1. CHAPTER 10 INTEGUMENTARY SYSTEM

2. Functions Functions Protects from injury and infection
Perceives environment with sensory receptors
Stores energy & vitamins,
produces vitamin D from sunlight
Some hormones & fat soluble vitamins, drugs may be absorbed through skin
Regulates homeostasis:
Temperature
retaining body fluids
eliminating wastes

3. Skin The largest organ of the body Varies in thickness
1/50 inch (0.5 mm) in the eyelids (thinnest)
1/4 inch (6.3 mm) in the soles of the feet (thickest)
Abnormalities in the skin can be caused by:
anemia
respiratory disorders
liver disorders
cancer
shock.
Have students look at their own skin and notice the different degrees of thickness of their skin (eyelids, arms, skin between fingers and toes, soles of feet, and palms of the hands etc.). Ask students to identify reasons for the different thicknesses.

4. Interesting facts Shed 40 lbs of skin in a lifetime
Did not shave face or legs for 16 years:
Extra 1 lb of hair
30 feet long

6. Epidermis
Outermost layer
Composed of dead cells with an underlying layer of living cells
Keratinocytes (water repellent cells) make up 90%

7. Epidermis cont’d Contains: sebaceous glands (oil)
sudoriferous glands (sweat)
hair follicles
Melanocytes (produce melanin)
Melanin: pigment that gives skin its color

8. Dermis AKA: true skin Contains blood vessels nerves
Sensitive to pain, pressure, touch & temperature changes
Ask the students why they think the dermis is called the true skin.
Discuss how adipose tissue cushions and insulates the body’s organs.

9. Subcutaneous layer
Innermost layer
Contains:
adipose tissue, which cushions and insulates the body’s organs

10. Hair and Hair Follicles
in all areas except the soles of the feet and palms of the hands.
blocks foreign particles from entering the body through structures such as the nose and eyes.
The visible portion is called the shaft.
The hair follicle is the root with its covering.
Arrector pili muscle creates goosebumps
Color and texture are genetic trait
Ask the students why the soles of the feet and the palms of the hands are hairless.

11. Glands Three types of glands in the skin Ceruminous glands
Sebaceous glands (oil)
Located everywhere except palms of hands and soles of feet
Sebum (oil) causes the skin to be soft and waterproof
Sudoriferous glands (sweat)
Help regulate body temperature & excrete body wastes
Ceruminous glands
Located in the auditory canal of the ear
Secrete wax that helps protect the ear from infection and prevents entry of foreign bodies
Query students why they think there are no sebaceous glands in the palms of hands and soles of feet.

12. Nails Nails protect fingers and toes from injury.
formed from dead, keratinized epidermal cells.
Root is covered by skin at the area of attachment to finger or toe.
Lunula is the crescent-shaped white area near the root.

13. Structures of the Skin
Have students identify the structures of the integumentary system.
FIGURE 10-1 Structures of the skin.

15. Assessment Techniques
Dermatology is the study of skin.
Dermatitis is inflammation of the skin.
Skin lesions can be seen with visual inspection.
Size, shape, texture, and color often reveal cause.
Biopsy is used to identify the causative organism.
Discuss fingerprint uniqueness and fingerprinting. Ask the students if they have gone through the process of being fingerprinted. Some police jurisdictions provide free fingerprinting of children for identification purposes. Why is it a good idea for everyone to have his or her fingerprints on file?

16. Assessment continued
Fingerprints and toe prints are unique to each person.
Papillae (ridges) form regular patterns in the fingers, palms of the hands, and soles of the feet where the skin is thick.
Pattern of ridges may be linked to disorders such as Down syndrome.

17. Disorders of the Integumentary System
Acne vulgaris
Caused by increased secretion of oil related to increased hormones during puberty
Primarily affects the face, chest, and back
Albinism
Inherited disorder in which melanin is not produced
Alopecia
Baldness
Athlete’s foot
Contagious fungal infection of the foot
Discuss each of the disorders of the integumentary system on this slide and the following three slides. If the students have completed their assignment of further researching a specific disorder, have students present their findings to the class at this time or follow-up later.

19. Disorders of the Integumentary System
Cellulitis
Bacterial infection of the dermis and subcutaneous layer of the skin
May be caused by many different bacteria
Cleft lip or cleft palate
Upper lip has a cleft where the nasal palate does not close properly.
Decubitus ulcers
Sores or areas of inflammation that occur over bony prominences of the body
Ask the students if they have ever encountered contact dermatitis. What were the symptoms, causes, and treatment of contact dermatitis?

22. Disorders of the Integumentary System
Skin lesions
Differ in texture, color, location, and rate of growth
Note: Skin cancer is addressed in more detail in Slides

23. Skin Lesions

24. Sun and Skin Cancer
Ultraviolet (UV) radiation in sunlight may change DNA structure in skin cells.
UV exposure is the main cause of skin cancer.
Damage to the skin from the sun is cumulative.
Ask students to explain what is meant by “damage to the skin from the sun is cumulative.”

25. Warning Signs of Melanoma

26. Types of Skin Cancer Tanning beds may be a major cause of increase.
Basal cell carcinoma
Most common type of skin cancer
Starts in the lowest layer of the epidermis
Waxy, pearly growths or red, scaly patches
Commonly found on the face, arms, and hands
May alternate bleeding and healing
Increase in the number of basal cell carcinomas found in women younger than 40 years
Tanning beds may be a major cause of increase.
Discuss rationale for why tanning beds may be a cause of basal cell carcinoma.

27. Types of Skin Cancer Squamous carcinoma
Second most common type of skin cancer
Starts in the middle layer of the epidermis
Spreads more quickly than basal cell carcinoma
Red, scaly patches
Appears on areas of the skin most often exposed to the sun
Discuss areas of the skin most often exposed to the sun and how this exposure may be limited or prevented.

28. Treatment of Basal Cell and Squamous Cell Carcinomas
Surgery
Mohs microscopic surgery
Removes affected tissue by layers
Best cosmetic results
Radiation therapy
Chemotherapy
Photodynamic therapy (PDT)
Inactive drug is injected into blood vessels surrounding cancer cells.
Laser light is shined on skin, activating the drug and killing the cancer cells.
Ask the students why they think that Mohs microscopic surgery as a treatment for basal cell and squamous cell carcinomas would have the best cosmetic results.

29. Types of Skin Cancer
Melanoma
Most serious form of skin cancer
Originates in the pigment-producing or melanin cells of the skin
Most often caused by exposure to the sun
Appears as a brown or black molelike growth on the back, legs, or torso
One half of cases develop from existing pigmented moles.
If treated early, cure rate is almost 100%.
If not treated early, melanoma may be fatal.

30. The Butterfly Child