Read Chapter 5. Review your notes.
Chap 5
Integumentary
System
Chapter Learning Objectives:
1.Name the tissue types composing the epidermis and dermis. List the major
layers of each and describe the functions of each layer.
2. Describe the factors of skin color. Discuss clinical indications of skin color
changes.
3. Compare the structure and locations of sweat and oil glands.
4.Compare eccrine and aprocrine glands.
5. Describe a hair follicle.
6. Describe the regions of hair & explain the basis of hair color. Describe hair
growth, distribution, etc. during the span of life.
7. Describe nail structure.
8. Describe at least 5 functions of skin.
9. Summarize the characteristics of the three major types of skin cancer.
10. Explain what serious burns are life threatening. Describe how to determine
the extent of a burn and differentiate first, second, and third-degree burns.
PREDICT
Whose ______ is this?
Predict
And, whose _____ is this?
Human Skin (Integument)
• Our protective covering (considered to be an
organ) – about as thick as a paper ________
• Weighs 9-11 lbs or ___% of total body weight
• Has 3 distinct regions:
a) ________ – outermost layer; no blood vessels
b) ______ – fibrous connective tissue; has
vessels
c) __________ (superficial fascia) – deepest
region
Functions of the Integumentary
• ________ – chemical, physical, and mechanical
barrier
• Body temperature _________ is accomplished by
dilation (cooling) and constriction (warming) of
dermal vessels and increasing sweat gland
secretions to cool the body
• Cutaneous _________ – exoreceptors sense
________ and _______
• Metabolic functions – synthesis of vitamin D in
dermal blood vessels
• ________ reservoir – skin blood vessels store up
to 5% of the body’s blood volume
• Excretion – limited amounts of nitrogenous wastes
are eliminated from the body in sweat
Skin (Integument) *Label your diagram
Epidermis
• Composed of __________ stratified
squamous epithelium, consisting of four
distinct cell types and four or five layers
• Cell types include keratinocytes,
melanocytes, Merkel cells, and
Langerhans’ cells
• Outer portion of the skin is exposed to the
external environment and functions in
protection
Specialized Cells of the Epidermis
• ___________ – produce the fibrous
protein keratin
• __________ – produce the brown pigment
melanin
• ___________ cells – epidermal
macrophages that help activate the
immune system
• ______ cells – function as touch receptors
in association with sensory nerve endings
Layers of the Epidermis
Stratum Basale
• _________ epidermal layer firmly
attached to the dermis
• Consists of a single row of the youngest
keratinocytes
• Cells undergo _____ division
Stratum Spinosum
(_______ Layer)
• Cells contain a web-like system of
intermediate filaments attached to
desmosomes
• Melanin granules and Langerhans’ cells
are abundant in this layer
Stratum Granulosum
(__________ Layer)
• Thin; three to five cell layers in which
drastic changes in keratinocyte
appearance occurs
• Keratohyaline and lamellated granules
accumulate in the cells of this layer
Stratum Lucidum
(_______ Layer)
• Thin, transparent band superficial to the
stratum granulosum
• Consists of a few rows of flat, dead
keratinocytes
• Present only in thick skin
Stratum Corneum
(_______ Layer)
• Outermost layer of keratinized cells
• Accounts for three quarters of the
epidermal thickness
• Functions include:
– ______________
– Protection from _______ and ___________
– Rendering the body relatively insensitive to
biological, chemical, and physical assaults
Review of Epidermis
1. What are the 3 distinct regions of skin?
2. What is the name of the deepest
epidermal layer?
3. What is the name of the outermost
epidermal layer?
Dermis
• _______ major skin region containing strong,
flexible connective tissue
• Cell types include fibroblasts, macrophages, and
occasionally mast cells and white blood cells
• Composed of two layers:
a) _________ (connective tissue with collagen
and elastic fibers)
b) ________ (collagen fibers add strength and
resiliency to the skin; elastin fibers provide
stretch-recoil properties)
Hypodermis
• Subcutaneous layer ______ to the skin
• Composed of ______ (fat) and areolar
connective tissue
Skin Pigments
– ________ – yellow to reddish-brown to
black pigment, responsible for dark skin
colors
• Freckles and pigmented moles – result
from local accumulations of melanin
– ________ – yellow to orange pigment,
most obvious in the palms and soles of the
feet
– __________ – reddish pigment responsible
for the pinkish hue of the skin
Pigment Disorders
Instructions: With a partner, quickly pair
and discuss the 5 pigment disorders found
in the Homeostatic Imbalance section on
page 143. Estimated Time: 2-3 minutes
Appendages of the Skin
•
•
•
•
•
N_________
S______ glands
O___ glands
H_____
H____ f________
Nails
__________ modification of the epidermis on the distal,
dorsal surface of fingers and toes
Sweat Glands
• Different types prevent overheating of the
body; secrete ________ and milk
– _______ sweat glands – found in palms, soles
of the feet, and forehead
– _________ sweat glands – found in axillary
and anogenital areas
– Ceruminous glands – modified apocrine
glands in external ___ canal that secrete
cerumen (wax)
– ________ glands – specialized sweat glands
that secrete milk
Sebaceous (Oil) Glands
• Simple alveolar glands found all over the
_______
• ______ skin when stimulated by hormones
• Secrete an oily secretion called _______
Hair
• Filamentous strands of dead keratinized
cells produced by hair follicles
• Contains hard keratin which is tougher and
more durable than soft keratin of the skin
• Pigmented by ____________ at the base
of the hair
• Hair is distributed over the entire skin
surface except palms, soles, lips, and
portions of external genitalia
Hair – 3 Layers
http://www.kidshealth.org/parent/general/bod
y_basics/skin_hair_nails.html
Functions of Hair
• Functions of hair include:
– Helping to maintain ________
– Alerting the body to presence of _______ on
the skin
– Guarding the scalp against physical ______,
____ loss, and sunlight
Hair Follicle
• Root sheath extending from the epidermal
surface into the dermis
• Deep end is expanded forming a hair ____
• A knot of sensory nerve endings (a root
hair plexus) wraps around each hair bulb
• Bending a hair stimulates these endings,
hence our hairs act as sensitive _______
receptors
Hair Follicle Anatomy
Types of Hair
• _______ – pale, fine body hair found in
children and the adult female
• _______ – coarse, long hair of eyebrows,
scalp, axillary, and pubic regions
Skin Cancers
• The three major types of skin cancer are:
– ______ cell carcinoma
– ________ cell carcinoma
– __________
Can you spot a suspicious skin area?
Basal Cell Carcinoma
• _______ malignant and
most common skin cancer
• Stratum basale cells
proliferate and invade the
dermis and hypodermis
• Slow growing and do not
often metastasize
• Can be cured by surgical
excision in 99% of the
cases
Squamous Cell
Carcinoma
• Arises from keratinocytes of
stratum spinosum
• Arise most often on scalp,
ears, and lower lip
• Grows ________ and
metastasizes if not removed
• Prognosis is good if treated
by radiation therapy or
removed surgically
Melanoma
Cancer of melanocytes is the most
______________ type of skin
cancer because it is:
- Highly metastatic
- Resistant to chemotherapy
Melanomas have the following characteristics
(ABCD rule)
– A: __________; the two sides of the pigmented area
do not match
– B: ______ is irregular and exhibits indentations
– C: ______ (pigmented area) is black, brown, tan,
and sometimes red or blue
– D: ________ is larger than 6 mm (size of a pencil
eraser)
Burns
• ______-degree – only the epidermis is damaged
– Symptoms include localized redness, swelling, and
pain
• _______-degree – epidermis and upper regions
of dermis are damaged
– Symptoms mimic first degree burns, but blisters also
appear
• ______-degree – entire thickness of the skin is
damaged
– Burned area appears gray-white, cherry red, or black;
there is no initial edema or pain (since nerve endings
are destroyed)
Rule of Nines
• Estimates the
severity of burns
• Burns considered
critical if:
– Over __ % of the
body has seconddegree burns
– Over __ % of the
body has thirddegree burns
– There are thirddegree burns on
face, hands, or feet