Chapter 5- Integumentary System Flashcards
Integumentary system functions
- regulate body temp
2.stores blood - protection from external environment
- detects sensations
- excretes/absorbs
- synthesize vitamin D
structure of skin
epidermis
dermis
SC layer
Epidermis
epithelial cells, thin, no blood vessels
Dermis
irregular connective tissue, thicker, has blood vessels, collagen and elastic fibers-stretch and recoil easy)
SC layer
anchor point and contains lamellated corpuscles-sensitive to pressure
Epidermis cells
keratinocytes
melanocytes
tactile epithelial
macrophages
Keratinocytes
product keratin, fibrous protein (wet suit), 90%, protection
melanocytes
produce melanin (absorb UV, contribute to skin colour), 8%
tactile epithelial
connects to tactile discs (detect touch), least amount, aka Merkel cells
macrophages
Langerhans cells, immune response, from RBM, against microbes
Skin layers
stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
Stratum Basale
row of cuboidal keratinocytes/produce keratin/ protects from injury, attaches to hemidesmosome/melanocytes and tactile epithelial cells, stem cells
Stratum Spinosum
can still divide, produce more keratin, (desmosomes hold cells to one another), macrophages and melanocytes present, 8-10 layers
stratum germination
forming new cells or stem cells
stratum granulosum
cells undergo apoptosis, too far from basale layer (no nutrition)
Keratohyalin
keratin filaments into keratin and inside cells are lamellar granules- release fat secretion into EFC
stratum lucidum
found only in thick skin, clear/dead keratocytes cells
stratum corneum
flatten, dead keratocytes cells (no cell parts),
Callus
thickening of SC layers
Dermis regions
Papillary region
Reticular region
papillary region
closest to epidermis (collagen and elastic fibers)
what does the papillary region consists of?
dermal papillary
capillary loops
corpuscles of touch
free nerve ending dendrites
dermal papillary
small, nipple shaped, projects upwards, increases surface area
capillary loops
found in dermal papillary, vascular
corpuscles of touch
nerve ending, sensitive to touch
free nerve ending dendrites
warmth, itching, tickling, no structure
reticular region
extensibility (stretch), elasticity (original shape), attached to SC, fibroblasts & wandering cells, thick collagen fibers
what does the reticular region of the dermis consist of?
blood vessels, nerves, sebaceous glands, sudoriferous glands, occupy spaces between fibers
epidermal ridges
downward projection of the epidermis between dermal papillary and papillary region-fingerprints/footprints, unique to each person, increases surface area
keratinization
cells move through epidermal layers, accumulate more and more keratin, then apoptosis
pigments of skin colour
melanin, hemoglobin, carotene
melanin
product of melanocytes (everyone has same number), colour is how much is produced and transferred to keratinocytes
functions of melanin
absorb UV rays
prevent DNA damage to neighboring cells (like tiny umbrella)