1. Chapter 5
Integument
Skin

2. Skin-Characteristics
Largest organ in the body
Weighs about 10 pounds
Covers the entire body

3. Quiz Picture

4. Layers of the Integument
Epidermis- outer layer
Dermis-under the epidermis
Hypodermis-not part of skin; skin attached to it

5. The saying “beauty is only skin deep” is only pertinent to the __________ layer, which is outwardly visible.
epidermal
dermal
hypodermal
integumentary
Answer: a. epidermal

6. Epidermis Keratinized Stratified Squamous Epithelium
Cell Types-Keratinocytes (most abundant)
- Melanocytes (produce melanin which protect against UV
radiation; tanning
- Merkel cells-sensory receptor for touch
- Langerhans- macrophages

7. Layers of Epidermis
Basale-bottom; location of melanocytes/Merkel cells
Spinosum-several cells thick; location of Langerhans cells
Granulosum-keratohyaline granules (keratin)/ Lamellated granules (waterproofing glycolipid)

8. Layers of Epidermis (con’t)
Lucidum-visible only in thick skin
Corneum- 20 to 30 cell layers thick; outermost layer; most of the thickness of the epidermis
All the cells in these layers are dead

9. Quiz Picture

10. A patient taking a drug that inhibits cell division (such as certain chemotherapy drugs) would expect which layer of the epidermis to be most noticeably affected?
Stratum corneum
Stratum lucidum
Stratum spinosum
Stratum basale
Answer: d. Stratum basale

11. Dermis Strong, flexible connective tissue
Rich supply vessels, nerve fibers
Contains hair follicles, oil, and sweat glands which are derived from the epidermis but seen in the dermis
Contains Pacinian Corpuscles that respond to deep touch

13. Layers of the Dermis
Papillary Layer
Reticular Layer

14. Papillary Layer Areolar Connective Tissue
Dermal papillae  folds of tissue
Meissner’s Corpuscles (Light touch receptors)
part of what makes fingerprints

16. Reticular Layer Dense Irregular Connective Tissue
contain cleavage and flexure lines
contain the collagen that gives skin strength/resilience

18. Homeostatic Imbalance
Striae  stretch marks

20. Skin Color Melanin- the more that is produced the darker the skin
Carotene-yellow/orange pigment in plants
Hemoglobin- causes the pink color of fair skin when well oxygenated

21. Homeostatic Imbalance
Cyanosis  appear blue, poorly oxygenated blood
Jaundice  yellow cast, bilirubin build up

23. Sweat Glands
Eccrine Sweat Glands (Merocrine)- most numerous; found all over but most on palms, soles, forehead; produce sweat
Apocrine Glands- axillary/ano-genital area
Ceruminous-ear; cerumen (ear wax)
Mammary Glands-produce milk

24. Sebaceous Glands (Oil)
Found everywhere except palms/soles
secrete sebum
holocrine secreting
blockage causes acne
associated with hair follicle

25. Homeostatic Imbalance
Acne  infected sebaceous gland
Whitehead, Blackhead
Seborrhea  cradle cap

27. One critical function of sebum, in addition to roles in waterproofing and skin softening, is that it provides protection against ____________.
overexposure to the sun
overheating
harmful bacteria
abrasions or cuts to the skin
Answer: c. harmful bacteria

28. Nails Covers distal ends of fingers/toes Contains hard keratin
Matrix is responsible for nail growth

30. Hair
Located everywhere except palms, soles, lips, nipples, and parts of genitalia
Contains 3 layers
Medulla-inner layer
Cortex- surrounds the medulla
Cuticle-outer layer; single layer of cells; arranged like shingles

33. Hair Follicle Usually found in the dermis
Hair matrix in the bulb produces the hair
Associated with arrector pili-smooth muscle that will pull hair straight up with cold/anxiety

35. Functions of Integument
Protection
Chemical Barriers- acid mantle; melanin
Physical Barriers- keratin, water proofing glycolipid
Biological Barriers- Langerhans cells

36. Functions of Integument (con’t)
Cutaneous Sensation-sensors that are part of the nervous system
Meissner’s Corpuscles/ Merkel’s Discs- light touch
Pacinian Corpuscles- deep pressure

37. Functions of Integument (con’t)
Metabolic Functions- convert inactive Vitamin D to active Vitamin D
Blood Reservoir- ~ 5% of total blood volume
Excretion- very small amount of nitrogenous waste; large amounts of salt and water

38. Skin Cancer
Basal Cell Carcinoma-starts in basale cell layer; almost always curable
Squamous Cell Carcinoma- starts in the spinosum layer; almost always curable
Melanoma- starts in melanocytes; > 4 mm and chance of cure almost zero; deadliest form of cancer

46. Use at least 30 sun block both for UVA and UVB rays
Stay out of Sun!!!!
Use at least 30 sun block both for
UVA and UVB rays

47. No tanning booths!

48. Burns First Degree Burn- red, painful, only epidermis
Second Degree Burn- red, blistered, epidermis and upper dermis
Third Degree Burn- gray white, ashen, cherry red; all layers involved

49. Rule of Nines
Used to determine the percentage of body covered in burns