1. INTEGUMENT

2. Surface Anatomy
Palpation
Bony landmarks
Dermatomes
Neural assessment

3. Integument Histology Epidermis: Basement membrane Dermis:
Stratified squamous epithelium
Resting on:
Basement membrane
Dermis:
Dense irregular connective tissue

4. Epidermis The epidermis is a stratified squamous epithelium.
It is made up of many layers of cells.
The stratum germinativum is the deepest layer:
Area of high mitotic activity.

5. Epidermis The stratum corneum is the most superficial layer:
The cells in this layer are dead and keratinized.
Between the stratum germinativum and the stratum corneum are several transitional layers represented by cells from the stratum germinativum that are transforming into dead, keratinized cells.

6. Epidermis
The epidermis is innervated.
The epidermis is avascular.

7. Dermis The dermis is the deepest region of the integument.
The dermis is classified as dense irregular connective tissue
The dermis has an abundance of collagen fibers
There may also be some elastic fibers:
Decrease with age.

8. Dermis The dermis is vascularized.
Refer to Figure 1 in your course packet.

10. Thick Skin vs. Thin Skin
Classification into thin and thick skin depends on the structure of the epidermis.
Layers of epidermis are well-formed in thick skin.
Layers of epidermis are not as well-formed or thick in thin skin.

11. Thick Skin
Thick skin is found only on the palms of the hands and the soles of the feet.
The epidermis of thick skin is 0.4 – 0.6 mm thick
Thick skin has no hair follicles.

12. Thin Skin Thin skin is found over the rest of the body.
The epidermis of thin skin is – mm thick.
Total skin thickness is 0.5 – 3 mm thick.

13. Skin Thickness Thickest skin found on back (= thin skin)
Thinnest skin found on eyelids (= thin skin)
Thicker on extensor surfaces than flexor surfaces.

14. Superficial Fascia: Synonyms
Subcutaneous fascia
Superficial fascia
Hypodermis
SubQ

15. Superficial Fascia
Consists of loose bundles of collagen and elastic fibers with variably sized aggregations of lipocytes (fat cells)
May be loosely or tightly attached
Supports cutaneous nerves and blood vessels

16. Deep Fascia
Synonyms:
Membranous fascia
Investing fascia
Usually several thin layers of tough collagen material
Tightly adherent to muscles, bones, tendons, etc.

17. Cutaneous Derivatives
Glands.
Hairs.
Nails.

18. Glands Glands are epithelial structures
Glands are classified according to the presence or absence of a secretory duct:
Exocrine
Endocrine

19. Epidermal Glands Sudoriferous glands Sebaceous glands
Ceruminous glands
Mammary glands

20. Sudoriferous Glands Are long, simple, tubular glands.
Their method of secretion is merocrine .

21. Sebaceous Glands Are holocrine .
Sebaceous glands are associated with hair follicles.

22. Ceruminous Glands Are located in the external auditory canal.
Secrete ear wax.

23. Mammary Glands Are modified sweat glands
Method of secretion is apocrine

24. Hairs Hairs develop during 3rd month of gestation.
The earliest fine embryonic hair = lanugo.
Lanugo is Shed before birth except around eyebrows, scalp, and eyelids.

25. Hairs A new downy coat of hair appears a few months after birth.
This new coat is called vellus.
Vellus is converted to terminal hair at puberty:
Vellus represents 95% of the hair coverage in males.
Vellus represents 35% of the hair coverage in females.

26. Parts of a Hair Shaft: Follicle: Dermal papilla with matrix.
Made up of dead cornified epidermal cells.
Follicle:
Derived from both epidermis and dermis.
Dermal papilla with matrix.

27. Parts of a Hair Arrector pili muscle. Sebaceous glands.
Hair bulb and connective tissue papilla.

28. Hair Growth Anlagen Active growth: Scalp hair = 2-3 years
Eyebrow hair = 3-4 months

29. Hair Function and Location
Hair follicles are innervated, and hairs serve as sensory receptors.
Hairs are found everywhere except palms, soles, dorsal distal phalanges, anal and urogenital apertures

30. Nails Ungis: Modified stratum corneum Matrix: Subungis Flattened
Avascular and not innervated
Travels over a nail bed guided by lateral nail grooves
Matrix:
Stratum germinativum produces ungis
Subungis

32. Melanocytes Found in deep layers of epidermis
Derived from nervous system components
Form:
Melanosomes:
Passed off to keratinocytes (cells of epidermis).
Phagocytized by keratinocytes.

33. Melanocytes All individuals produce same number of melanosomes.
Skin color depends on number of remaining melanosomes.

34. Langer’s Lines
Represent tension lines created by orientation of collagen fibers in the dermis of the skin.
Used by surgeons as guides for incisions:
Incisions normally made parallel to Langer’s lines

35. Dermatomes
Specific region of skin innervated by a specific spinal cord level.
Refer in syllabus to figure 3