Transcript The Integumentary System

The Integumentary System
Integumentary System
Integumentary system =
Skin
Nails
Hair
Glands
Nerve endings
Integumentary System:
Functions
PROTECTION from:
Mechanical damage
Chemical damage
Bacterial damage – antibacterial
secretions
UV radiation – melanin pigment
protects
Thermal damage – cold/pain
receptors
Dessication – keratin waterproofing
Even more functions…
Helps with heat loss or heat retention –
sweat glands and capillaries
Helps excrete urea – perspiration
Makes Vitamin D – sunlight
converts cholesterol molecules in our
skin
Skin Structure
2 Types of Skin Tissue
Epidermis
Keratinocytes that can make the
protein keratin (become hard &
tough)
Dermis
Connective tissue that contains
glands, capillaries and nerves
Epidermis
The Stratums
Corneum
Lucidum
Granulosum
Spinosum
Basale
College Life
Gives Snoopy
Brains
Stratum Basale
These are the “stem cells” of skin
As they mature, they climb the layers
of epidermis
Melanocytes are here and make
melanin (keratinocytes gobble up the
melanin)
Melanin Pigment
Melanin Pigment Protects Nucleus
Stratum Spinosum
Stratum Granulosum
Stratum Lucidum
By this point, cells are full of keratin
and are dead
Stratum Corneum
20 to 30 layers of dead skin cells filled
with keratin
Waterproofing material
This layer is thicker on palms and
soles
“Beauty is only skin deep”?!
Harlequin Ichthyosis
Autosomal recessive
Generate in 1 day the amount of skin
a normal person would generate in 14
days
Constant care, moisturizing, bathing
to remove keratin layer
Oldest living person is 24
Blind from corneal abrasions
Harlequin Ichthyosis
Dermis: Papillary and Reticular
The Dermis – Home of the Tattoo
Tattoo Removal
Dermabrasion
Salabrasion (rub with salt)
Cryosurgery
Excision
Latest: Q-switched lasers
Different lasers for different color
pigments
Black, purple, red easiest
Yellow, green hardest
Burns: 1st Degree
1st degree: only epidermis is
damaged
Heal in 2 to 3 days without a
problem
Sunburn without blistering
Burns: 2nd Degree
Injury to the epidermis and part of the
dermis
Characterized by pain, redness,
swelling, and blisters
Still enough epithelial cells to
regenerate
“Partial-thickness”
burn
Burns: 3rd Degree
Worst
Entire epidermis and dermis is
destroyed
No more stem cells, no blood
supply
No nerve endings (no pain, but
only at first)
Must skin graft
Examples of Burns
Rules of Nines
Skin Grafting
Albinism: Melanocytes, but no
melanin
Albinism
Visual Problems in Albinism
Vitiligo: Destruction of Melanocytes
Psoriasis
Silvery, scaly patches
of skin overgrowth
Prevalence 2 – 3 %
Onset: 15-25 years
of age
Thought to be
autoimmune
Cold Sores
Viral infection
Herpes
Simplex Type 1
Hansen’s Disease (Leprosy)
Spinalonga, Greece
3 Main Types of Skin Cancer
Basal cell carcinoma:
most common
least malignant
sun-exposed areas
99% cure rate with
excision
3 Main Types of Skin Cancer
Squamous cell
carcinoma:
Shallow ulcer that won’t
heal
Sun-exposed areas
Can grow rapidly
Metastasizes (travels to
lymph nodes and other
parts of the body)
3 Main Types of Skin Cancer
Malignant melanoma:
Only about 5% of all skin
cancers, but incidence is on
the rise
Arises from accumulated
damage to DNA in a
melanocyte
Chance for survival: 50%
ABCD rule
ABCD Rule of Malignant
Melanomas
Asymmetry: 2 sides of the pigmented
spot do not match
Border irregularity: borders are not
smooth but exhibit indentations
Color: pigmented spot contains areas
of different colors (black, brown, tan,
red)
Diameter: spot is larger than 6 mm in
diameter (size of pencil eraser)
Skin Appendages
Sebaceous (Oil) Glands
Sweat Glands
Hair and Hair Follicles
Nails
Sebaceous Glands
Everywhere except palms and soles
Usually empty into hair follicle
Makes “sebum”
Keeps skin soft/moist
Antibacterial
Increased production during puberty
When gland is blocked:
whiteheads/blackheads
Sweat Glands: 2 Types
Eccrine glands: make “sweat”
Clear secretion of water, salts, urea,
lactic acid
Acidic, inhibits bacteria
Apocrine glands: axilla (armpit) and
genital area
Contain sweat plus proteins/fats (not
antibacterial)
Hair Follicles
Hair follicle: makes
the hair
Hair root: alive
Hair shaft: dead
material; almost all
protein
Arrector pili: tiniest
muscles; goose bumps
Nails
Body:
thickened
keratin
Root,nail
fold and nail
bed are
alive
Lunula:
white moon