Transcript Intriguing Integumentary System

Intriguing Integumentary
System
The Skinny on the Skin
System Anatomy
*Skin
*Sweat
*Oil Glands
*Hair
*Nails
System Physiology-PROTECTION
• Mechanical Damage (Injury)
• Chemical Damage (acids, bases)
• Bacterial Damage
• UV Radiation (melanin)
• Thermal Damage (temperature receptors)
• Drying Out (outer layer is hard)
System Physiology
Temperature Regulation
*Rich blood supply and
sweat
Excretion
*Urea, salt, and water
System Physiology
Production of Proteins
*Vitamin D
Sensory Receptors
*touch
*pressure
*pain
*temperature
The Skinny on the Skin
1. Epidermis
– Outer layer
– Stratified Squamous
2. Dermis
– Fibrous Connective
- Blister
– When the two layers
get rubbed and
separate
Subcutaneous Tissue
• Adipose anchors skin
•
•
to organs
Shock absorber
Insulates deeper
tissues
I. Epidermis
• Avascular-no blood
•
supply (shaving)
Made of up to 5
layers
Skin Layers
A. Stratum Corneum
• 20-30 cell layers thick
• Outer layer
• DEAD
• Contains Keratin fibers (water repellant)
• Constantly worn away
• You get a new epidermis every 35-45 days
More Skin Layers
B. Stratum Lucidum
Only in hairless skin
Extra thick
Palms of hands, soles of feet
C. Stratum Granulosum
*Cells die
D. Stratum Spinosum
More Skin Layers
•
•
•
•
•
•
Stratum Basale
Deepest Cell Layer of Epidermis
Constantly in Cell Division (millions of
new cells daily)
Cells get pushed to surface as they grow
Melanin is in this layer
Receives nourishment from dermis by
diffusion
Diagram of the Skin Layers
F. Tanning
• Melanocytes produce
•
•
melanin in the
stratum basale
Sunlight stimulates
the melanocytes to
produce melanin
(brown color)
Melanin shields the
nucleus from the
sun’s UV rays
Basal Cell Carcinoma
• Happens when cells in stratum basale
divide uncontrollably
• Usually Slow growing and easy to remove
Squamous cell carcinoma
• Happens in stratum spinosum
• Grows rapidly
• Needs to be removed and followed with
radiation
Malignant Melanoma
• Cancer of melanocytes
• 50% survival rate
• Needs removal, chemotherapy
• Can spread to other parts
Signs that a mole might be
Cancerous
A. Asymmetry – mole is not
symmetrical
B. Border – jagged borders
C. Color – multiple colors
D. Diameter – larger than
¼ inch (size of pencil
eraser)
E. Evolution – mole is
evolving or changing
II. Dermis
-Strong and Stretchy (hide)
A. Papillary layer
-Upper layer of dermis
-Dermal papillae – give
nutrients to epidermis
-Ridges form Fingerprints:
increase gripping,
friction- hands/feet
--pain and touch
receptors live here
Dermis - Cont
B. Reticular Layer
-Deepest layer of dermis
-Contains BLOOD
VESSELS!
-Sweat and Oil glands
-Deep pressure
receptors
-Phagocytes to eat
bacteria
-Collagen fibers-keep
skin hydrated
-Elastic fibers-decrease
with age - wrinkles
Skin Appendages
Sebaceous Glands (Oil)
• All over the body, EXCEPT palms and soles of
•
•
the feet
Usually empty into a hair follicle
Make SEBUM: Oil and fragmented cells
-Lubricant: Keeps skin soft
-Prevents hair from being brittle
-Chemicals that kill bacteria
•
Yuk
-Whitehead--when oil gland is blocked
-Blackhead--dries and darkens
II. Sudoriferous Glands
(SWEAT)
A. Eccrine
-Produces sweat
(water, urea, salt,
uric acid)
-Acidic (pH 4-6,
inhibits bacteria
-Found all over body
-Help Regulate heat
B. Apocrine
-Found in Genital
and Axillary regions
-Large
-Secrete Fatty Acids
and proteins also
-ODORLESS, but
stinks when bacteria
eats it!
First Degree Burns
Only Epidermis Damaged
Second Degree Burns
Epidermis and Upper Dermis Damaged
Third Degree Burns
Destroys whole thickness of skin