Integument Flashcards
Integument functions (5)
protections, thermoregulation, sensory organ, metabolic (Vitamin D synthesis), excretion (water, salt, and nitrogenous waste)
Generally has 3 types
epidermis, dermis, hypodermis
thick skin is usually found on
palms of hand and soles of feet
thick skin has no
hair follicles
thin skin is found on
skin other than palms and soles
thin skin has
hair follicles and thinner epidermis
epidermis has stratified squamous epithelial cells called
keratinocytes (produce keratin)
Types of epidermis (5) all start with stratum
basale, spinosum, granulosum, lucidum, corneum
stratum basale has numerous intermediate filaments called _; _ bind cells to basal lamina
tonofilaments
hemidesmosomes
stratum spinosum has fibrillar protein called _ that aggregates to form _
cytokeratin
tonofibrils
stratum basale and spinosum also have
mitotic figures
stratum granulosum cytoplasm has basophilic _
keratohyaline granules
stratum granulosum cells also have oval or rod-like _
lamellar granules
lamellar granules are formed by lipid bilayers which fuse with cell membranes and _
discharge contents into intercellular spaces of the S. granulosum
the product of the lamellar granules and its discharge contents is
glycolipid called acylglucoceramide
purpose of acylglucoceramide
penetration barrier to foreign materials and to maintain hydration of the body
stratum lucidum is only in
thick skin
stratum lucidum has no organelles or nuclei evident; cells contain eleidin, which is a
transformation product that becomes keratin
stratum corneum has what kind of cells
dead flattened cells called squames
if epidermis is injured, surrounding _ cells _ and _ to cover the wound
basal
migrate
divide
what is needed for proper skin healing
retinol (vitamin A) because it’s needed for keratinocyte differentiation
first degree burns extend to
S. lucidum
2nd degree burns extend to
S. basale
3rd degree burns extend to
dermis
lipids from lamellar bodies are linked to protein in the cell membrane called
involucrin
_ protein aggregates keratin filaments
filaggrin
pigment producing cells of S. basale derived from neural crest
melanocytes
melanocytes distribute _ to other cells and hair via _
melanin
cytocrine secretion
melanin formation occurs within
melanosomes (Derived from Golgi)
what enzyme is needed for melanin synthesis
tyrosinase
lack of cortisol from the adrenal cortex causes overproduction of ACTH leading to
Addison’s disease (increased skin pigmentation)
(likely unnecessary) melanin is produced by oxidation of _ to _ and then transformed into melanin
tyrosine
dihydroxyphenylalanine (DOPA)
melanocyte cytoplasm is _ than neighboring keratinocytes
less dense
star-shaped cells mainly in S. spinosum
Langerhans’ cells (epithelial dendritic cells)
Langerhans’ cells are derived from what
bone marrow (macrophage lineage)
Langerhans’ cells can migrate out of epidermis to lymph nodes and _ to T cells and differentiate into activated dendritic cells
present antigens
do Langerhans’ cells form desmosomal attachments with other cells
no
Langerhans’ cells have unique membrane-bound, rod-like to racquet shaped granuales called
vermiform granules
Merkel’s cells are tactile epitheloid cells found primarily in
thick skin of palms and soles
Merkel’s cells cytoplasm has
small dense granules
Merkel’s cell is involved in
2-point touch discrimination
Merkel’s cells are in contact with the peripheral neuron terminal and can become _
cancerous
dermis supports _ and binds it to the _
epidermis
hypodermis
dermis interacts with epidermis via
dermal papillae
epidermal counterpart to dermal papilla is called
epidermal ridges or rete ridges
dermis binds to the epidermis via _ that extend from the basal lamina and terminate in _
anchoring fibrils
anchoring plaques
outermost layer of dermis is called the _ and is _ connective tissue
papillary layer
loose
(papillary layer may have fibroblasts, mast cells, and macrophages)
_ layer of dermis is composed of
reticular layer
dense irregular connective tissue
dermis has follicles, sweat and sebaceous glands, and nerves; its extensive capillary network in the papillary layer functions in
thermoregulation
deeper continuation of the dermis is called
hypodermis
hypodermis is primarily what kinds of tissue
loose connective tissue and adipose tissue
what is found near dermis-hypodermis junction
Pacinian corpuscles (pressure/vibration sensors)
invagination of epidermis is called a
hair follicle
hair follicle terminates in
hair bulb
_ projects into 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 that form the
hair medulla
other cells around the papilla differentiate into fusiform, heavily keratinized cells that form the
hair cortex
cells more peripheral in the hair root produce the
hair cuticle
most peripheral root cells produce the
internal and external root sheath
hair follicle separated from the dermis by a thickened basal lamina called the
glassy membrane
smooth muscle bundles extending from dermis papillary layer to hair follicle connective tissues sheath are
arrector pili muscles
sebaceous glands are not found in thick skin; sebaceous glands what type of gland
holocrine
dead cells and cell contents of sebaceous glands are called
sebum
sudoriferous (sweat) glands are what type of gland
eccrine (merocrine)
sweat glands contain 3 types of cells
myoepithelial cells (contractile) dark cells (pyramidal cells) clear cells (abundant glycogen but no secretory granules)
dark cells secrete _ while clear cells secrete _ into intercellular canaliculi
glycoproteins
water and electrolytes
sweat glands have a non-viscous secretion and is considered an
ultrafiltrate of plasma
apocrine glands have only one kind of secretory cell that produces a viscous protein containing secretion; apocrine sweat glands have what kind of secretion
merocrine
plates of keratinized epithelial cells
nails
_ is embedded in fold of skin
nail root
the stratum corneum of the epithelium over the nail root forms the
eponychium (cutile)
_ rests on a bed of epidermis called the _
nail plate
nail bed
nail bed contains what
only S. basale and S. spinosum
the nail matrix extends from the nail root to the
lunula (white crescent and the base of the nail)
little melanin production and vision problems
albinism
melanocytes are destroyed-patchy pigmentation
vitiligo
freckle due to being in sun
liver spots (not liver related)
actinic keratosis is
pre skin cancerous condition where an individual has thick scaly patches of skin
slow growing and treatable kind of skin cancer
basal cell carcinoma
skin cancer that develops from sun damaged areas
squamous cell carcinoma
skin cancer derived from melanocytes
malignant melanoma
immune-mediated, genetic disease where an individual has red scaly patches of skin due to inflammation and hyperplasia; individuals may have joint problems
psoriasis
