Download Stratum Corneum

Start Ch. 5 Notes
Wednesday:
 Notes
 Rip Art
Thursday:
Review Questions
Quiz over rip art
Friday:
Vocab Quiz
Lab Activity
CH 5: INTEGUMENTARY SYSTEM
OBJECTIVES
1.
2.
List functions of skin
Explain role of skin in
temperature regulation
3. Describe layers of skin and
characteristics
4. Explain factors that affect skin
color
5. Describe accessory organs of skin
INTEGUMENTARY SYSTEM
Integument: covering
Cutaneous: of or relating to skin
Consists of skin and accessory organs
Accessory organs:
Hair Follicles
Skin Glands
Nails
Skin is the body’s outer covering and its largest
organ.
FUNCTIONS
1. Protection
2. Temperature
Regulation
3. Vitamin D
4. Sensory
5. Excretion
Structure of Skin
Epidermis
Dermis
Hypodermis
( subcutaneous)
Epidermis
1. Corneum
2. Lucidum
3. Granulosum
4. Spinosum
5. Basale
Dermis
1. Papillary
2. Reticular
Hypodermis
( subcutaneous)
Structure of Skin
EPIDERMIS
Tissue type: Stratified Squamous
Epithelium
Keratinocytes: make up 90% of cells in
epidermis
EPIDERMIS
Most Superficial
No direct blood supply: AVASCULAR
Nutrients must diffuse into the epidermis
CELLS IN THE EPIDERMIS
1. Keratinocytes – produce a protein called
keratin
2. Melanocytes - make dark skin pigment
melanin
3. Merkel cells – associated with sensory nerve
endings
4. Langerhans cells – macrophage-like dendritic
cells
* CELLS MIGRATE FROM BASALE LAYER TO
CORNEUM.
* BY THE TIME CELLS REACH SURFACE,
LITTLE MORE THAN KERATIN FILLED SACS CALLED KERATINOCY TES
* DESQUAMIFICATION: SHEDDING OF
OUTERMOST LAYER OF A TISSUE
Your skin constantly sheds dead cells, about
30,000 to 40,000 every minute! That’s 9
pounds per year!
Stratum Corneum:
 rows of dead cells
 Soft keratin, Moisture lock
Stratum Lucidum:
Stratum Granulosum:
Statum Spinosum:
Stratum Basale:
Stratum Corneum:
Stratum Lucidum:
Found in areas of thick skin
Palm, sole of foot
Stratum Granulosum:
Statum Spinosum:
Stratum Basale:
Stratum Corneum:
Stratum Lucidum:
Stratum Granulosum:
Thin layer
Granular cells (contain protein granules)
Statum Spinosum:
Stratum Basale:
Stratum
Stratum
Stratum
Stratum
Corneum:
Lucidum:
Granulosum:
Spinosum:
Cells interlock to support skin
Resist tension
Langerhans cells (found more here than
other layers) assist with immune
system
Stratum Basale:
Stratum Corneum:
Stratum Lucidum:
Stratum Granulosum:
Statum Spinosum:
Stratum Basale:
Single layer of cells
Rest on basement membrane
Cells divide continuously
Older pushed to surface
Melanocytes & Merkel cells here
LAYERS (ON LEFT) & CELL T YPES (ON RIGHT)
CHECK YO’SELF
Review
questions
REVIEW
1. The functions of the skin include all of
the following except:
a. Taking in nutrients
b. Preventing entry of microorganisms
c. Retarding water loss
d. Regulating body temperature
REVIEW
1. Which layer of the Integumentary
System is the foundation for the skin?
a. Epidermis
b. Hypodermis
c. Dermis
d. Stratum Corneum
REVIEW
1. Which of the following is NOT
considered an accessory organ of the
Integumentary System?
a. nails
b. hair
c. arteries
d. glands
REVIEW
1. Which of the following cell types is
responsible for sensory in the
epidermis?
a. Langerhans
b. Keratinocytes
c. Melanocytes
d. Merkel