Flashcards in Skin Deck (80):
What kind of epithelium is the epidermis?
Basal layer of the epidermis
stratum basale (germinativum)
What type of cells make up the stratum basale layer?
single layer of columnar or cuboidal shaped cells - which undergo mitotic division
Daughter cells of the stratum basale either become ... or function as...
keratinocyes or function as stem cells
How do cells adhere to the basal lamina?
by hemidesmosomes and anchoring filaments (type VII collagen)
What is the layer superior to the stratum basale?
What types of cells is the stratum spinosum composed of?
multiple layers of polyhedral-shaped cells, joined to one another by numerous desmosomes
What in the stratum spinosum gives it the appearance of "spiny"?
desomosomes and their associated monofilaments as intracellular bridges
What occurs in the deepest portion of stratum spinosum?
Synthesis of membrane-bounded membrane-coating granules called ...., begins in the stratum spinosum.
What does the lipid-rich material in the lamellar bodies do upon exocytosis in the stratum granulosum?
coats the cell membrane of the keratinizing epithelium, making it relatively impermeable to water
The stratum granulosum is so named because of the appearance of dense, retractile, basophilic ... in the cytoplasm
The strong basophilia of the stratum granulosum reflects the presence of RNA and acidic proteins which are precursors to the protein...
Filaggrin is a protein which binds what? and in what process?
binds tonofilaments together in a process of keratinization. Desmosomes continue to bind cells together.
In the stratum granulosum cells are becoming ...
The stratum lucidum is recognized in thick epidermis by its ...
transparent refractile appearance
What has disappeared in the stratum lucidum?
nuclei and organelles
The thickest and most superficial stratum of thick epidermis
What is the stratum corneum composed of?
scale-like, desiccated remnants of keratinocytes
The cell membranes of the stratum corneum are thickened by the ...
lipid-rich compound released from membrane-coating granules
In the stratum corner the interior of the keratinized cell remnants is completely filled with filamentous material embedded in a dense matrix. Presumably this represents the ...
coalescence of the tonofilaments and keratohyaline granules
In the thin epidermis the stratum corneum appears ...
thin and net-like rather than thick and compacted
In the thin epidermis what layer is not seen?
Keratinocytes of what layers typically contain the pigment melanin?
basal and spinous layers
Where are the cell bodies of melanocytes located?
Long cytoplasmic processes of melanocytes extending between the keratinocytes of what layer?
Melanin is produced by oxidation of ... within...
tyrosine within melanosomes
Lack of pigmentation, albinism, is due to lack of ...
What breaks down melanin in keratinocytes?
Lysosomal breakdown of melanin in keratinocytes occurs most rapidly in ...
Dendritic cells in the supra basal layers of the epidermis?
Cells of Langerhans
The cytoplasm of Cells of Langerhans is distinguished by rod or flask-shaped ....
Cells of Langerhans are regarded as an .... cell, probably of bone-marrow origin.
Cells of Langerhans migrate into dermis to... by interacting with lymphocytes in lymphatics
initiate immune response
Modified keratinocytes, granule-containing cells
Merkel cells are regularly associated with ...
Merkel cells have what function?
The dermis is a layer of ... subjacent to the epidermis
At the interface of the epidermis and dermis is the basement membrane which is the location of collagen types..., that help establish the strength of the dermal-epidermal junction.
Types III, IV, VII
The papillary layer of the dermis is a layer of loosely textured connective tissue containing what types of collagen? along with elastic fibers.
Type I and Type III collagen
What are the elastic fibers of the papillary dermal layer labeled as?
elaunin and oxytalan fibers
The elastic fibers (elaunin and oxytalan) of the papillary dermal layer are rich in the protein ...; also significant component of the periodontal ligament
The papillary layer sends finger-like projections, the ..., into the overlying epidermis.
The epidermis that lies between the dermal papillae is referred to as...
epidermal pegs or rete ridges
In thick skin parallel arrays of dermal papillae cause ridges to be formed at the free surface of the skin; separated by grooves & run parallel to one another. They are the basis for fingerprints.
What in the papillary layer of the dermis provides oxygen and nutrient supply for the overlying epidermis?
Sensor nerve endings located in the dermal papillae, that innervate..., which are sensory for touch and pressure
The reticular layer of the dermis is the classic example of ...
dense, irregularly arranged CT
Which of the layers compromises the bulk of the dermis?
The reticular layer of the dermis consists mainly of what, giving skin both its toughness and resiliency?
Type I collagen with a liberal sprinkling of elastic fibers
What 3 things is the ground substance of the reticular layer of the dermis composed of?
hyaluronic acid, chondroitin sulfate and dreamt sulfate
Which layer of the dermis contains the appendages of skin, glands and/or hair follicles?
The reticular layer of the dermis experiences a loss of what, with aging?
hyaluronic acid and associated water
Hypodermis serves in certain locations as a major site for...
What transverse the hypodermic, connecting the dermis with the deep fascia?
collagenous septae & the retinacula cutis
In what layer are the Pacinian corpuscles?
Pacinian corpuscles are structures with multiple layers of flattened cells enclosing sensor nerve endings; the corpuscles are mechanoreceptors sensitive to ...
vibration and deep pressure
What are the 2 types of sweat glands?
eccrine & apocrine
Simple, tubular glands occurring over most of the body, independent of hairs.
Eccrine (merocrine) glands
The secretory segments of eccrine glands are coiled and lined with ..., which are described as "clear" or "dark" when examined by EM.
What product do the dark cells of the eccrine glands secrete?
release a proteinaceous product
Duct segments of sweat glands are lined with?
stratified cuboidal epithelium
Gland innervation of eccrine glands is?
Larger simple tubular glands, distribution limited to axillary, circumanal regions, external genitalia, and areola and nipple of the mammary gland. Connect with hair follicles and become functional at puberty.
The secretory segment of apocrine glands is lined with..., whose proteinaceous secretion is stored in a dilated-appearing lumen.
simple cuboidal epithelium
Apocrine secretion contains ...
Apocrine gland innervation is ...
Generally associated with hair follicles; closely associated with smooth muscle fibers may assist in rupture of secretory cells.
sebaceous glands have a simple acing form, with a short duct that empties into a neighboring ...
Sebaceous glands cells arise by ... in the basal layer of the acinus.
As the cells of the sebaceous gland reach the duct, the lipid-packed cells degenerate creating ...
Sebaceous glands use what kind of secretion mechanism?
Hair follicles arise as ingrowths of the ...
Continuous series of air pockets at the center of the hair
dense, compacted "hard" keratin; the cells that give rise to the ... undergo a process of keratinization
layer of keratinized scale-like cells covering the hair
What attach to the hair follicles and are capable of erecting and extending them; basis of "goose bumps"?
arrector pili muscles, & delicate bundles of smooth muscle fibers
The region where new nail is formed; can be seen through the nail at is base as the "moon"; is called the?
If the ... is destroyed, a nail will not regrow.