Skin Flashcards
functions
Protection Waterproof Cushion Excretion Sensory reception
2 categories Body membranes
Epithelial membrane - epithelial and underlying connective tissue
Connective tissue membrane - no epithelial cells
3 epithelial membrane
Cutaneous
Serous
Mucous
Cutaneous
SKIN
Epithelial cells
Serous membrane
On surface of closed cavities
2 layers (epithelial and connective)
Parietal (body cavity)
Organ (visceral) (thoracic pleural, abdominal peritoneal)
Secrete watery fluid to reduce friction, organ lube)
Mucous membrane
Line openings to exterior
Respiratory excretory digestive
Secrete mucous
Connective tissue membranes
No epithelial
Smooth, secrete thick synovial fluid
Reduce friction between bones
Line bursae between moving body p
Skin function
Protect against invasion, dehydration, temp change, excrete waste, receptor, generate vit d
Store water, fat, sugar, vit d
Skin layers
Epidermis - outer thin
Dermis - thicker, connective
SSubcutaneous- fat and connective houses vessels and nerves
Epidermis layers
Innermost = stratum germinativium - undergo mitosis , move upwards and specialize (repair itself), cytoplasm replaced with keratin at surface
Keratin
Outermost skin layer, abrasion resistant, waterproof,
In stratum corneum (outer layer)
Melanin
Deepest layer (stratum germinatvium)
Pigment from melanocytes
Genetics and sunlight determine cor
Low concentrations, change to skin more obvious (cyanosis vs flush from blood flow)
Dermis - function and structure
Thicker than epidermis
Connective tissue
Fibroblast - form collagen and elastin
Dermal papillae - bind skin together
Subcutaneous
Connective tissue and fat
Insulate and energy source, shock absorbing pad
Hair
Cell grows down to form follicle , hair papilla grows through all layers of epidermis
Receptors
Allow body to sense change and relay messages
Nails
Produced by epidermis cells and fill with keratin
Skin glands
Sweat (sudoriferous)
Sebaceous
Sweat glands - 2 kinds
Eccrine - all over body
Apocrine - armpit and groin, larger and secrete thicker sweat
Sebaceous glands
Near hair follicle, produce sebum (skin oil)
Sebum secreted up follicle, moving debris and lubricate skin.