1. INTEGUMENTARY SYSTEM Exercise # 8 Page#73

2. Competency 3: The Integumentary System
Upon successful completion of this laboratory, the students should be able to recognize the various skin components of the integumentary system by:
Recognizing, from prepared slides, selected skin tissues and structures.
Explaining the structures and functions of epidermal and dermal layers of skin. 
Identifying the major parts of the hair.

3. INTEGUMENTARY SYSTEM (Martini, chapter 5)
LAYERS OF THE SKIN
FROM EXTERNAL TO INTERNAL:
1- EPIDERMIS
2- DERMIS
3- HYPODERMIS

4. ALFONSO A. PINO MD.

5. EPIDERMIS Stratum corneum
Function- protection from chemical, physical & biological agents
5 stratum (from external to internal)
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum germinativum (basale)

6. Stratum corneum- 15-30 layers of keratinized cells. Water
resistant
F- allows insensible perspiration
More or less 500 ml of water every day
Stratum lucidum- clear layer only in thick skin (palms & soles).
F-contains flattered & packed cells filled with the protein
keratin
Stratum granulosum- grainy layer
F- to produce protein keratin & keratohyalin basic
structural component of hair & nails
Stratum spinosum (8 to 10 layers)
F- it contains Langerhands cells for Immune response
against microorganisms & Cancer cells
Stratum germinativum or basale (The innermost)
F- cells divide to replace superficial cells
it contains Melanocytes –to produce melanin
For protection against uv radiation

7. Epidermis (5 stratums)
ALFONSO A. PINO MD.

8. DERMIS Function- thermoregulation & protection
2 mayor components- papillary & reticular layers
Papillary - contains capillary & lymphatic
vessels & sensory neurons
function- support & nourishment of the
overlaying epidermis
Reticular - deep to papillary layer
function- to resist tension in the skin

9. HYPODERMIS
FUNCTION- ENERGY STORE
CUSHIONING
INSULATION

10. ACCESSORY STRUCTURES Meissner’s corpuscles (white in models)
F- light touch & tactile receptors
Pacinian corpuscles (olive in models)
F- deep pressure & vibration receptors
Sebaceous glands- discharges waxy sebum into the hair
follicle
F- lubrication
Hair: for protection, insulation, and tactile reception.
It is divided into:
Shaft: exposed hair and first part under skin
Root- surrounded by hair follicle. Contains hair
papilla- at the base
Hair bulb- surrounds the papilla
Arrector pili- smooth muscle that erects the hair
Sweat glands- Apocrine
Merocrine

11. Sebaceous Glands and Sweat Glands
Exocrine Glands in Skin
Sebaceous glands (oil glands)
Holocrine glands
Secrete sebum
Sweat glands
Two types: apocrine glands and merocrine (eccrine) glands
Merocrine – products are secreted by exocytosis (e.g., pancreas, sweat, and salivary glands)
Apocrine-- producing a fluid secretion by pinching off one end of the secretory cell while leaving the rest intact.
Holocrine – products are secreted by the rupture of gland cells (e.g., sebaceous glands)
Watery secretions
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

12. Hair follicle
ALFONSO A. PINO MD.

13. Hair follicle
ALFONSO A. PINO MD.

14. Nails Nails protect fingers and toes
Made of dead cells packed with keratin
Metabolic disorders can change nail structure
Nail production
Occurs in a deep epidermal fold near the bone called the nail root

15. Copyright © 2009 Pearson Education, Inc
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

16. Nails Structure of a Nail Nail body The visible portion of the nail
Covers the nail bed
Lunula
The pale crescent at the base of the nail
Sides of nails
Lie in lateral nail grooves
Surrounded by lateral nail folds
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

17. Nails Structure of a Nail
Skin beneath the distal free edge of the nail
Is the hyponychium (onyx = nail)
Visible nail emerges
From the eponychium (cuticle)
At the tip of the proximal nail fold
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

18. REMEMBER, GO TO THE TUTORING ROOM AND PRACTICE WITH MODELS!