Transcript Integumentary System

Integumentary System
Skin and Its Appendages
Anatomy & Physiology
Skin or Integument
 Largest
organ in the body
 Integumentary System: denotes the
skin and its appendages
Structure of the skin
Layers of the skin
 Epidermis:
Outer, thinner layer
 Dermis: Thicker layer, connective
tissue
 Hypodermis: Subcutaneous layer,
superficial fascia
Thick Skin
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Refers to epidermal layer
only
Found: palms of hands,
soles of feet, fingertips
Each of the 5 layers
present
Dermal papillae:
fingerprints
No hair
Cell Types of Epidermis
Keratinocytes: contain
keratin, make up 90%
of epidermal cells
 Melanocytes:
contribute color to skin
 Langerhans cells:
immunological
reactions in skin

Cell Layers of Epidermis
Stratum corneum
 Stratum lucidum
 Stratum granulosum
 Stratum spinosum
 Stratum basale
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Stratum corneum (horny layer)
Flat thin squamous
cells
 Surface cells dead &
continually being shed
 Cytoplasm in cells
replaced by keratin
 Desmosomes hold cells
together
 Barrier layer of the skin
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Stratum lucidum (clear layer)
Nuclei absent
 Cells contain eleidin
which will be
transformed to
keratin
 Blocks water
penetration or loss
 Absent from thin skin
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Stratum granulosum (granular layer)
Keratinization begins
 2-4 layers deep
 Maybe absent in thin
skin
 Cells filled with
granules called
keratohyalin
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Stratum spinosum (spiny layer)
8-10 layers with
prominent
desmosomes which
appear spiny under a
microscope
 Cells rich in RNA
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Stratum basale (base layer)
Single layer of columnar cells
 Only cells which undergo mitosis
 Cells migrate from basal layer thru the
outer layers

Dermal-Epidermal Junction
 Contains
basement membrane
 Also contains a polysaccharide gel
that “glues” 2 layers together
Dermis
Thin papillary layer
& thick reticular layer
 Thickest on soles &
palms
 Thinnest on eyelids
& penis
 Mechanical strength
of skin
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Papillary layer
 Forms
the bumps,
dermal papillae
which project into
epidermis
 Allows us to grip
surfaces & creates
fingerprints
Reticular layer
More dense collagen & elastic fibers
 Serves as point of attachment for muscle
fibers
 Skeletal muscle: muscles of facial
expression
 Smooth muscle:
arrector pili muscles
on hair follicles
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Skin Color
 Determined
by quantity of melanin in
cells of epidermis
 All races have about the same number
of melanocytes but differ in amount of
melanin produced
 Sun can increase melanin production
Functions of skin
 Protection
 Sensation
 Movement
without injury
 Vitamin D production
 Excretion
 Immunity
 Temperature regulation
Heat Loss
 Evaporation
 Radiation
 Conduction
 Convection
Burns
 Predict
body
surface area to
determine how
much fluid to
replace:
 Rule
of palms
(1%)
 Rule of nines
First degree burn
Involves only the
epidermis
 No blistering or
scarring
 Sunburn
 Reddening of the
skin, mild discomfort
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Second degree burn
 Involves
epidermis &
dermis
 Blistering, pain,
swelling
 May scar
Third degree burn
Destruction of
epidermis &
dermis, may
involve underlying
tissue
 Severe scarring
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Appendages of the skin
 Hair
 Nails
 Skin
glands
Hair
 Lanugo
hair: fine hair covering fetus
 Vellus hair: replacement for lanugo
hair, first appears on scalp, eyelids,
eyebrows
 Terminal hair: Coarse hair that
replaces vellus hair-axillary, pubic,
beard, chest & hair on arms & legs in
men
Hair follicle
Stratum germinativum
develops into follicle's
inner layer and forms
the germinal matrix
 Small mound of
dermis protruding
into germinal matrix
is the papilla (contains
blood capillaries)
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Nails
Parts of the Nail
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Matrix- the thickened, proximal area of the nail
that is responsible for growth
Bed- the hard translucent visible part of the nail
 Root- the point of attachment under the skin
 Cuticle- the layer of skin that prevents dirt and
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bacteria from getting into the nail bed
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Free Body- the end of the nail that is not
connected to the skin
Glands
 Sweat
or sudoriferous glands
 Eccrine
sweat gland
 Apocrine sweat glands
 Sebaceous
glands
 Ceruminous glands
Eccrine sweat glands
Most numerous
 Over most of the
body
 Secretory portion
located in the
subcutaneous tissue
 Simple coiled
tubular gland
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Apocrine Sweat glands
Found in armpit,
areola of breast,
around the anus
 Large than eccrine
 Connected with
hair follicles

Sebaceous glands
 Secrete
sebum
into each
follicle
Ceruminous glands
 Modification
of apocrine sweat glands
 Open into ears
 Produce cerumen
Image Citations
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Slide 1: cross section of skin, 7/12/06,
http://vilenski.org/science/humanbody/hb_html/skin.html
Slide 3: Anthony’s Textbook of Anatomy & Physiology, Seventeenth Edition by Thibodeau &
Patton, Chapter 6.
Slide 5: Thick skin, 7/30/06, http://erl.pathology.iupui.edu/HISTO/LABE151.HTM
Slide 6: Melanocytes, 7/30/06,
http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Integumentary/Integum.htm
Slide 7: Thick skin trichrome, 7/30/06,
http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Integumentary/Integum.htm
Slide 8: Slide 43, Thick skin, 7/30/06, http://w3.ouhsc.edu/histology/Glass%20slides/43_09.jpg
Slide 9: Stratum lucidum human foot, 7/30/06,
http://oregonstate.edu/~hanba/Projector%20Slides/Projector%20Slides/Skin%20Stratum%20L
ucidum%20Human%20Foot-2.jpg
Slide 10: Stratum granulosum, 7/30/06,
http://anatomy.iupui.edu/courses/histo_D502/D502f04/Labs.f04/Lab14/s31.100x.i3.jpg
Slide 11: Stratum spinosum, 7/30/06,
http://anatomy.iupui.edu/courses/histo_D502/D502f04/Labs.f04/Lab14/s31.100x.i2.jpg
Slide 12: Stratum basale, 7/30/06, http://online-media.unimarburg.de/histologie/introhis/HIS/skin/skin06.gif
Slide 14: Dermis, 7/30/06, http://sprojects.mmi.mcgill.ca/dermatology/dermis.htm
Slide 15: Dermis, 7/30/06,
http://neuromedia.neurobio.ucla.edu/campbell/skin/wp_images/7%20dermis.jpg
Slide 16: 7/30/06, http://www.potterleague.org/Potter_Kids_Final/pet_body_lang.htm
Image Citations
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Slide 20: Wallace’s rule of nines, 7/30/06, http://www.sunmed.org/burns.html
Slide 21: First degree burn, 7/30/06, http://www.grossmanburncenter.com/origsite/web/care/causes.htm
Slide 22: Burn symptoms, 7/30/06, http://www.maggiessecret.com.au/burnsscalds.aspx
Slide 23: Third degree burn, 7/30/06, http://www.grossmanburncenter.com/origsite/web/care/causes.htm
Slide 26: Thibodeau & Patton, Anthony’s Textbook of Anatomy & Physiology,
Seventeenth Edition.
Slide 27: Thin Skin, 7/30/06,
http://biology.clc.uc.edu/fankhauser/Labs/Anatomy_&_Physiology/A&P201/Integu
mentary/hair_follicle_100x_PA112040labeled.JPG
Slide 28: Sebaceous gland and shaft of hair follicle, 7/30/06,
http://www.keele.ac.uk/depts/ms/resources/anatomy/histologyimages/t146.html
Slide 29: “Structure of nails”, Thibodeau & Patton, Anthony’s Textbook of Anatomy
& Physiology, Seventeenth Edition.
Slide 31: “Skin Glands”, Thibodeau & Patton, Anthony’s Textbook of Anatomy &
Physiology, Seventeenth Edition.
Slide 32: Dermis (Apocrine sweat glands), 7/30/06,
http://www3.umdnj.edu/histsweb/lab11/lab11apocrine.html