L4 - Integumentary system (protection) Flashcards
(21 cards)
Integumentary system
Skin
Hair
Nails
Glands
Skin
Mechanical protection
Waterproof layer
Barrier to infection
Repair
Layers of skin
Epidermis
Dermis
Hypodermis
Epidermis
Stratified squamous epthelium
0.5-4mm
Dermis
Dense connective tissue
Fibroblasts: collagen and elastic fibres
Strength, flexibility, elasticity
Capillaries provide blood to epidermis
Dermal Papilla
On palms, fingers, toes and feet
Fingerprints
Interlock Epidermis and Dermis
Increase surface area to enhance receptors
Hypodermis
Areolar and adipose tissue
Layers of epidermis
Stratum corneum
Stratum lucidum
Stratum granulosm
Stratum spinosum
Stratum basale
Stratum basale
Stem cells
differentiate into keratinocytes
regenerates epidermal cells
Melanocytes
In Stratum Basale
Synthesise melanin pigments
Granules of melanin cluster around keratinocyte nucleus»_space; UV Protection
Stratum spinosum
Keratinocytes with keratin filaments, attached to desmosomes
Langerhan cells
- Macrophages
- Immune cells
Stratum granulosum
Flattened keratinocytes
Undergoing apoptosis (because far away from blood supply)
Lamella granules
Stratum lucidum
Present in thick skin
Dead keratinocytes
Stratum corneum
Polymerised keratin fibres
No nucleus or organelles
Continually shed
Keratinocyte migration
Stratum Basale to Stratum Corneum
Label
Label
Hair
Protects hair on head fromsun
Eyebrows and eyelashes protect against foreign particles
Cells in bulb divide and grow»_space; Pushes shaft upwards»_space; Cells keratinise and die
Arrector pilli (hair)
Attaches to superficial dermis to sheath of hair follicle.
Pulls hair shaft to perpendicular position when contracted
Goosebumps
Label
Nails
Plates of hard keratinised dead epidermal cells
Grows from nail matrix cells surrounding root
