Integumentary system

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Integumentary system

• The skin and accessory organs (Hair, membranes,
  glands, etc)

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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.

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Membranes

• Serous membranes Basically they cover
• areas such as the
• thoracic cavity
• the heart and
• lungs area, and
• ventral cavity.

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Membranes

• Serous membranes

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Membranes

• Mucous membranesare 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.

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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?

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Membranes
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Membranes

• Synovial membranes is the soft tissue that lines
  the non-cartilaginous surfaces within joints
  (synovial joints).
• They secrete a fluid to lubricate the joints.

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Membranes

• Synovial membranes

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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.

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Membranes

• Cutaneous membranes

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THE THREE LAYERS OF SKIN

1. EPIDERMIS
2. DERMIS
3. SUBCUTANEOUS LAYER

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EPIDERMIS

• The outer layer
• Composed of
• stratified
• squamous
• epithelium

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EPIDERMIS
Contains five separate layers Stratum Corneum-
outer most layer- mostly 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.
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• 5 Layers of Epidermis

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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)

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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.

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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?

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EPIDERMIS

• HOW or why do you think people have different
  colors of skin then? DISCUSS with your table and
  come up with an answer!

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EPIDERMIS

• 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.

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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.

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EPIDERMS

• 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?

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EPIDERMIS

• 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 temperature- here is one way it
  doe that!

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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.

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DERMIS

• Contains sensory receptors (touch receptors,
  temperature receptors- sweat glands, and so
  forth)
• Also contains the HAIR FOLLICLES, SWEAT GLANDS,
  and SEBACACEOUS GLANDS

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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 of dead cells do you
think they are? DISCUSS and come up with an
answer.
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DERMIS

• 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.

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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?

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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.

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• 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.

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DERMIS

• Sebaceous Glands associated with hair follicles.
  Secrete oil called sebum through small ducts into
  the hair.
• Helps keep hair and skin soft and waterproof.

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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).

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• Sweat Gland

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DERMIS

• Sweat glands sweat is more than just water-
  contains salts and other wastes.
• Sweat glands help regulate body temperature.

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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.

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• THE THREE LAYERS

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THE SKIN

• LABEL THE
• DIAGRAM