1. Integumentary System
Chapter 4

2. Classification of Body Membranes
Epithelial Membranes
Cutaneous membrane -skin
made of keratin
tough protein found in skin, nails, and hair
Keratinocytes - cells that make keratin
Stratified squamous

3. Classification of Body Membranes (cont.)
Mucous membrane
Secretes mucus
Found lining the respiratory and digestive tracts

4. Classification of Body Membranes (cont.)
Serous membrane
Simple squamous
Two layers
Visceral – covers outside
the organ
Parietal – covers the
visceral layer
Has serous fluid

5. Classification of Body Membranes (cont.)
Specific names of serous membrane
Peritoneum – abdominal
Pleura – around lungs
Pericardium – around
the heart

6. Structure of the Skin Roles Protection from airborne pathogens
Maintenance of normal body temperature
Storage (of fat)
Synthesis (of vitamin D)
Excretion (of salts, water, and waste in sweat)

7. Structure of the Skin (cont.)
Tissues of the skin
Epidermis
Stratified squamous epithelium
Basement membrane
Dermis
Largely connective tissue
Many nerves and blood vessels
Smooth muscle
Hypodermis
Adipose tissue and more loose connective tissue

9. Structure of the Skin (cont.)
Epidermis
Stratum corneum
dead, keratinized cells
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale – base
Rapidly dividing cells
Have melanocytes
Mnemonic device
Come
Let’s
Grab
Some
Beers

10. Skin Color Three pigments attribute to skin color Melanin Carotene
Found in stratum basale
Light-skinned people produce less melanin than dark-skinned people
Carotene
Stored in stratum corneum
Produces an orange-yellow color found in vegetables
Hemoglobin
Found in red blood cells (erythrocytes)
Provides red color in light-skinned people

11. Appendages of the Skin Cutaneous Glands
Exocrine glands – release their
secretions via ducts
Two types of exocrine glands
Sebaceous glands
Secrete sebum (oil)
Keeps the skin soft and prevents
the hair from becoming brittle
Has chemicals that can kill bacteria

12. Appendages of the Skin (cont.)
Sebaceous glands
Whiteheads form when sebaceous
gland’s duct become blocked with
sebum
Blackheads form when whiteheads
dry

13. Appendages of the Skin (cont.)
Sudoriferous glands
Secrete sweat
Two types of sweat glands
Eccrine gland – produce sweat
and maintains
body temperature
Apocrine gland – produce musky,
unpleasant odor when bacteria
is present; found in armpits
and groin

14. Appendages of the Skin (cont.)
Hair and Hair Follicles
Shaft – Hair that is exposed
Root – Part of hair enclosed
in hair follicle
Follicle – Part of the scalp
that produces the hair
Arrector pili – small band
of smooth muscle cells
When muscle contracts, hair
is pulled upright forming
“goose bumps”

16. Appendages of the Skin (cont.)
Nails – composed of keratin
Nail plate – fingernail
Nail bed – lies proximally to the nail plate
Lunula – white crescent that is the basal part of the nail
Cuticle – strip of hardened skin at the base and sides of a nail plate

18. Aging and the Integumentary System
Declines in:
Cell division in stratum basale
Melanocyte production
Glandular activity
Hair follicle function
Blood supply to skin
Rate of repair

19. Problems of Skin Lesions - any abnormality of tissue in the body
infections (bacterial, viral, fungal, parasitic)
inflammatory reactions
allergens
Hyperkeratinization
excessive development or retention of keratin in the epidermis
Blister
Epidermis and dermis separate and fluid enters the space

20. Burns
A burn is tissue damage and cell death caused by intense heat, electricity, UV radiation (sunburn), or certain chemicals.
Severity of burns
First-degree – only the epidermis is damaged
Second-degree – the epidermis and upper region of the dermis is damaged
Third-degree – destroy the entire thickness of the skin
Number one threat for burn victims
Infection
Burning of the palms of hands and soles of feet can result in death

21. Burns (cont.)