Today Essential Question and Activities:
Review Yesterday’s Lesson Essential Question: What are the
different layers and functions of skin.
LEQ: How is the Integumentary system imperative
in maintaining homeostasis?
Warm up:
What does the Integumentary system
contain?
2. Where is melanin found and give one
characteristic you learned yesterday
about melanocytes?
3. Why are sebaceous glands always found
near the hair?
4. Hand in Tree Man Homework
1.
Today Essential Question and Activities:

LEQ: How is the Integumentary system
imperative in maintaining homeostasis?

ACTIVITIES: Graphic Organizer, Build the Skin,
Lost in the desert.

1. Complete the Graphic organizer. Once finished
bring it up to me to be checked off.
2. When your partner is done too- make a list of
the supplies for the lab and for each supply come
up with an educated guess about what part of
the skin it could correlate to and WHY.
3. Have me check that off when finished and I
will give you the lab instructions and materials.
4. Once you have constructed your skin bring it
up to show me, finish ALL questions and hand in.



Integumentary system
The skin and accessory organs
(Hair, membranes, glands, etc)
Membranes
 Serous
membranes: Line
body cavities that lack openings to
the outside.
 is
a smooth membrane consisting
of a thin layer of epidermal cells
 They
line and enclose several body
cavities, where they secrete a
lubricating fluid which reduces
friction from muscle movement.
Membranes
Serous
membranes:
Basically they cover
areas such as the
thoracic cavity
the heart and
lungs area, and
ventral cavity.
Membranes
Serous
membranes:
Membranes
Mucous
membranes:are
involved in absorption and
secretion.
 They line various body cavities
that are exposed to the external
environment and internal organs.
 Examples are the nasal and oral
cavities, tubes of the respiratory,
digestive and reproductive tracts.
Membranes
 Mucous membranes:
 Usually found near or
on glands
that will help secrete a mucous.
 It
is at several places continuous
with skin.
 Why
would you find mucous
membranes continuous or near
or connected to your skin?
Membranes
Membranes
 Synovial
membranes: is the soft
tissue that lines the noncartilaginous surfaces within joints
(synovial joints).
 They
secrete a fluid to lubricate
the joints.
 Synovial
Membranes
membranes:
Membranes
 Cutaneous
membranes: The skin
They consist of stratified
squamous epithelium and the
underlying connective tissues.
Cutaneous membranes are thick,
relatively waterproof, and dry.
 The
skin helps in regulating body
temperature and maintaining
homeostasis.
Membranes
 Cutaneous
membranes:
THE THREE LAYERS OF
SKIN
1. EPIDERMIS
2. DERMIS
3. SUBCUTANEOUS
LAYER
EPIDERMIS
 The
outer layer
 Composed
stratified
squamous
epithelium
of
EPIDERMIS
Contains five separate layers:
Stratum Corneum- outer most layermostly dead cells
Stratum Basale- The area where
cells divide rapidly
Stratum Spinosum
Stratum Granulosum- only in areas
where the skin is thick
Stratum lucidum- only on the palms
and soles.

5 Layers of Epidermis:
EPIDERMIS
 Here
is what happens to make
these layers:
◦ 1. The basale layers divide rapidly
pushing the cells and tissues up
toward the top.
◦ 2. The closer they get to the top
the less nutrients they have from
the connective tissue so they
eventually die (This becomes your
Corneum layer)
EPIDERMIS

The process of these cells hardening and
dying is called KERATINIZATION
◦ This is when they can secrete
the protein Keratin to make the
skin tough and water proof.
EPIDERMIS
 Your
epidermis also contains
MELANIN: is a dark pigment that
provides your skin color.
◦ Melanocytes are the cells that
produce the melanin. They are found
in the deep layers of the epidermis.
◦ WHY Would you want them in the
deep layers instead of the corneum?
EPIDERMIS

HOW or why do you think people have
different colors of skin then? DISCUSS
with your table and come up with an
answer!

Most people have the same number of
melanocytes but the differences are due
to the amount of melanin they produce.

It is genetic!!

If genes instruct the melanocytes to
produce a lot of melanin then your skin is
darker.
EPIDERMIS

How do you think sunlight plays a role in
melanin and skin color? (Obviously sun
UVA rays can make you darker- but why
do you think so?) DISCUSS as a table and
come up with an answer to report out.
Epidermis

ANSWER: The sun stimulates (Speeds up)
production of the melanin pigment.

Some people depending on how dark their
skin is can turn “red” or “blush” and it can
be seen. What do you think is happening
there to temporarily change the skin
color?
EPIDERMS

ANSWER: When the blood vessels in the
lower layers of the skin are well
oxygenated the blood pigments appear
bright red (hot). When the oxygen
content is low, the skin can appear
blueish (cold).

Remember I said skin has something to
do with regulating body temperaturehere is one way it doe that!
EPIDERMIS
DERMIS





Known as the Inner layer
Very thick
Contains: Connective tissues, epithelial
tissues, smooth muscle tissue, nervous
tissue and blood vessels.
This is where your fingerprints come from.
Supplies nutrients to the epidermis and
regulates body temperature.

Contains sensory receptors (touch
receptors, temperature receptors- sweat
glands, and so forth)

Also contains the HAIR FOLLICLES,
SWEAT GLANDS, and SEBACACEOUS
GLANDS
DERMIS
 HAIR
FOLLICULE: Hair is present
everywhere except: palms, soles,
nipples, and some external
reproductive parts.

Hair develops from a group of
epidermal cells at the base of a hair
follicule that divide and grow until
they are pushed up and out and are
dead.
SO HAIR IS DEAD- What type
DERMIS
of dead cells do you think
they are? DISCUSS and come
up with an answer.

ANSWER: Once the cells get pushed up
they become the keratinized dead
epidermal cells.

Think back to what we talked about with
Melanin and skin color. HOW do you think
genetics and melanin determine hair
color? DISCUSS as a group and come up
with an answer.
DERMIS

Answer: Genes determine the type and
amount of pigment the melanocyte cells will
produce. So your hair follicles have
melanocyte cells at the base of them.

If these cells at the base of the follicle
produce a lot of melanin the hair will be
darker.
 When
you get older how
does your hair start to
turn gray and then white?
DERMIS

ANSWER: The melanocyte cells eventually
over time die and stop producing melanin.
A person with RED hair is the
exception- they have a pigment
called: Trichosiderin.

DERMIS

Arrector Pili muscle: a smooth muscle
attached to the hair follicle.

Why do you think your skin would need a
muscle attached to the hair? What does it
do?

Answer: Causes your hair to “stand up”
when you have the goosbumps- either
emotional response or cold.
 Sebaceous
Glands: associated
with hair follicles. Secrete oil
called sebum through small
ducts into the hair.
 Helps
keep hair and skin soft
and waterproof.
DERMIS
 SWEAT
GLANDS: There are different
types of sweat glands.
◦ Eccrine glands: respond to a rise in
temperature and are located on the
forehead, neck and back where they
produce droplets of sweat to cool the
body down.
◦ Apocrine glands: become active at
puberty or when a person is
emotionally upset. (arm pit region or
groin).
DERMIS

Sweat Gland:

Sweat glands: sweat is more than just
water- contains salts and other wastes.

Sweat glands help regulate body
temperature.
DERMIS
SUBCUTANEOUS LAYER
Beneath the dermis
 Consists of Loose Connective tissue and
Adipose.
 Contains most of the blood vessels for
supplying the epidermis nutrients
 Also insulates- conserving body heat and
keeps too much heat from coming into
the body.


THE THREE LAYERS:
LABEL THE
DIAGRAM:
THE SKIN: