For medical, nursing and physiotherapy undergraduates, and postgraduates

1. INTEGUMENTARY
SYSTEM
DR. SUNDIP CHARMODE
ASSISTANT PROFESSOR

2. OBJECTIVES
• Layers of skin
• Types of skin
• Histologic features
• Clinical significance

3. THIN SKIN
• Present where less amount of abrasion and wear and tear
• Epidermis is thinner
• Cellular composition is simpler than thick skin
• Two principal layers – Epidermis and Dermis. Also there is
Hypodermis.

7. THIN SKIN - EPIDERMIS
• Superficial cellular layer with different cell types
• Epithelium: Stratified squamous keratinized epithelium
• Stratum corneum: Thin layer of keratinized cells, superficial
layer which desquamate constantly from the surface
• Stratum spinosum: Few layers of polygonal cells

8. THIN SKIN – EPIDERMIS - OVERVIEW
1. Stratum Basale – contain intermediate keratin filaments
2. Stratum spinosum – I-C adhesions appear as spinous extensions
3. Stratum granulosum – dense basophilic kerato-hyaline granules
4. Stratum lucidum – translucent, barely visible, tightly packed
dead cells
5. Stratum corneum – flattened dead cells filled with keratin
filaments.

10. THIN SKIN - DERMIS
• Consists of connective tissue fibers with cellular
components of epidermal origin
• Papillary layer: narrow zone of irregular, lighter staining
connective tissue directly below the epidermis indenting
the base of the epidermis
• Deeper reticular layer: dense irregular connective tissue
layer, forming the bulk.

11. THIN SKIN – DERMIS – PAPILLARY LAYER
• More cellular content

12. THIN SKIN – DERMIS – RETICULAR LAYER
• Cross sections of coiled portion of sweat gland
• Excretory ductal and secretory portions of the sweat gland

13. THIN SKIN – DERMIS - COMPONENTS
• Sweat glands (Apocrine and Eccrine)
• Sebaceous glands
• Hair follicles
• Arrector Pilli
• Blood vessels
• Pacinian corpuscles

14. SWEAT GLANDS
• Two types:
1. Eccrine
2. Apocrine

15. ECCRINE GLANDS
• Simple highly coiled tubular glands extend deep in the
dermis or upper hypodermis.
• Secretory cells – large, columnar and stain eosinophilic
(light)
• Myoepithelial cells are present
• Excretory duct is lined by double layer of dark staining
cuboidal cells.

16. ECCRINE GLANDS
• Cells of excretory duct are smaller than the secretory cells
• Excretory ducts have small lumen
• Lined by dense staining stratified cuboidal cells.
• No myoepithelial cells around excretory ducts.

17. ECCRINE SWEAT GLANDS

18. APOCRINE GLANDS
• Glands embedded deep in the connective tissue of dermis
or hypodermis with adipose cells and blood vessels.
• Secretory portion – wide and dilated lumen than
eccrine glands
• Secretory cells are surrounded by numerous myoepithelial
cells located at the base of secretory cells.
• Excretory duct similar to eccrine glands

19. EPOCRINE SWEAT GLANDS

22. SEBACEOUS GLANDS
• Each hair follicle is surrounded by numerous sebaceous
glands lying in the connective tissue of dermis.
• Lined with a stratified epithelium which is continuous with
external root sheath.
• Epithelium of sebaceous gland along the base is lined by
cuboidal or columnar – Basal cells with flat nucleus.

24. SEBACEOUS GLANDS
• Basal cells proliferate and fill the acinus with larger,
polyhedral secretory cells.
• Secretory cells enlarge, accumulate secretion and undergo
degeneration, release sebum – oily product

25. ARRECTOR PILLI
• Smooth muscles aligned at an oblique angle to the hair
follicle
• Connect papillary layer of dermis to the connective tissue
sheath of hair follicle

26. HAIR FOLLICLE
• Connective tissue sheath
• External root sheath
• Internal root sheath
• Cuticle
• Cortex
• Hair root
• Dermal papilla hair matrix
• Melanin pigment
• Capillaries

28. THIN SKIN - HYPODERMIS
• A small portion of hypodermis is seen.
• Superficial region of underlying subcutaneous adipose
tissue is seen.
• Basal portions of highly coiled sweat glands

30. THICK SKIN
• Present where larger amount of abrasion and wear and
tear
• Epidermis is thicker
• Cellular composition is complex than thick skin

35. GLOMUS
• Arteriovenous anastomoses are numerous in thick skin.
• In some cases, the arterial portion of the anastomosis
forms a specialized thick walled structure called the
Glomus
• Blood vessel is highly coiled or convoluted
• Enlarged smooth muscle fibers in tunica media –
Epithelioid cells

36. GLOMUS
• Connective tissue sheath (with numerous blood vessels,
nerves and excretory sweat gland ducts) encloses glomus.
• Function: Regulate blood flow, conserve heat.
• Site: Finger tips, external ear, etc.

38. PACINIAN CORPUSCLES
• Ovoid structure with an elongated central myelinated
axon.
• The axon in the corpuscle is surrounded by concentric
lamellae of compact collagenous fibers that condenses at
the periphery to form Connective tissue capsule.
• Lymph like fluid present between the lamellae.
• Resembles like a sliced onion in transverse section

39. PACINIAN CORPUSCLES
• Connective tissue (of dermis) surrounding Pacinian corpuscles
consists of
• Numerous adipose cells
• Blood vessels
• Nerves
• Cross sections of excretory ducts and secretory portion of sweat
gland
• Function: Important sensory receptors for pressure, vibration and
touch

45. SUMMARY