Mammalian Integument

1. MAMMALIAN
INTEGUMENT

2. 2 PRIMARY LAYERS
1. Epidermis – waterproofing and
barrier
2. Dermis – location for appendages

3. EPIDERMIS
•Outer layer
•Protective barrier over the body’s
surface
•Keratinocyte are the major cells
•No blood vessels
•Can be further subdivided into 5
strata

4. EPIDERMIS LAYERS
•Stratum corneum
•Stratum lucidum
•Stratum granulosum
•Stratum spinosum
•Stratum germinativum

6. Stratum Corneum
•Outermost layer
•Consist of dead cells
(corneocytes)
•Protect underlying tissue
•Contains a dense network of
keratin
•Will be desquamated

7. •Thickness varies throughout
the body
•Contain 15 to 20 layers of dead
cells

8. Stratum Lucidum
•Thin, clear layer of dead skin
cells
•Composed of 3 to 5 layers of
dead keratinocytes
•Cells are flattened
•Surrounded by an oily
substance as a result of
exocytosis by lamellar bodies

9. Stratum Granulosum
•Thin layer of cells in the
epidermis(granular cells)
•No cell division
•Keratin accumulates

10. Stratum Spinosum
•Keratinization begins
•Living cells
•Dividing
•8-10 layers of cells
•Polygonal in appearance

12. Stratum Germinatuvum
•Reproduces by mitosis
•Cuboidal, columnar in shape
•Moves to upper epidermis in 27
days

15. Epidermal glands
2 Types
. Sebaceous – oily secretions
. Sudoriferous – sweat glands
Mammary glands – (viviparous)
modified sebaceous glands

16. Sudoriferous glands
• Coiled tubular glands that extend
deep into the dermis
• Their secretions ooze via canals
that open as pores
• Sweat glands in fury animals are
confines to the least furry regions

17. Sebaceous glands
• Are present wherever there are
hairs, and the secretion, sebum, is
usually exuded into hair follicles.
Ceruminous gland – outer ear,
secrete cerumen
Meibomian glands – assist in
moistening conjunctiva of eye

18. SCENT GLANDS
• Sebaceous and sudoriferous
glands both produce a variety of
scents, all of which may be
pheromones
MAMMARY GLANDS
. Develop in both sexes from milk
lines

21. BASEMENT MEMBRANE
•Separates the epidermis and
dermis
•A thin sheet of fibers

22. DERMIS

23. • Consist of connective tissue
• Provides tensile strength and
elasticity
• Harbors many mechanoreceptors
• Contains hair follicles, sweat
glands, sebaceous glands,
apocrine glands
• Produces dermal bones

24. • Regulates heat loss through
vasodilation and vasoconstriction
• Structurally divided into two areas
- papillary region
- reticular region

25. PAPILLARY
• region(1/5) of the dermis,consists of
areolar connective tissues with elastic
fibers
• Provides dermis with a “bumpy” surface
RETICULAR
. Much thicker than papillary (4/5 of the
dermis)
. Composed of dense irregular dense tissue
. where roots of hair, sebaceous glands,
sweat glands, receptors, nails, and blood
vessels

26. • MAMMALIAN SKIN IS SEPARATED FROM
THE UNDERLYING MUSCLE BY A
CUSHION OF LOOSE CONNECTIVE
TISSUE, THE FASCIA.

27. SKIN DERIVATIVES
•Hair
•Nails
•Horns
•hoofs