w7 integument Flashcards
epidermis epithelium shape
stratified squamous keratinized
what is the primary cell type in epidermis
keratinocytes
what are langerhans
antigen-presenting cells
what are merkel cells
associated w sensory nerve fibers
stratum basale what layer and what shape of cells and how many layers
basal layer - single layer of cuboidal to columnar basophilic cells
in basal layer, basal cells attach to basal lamina by what and to neighboring cells by what
hemidesmosomes
desmosomes
what is the thickest layer of the epidermis
stratum spinosum (spinous or pricle layer
stratum spinosum what shape cell and how are the nucleus
polyhedral cells w central nuclei
in stratum spinosum, cytoplasm actively synthesizes what in form of tonofibrils which attach to desmosomes
keratin
stratum granulosum is what layer and how many layers and what shape cell
3-5 layers for flattened cells
what layer has cytoplasm that contains keratohyalin granules that contain filaggrin and other proteins involved in keratinization
stratum granuolusm
what layer is strictly seen on thick skin
stratum lucidum
stratum lucidum structure and cells packed w what
cells packed w keratin filaments
translucent layer, formed of flattened eosinophilic cells
nuclei and organelles have been lost
stratum corneum structure, and what are the cells called
cells called squames
15-20 layers thick, flattened, non-nucleated keratinized cells
what layer has the cytoplasm filled w birefringent filamentous keratins and cells that contain only amorphous proteins
stratum corneum
eumelanin
pheomelanin
brownish or blackish pigment
pigment found in red hair
melanocytes are derived from what and do not form desmosomes w basal cells
neural crest cells
tyrosinase converts what
tyrosine to DOPA to melanin
melanin is stored in granules called what
melanosomes
langerhans cells (dendritic cells) act as what presenting cells an most evident in what stratum, and what do they do
antigen-presenting cells
most evident in stratum spinosum
process and present antigens to T cells
what do merkel cells do and where are they located
located in the stratum basale of epidermis, and also at base of hair follicles
partially surrounded by terminal discs of sensory nerve fibers
contain dense-core neurosecretory granules
mechanoreceptors
what does dermis do and separated from epidermis by what membrane which includes what 2 layers
connective tissue that supports the epidermis
separated from epidermis by basement membrane which includes (basal lamina and reticular lamina)
dermis layers and composed of what
papillary layer - type VII collagen, loose connective tissue, contains dermal papillae
reticular layer - thicker, less cellular, more fibrous, contains type 1 collagen an elastic fibers
what layer are hair follicles and glands located
reticular layer of dermis
reticular layer of dermis contains an extensive nerve plexus made up of what type of fibers
sensory and sympathetic fibers (no parasympathetic)
hypodermis composed of what type of connective tissue and often contains what kind of cells and is vascular or avascular
loose connective tissue
binds skin to underlying organs or tissues
equivalent to superficial fascia in gross anatomy
often contains adipose cells
contains extensive vascular network
is the epidermis vascular or avascular
avascular - no direct blood supply
subpapillary plexus vs cutaneous plexus in blood vessels
subpapillary plexus - at interface of papillary and reticular layers of the dermis
(capillary loops extend upward into the dermal papillae from this plexus)
cutaneous plexus - between hypodermis an reticular dermis
lymphatic plexuses accompany what
blood plexuses
arteriovenous anastomoses help w what
thermoregulation
(shunt blood away from the papillary dermis to prevent heat loss when the skin is exposed to cold temp)
(can increase blood flow to papillary dermis to get rid of excess heat)
tactile discs accompany what cells and function
encapsulated or non-encapsulate
merkel’s cells
act as light touch and mechanoreceptors
non-encapsulated
free nerve endings function and terminate where
encapsulated or non-encapsulate
terminate in both dermis and epidermis
respond to pain, temperature, itching and light touch
non encapsulated
root hair plexuses location and function
surround the base of hair follicles
detect movements of hairs
root hair plexuses location and function
encapsulated or non-encapsulate
surround the base of hair follicles
detect movements of hairs
non-encapsulated
meissner corpuscles function location
is it encapsulated or on noncapsulated
function -detect light touch
location - located primarily in dermal papillae, esp in fingertips, palsm, an soles
encapsulated
Pacinian corpuscles function and what does it surround
is it encapsulated or non encapuslated
detect coarse touch, pressure or sustained touch, vibrations
capsule surrounds unmyelinated axon
ruffini’s corpuscles detects what and where
is it encapsulated or noncapsulated
detect stretch and torque
formed a simple capsule enclosing fluid and terminal arborizations of a sensory neuron
encapsulated
krause end bulb what kind of receptors
is it encapsulated or noncapsulated
thermoreceptors, mechanoreceptors
sebaceous gland located throughout the skin accept where
palms and soles
in eccrine sweat glands, clear cells produce what and contain what
dark cells are what and produce what
clear cells produce sweat (contain abundant mitochondria and microvilli)
dark cells are mucoid (produce glycoprotein involved w immune response)
what do myoepithelial cells in eccrine sweat glands
contract to help discharge secretion
apocrine sweat glands function apocrine or merocrine
merocrine
eccrine vs apocrine sweat glands
Eccrine sweat glands occur over most of the body and open directly onto the skin’s surface. Apocrine glands open into the hair follicle
terminal vs vellus hair
terminal - long coarse hairs such as scalp and beard
vellus - very fine such as forehead
hair grow cycle
anagen, catagen, telogen
anagen - period of hair growth
catagen - period of follicle regression
telogen - period of inactivity
facial and pubic hair growth controlled by what
androgens
hair follicle parts (3)
bulb, dermal papilla
arrector pili muscle how does it work and what does it cause
when muscle contracts, hair becomes erect
causes goose bumps
small smooth muscle which connects the hair shaft to the papillary dermis
hair color caused by melanin, produced by what where
melanocytes in the bulb
eponychium
staratum corneum of skin fold forms cuticle
distal free end of nail plate called what
hyponychium
