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Integumentary PPT

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					THE INTEGUMENTARY SYSTEM
More Morphemes:
   Cutane/o
   Cyan/o
   Erythro
   Epi
   Lip/o
   Melano/o
   Sub-
   Cornu-
   Keros-
   Demos-
   Soma
   papilla
4 types of skin:
 Mucocutaneous (both skin and mucous membrane)
  junction of the mucous membrane, hairy skin, lips, and
  tongue.
 Mucous membrane: lining the inside of body orifices.
 Glabrous: skin without hair.
 Hairy: skin with hair.

Accessories

 Hair (Keratinized protein secreted by cells)
 Nails (Hard keratinized protein)
Integumentary System

  Skin
  Skin is like the ideal coat
 a. Water resistant
 b. Stretchable (2.2 m2) (~11 lbs)
 c. Washable
 d. Auto-repairing (Cuts, tears, & burns)
 e. Lasts a lifetime
Functions
 Protection
   dehydration
   UV
   Immunity(chemical & physical barrier):
     bacterial
     viral

 Most substances cannot penetrate; exceptions are:
   a. Vitamins A,D,E,K
   b. Oxygen & Carbon dioxide (in limited amounts)
   c. Organic solvents (paint thinner, acetone) which
  dissolve cell lipids
Function cont.

   d.      Oleoresins of certain plants
      (e.g. Poison Ivy, Oak, Sumac, etc…)
  e.      Salts of heavy metals
     (e.g. Lead, Mercury, Arsenic, etc…)
 Sensation
   Pain
   Pressure
   Temp
   Touch
 Storage
   Fat
    glucose
   Water
   Vitamins
   salts
Skin Functions

 Homeostasis:
   body temperature
   Wound healing


 Vitamin D synthesis (Needed to absorb
  calcium in the digestive tract)
 Blood reservoir (Blood can be shunted to
  other organs in need e.g. skeletal muscles)
 Excretion – Water, salt, ammonia, urea,
  and uric acid are excreted in sweat
Epidermis
(starting top to bottom)

        Stratified squamous epithelium
        ~30 days (basale corneum)
   Five layers
1. Stratum corneum (Horny layer)
    a.    Top layer
    b.    fully keratinized
    c.    20-30 cell layers
    d.    Function is:
    e.    Glycolipids: Why?
    f.    40 lbs shed in a lifetime
    g.    Too far from blood vessels for diffusion so cells die
 Epidermis Con’t
2.        Stratum granulosum (Granular layer)
     a.      3-5 cell layers
     b.      Keratinocytes (from spinosum)
          i. produce keratin
          ii. squamous cells flatten (dehydrate b/c keratohyalin) as they are
               pushed upward
          iii. Desmosomes & keratin fibers cross


3.        Stratum spinosum (Prickly Layer)
     a. Keratinocytes shrink but desmosomes hold in place- spiny
       a. Melanin granules (UV protection) from melanocytes (from
          basale)
     b. Langerhan’s (macrophage):
       i. Pathogens
       ii. Cancerous cells
Epidermis Con’t

4.     Stratum basale or germinativum
     a. Deepest layer of the epidermis
     b. Single layer thick
     c. Epidermal ridges=
       i. Surface area
       ii. contours
     d. Contain:
      i. Germanative cells/stem
      ii. melanocytes
      iii.Merkel cells (Fine touch receptors)
Epidermis Con’t

5.          Stratum lucidum (Clear layer)
     a. a.      Found only in thick skin between the
         Stratum granulosum and Stratum corneum
       i. Palms of hands
       ii. Fingertips
       iii. Soles of feet
     b. Only a few cell layers thick
     c. Densely packed
     d. Filled with keratin
Dermis

  Areolar Tissue
    Strong flexible connective tissue
      Collagen
      Elastin
      reticular fibers
    Papillae
      Grip
      Fingerprints/footprints: 20% of thickness
  Reticular layer of lower dermis 80% of
   thickness made up of dense irregular
   connective tissue
Pigments which affect skin color

Melanin
THE ONLY PIGMENT
PRODUCED IN THE SKIN –
  varies in color from yellow
  to brown to black
Key
             Phenotype
# Genotype
             Black Skin
1 M1M1M2M2
             Dark Brown Skin
2 M1M1M2m2
             Brown Skin
3 M1M1m2m2
             Light Brown Skin
4 M1m1m2m2
             White Skin
5 m1m1m2m2
Pigments which affect skin color

Carotene
Yellow/orange pigment
  found in plants which
  accumulates in the thick
  epidermis…this is why
  the soles of your feet
  appear orange


* The amounts of these two
   pigments determine a
   person’s skin color
    Pigments which affect skin color

    Cyanosis – bluish hue to the skin due to heart failure
    or respiratory distress
.   Erythema – reddish hue to the skin due to blushing,
    fever, hypertension, polycythemia
.   Pallor or blanching – pale skin hue due to emotional
    stress (fear, anger), anemia, or hypotension
.   Jaundice – yellow hue to the skin due to liver disorder
.   Bronzing of the skin due to Addison’s disease (adrenal
    cortex of the kidney hypofunctions)
.   Hematoma – (Bruises) blood leaks out of capillaries due
    to trauma and clots under the skin
Dermal Structures
   Sudoriferous (sweat) glands ( 2.5 million per person)
   2 types:
1. Merocrine– Most abundant sweat gland covers most of
  the body
     a. Exocytosis
        Pores skin surface (500 mL per day… up to 12 L per day)
     b. 99% water
     c. Solutes:
          a.   sodium chloride
          b.   vitamin C, urea
          c.   uric acid, ammonia
          d.   lactic acid (attracts mosquitoes)
     d. Hot sweat: forehead and radiates outward
     e. Cold sweat (fright or nervousness):palms, soles, and axillae (armpits) and
        radiates outward
 Merocrine
 Simple tubular glands
 Excretory duct coiled
 Empties directly onto
  surface of skin
Dermal Structures
2.        Appocrine - Located in the axillary and anogenital areas
     a. Secreted into hair follicles
     b. Stimulated by sexual hormones
     c. Contains
       i.   sweat
       ii. Lipids
       iii. proteins
     d. Appears viscous with a white/yellow hue
     e. odorless upon secretion, but bacteria decompose molecules forming body
        odor
     f. Increase of secretions during pain, stress, or sex but physiological
        function is unknown
3.     Ceruminous glands are modified apocrine glands found in the
      external ear canal
     a.    secrete cerumen (ear wax)
4. Mammary glands are modified apocrine
     a.    secrete milk
Apocrine
 Does not open directly to
  skin
 Empties sweat to upper
  part of hair follicle
 Lumen of secretory tubule
  much larger
   Dermal Structures

   Sebaceous (Oil) glands
1. Located all over body except palms and soles
2. Secrete sebum:
  a.   lubricates and softens hair and skin
  b.   prevents water loss
  c.   bactericidal properties
3. Whitehead
  a.   duct is blocked by accumulated sebum & staphylococcus
       infection begins
4. Blackhead
  a.   whitehead oxidizes & dries out
Dermal Structures
           Hair
1.        Body hair function:
     a.     detect insects before they bite or sting
     b.     Possible vestigial structure for warmth
2.        Found all over body except palms, soles, lips, nipples,
          and genitalia
3.        Hair on the scalp:
     a.      prevents heat loss
     b.     UV protection
     c.     protects against trauma
4.        Eyelashes shield eyes from foreign particles
5.        Nose hair: filters respiratory passages
6.        Hair appearance due to shaft shape
          (Flat shaft = curly hair, oval shaft = wavy hair, round
          shaft = straight hair)
Dermal Structures
7. Hair coloration due to deposition of melanin
  a) Grey hair and albinism is lack of melanin
8. Hair growth:
  a) Controlled by androgens (testosterone)
           Hirstutism can be caused by:
             Cushings disease ( increased cortisol)
             polycystic ovarian syndrome
9. Average growth ~ 2 mm/wk
10. ~100 hairs fall out daily
  a) Baldness or thinning results from decreased
        growth compared to new growth
Hair Coloration

1. Two kinds of melanin:
  a. Eumelanin: brown  black (ferrous rich)
    i. Grey hair: presence of small amount of black
        eumelanin without any other pigmentation
    ii. Blond: presence of small amount of brown
        eumelanin
  b. Pheomelanin: red strawberry blond


2. Hair type will depend on type of melanin,
   amount, and density of distribution
Dermal Structures

Hair follicle
1.        Extend from epidermis into the dermis


2.        Form hair bulb and root plexus
     i.     Nerves surrounding the bulb ( can feel stimuli of hair due to
            nerves)
3. Arrector pili muscles attach to hair and epidermis
      (stratum basale)
     i.     cause Goosebumps upon contraction
4. Trap air close to skin for warmth
5. Make us appear larger to predators
Dermal Structures

Nerves
1.      Meissner’s corpuscles – light touch
2.    Merkel’s disks – light touch
3.    Pacinian corpuscles – deep pressure
4.    Ruffini’s corpuscles – deep pressure and stretch
5.    Bare nerve endings – pain, heat, cold


Nails
1.    Analogous to hooves or claws of other animals
2.     Nail matrix responsible for growth of new nail pushing
     nail distally
Meissner’s corpuscles
•Light touch
•Low freq
vibrations
•Locations
(glabrous
skin):
  • Palm
  • Fingertips
  • Soles of feet
  • Face/lips
  • Tongue
  • Genitalia
Merkel’s disk
•Light touch
•Aligned with
Papilla
•Discerns: shapes,
edges, rough
textures
•Particularly
dense:
   • Lips
   • Fingertips
   • External
     genitalia
Bare nerve endings
•No complex
sensory
structures
•Detect pain &
temp
•Branched
terminations of
axons (lose
myelin sheath)
Pacinian corpuscles
•Larger/ onion
like
•Detect deep
pressure
changes and
vibration
•Sensitive to
high freq
  • Vibration
  • Tickle
•interosseous
membranes
Ruffini’s corpuscles
•Sensitive
cutaneous
stretching of
limbs or digits
•Location:
  • Deep skin
  • Ligaments
  • tendons
1.    Papillae                      13. Errector pilli muscle
2.    Meisser corpuscle                   (dermal papillae muscle)
3.    Free nerve endings            14.   Adipose
4.    Sebaceous gland               15.   Hypodermis
5.    Hair shaft                    16.   Dermis
6.    Root sheath                   17.   Epidermis
7.    Pacinian corpuscle            18.   Hair shaft
8.    Errecto pilli muscle
9.    Sweat tubule
10.   Merocrine free sweat gland
11.   Apocrine sweat gland
12.   Hair follicle (shaft, bulb,
      root)
Nail
•E- Eponychium
(corneum)
  • Barrier
•N- Nail plate
(heavily
keratinized)
•H-hyponychium
(corneum)
attachment
•Dermis/Phalanx
•Lunula
hidden vessels by
root (half moon)
Pathophysiology
Cancer & Burns
 Skin Cancer
 Benign (Non-spreading) vs. malignant (spread into
other tissue)

 Basal cell carcinoma – most common & least
malignant
1. Shiny lesions in the stratum basale which grow
into the dermis
2. 99% cure rate after surgery
Squamous Cell Carcinoma

Squamous cell carcinoma
1. Cells of the stratum spinosum form a lesion
   which appears small red and round
2. Lesion usually forms on scalp, ears, lips, or
   hands
3. Grows rapidly and can metastasize if not
   removed
4. If caught early & removed chance of cure is
   good
 Melanoma
Melanoma (5% of skin cancers)
1. Cancer of the melanocytes
2. Most dangerous of the skin cancers
3. Appears as a brown or black spreading patch
4. Metastasizes rapidly to lymph and blood
5. ABCDE rule to detect
  a. Asymmetry – two sides don’t match
  b. Border irregularity – not smooth & have
   indentations
  c. Color – more than one color
  d. Diameter – larger than 6 mm in diameter
  e. Elevation – elevated above skin surface
How do you get rid of basal cell
carcinoma?
Ulcerative BCC
Ulcerative SCC
SCC with Facial Lymph Node
Metas
Melanomas
Burns
    1st degree
   only epidermal damage e.g. sunburn
Heal in 2-3 days

   2nd degree
 epidermis & upper dermis (papillary) damaged
 Blisters form (Fluid collects between dermis &
  epidermis)
 Heal in 3-4 weeks
 Critical if more than 25% of the body is
    affected
Burns
3rd degree – epidermis & all of dermis is damaged
1. Charring of muscle is common
2. Nerve endings are destroyed so not painful
3. Fluid loss can be catastrophic (dehydration &
   electrolyte imbalance lead to renal failure and
   shock)
4. Infection can be rampant
5. Skin grafting necessary Critical if more than
   10% of the body is affected or if the face,
   hands, or feet have 3rd degree burns
1st Degree Burns
2nd Degree Burns
Scalding Burns
(2nd Degree)
3rd Degree Burns
Campfire burn
Bathtub scalding
Burn Contracture
Skin Grafting
Debriding
Before & After Skin Graft
Pitting Edema
Umbilical Hernia
(Before & after Valsalva Maneuver)
Epigastric
Hernia
Abnormal Colors of the Skin
 Albino : the absence
  of pigmentation



 Erythema : reddish
  color of skin



 Jaundice : yellow
  discoloration of skin
Cyanosis : a bluish discoloration of the skin
due to a lack of oxygen
Skin Eruptions


                  Macules : flat spots
                   on the skin
 Papules : firm raised
  areas




 Vesicles : fluid-filled
  sacs or blisters
 Pustules : pus-filled
  sacs




 Crusts : areas of
  dried pus and blood
  (scabs)
 Wheals : itchy,
  elevated areas with
  an irregular shape




 Ulcer : a deep loss of
  skin surface
  Decubitus Ulcers
  (Bedsores)
 Open sores in the
  skin and underlying
  tissues due to
  pressure over a
  bony area
 Cuts off the blood
  supply and the
  tissue dies
Diseases

Acne : an inflammation
   of the sebaceous
   glands
 - Caused by a blockage
   of the hair follicles
   with dirt, cosmetics,
   excess oil, and/or
   bacteria
Alopecia : baldness; a
  permanent loss of
  hair on the scalp
Verrucae : rough, hard, elevated, rounded surface
  forms on the skin - warts
 - Caused by a viral infection of the skin
Skin Cancers :
 - Forms that are usually localized – don’t spread to
   other areas of body
Basal cell carcinoma      Squamous cell carcinoma
Skin Cancers
- Form that CAN spread to other parts of the body
  and be fatal
               Malignant Melanoma
Signs of Malignant Melanoma

Asymmetrical in shape
Borders of lesion are scalloped or irregular
Colors are varied – black, brown, white, red
Diameter is larger than a pencil eraser
Bibliography
“Integumentary system” www.unit5.org/biology/PowerPoints/Integumentary System.ppt accessed
     9-24-09


“Blue histology”
    http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Integumentary/Integum.htm#Dermis
    accessed 9-24-09

				
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