Integumentary System I and II Flashcards
What are the essential functions of the integumentary system?
barrier immunologic homeostasis sensory endocrine excretion
what type of epithelium makes up the epidermis?
keratinized stratified squamous epithelium
what is the epidermis derived from?
ectoderm
what type of tissue is the dermis made of?
dense CT
what is the dermis derived from?
mesoderm
what type of cells make up the stratum corneum?
keratinized cells
what is eleiden?
protein similar to keratin - transformation product of keratonhyalin
what type of skin is stratum lucidum found in?
thick skin only
what type of cells are found in the stratum basale?
mitotically active cells
what layers make up the stratum malpighii?
basale and spinosum
what type of cells make up the single layer of cells found in the stratum basale?
small, cuboidal to low columnar
how do the cells of the stratum basale attach to ECM while resting on basal lamina?
hemidesmosomes
what type of granules are found in the stratum granulosum?
keratohyalin granules
what is Parakeratosis?
keratin layer is abnormal - contains nuclear remnants
what is acanthusis?
abnormal epidermal thickening
- due to increase depth of stratum spinosum
common feature of many skin conditions
what layers make up the dermis?
papillary layer
reticular layer
what type of CT is found in papillary layer?
loose CT
what type of CT is found in reticular layer?
dense CT
what is the main cell type of epidermis?
keratinocytes
what are the cells of the epidermis?
keratinocytes
melanocytes
langerhan’s cells
merkel cells
what type of cells Langerhan’s cells?
antigen presenting cells
what types of cells are merkel cells?
cutaneous sensation
What are the two essentials activities of keratinocytes?
produce keratin
epidermal water barrier formation
what do keratohyalin granules contain?
intermediate filament associated proteins = filaggrin
trichohyalin
what are tonofilaments?
intermediate filaments = keratin filaments
what are tonofibrils?
bundles of tonofilaments
what is the ABCD rule of Malignant melanoma?
Asymmetrical
Border is irregular
Color variation
Diameter
where are the melanocytes in light skin?
concentrated near basal layer
where are the melanocytes in dark skin?
throughout the epidermis
in what skin is melanocyte degradation more rapid?
light skin
what does exposure to UV light accelerate?
melanin production
what is albinism?
lack of pigmentation
absence of tyrosinase - inability to produce melanin
what makes up merkel’s corpuscle?
neuron and merkel’s cells
what are the types of sensory receptors?
free and encapsulated
what are in free sensory receptors?
free nerve endings
merkels corpuscle
what makes up encapsulated sensory receptors?
pacinian corspuscles
krause’s end bulb
meissner corpuscles
ruffinis corpuscles
what are the deep pressure receptors?
pacinian corpuscles
what are meissner’s corpuscles?
touch receptors
what are nails?
plates of keratinized cells containing hard keratin
what does an eccrine sweat gland produce?
sweat
what does apocrine sweat glands produce?
mixed product -
sweat with high concentration of carbs lipids and proteins
what is the eponychium?
cuticle - hard keratin covering of nail root
what is hyponychium?
thick epidermal layer
secures free edge of nail plate at fingertip
what are the layers of the epidermis?
stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale
where are stem cells present?
stratum basale of epidermis
how do the spinous processes of the cells in the stratum spinosum attach to adjacent cells?
desmosomes
what skin layer of the epidermis has a water barrier?
stratum corneum
which layer of the skin forms the regular tension lines of the skin called langer’s lines?
reticular layer
what is in the reticular layer?
collagen type I and elastic fibers
what structural elements make up the epidermal water barrier of the keratinocytes?
cell envelope - insoluble proteins on inner plasma membrane
lipid envelope - lamellar bodies
what is the purpose of the epidermal water barrier?
maintian body homeostasis
essential for mammalian dry skin
what are lamellar bodies?
in lipid envelope
- glycosphingolipids, phospholipids, ceramides
- secreted by exocytosis
where are melanocytes found in epidermis?
stratum basale
where are melanocytes derived from?
neural crest cells
what does melanocytes do?
make and donate melanin to keratinocytes - keratinocytes phagocytize the tips of melanocyte processes (dendrites)
is the number of melanocytes equal in light skin and dark skin?
yes
what layer of epidermis is Langerhan’s cells found?
stratum spinosum
where are merkels cells found?
stratum basale
what does the cytoplasm of merkels cells contain and what is it closely associated with?
dense neurosecretory granules
closely associated with terminal bulb of afferent nerve fibers
what is the function of Merkel’s corpuscle?
mechanoreceptor
cutaneous sensation
where are pacinian corpuscles located?
deep dermis and hypodermis
- myelinated n. ending at one pole
- unmyelinated portion of axons extends to opposite pole
where are Meissner’s corpuscles located?
dermal papillae of hairless skin - lips, fingers, toes
what types of nerves are found in Meissner’s corpuscles?
unmyelinated endings of myelinated nerve fibers
what are epidermal skin appendages derived from?
downgrowths of epidermal epithelium during development
what are the epidermal skin appendages?
nails hair follicles sebaceous glands eccrine sweat glands apocrine sweat glands
what is hair?
keratinized cells containing hard keratin
what is nail bed continuous with?
stratum basale and spinosum of epidermis
which part of the nail is the germative zone?
nail matrix
what does hair color depend on?
content and type of melanin
what is the dermal sheath?
CT surrounding hair follicle
what is root sheath?
outer - 1 = cont. with epidermis inner 2-4 = extends to sebaceous gland level - henle's layer - huxleys layer - cuticle of inner sheath
how do sebaceous glands develop?
outgrowth of external root sheath of hair follicle
what is sebum?
oily substance
coats hair and skin surface
holocrine secretion
role in acne
what cells in sebaceous glands are mitotically active and sit on basal lamina?
basal cells
what is the function of eccrine glands?
regulate body temp
what are the two segments of eccrine sweat glands?
secretory - clear cells, dark cells, myoepithelial cells
duct
where are apocrine sweat glands found?
axilla
areola
gentitoanal
which sweat gland secretions contain pheromones?
apocrine sweat glands
what type of secretion do apocrine sweat glands have?
merocrine - apical vessicles released by exocytosis
