1. Integumentary System
Chapter 5

2. Integumentary System Page 65 Made up of skin & its appendages Hair
Nails
Sebaceous glands
Sweat glands
Integumentary means “covering”
3,000 square inches of surface area

3. Functions of the Skin Page 65 Covering Regulate body temperature
Manufacture Vitamin D
Nerve receptors
Temporary storage of fat, glucose, water & salts
Screen out ultraviolet radiation
Special absorptive properties
A covering – protecting deeper tissues from dehydration, injury, & germ invasion
Regulate body temperature – controls the size of the blood vessels in the dermal layer of the skin
Manufacture Vitamin D – through absorption of ultraviolet light
Nerve receptors – 1 sq. inch contains 72 feet of nerves & hundreds of receptors.
Temporary storage of fat, glucose, water & salts
Screen out ultraviolet radiation
Special absorptive properties – for certain drugs & other chemical substances. We can apply drugs locally for rashes or medication

4. Structure of the Skin Page 65 Epidermis Dermis Outermost covering
Avascular
Dermis
True skin
Connective tissue
Vascular
Two layers

5. Page 66
Figure 5 - 2

6. Page 65
Epidermal Cells
Keratinocytes – comprise most of the epidermis & produce keratin
Merkel cells – Sensory receptors for touch
Melanocytes – Produce the pigment melanin which protects the skin against the ultraviolet rays of the sun
Langerhans cells – Macrophages that defend against microorganisms

7. Page 67
Epidermal Layers
Stratum germinativum – Deepest epidermal layer; undergoes continuous cell division. Papillae originate in this layer (fingerprint).
Stratum spinosum – 8-10 cell layers thick
Stratum granulosum – Where keratinization occurs
Stratum lucidum – Palms & soles
Stratum corneum – Dead cell layer
Stratum germinativum – it consists of a layer of cells that are mostly keratinocytes. They grow upward & become part of the more superficial layers. Melanocytes & merkel cells are also found in the germinativum layer.
Stratum spinosum – melanocytes, kerationocytes, & Langerhans cells. When seen under a microscope this layer looks prickly – thus the name which means little spine.
Stratum granulosum – cells begin to die. Keratinzation is the process whereby the keratinization is the process whereby the keratinocyte cells change their shape, lose their nucleus, lose most of their water, & become mainly hard protein or keratin.
Stratum lucidum – the cells in this layer appear clear
Stratum corneum – composed of dead, flat, scale-like keratinized cells, which slough off daily. Complete cell turnover occurs every 28 to 30 days in young adults, while the same process takes 45 to 50 days in older adults. This layer is also slightly acidic, which helps in the defense against harmful microorganisms.

8. Skin Color Page 67 Three pigments contribute to skin color:
Melanin – produces two distinct classes of melanin
Pheomelanin – which is red to yellow
Eumelanin – which is dark brown to black
Carotene – a yellow to orange pigment found in certain plants.
Hemoglobin – pinkish color of some fair-skinned people is due to the presence of oxygen in the hemoglobin
Those who have light skin generally have a greater proportion of pheomelanin than those who have dark skin
Some drugs bind to melanin & therefore make it easer for people to burn
In older adults, melanin collects in spots, often called “aging” or “liver” spots.
*****
Tends to accumulate in the stratum corneum. The yellowish tinge of the skin of some Asians is due to variations in melanin as well as to carotene.

9. Dermis (Corium) Pages 67 – 68
Thicker, inner layer of the skin below the epidermis
Composed of:
dense connective tissue
white blood cells
oil & fat glands
collagen tissue bands
fat cells
elastic fibers
Many nerve receptors
muscle fibers
some mast cells
Blood vessels & heat regulation
Mast cells respond to injury, infection or allergy & produce histamine & heparin

10. Subcutaneous Layer Page 68
Also called hypodermal layer (Lies under dermis)
Not a true part of the integumentary system
Attaches integumentary system to the surface muscles underneath
Injections given in this area are called hypodermic or subcutaneous.

11. Page 68
Appendages - Hair
Hair is composed of Root shaft, Outer cuticle layer, the Cortex & the Inner medulla.
Root = the part of the hair that is implanted in the skin.
Shaft = projects from the skin’s surface
Hair follicle = an inpocketing of the epidermis where the hair is embedded. The shape determines the curl of the hair.
Arrector pili muscle – attached to the hair & when you get chilled your hair stands up.
Round follicle = straight hair
Oval follicle = wavy hair
Flat follicle = curly hair
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Alopecia = baldness

12. Page 69
Figure 5 – 3

13. Appendages - Nails Page 69
Hard structures covering the dorsal surfaces of the last phalanges of the fingers & toes
Formed in the nail bed or matrix
Lunula: white crescent at the proximal end of the nail

14. Page 69
Figure 5 – 4

15. Appendages – Nails (Cont’d)
Page 70
Appendages – Nails (Cont’d)
Disease Condition & Nail Color
Condition
Nail Color
liver disease
white nails
kidney disease
half of nail is pink; half is white
heart condition
nail bed is red
lung disease
yellow & thickening nails
Anemia
pale nail bed
diabetes
yellowish with a slight blush at the base
hypoxia
bluish nails

16. Appendages – Sweat Glands
Pages 69 – 70
Appendages – Sweat Glands
Also called sudoriferous glands
Perspiration is 99% water; it is excreted through pores
Under the control of the nervous system, these glands may be activated by several factors including heat, pain, fever, & nervousness.
500 ml water lost per day through the skin
Ceruminous or wax glands are modified sweat glands & are found in ear canals

17. Sebaceous Glands Page 70 Secretes sebum which is thick, oily substance
Sebum lubricates the skin, keeping it soft & pliable

18. Page 70
Microorganisms
Intact skin is the best way to protect against pathogens
Most skin bacteria are associated with hair follicles & sweat glands
Handwashing
Most effective action to prevent spread of disease
20 seconds for washing hands
2–4 minutes for infectious material
If soap & water are not available, use an alcohol-based hand sanitizer that contains at least 60% alcohol. Sanitizers quickly reduce the number of germs on the hands in some situations but do not eliminate all types of germs.

19. Aging Skin Page 71 SB Becomes more fragile and dry Loss of elasticity
Less effective body temperature control
Melanocytes decrease
Physiological changes can impact self-worth

20. Disorders of the Skin Pages 70 – 71 Acne vulgaris
Common & chronic disorder of sebaceous glands
Occurs mostly during adolescence & marked by blackheads, cysts, pimples and scarring
Athlete’s foot
Contagious fungal infection
Blisters between fingers & toes causing cracking & scaling
Dermatitis
Non-contagious inflammation of the skin

21. Disorders of the Skin (Cont’d)
Page 71
Disorders of the Skin (Cont’d)
Eczema
Acute or chronic, noncontagious inflammatory skin disease
Dry, red, itchy & scaly
Impetigo
Acute, inflammatory, & contagious skin disease
Caused typically by staph or strep
Honey crusted exudates

22. Disorders of the Skin (Cont’d)
Page 71
Disorders of the Skin (Cont’d)
Psoriasis
Chronic inflammatory skin disease (reddish patches covered by silvery-white scales)
Autoimmune disease triggered by stress, trauma or infection
Ringworm
Highly contagious fungal infection
Red, circular patches with scaly borders
Urticaria (hives)
Intensely itchy, red, raised wheals or welts
Response to an allergen

23. Disorders of the Skin (Cont’d)
Page 73
Disorders of the Skin (Cont’d)
Boils (carbuncles)
Painful, bacterial infection of the hair follicles or sebaceous glands
May require an incision and drainage
Rosacea
Common inflammatory disorder (chronic redness and irritation to the face)
Triggers include stress, caffeine, hot foods, and alcohol

24. Disorders of the Skin (Cont’d)
Page 73
Disorders of the Skin (Cont’d)
Herpes
Viral infection that is usually seen as a blister
Simplex includes cold sores involving the lips or beneath the nose
Genital herpes
Virus that may appear as a blister in the genital area; this is covered in Chapter 21
Shingles (herpes zoster)
Skin eruption due to a viral infection of the nerve ending
Reactivation of the chicken pox virus (varicella)

25. Disorders of the Hair & Nails
Page 73
Disorders of the Hair & Nails
Head lice
Parasitic insects
Intense itching & sores on the head
Ingrown nails
Common nail problem
Fungal infections
Infections of the nail
Makes up 50% of all nail problems

26. Disorders of the Hair & Nails (Cont’d)
Page 73
Disorders of the Hair & Nails (Cont’d)
Warts
Viral infections that affect the skin surrounding or underneath the nail
Caused by human papilloma virus (HPV)

27. Pages 73 – 74
Skin Cancer
Basal cell carcinoma = Most common & least malignant
Squamous cell carcinoma = Most often found on the scalp & lower lip
Malignant melanoma = Metastasizes to other areas quickly
Change in color, size, shape of a mole
Skin & sun exposure

28. Pages 74 – 76
Burns
Rule of nines – measures the percent of the body burned; the body is divided into 11 areas & each area = 9% of the body
First-degree burns = Superficial, epidermis only, no blister, redness swelling & pain
Second-degree burns = Epidermis & dermis, blister forms
Third-degree burns = Complete destruction of epidermis, dermis & subcutaneous layers forming an eschar (black skin)

29. Page 76
Skin Lesions
Abrasion = an injury in which superficial layers of the skin are scraped or rubbed away.
Fissure = a groove or crack like break in the skin
Laceration = a torn or jagged wound

30. Pressure ulcer (decubitus ulcers)
Page 76
Pressure ulcer (decubitus ulcers)
Also known as Bedsores they occur along the spine, coccyx, hips, elbows & heels
Preventable & are a primary concern of health care professionals.
Stage I – Redness only, skin intact
Stage II – Blistered skin, broken or unbroken
Stage III – Skin breaks through all layers
Stage IV – Ulceration to underlying muscle & bone

31. Page 79
Figure 5 – 10