Dermis (skin) 1 Flashcards
What are the 3 layers of the skin
Cutaneous: Epidermis, Dermis
Subcutaneous: Hypodermis
What are the physical functions of skin
Protecting underlying tissue and organs from; abrasion, fluid loss, chemical attack
Detect touch, pain temp etc.
What are the physiological functions of the skin
Excrete organic waste
Temperature maintained
Produces melanin - UV protection
Produces keratin - Abrasion resistance and water repellent
Vitamin D3 synthesis (steroid) - calcium metabolism
Stores lipids - energy
How do the different layers of skin get nutrients
Epidermis - papillary layer between dermis. Large surface area to easier nourish
Dermis - Vascular
Hypodermis - adipose tissue/vascular?
What is the basic structure of the layers
Epidermis - Stratified barrier - Keratinocytes. Avascular
Dermis - Protein fibres (Collagen, elastin) Vascular
Hypodermis - Adipose tissue (storage and insulation)
What the layers of the epidermis
Stratum Corneum
Stratum Granulosum
Stratum Spinosum
Stratum Basale
Describe the stratum corneum layer
(Horny layer) - Dead, dried out and hard cells with no nuclei
Describe the stratum granulosum layer
(granular) - Granules promote dehydration, cross linking of keratin fibres. Waxy material secreted into intercellular space
Describe the stratum spinosum layer
(spiny or spinous) - Intercellular bridge - desmosomes link together)
Describe the stratum basale layer
Regenerative/dividing, moves cells up layers. Tall cells
What is the difference between thick and thin skin
Thick skin - sole of feet and palm of hands. Stratum corneum thicker. Extra layer - Stratum lucidum
How does aging affect skin
Reduces structural integrity (collagen production)
Slower repair (less circulation therefore less nourishment)
Dryer skin (less sebum)
Thinner epidermis
Impaired cooling (less sweat glands)
Less pigmentation produces (grey hair, pale skin)
