The integumentary system provides protection, support, sensation, excretion, respiration, thermoregulation, locomotion, determines body shape, and enables vitamin D synthesis. It is composed of three layers: the epidermis, dermis, and hypodermis. The epidermis is the outer layer and contains keratinocytes that produce keratin for protection and melanocytes that produce melanin pigment. The dermis lies underneath and contains collagen, elastic fibers, blood vessels, hair follicles, and sensory cells. The deepest layer, the hypodermis, contains adipose cells.

1. Integumentary System
Ivana Damnjanović

2. Integumentary System
Protection & support
Sensory
Excretion
Respiratory (amphibians)
Thermoregulation
− Dissipate heat (blood vessels, sweat)
− Conserve heat (blood vessels, hair, feathers)

3. Locomotion
Body shape
Protective coloring
Vitamin D synthesis

4. Epidermis, dermis and hypodermis

5. Epidermis
-surface layer
Dead cells
Nonvascular

7. Feathers
Scales

8. Horns

9. hooves
clutches
nails

10. Epidermis
-inner layer
Mucus cells (amphibians, fish)
Proteinaceous cells/granular cells
(Poisons, photophores, pheromones)

11. Keratinocytes – Produce keratin protein a fibrous protein
that helps protect the epidermis
Melanocytes - produces the brown pigment melanin, a
pigment in the skin, eyes, and hair

13. Dermis

14. Dermis
Collagen for strength
Elastic fibers
Smooth muscle
Blood and lymph vessels
Hair follicles

15. Dermis
Sensory cells
Skin glands

16. Dermis
Chromatophores
− Homeotherms have melanophores & pigment is
INJECTED into epidermis
− Poikilotherms – the pigment stays in the dermis

17. Hypodermis
- adipose cells