Integumentary Flashcards
It is the largest single organ of the body
Integumentary system
What % comprises the body weight of skin
15 to 20%
What are the functions of the integumentary system
Protection Sensory Thermoregulatory Metabolic Sexual Signaling
Physical barrier against thermal and mechanical insults such as friction pathogens and other material
Protection
Receptors allow skin to constantly monitor the environment
Sensory
Has mechanism for accelerating heat loss through sweat production and dense superficial microvasculature
Thermoregulatory
Synthesize ___ through the local action of UV light on the vitamin’s precursor.
Metabolic; vitamin D3
Visual indicators of health involved in attraction
o Hair
o Pigmentation
Sexual signaling
Produced by apocrine sweat glands are also important
Pheromones
Peg-and-socket interdigitations in most skin that form distinctive patterns unique for each individual
Epidermal Ridges
Combinations of loops, arches, and whorls
Dermatoglyphs
Contain many blood vessels that supply the overlying epidermis with nutrients, remove waste products and aid in regulating body temperature
Dermal Papillae
It has a ectodermal origin
Epidermis
What type of tissue is the epidermis
Stratified squamous keratinized epithelium
It has a mesodermal origin
Dermis
What type of tissue is the dermis
connective tissue
A loose connective tissue that attaches the skin to the underlying tissues
Hypodermis
What cells compises the epidermis
Keratinocytes
When is the human epidermis renewed
Every 15 to 30 days
It lacks microvasculature, cell receives nutrients through the dermis
Epidermis
Pigment-producing cells
Melanocytes
Where can the melanocytes be found
Basal layer
It is an antigen-presenting cells to T-lymphocytes found in stratum spinosum layer
Langerhans cells
Where can the langerhans cells be found
Stratum spinosum
Tactile epithelial cells for light touch mostly found in thick skin
Merkel cells
Where is the merkel cells located
Granular basal epidermal cells
Where is the merkel cells abundant
Fingertips
Bases of hair follicles
It is a disease that is uncommon, are very aggressive and difficult to treat.
Merkel cell carcinoma
This layer consists of 15 –20 layers of flattened, nonnucleated keratinized cells whose cytoplasm is filled with birefringent filamentous keratin.
Stratum corneum
Horny cornified or fully keratinized cells which are continuously shed as desmosomes and lipid rich cell envelopes break down.
Squames
Chronic skin condition in which keratocytes are typically produced and differentiate at accelerated rates, causing at least slight thickening of the epidermal layers and increased keratinization and desquamation.; cause by T lymphocyte
Psoriasis
This layer is only seen on THICK skin;
Consists of thin, translucent layer extremely flattened eosinophilic cells
Stratum lucidum
Nuclei and organelles have been lost and cytoplasm contains packed keratin
Stratum lucidum
Consists of 3 -5 layers of flattened polygonal cells undergoing terminal differentiation process of keratinization
Stratum granulosum
Dense, non-membrane bound masses of filaggrin and other proteins
Keratohyaline granules
Small ovoid structures with many lamellae with lipids and glycolipids, undergo exocytosis to produce lipid rich layer which contributes to skin’s barrier against water loss
Golgi-derived lamellar granules
Thickest layer, especially in epidermal ridges
Stratum spinosum
It consist of polyhedral or slightly flattened cells having central nuclei with nucleoli and cytoplasm actively synthesizing keratin filaments
Stratum spinosum
Combination of stratum spinosum and basale where cells may still divivde
Stratum germinativum
Keratin filaments assemble into microscopically visible bundles called _____ that converge and terminate at the desmosomes
Tonofibrils
This is the basal layer with intense mitotic activity
Stratum basale
What type of tissue is in the stratum basale
Basophilic columnar or cuboidal cells
Join cells to basal lamina
Hemidesmosomes
Bind cells in lateral and upper
Desmosomes
This condition are lymph-filled spaces created between the epidermis and dermis of thick skin by excessive rubbing, as with ill-fitting shoes or hard use of the hands.
Friction blisters
One cell thick containing most mitotic cells
Stratum basale
Where synthesis of much keratin and other proteins takes place
Stratum spinosum
Consisting of dead squames composed mostly of keratin
Stratum corneum
It synthesize melanin granules and transfer them into neighboring keratinocytes
of the basal and spinous layers
Melanocytes
Brown or black pigment
Eumelanin
Red pigment
Pheomelanin
Pale staining rounded cell bodies attached by hemidesmosomes to basal lamina, with no attachment to keratinocyte
Neural crest
1 melanocyte + keratinocytes which receives melanosomes
Epidermal-melanin unit
Congenital disorder producing skin hypopigmentation due to a defect in tyrosinase or some other component of the melanin-producing pathway
Albinism
Acquired condition which involves skin depigmentation, often only in affected patches, due to the loss or decreased activity of melanocytes.
Vitiligo
it converts tyrosine into 3,4-
dihydroxyphenylalanine (DOPA)
Tyrosinase
In stage does melanin synthesis occurs
Stage II melanosomes
This is the stage when a mature melanin granule has lost tyrosinase
Sage IV
What comprises the dermis
Hair follicles
Glands
and nerves
Is always found between the stratum basale and
the papillary layer of the dermis.
Basement membrane
Blistering disorder due to abnormalities of the
dermal-epidermal junction
Bulbous pemphigoid
Blistering disorder caused by autoimmune damage
to intercellular junctions between keratinocytes.
Pemphigus
Constitute the major part of the dermal papillae.
Papillary layer of dermis
What is the composition of papillary layer of dermis
Loose CT, Type I and III collagen with fibroblast, and other connective tissue such as mast cells and macrophage
Capillary branches extend into the dermal papillae and
form a rich, nutritive capillary network
Subpapillary vascular plexus
Composed of irregular dense connective tissue
and has more fibers and fewer cells
Reticular layer of dermis
Consists of loose connective tissue that binds the skin loosely to the subjacent organs, making it
possible for the skin to slide over them.
Subcutaneous layer or hypodermis
Including both simple nerve endings with no glial or
collagenous covering structure
Sensory receptors of the skin
Associated with epidermal tactile cells, which function as receptor for light touch
Tactile disc
Respond primarily to high and low temperatures, pain, and itching, but also function
as tactile receptors
Free nerve endings
A web
of sensory fibers surrounding the bases of hair follicles
in the reticular dermis that detects movement of the
hairs
Root hair plexus/hair follicle receptor
Elliptical structures, perpendicular to the epidermis in the dermal papillae and papillary layer of the fingertips, palms and soles
Tactile corpuscles/Meissner’s Corpuscles
Test than can determine the density of tactile Meissner
corpuscles in skin
Two-point discrimination tests
Lamellated corpuscles
Pacinian corpuscles/Vater-pacinian corpuscles
pressure sensing mechanoreceptors in the dermis.
Krause corpuscles
Where is the krause corpuscles found
skin of penis and clitoris
Pressure sensing mechanoreceptors in the dermis.
Ruffini corpuscles
What are the accessory skin structures
Hair, arrector pili muscle, nails, glands of the skin
Elongated keratinized structures
Hair
Invaginations of the epidermal epithelium
Hair follicles
Part of hair that is large, vacuolated and moderately
keratinized
Medulla
Heavily keratinized, densely packed cells
Cortex
Thin layer of heavily keratinized, squamous cells covering the cortex
Cuticle
Epidermal invaginations that are sites of growth for
hair
Hair follicles
Completely surrounds
the initial part of the hair root but
degenerates above the level of attached
sebaceous glands.
Internal root sheath
Covers the internal
sheath and extends all the way to the
epidermis, where it is continuous with the
basal and spinous layers.
External root sheath
Thickened basement membrane of an acellular
hyaline layer separating hair follicle from the
dermis
Glassy membrane
Terminal dilation of the growing hair follicle
Hair bulb
inserts into the base of the
hair bulb and contains a capillary network
Hair dermal papilla
Matrix is formed by
keratinocytes covering the
dermal papillla
Hair root
Part of hair extending beyond skin surface
Hair shaft
Is a strap of smooth muscle tissue connecting the
side of a follicle to the superficial surface of the
dermis
Arrector pili muscle
Raised area of skin
Goose flesh
Hard, flexible plates of keratin or the
dorsal surface of each distal phalanx.
Nails
The free part
Free edge
Visible part of the nail
Nail body
A whitish crescent shaped area at the base of the nail
Lunula
stratum corneum that
extends into the nail body
Eponychium (cuticle)
Bound to a bed of epidermis
Nail plate
Distal end of the plate free of the nail bed at the epidermal fold
Hyponychium
Contains only basal and spinous epidermal layers
Nail bed
Proximal part of the nail; portion of the
nail under the fold
Nail root
Forms the nail root, in which cells divide, move distally and become keratinized
similar to hair but without keratohyaline granules
Nail matrix
Embedded in the dermis over most of the body surface EXCEPT thick, hairless skin of the palms and soles
Sebaceous Gland
What is the shape of the sebaceous gland
Branched acinar glands
Hair follicle and associated
sebaceous glands
Pilosebaceous units
An inflammatory disorder of the pilosebaceous unit,
which can be expected to occur during
adolescence.
Acne vulgaris
Epithelial derivatives embedded in the dermis
Sweat Gland
Is the physiological response to increased body temperature during physical exercise or thermal stress and in humans the most effective means of temperature regulation
Sweating
Widely distributed
in the skin are most
numerous on the
soles of the feet
Eccrine sweat glands
Located on the basal lamina to produce the sweat
Clear cells
Line the lumen and release
glycoproteins with bactericidal activity
Dark cells
Contract to move the
watery secretion
Myoepithelial cells
How many layers of acidophilic cells does eccrine sweat glands have
2
Largely confined to skin of the axillary perianal regions; Depends on sex hormones and is not complete until puberty
Apocrine sweat glands
Have much larger lumens (glands)
Apocrine sweat glands
What is the type of tissue of apocrine sweat glands
simple cuboidal
