Post on 27-Dec-2015
Functions of the Integumentary System
• Protection
• Body temperature regulation – Dilation – Constriction – Sweat gland secretions
• Cutaneous sensation
• Metabolism
Epidermis
Five layers:•Stratum corneum: dead cells; keratin dominate cells; can become thick from irritation
•Stratum lucidum: Present in thick skin only, dead cells
•Stratum granulosum: cells dying; begin keratinization
•Stratum spinosum: living cells, keratin generation
•Stratum basale: youngest cells; specialized cells present
Dermis
• Strong, flexible connective tissue
• Cell types: fibroblasts
macrophages
mast cells
white blood cells
• Composed of two layers – papillary and reticular
Skin Color• Three pigments contribute to skin color
– Melanin• yellow to reddish-brown to black pigment• Freckles and pigmented moles
– Carotene • yellow to orange pigment
– Hemoglobin• reddish pigment
Nails• Consist of:
– free edge– Body– Root– Cuticle– Lunula– keratin
Growth- 0.5 mm/week fingernails faster than toe nails …why?
Hair Thinning and Baldness
• Alopecia – hair thinning in both sexes
• True, or frank, baldness – Genetically determined – Sex-influenced condition – Male pattern baldness
• Oil, hair and acne…oh my!• Sweat!• Cumulative environmental assaults• Scaling• Dermatitis
Adolescent to Adult