and is not thought to be genetic.
ALL BODY HAIR is lost!!! Factoid:
causes hair growth
to go into hyper speed.
Instead of years
of growth, they have weeks.
hair barely immerges
went the old is pushed out.
What are the problems with
smoking and sun on the
• Leathery skin
• Cold sore (herpes outbreak)
• Depressed immune system
• All from DNA damage.
Review Burns and Skin Cancer
• A: Asymmetry, spots will not look the same on both
• B: Border irregularity, blurry and/or jagged edges
• C: Color, more than one hue
• D: Diameter, larger than a pencil eraser
• E: Elevation, raised above the surface and has an
uneven surface & Evolving, changing
• Most cells undergo mitosis until
end of puberty; after that only
skin and intestinal cells keep
• Aging: epithelial membranes
thin, skin loses elasticity/sags,
glands become less active
Cosmetic Collagen - Botox
• What is collagen? A protein that makes
tendons, ligaments, and other connective
• In 1981, FDA approved the use of cattle
collagen by injection to minimize wrinkles and
• Drawbacks – lasts only a few months, expense,
allergic reactions to cattle collagen (now use
person’s own collagen from thighs and hips).