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					Integumentary System & Body

            Ch. 4

     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
       Epithelial Membranes
• 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:
• Serous
  – 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.
But Repairable!
    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
                 the skin.

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
      integumentary system?
• No.
• 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
                                   Your epidermis
                                    is completely
                                  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.
                                  90%grow/10% rest.
                                 Loose: 100/day
What are the parts of the hair follicle?
Fig 5.3
• 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
    hair follicle
  – 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
  Lun= moon
   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.
  Excrete waste.
• 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

                                 Fat Lab
Diseases of the Skin and Aging

         Brace Yourself
         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
           Other Problems
• 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:
                                     Testosterone overload
                                                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

• .
                 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

                      Skin Cancer
      Developmental Aspects
• 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
            Cosmetic Collagen
• What is collagen? A protein that makes
  tendons, ligaments, and other connective
  tissues strong.
• 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).

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