Integument Flashcards
Name the 5 functions of the integument
protection
thermoregulation
sensory organ
metabolic
excretion
vitamin D synthesis in epidermis, energy storage (fat-triglycerides in the hypodermis)
metabolic function of the integument
where is thick skin found?
palms of hand and soles of feet
What is NOT found in thick skin?
hair follicles
Where is thin skin found?
everywhere except for the palms of hand and soles of feet
What do keratinocytes produce?
keratin
Name the 5 epidermal layers from bottom to top (in thick skin).
stratum basale (stratum germinativum)
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
What epidermal layer is absent in thin skin?
stratum lucidum
Which epidermal layer is a single layer of columnar to cuboidal cells?
stratum basale
Cells in the stratum basale contain numerous types of what filaments?
intermediate filaments (tonofilaments)
Cells in the stratum basale contain which types of cell junctions.
dermosomes and hemidesmosomes
Cells in the stratum spinosum are shaped like what?
cuboidal, polygonal, to slightly flattened
Cell processes in the stratum spinsosum are filled with?
intermediate filaments (terminate with desmosomes)
What do cells in the stratum spinosum accumulate with?
fibrillar protein (cytokeratin) that aggregate to form tonofibrils
What do cells in the stratum granulosum look like?
flattened polygonal cells
cytoplasm of stratum granulosom cells have what?
basophilic keratohyaline granules and lamellar granules
glycolipid (acylglucoceramide)
serves as a penetration barrier to foreign materials and to maintain hydration of the body
thin layer of eosinophilic, newly keratinized cells
stratum lucidum
transformation product of keratohyalin
eleidin
15-20 layers of flattened nonnucleated cells filled with keratin
stratum corneum
squames
dead flattened cells
If epidermis is injured, which cells migrate and divide to cover the wound
basal cells
necessary for proper skin healing as it is a factor needed for keratinocyte differentiation
Vitamin A
1st degree burns extend to which layer?
stratum lucidum
2nd degree burns extend down to which layer
S. basale
3rd degree burns extend into the?
dermis
What are expressed as keratinocytes differentiate
different keratins
secreted to form multilayered lipid layer on the outside of the cell membrane in the S. granulosum
glycolipids
What links to the cytoplasmic side of the cell membrane in the s. corneum?
a protein complex of involucrin-small proline-rich-loricrin complex and keratin-filagrin aggregates
Pigment producing cells of the S. basale are derived from?
neural crest
pigment producing cells of the S. basale
melanocytes
melanocytes rest on the ________and send processes into the _________
b. lamina
s. spinosum
melanin are produced by which cells
melanocytes
cytocrine secretion
how melanocytes distribute melanin to other cells and hair via their processes
pigment granules are ________ by melanocytes and _________by keratinocytes
exocytosed
endocytosed
melanin formation occurs within
melanosomes
enzymes needed for melanin synthesis
tryosinase
Lack of this from the adrenal cortex causes overproduction of ACTH
cortisol
increase in skin pigmentation
Addison’s disease
albinism
melanocytes do not make melanin
loss of melanocytes
depigmentation (vitiligo)
star-shaped cells mainly in the S. spinosum
Langerhans’ cells
Langerhans’ cells are derived from what?
bone marrow
Fc and complement C3 receptors are on what cells?
Langerhans’ cells
can migrate out of epidermis to lymph nodes
langerhans’ cells
present antigens to T cells and differentiate into activated dendritic cells
langerhans’ cells
Do langerhans’ cells form desmosomal attachments?
No
membrane-bound, rod-like shaped granues in langerhans’ cells
Birbeck or vermiform granules
langerin
proteins in vermiform granules necessary for antigen uptake
tactile epitheliooid cells associated with sensory nerve ending
merkel cells
Where are merkel cells primarily
thick skin of palms and soles
base of merkel cell in contact with?
peripheral neuron terminal
cytoplasm of merkel cells contains what?
small dense neuroendocrine granules
supports epiderms and binds it ot the subcutaneous tissue (hypodermis)
dermis
surface of dermis interdigitates with epidermis via
dermal papillae
epidermal counterpart to dermal papillae
epidermal ridges or rete ridges
extend from the basal lamina and terminate in anchoring plaques to bind the dermis to the epidermis
anchoring fibrils
outermost layer of loose connective tissue where fibroblasts, mast cells and macrophages may be present in the dermis
papillary layer
layer of the demris composed of dense irregular connective tissue
reticular layer
the dermis has:
follicles, sweat and sebaceous glands, and nerves
extensive capillary layer is in which layer of the dermis
papillary layer
extensive capillary network in the papillary layer of the dermis functions in
thermoregulation
deeper continuation of the dermis
hypodermis
primarily loose CT and adipose tissue
hypodermis
pressure/vibration sensors
pacinian corpuscles
Pacinian corpuscles are found where
near the dermis-hypodermis junction
invaginations of the epidermis
hair follicles
hair follicles terminate
in hair bulb
projects into the hair bulb
dermal papilla
epidermal cells covering the dermal papilla form the
hair root
cells at the apex of the dermal papilla produce
large, vacuolated, moderately keratinized cells - form hair medulla
hair cortex
cells around the papilla differentiate into fusiform, heavily keratinized cells
cells more peripheral inthe root produce
the hair cuticle
most peripheral root cells produce
internal and external root sheath
hair follicle separated from the dermis by a thickened basal lamina
glassy membrane
smooth muscle bundles extending from dermis papillary layer to hair follicle connective tissue sheath
arrector pili muscles
cells that migrate from hair follicle if epidermis is lost
clonogenic keratinocyte stem cells
glands not found on palms and soles
sebaceous glands
basal layer of undifferentiated flattened epithelial cells on basal lamina
acini
sebum
dead cells + cell contents
simple coiled tubular gland - duct opens onto skin surface
eccrine (merocrine) sweat glands
gland that contains myoepithelial cells, dark cells and clear cells
sudoriferous (sweat) glands
contractile cells in sweat glands
myoepithelial cells
mucoid, pyramidal cells
dark cells
devoid of secretory granules, but have abundant glycogen
clear cells
dark cells secrete what?
glycoproteins
secrete water and electrolytes into intercellular canaliculi
clear cells
non-viscous secretion
little protein, contains water, NaCl, urea, ammonia, and uric acid
glands present in axillary, areolar, and anal regions - ducts open into hair follicles
apocrine gland
what do apocrine glands receive
adrenergic nerve fibers
apocrine glands have what mechanism of secretion?
merocrine
plates of keratinized epithelial cells
nails
embedded in fold of skin
nail root
stratum corneum of the epithelium over the nail root
eponychium (cuticle)
Nail plates arises from the?
nail matrix
Nail plate rests on a bed of epidermis called the what?
nail bed
nail bed contains only?
s. basale and s. spinosum
white crescent and the base of the nail
lunula
albinism
little melanin production. vision problems due to abnormal retina development and abnormal nerve connections between the eye and brian
vitiligo
melanocytes are destroyed - patchy pigmentation
liver spots
freckle due to being in the sun (NOT liver related)
actinic keratosis
precancerous condition. thick scaly patches of skin
basal cell carcinoma
(~90% of all skin cancers) slow growing and treatable if found early
squamous cell carcinoma
often develop from sun damaged areas
malignant melanoma
derived from melanocytes. hard to treat once metastasized
psoriasis
immune-mediate, genetic disease. red scaly patches of skin due to inflammation and hyperplasic (individuals often have joint problems)
