Mr. Stephens
Anatomy & Physiology
Chapter 5 Lecture Notes (page 1)
The Integumentary System
The integument is the largest system of the body: ______ of body weight, 1.5 to 2m2 in area.
Connects to other systems
___________________ system: blood vessels in the dermis
___________________ system: sensory receptors for pain, touch, and temperature.
Functions of Skin
___________________ underlying tissues and organs.
___________________ salts, water, and organic wastes (glands)
___________________ body temperature (insulation and evaporation).
___________________ vitamin D3.
___________________ lipids.
___________________ touch, pressure, pain, and temperature.
Parts of the Integument
1. ___________________ membrane (skin).
2. ___________________ structures (hair, nails and glands).
Parts of the Cutaneous Membrane
Outer _______________ superficial stratified squamous epithelium, outer layer keratinized).
Inner _______________ dense connective tissue (beneath thin layer of loose CT).
Layers of the Epidermis (from Top to Bottom)
“Come Let’s Get Sun Burned!”
Stratum ____________________ -- outer 20-30 layers of dead, heavily keratinized cells.
Stratum ____________________ -- thick, hairless skin, only on palms and feet, “clear layer”
Stratum ____________________ --“grainy layer”, produces keratin
Stratum ____________________ --“spiny layer”, has an immune response
Stratum ____________________ -- a.k.a. stratum germinativum; stem cells here, gives rise to all other
epidermal cells. Melanocytes located here.
___________________ – covers most of the body, has 4 layers. Stratum lucidum NOT present!
(About as thick as a plastic sandwich bag)
___________________ – covers the palms of the hands and soles of the feet, has 5 layers.
(About as thick as a paper towel)
Keratin, Melanin, Amazing Factoids
 Keratin – tough, pliable protein water resistant; gives skin, hair, and nails protective properties.
 Melanin – produced by melanocytes (in the stratum basale). Color is yellow to brown to black.
The amount produced depends upon genetics and exposure to sunlight. Protects skin from sun
damage.
 Cells are shed every day, stratum basale totally replaces epidermis every 25-45 days!!
Dermis “The true layer of skin”
Deep to the epidermis: 2 layers
1. _____________________ layer (upper dermal region) Location of capillaries, pressure and pain
receptors, fingerprints. Consists of areolar tissue.
2. _____________________ layer (deepest skin layer) Location of blood vessels, sweat and oil glands,
hair follicles, deep pressure receptors. Made of collagen and elastic fibers.
REVIEW
Circle the statements that are false.
1. Skin pigmentation cells are found in the epidermis.
2. The epidermis is considered the true layer of skin.
3. The epidermis is your first barrier protection from disease.
4. One function of the integumentary system is temperature regulation.
5. One function of the integumentary system is to hold muscles and bones in place.
6. The skin allows us to feel hot, cold, pain, and pleasure.
7. The dermis is your most superficial layer of skin.
8. The dermis is known as the “true layer” of skin.
9. Your sensory nerves for touch, temperature, and pain are located in your dermis.
10. Pressure receptors are located deep in the dermal layer.
Mr. Klatt
Anatomy & Physiology
Chapter 5 Lecture Notes (page 2)
Skin Damage
Sagging and wrinkles (reduced skin elasticity) are caused by: dehydration, age, hormonal changes, UV
exposure
Stretch Marks – thickened tissue resulting from excessive stretching of skin due to: pregnancy, weight
gain
Lines of Cleavage – Clinically significant:
 A cut _________________________ to a cleavage line will usually remain closed and heals
with little scarring.

A cut at a _______________________ to a cleavage line will be pulled open as severed
elastic fibers recoil and will result in greater scarring.
Exocrine Glands (2 types)
1. Sebaceous: secrete sebum -- inhibits bacteria growth, lubricates and protects hair and skin.
2. Sweat (2 types)
I. _____________________ – located in armpits and pubic region, produce a sticky, cloudy, and
potentially odorous secretion. Begin secreting at puberty. A nutrient source for bacteria.
Mammary glands of the breast are modified apocrine sweat glands, a complex interaction between
sex and pituitary hormones controls their development and secretion.
II. ____________________ – secrete “sweat” onto the skin, composed of 99% H2O. Found all over
the skin, the palms and soles have the highest number per cm2. Cools the skin surface, flushes the
surface of the skin, excretes waste, and inhibits bacteria growth.
Hair
Produced by hair follicles, consists of keratinized epithelial cells,
melanocytes provide pigment.
______________________ -- smooth muscle attached to follicle and
papillary layer causes “goosebumps”.
Nails – heavily keratinized modifications of epidermis.
Stratum basale in nail matrix responsible for growth, nail itself
is mostly dead cells (like hair)).
The Subcutaneous Layer (hypodermis)
Not part of the skin.
Composed of loose connective tissue, areolar and adipose tissue.
One half of your stored fat is here.
Lots of blood vessels, site of hypodermic injections.
REVIEW
Circle the statements that are false.
1. The nail is located on the ventral side of the phalanges.
2. The matrix is another term for the nail bed in your hands and feet.
3. The nail itself is mostly dead cells.
4. The subcutaneous layers is not a true layer of skin.
5. Intramuscular injections are often given in the subcutaneous layer.
6. Approximately 1/3 of your stored fat in the body is found in the subcutaneous layer.
7. The subcutaneous layer is located deep to the dermis.
Mr. Stephens
Anatomy & Physiology
Chapter 5 Lecture Notes (page 3)
Burns – damage from heat, electricity, UV, chemicals. Rule of 9’s – estimate of burn area
Severity of Burns
____________________ -- epidermis only, red and swollen (typical sunburn).
____________________ -- epidermis and upper dermis damaged, red with blisters.
____________________ -- entire skin layer destroyed, burn is gray-white or black.
Rule of Nines
Answer the following math problems using the
“Rule of Nines”. Show all work.
1. What percentage of the body is burned if a
16 year old male burned his back, the back of his
left leg and his entire right arm?
2. Suzie, and active 6 year old girl, was burned while playing
around a fireplace. Her nightgown caught on fire and she
burned both her legs, her back, her left arm, and one side
of her face. What percentage of body tissue was burned?
3. A 25 year old involved in a car accident burned his chest and perineal area. What percentage of his body was
burned?
4. Marion was burned by exploding gas while trying to start his lawn mower. He burned both legs above the knees
up through his chest, half of both arms, and the perineal area. What percentage of his body was burned?
5. Julian burned half of his chest, a third of his back, and two-thirds of his left leg. What percentage of his body
was burned?
Mr. Stephens
Anatomy & Physiology
Chapter 5 Lecture Notes (page 4)
Skin Cancer – Uncontrolled cell division in skin, # 1 cancer in U.S.
____________________ cell carcinoma – least malignant, most common, (stratum basale)
____________________ cell carcinoma – easy cure early, but does metastasize to lymph nodes,
(stratum spinosum)
____________________ melanoma – most deadly, rapid metastasis to lymph and blood
ABCD Rule: detecting malignant melanoma

A = __________________________ -- opposite sides don’t match.

B = __________________________ -- borders not smooth.

C = __________________________ -- one mole, several colors.

D= __________________________ -- larger than 6mm (pencil eraser)

E= __________________________ -- when a mole changes in size, shape or color, or begins to
bleed or scab.