L9 Skin Flashcards
(92 cards)
Skin functions
Protection
Sensation
Thermoregulation
Immune System
Endocrine System/Metabolism
Somatosensory receptors
Merkel’s disk
Meissner’s Corpsule
Ruffini Ending
Pacinian Corpuscle
Skin layers
Epidermis
Dermis
Subcutaneous Tissue
Epidermis
outermost layer that provides 1st barrier of protection
avascular
Keratinocytes and Nonkeratinocytes
Keratinocytes
primary cells of epidermis, synthesize keratine
Non-kertinocytes
Melanocytes
Langerhans’ cells
Mechanoreceptors
Melanocytes
synthesize melanin and pigment responsible for skin color
protects against UV
Langerhans’ cells
involved in immune response as antigen-presenting cells
Mechanoreceptors
Merkel, Meissner, Ruffini
Layers of Epidermis
Stratum…
Corneum
Lucidum
Granulosum
Spinosum
(Langerhan’s, Melanocytes, Merkel)
Basale
(Come, let’s get sun-burnt)
Dermis
provides thermoregulation and supports vascular network to supply nutrients to avascular epidermis
2 regions: papillary, reticular
contains many cells, vascular, nerve
Papillary layer of Dermis
thin, loose connective tissue just under epidermis
free nerve endings
Reticular Layer
thicker, irregular tissue beneath papillary layer, provides strength and elasticity
What does the dermis contain?
fibroblasts, macrophages, mast cells, lymphatic vessels, blood vessels, nerves, eccrine/apocrine units
Epidermal appendages
sweat glands
hair follicles
nails
sebaceous glands
Eccrine glands
directly to surface of skin, thermoregulation
Apocrine
joins at hair follicle
does not produce sweat continuously, but at times of stress
Hypodermis role
- largest store of energy
- provides insulation from thermal stress of cold environment
- largest endocrine organ in body
- significant effects on immune system
Effects of aging on epidermis
becomes thinner
decreased number of melanocytes
fewer langerhan’s cells
decreased vitamin d synthesis
Epidermis becomes thinner
more hyper-reactive to skin irritants
increased risk of skin tearing
Decreased # of melanocytes in epidermis
loss of photoprotection
increased risk of cancer
Fewer Langerhans’ cells in epidermis
decreased immune response
increased risk of skin cancer
Decreased Vitamin D Synthesis in epidermis
increased risk of osteoporosis
Dermis and Aging
- Decreased dermal thickness and degeneration of elastin fibers
- Changes in epidermal appendages