1. The Northern Red Salamander
He has no lungs!

2. Skin
Integumentary
System
Skin
Derivatives
Sweat glands
Sebaceous glands
Hair
Nails

3. Integumentary System Functions Pathogens UV radiation Dehydration
Protection
Injury
Production of vitamin D
Sensation of T° and touch
Regulation of body T°

4. Stratified squamous epithelium Skin Areolar CT + Dense Irregular CT
Epidermis
Skin
Dermis
Areolar CT +
Dense Irregular CT

6. Deep to the dermis
Hypodermis
a.k.a. Superficial fascia
Anchors, insulates , energy storage

7. Epidermis
Stratified squamous epithelium
Protection!
Most of the cells = keratinocytes
Cells that contain keratin
Fibrous, waterproof protein

8. Epidermal dendritic cells
Other epidermal cells
Tactile cells
Melanocytes

9. Melanocytes
Produce the
pigment melanin
Transferred to the
keratinocytes and
protects their DNA
from UV radiation

11. Epidermal dendritic cells (Langerhans cells)
Engulf and destroy pathogens
Travel to lymph nodes to
present pathogen fragments
to WBCs
Mount an immune response

12. Tactile cells Light touch (Merkel cells) Associated with a
nerve ending
Tactilecell
Sensory nerve
ending

13. Thick skin 2 Basic Types of Skin Thin skin soles/palms 5 thick layers
everywhere else
4 thin layers

14. 5 Layers of Thick Skin Thin skin lacks the stratum lucidum
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
Dermis
Thin skin lacks the
stratum lucidum
(b)

16. Stratum Basale
Basal most
Superficial to dermis
Single layer
Mitotic cells
Epidermal dendritic
cells
Tactile cells

17. Stratum Spinosum
Several layers
Cells linked by
desmosomes
Mitotic cells
Epidermal dendritic
cells
Melanocytes

18. Stratum Granulosum
Several layers
Cells becoming
keratinized
Cells have visible
granules

19. Stratum Lucidum
Several layers
Thick skin only
Eleiden

20. Stratum Corneum
Several layers
Cells are dead bags
of keratin
Constantly shedding
Strong

22. Dermis
2 Major Layers:
1. Papillary dermis
2. Reticular dermis

23. Papillary Dermis
Upper ⅕
Areolar CT
Vascular
Upward projections
called dermal papillae
Anchored to
epidermal ridges

25. Body T° Regulation Abundant blood vessels Allows heat to be
delivered to skin surface

28. Reticular Dermis
Upper ⅘
Dense Irregular CT
Structural integrity

30. Epithelial derivatives
Skin Appendages
Sweat glands
Sebaceous glands
Hair
Nails
Epithelial derivatives

31. Merocrine sweat glands
Types of Sweat Glands
Apocrine sweat glands

32. Merocrine Sweat Glands
3,000,000
Exocrine
Coiled tube + duct
Water + ions, wastes,
antibodies
Evaporative cooling

33. Apocrine Sweat Glands
Found in the axillae,
pubic region, anal
region.
Exocrine
Coiled tube + duct
that empties into a
hair follicle
Sweat contains lipids
and proteins

34. Ceruminous Glands
Modified sweat glands
External ear canal
Cerumen
Bactericide
Fungicide
Insect repellant

35. Sebaceous Glands
Exocrine
Branch from hair
follicles
Sebum
Moisturizing
Absences
Bactericide

36. Hair Head (We’re bipeds!) Axillae & Pubic region Hair bulb
Shaft
Hair bulb
Hair papilla
Shaft + root
Follicle
Cuticle
Medulla
Cortex
Arrector
pili muscle
Sensation
Hair follicle
Connective tissue
root sheath
Epithelial tissue
root sheath
Root
Matrix
Hair bulb
Hair papilla
(a)

38. Arrector Pili Muscle
Vestigial
Piloerection

39. More on Hair Functions of hair include: Helping to maintain warmth
Alerting the body to presence of insects on skin
Guarding the scalp against physical trauma, heat loss, and sunlight
Hair is distributed over entire skin surface except
Palms, soles, and lips
Nipples and portions of the external genitalia
Types of Hair
Vellus – pale, fine body hair found in children and the adult female
Terminal – coarse, long hair of eyebrows, scalp, axillary, & pubic regions
Hair Thinning and Baldness
Alopecia – hair thinning in both sexes
True, or frank, baldness
Genetically determined and sex-influenced condition
Male pattern baldness – caused by follicular response to DHT (dihydrotestosterone)

40. Most skin tumors are benign and do not metastasize
Skin Cancer
Most skin tumors are benign and do not metastasize
Crucial risk factor for nonmelanoma skin cancers is disabling of the p53 gene
The three major types of skin cancer are:
Basal cell carcinoma
Least malignant and most common skin cancer
Stratum basale cells proliferate and invade dermis and hypodermis
Slow growing and do not often metastasize
Can be cured by surgical excision in 99% of the cases
Squamous cell carcinoma
Arises from keratinocytes of stratum spinosum
Arise most often on scalp, ears, and lower lip
Grows rapidly and metastasizes if not removed
Treated by radiation therapy or removed surgically
Melanoma (next page)

41. Melanoma Melanomas have the following characteristics (ABCD rule)
Melanoma - Cancer of melanocytes is the most dangerous type of skin cancer because it is:
Highly metastatic
Resistant to chemotherapy
Melanomas have the following characteristics (ABCD rule)
A: Asymmetry; the two sides of the pigmented area do not match
B: Border is irregular and exhibits indentations
C: Color (pigmented area) is black, brown, tan, and sometimes red or blue
D: Diameter is larger than 6 mm (size of a pencil eraser)
Treated by wide surgical excision accompanied by immunotherapy
Chance of survival is poor if the lesion is over 4 mm thick

42. Burns Rule of Nines - Estimates the severity of burns
First-degree – only the epidermis is damaged
Symptoms include localized redness, swelling, and pain
Second-degree – epidermis and upper regions of dermis are damaged
Symptoms mimic first degree burns, but blisters also appear
Third-degree – entire thickness of the skin is damaged
Burned area appears gray-white, cherry red, or black; there is no initial edema or pain
Rule of Nines - Estimates the severity of burns
Burns considered critical if:
Over 25% of the body has second-degree burns
Over 10% of the body has third-degree burns
There are third-degree burns on face, hands, or feet
Lund and Browder

48. Developmental Aspects of the Integument
Fetal
Epidermis develops from ectoderm
Dermis and hypodermis develop from mesoderm
Lanugo – downy coat of delicate hairs covering the fetus
Vernix caseosa – substance produced by sebaceous glands that protects the skin of the fetus in the amnion
Adolescent to Adult
Skin and hair become oilier and acne may appear
Skin shows effects of cumulative environmental assaults around age 30
Scaling and dermatitis become more common
Old Age
Epidermal replacement of cells slows and skin becomes thinner
Skin becomes dry and itchy
Subcutaneous fat layer diminishes, leading to intolerance of cold
Decreased elasticity and loss of subcutaneous tissue leads to wrinkles
Decreased numbers of melanocytes and Langerhans’ cells increase the risk of skin cancer

49. Homeostatic Imbalances of the Skin
Stretch marks, blisters, calluses, bed sores (Decubitus Ulcers)
Erythema, pallor, jaundice, cyanosis, black and blue marks
Acne Vulgaris
most common skin disorder
sebum and epithelial cells clog glands
produces whiteheads and blackheads (comedones)
anaerobic bacteria trigger inflammation (pimple)
largely hormonally induced
androgens stimulate sebum production
treatments include antibiotics, topical creams, birth control pills
Terms - intradermal injection; hypodermic (subcutaneous injection; intramuscular injection)