Skin Flashcards
Mammary glands develop under influence of ____ and _____ homrones
ovarian and pituitary
Are mammary glands active or inactive glands?
Inactive
In haired skin, migration of cells from external root sheath of hair follicles augments ______
re-epithelialization
Brown, black pigment present in dark haired individuals (elongate)
eumelanin
stratum spinosum cells held together by what cell junction?
desmosome
4 function of skin
protection, sensation, thermoregulation, metabolic funtions
in first intention healing, days 3-7 neutrophils are replaced by ____ (marks transition from acute to subacute phase)
macrophages
Hair shaft consists of what 2 layers?
outer cortex and inner medulla
in first intention healing, within 3-24 hours, _____ infiltrate the clost
neutrophils
Emotional sweating is ________; begins on palms and sole
adrenergic
vascular plexus located deep within hypodermis; largest of three
Subcutaneous plexus
membrane-bound, lamellar structures found in the cells of granular layer that contain glycolipids, provide waterproofing coat for skin cells
keratinosomes
_____ functions as UV shield to protect nucleus; inhibits mutagenesis
Melanin
pigmented region of epidermis surrounding nipple
areola
After tyrosine is oxidized to DOPA, DOPA is converted to _____ in melanosomes
melanin
Takes about ____ days for cells to mature from stratum basale to stratum corneum leading to keratinization
25
Vascular plexi of skin from superficial to deep
subpapillary plexus, cutaneous plexus, & subcutaneous plexus
At the base of bulb is a vascular core which is a finger-like invagination of dermis containing blood vessels
dermal papilla
largest organ of the body
skin
Affected individuals of androgenic alopecia have high levels of ______ (enzyme)
5-alpha-reductase
the _____ consists of densely packed, parallel hard keratin filaments embedded in amorphous matrix; slides over underlying nail bed as it frows
nail plate
act as a hydrophobic barrier that prevents desiccation in the stratum corneum
soft keratin
rupture of keratohyaline granules & polymerization of their contents forms a matrix for tonofibrils of cytokeratin that lead to an amorphous mass of mature ________
keratin
Develop along paired epidermal ridges that extend axillae to groin; form milk lines
Mammary glands
Langerhans cells contain distinct ______ granules that are visible on EM
Birbeck
________ is initiated by release of lysosomal enzymes => rupture of keratohyaline granules & polymerization of their contents
Keratinization
skin function: ______ largest sense organ of body; contains receptors for touch, pressure, pain, & temperature
sensation
contains cells that look spiny; have polyhedral cell with prominent intercellular bridges; has numerous cytoplasmic processes and lateral folding of cell membrane
stratum spinousum
Takes about ____ weeks to fill a 1 cm wide cut; this is why we suture
3
2 layers of dermis layer
superficial papillary layer and deep reticular layer
Burn involving all 3 layers (epidermis, dermis, and hypodermis)
3rd degree
_____ glands have secretory, cuboidal epithelium 2-3 cell layers thick that surround large glandular lumen
apocrine
____ form fingerprints
dermal ridges
non-membrane bound electron dense granules found in stratum granulosum
keratohyaline granules
Piloerection is caused by _______ (parasmy or sym) stimulation due to cold/fear/aggression
sympathetic
in first intention healing, in week 2 continued fibroplasia and ______ accumulation that leads to mature ______ tissue; leads to decrease in inflammation
collagen; granulation
mechanoreceptors/ touch receptors in dermal ridges of papillary layer; Especially prominent in hands, feet, lips, genitalia; afferent nerve fibers associated with minimally modified schwann cells
meissner’s corpuscles
the reticular layer contains
hair follicles, sweat glands, and sebaceous glands
tyrosine is oxidized to DOPA by _______
tyrosinase
Apocrine sweat glands are located in _____ and _____; develop at _______
axillae and groin; puberty
White crescent at the base of nail covered by the eponychium
lunula
Shedding of old hair shaft of hair
exogen
T/F: Melanocytes adjacent to hair follicle produce melanin, becomes incorporated into cortex => hair color
True
Modified basement membrane separates hair bulb from surrounding dermis
Glassy membrane
used in thermoregulation in fingertips and ears associated with AV shunts containing glomus bodies
Subcutaneous plexus
Wound repair from a clean (surgical), approximated incision
first intention healing
3 main layers of skin
epidermis, dermis, and hypodermis
Sweat contains a hypotonic solution of what 4 things?
salts, ammonia, urea, and uric acid
epidermal cells derived from neural crest; Look like melanocytes; located in stratum basale, contain dense core granules
Merkel cells
The hair shaft is covered by a thin _______ of overlapping keratin plates; prevents matting
cuticle
Pacinian corpuscles detect
mechanical and vibratory pressure
in first intention healing, the incision immediately fills with what?
blood and clots
most of the body covered in ____ skin epidermis
thin
merocrine sweat glands secrete sweat glands onto skin surface via a _________ on epidermal ridge
sweat pore
small dermal mechanoreceptors, especially common in soles of feet
Ruffini corpuscles
cells of epidermis is called
keratinocytes
proximal end of the nail that extends into the dermis and attaches to periosteum of distal phalanx
nail root
Which skin tumors are derived from melanocytes?
Melanoma
Embryological outgrowths of epidermis; include hair, nails, sebaceous and sweat glands, horns
Skin appendages
stratum basale is attached to basement membrane by
hemidesmosomes
most numerous, present in epidermis & papillary dermis—surround most hair follicles• Lack connective tissue capsule & associated Schwann cells;
“free” N endings
lipid secretion is primarily _____ (gland)
apocrine
With _______ deficiency, collagen breaks down; old scars can reopen and bleed
Vitamin C
____ are fixed tissue macrophages; phagocytic antigen presenting cells
Langerhans cells
Langerhans cells are located within what layer of skin?
Stratum spinousm
During ______, mammary glands enlarge due to hypertrophy of secretory cells and accumulation of secretory product
lactation
in second intention healing, following initial clot formation, epithelial cells of _______ migrate from edges of wound at ~ 0.5 mm/day
stratum basale
layer of epidermis only present in thick skin
stratum lucidum
germinative zone where nail growth occurs by proliferation and differentiation at nail root
nail matrix
portion of the nail the nail plate sits on; make up of stratified squamous epithelium
nail bed
thickest layer of epidermis in the skin; prickle cell layer
stratum spinosum
T/F: in first intention healing, in month 2, there is connective tissue scar without inflammation covered by intact epithelium
True
most superficial layer of epidermis, thickest layer of epidermis in thick skin; contains squames and is constantly exfoliated
stratum corneum
hypodermis is made up of what 2 things?
irregular connective tissue and adipose tissue
stratum basale is attached to underlying dermis by
anchoring filaments and microfibrils
Involuting phase (loss of blood supply) of hair
catagen
dermal projections of the papillary into the epidermis
dermal ridges
fibroblasts elaborate collagen
fibroplasia
______ skin epidermis is restricted to volar (soles) and palmar (palms) surfaces; lacks hair (glabrous)
thick
In ______, keratinocyte maturation only takes 1 wk due to Absence of a granular layer and abnormal keratohyaline & tonofibrils
psoriasis
_____ glands discharge a thick viscid secretions into hair follicle; odorless when secreted but produces acrid odor from bacterial breakdown; in mammals serve as pheromones; secretion is adrenergic
apocrine
alveolar, holocrine glands consisting of branched acini; one or more glands associated with each hair follicle; develop as outgrowths of external root sheath
sebaceous glands
The hair shaft is produced by _______
hair follicles
Melanin is released from melanocytes in organelles called _____ and are taken up by surrounding epidermal cells
melanosomes
relatively thin layer that interdigitates with epidermis; corrugations increase the surface area for attachment, prevent shear and mechanical abrasion; contains epidermal and dermal ridges
Papillary layer of dermis
Coarse hair on scalp, axillae and pubis is know as ______ hair
terminal
_____ is composed of dense, irregular collagenous ct (type 1 collagen), interspersed with elastic fibers
dermis
Lines of tension in the reticular layer of dermis are called ______; formed by what 2 fibers?
Langer’s lines; elastic and collagen
mechanoreceptors located in dermis & hypodermis; Large, ovoid structures; Prominent in fingertips & around joints
Pacinian corpuscles
Hair growth occurs within deep terminal expansion of hair follicle called
hair bulb (root)
skin function: ______ insulation via hair & SQ fat; heat loss facilitated by sweat glands & dermal capillary network
thermoregulation
Mammary gland drainage
Terminal duct => lactiferous duct => lactiferous sinus => nipple
Bundles of smooth Mm cells (arrector pili M) attach to hair follicle sheath & insert on epidermal ridges; contraction raises hair => “goose bumps”: process is called
piloerection
_____ is a flattened portion of nail that rests on nail bed
nail plate
Homogenous, compact layer of enucleate cells between stratum granulosum & stratum corneum
stratum lucidum
Neuroectodermal dendritic cells present in epidermis; small number of cells usually restricted to basal layer with extensive cytoplasmic processes may extend into stratum spinosum
melanocytes
Thermoregulatory sweating is ____________; first occurs in axillae, forehead, and scalp: last on hands and feet
cholinergic (parasympathetic)
Which skin tumors are derived from epithelial cells?
squamous cell carcinoma basal cell carcinoma
basal layer of epidermis; mitotic layer of cuboidal germinal cells bound to basement membrane by hemisdesomes
stratum basale or germinativum
Secretion product of ceruminous glands
cerumen (ear wax)
At puberty vellus hair is replaced by coarser _____ hair
terminal
epidermal projections of the papillary layer into the dermis
epidermal ridges
can be called thick skin or thin skin
epidermis
skin function: _______ from UV, mechanical, chemical, & thermal insultPrevents dehydration; provides physical barrier to microorganisms
protection
Function of free nerve endings
sensory modalities—heat/cold, touch, pain, movement
Burn involving both epidermis and dermis
2nd degree
What kind of glands are ceruminous glands>
Modified apocrine
progressive damage to _____ fibers leads to aging and loss of skin tone
elastic
Epidermis is supplied and nourished b blood vessel in _____
underlying dermis
located below dermis; irregular connective tissue and adipose tissue
hypodermis
Takes ______ days for cells to travel from deep germinal layer, mature, & be sloughed from superficial epidermis
25-50 days
in first intention healing, epithelial cells of _________ begin mitosis leads to epithelial closure within 24-48 hrs
stratum basale
a pilosebaceous unit consists of what 3 things?
hair follicle, arrector pili muscle, and sebaceous gland
T/F: Cells of granular layer mature to form waterproof layer of keratinized cells, with glycolipid coating on surface of epidermis
True
autoimmune disease leading to destruction of melanocytes that leads to depigmentation
Vitiligo
T/F: Melanin is necessary for normal neural development
True
_____ is caused by excess fibroplasia that leads to raised, thickened. ct scar
Keloid
Pressure sensitive mechanoreceptors associated with free afferent nerve endings
merkel cells
vascular plexus located at junction of reticular layer & hypodermis
Cutaneous plexus
As epithelial cells lining hair bulb mature, they fill with hard ______ filaments arranged in parallel bundles
keratin
What kind of glands are mammary glands?
highly modified apocrine sweat glands
_______ glands are used for waterproofing and moisturizing skin and hair; also found on non-haired transitional skin where secrete directly onto skin surface
sebaceous
granular layer of epidermis characterized by by containing basophilic keratohyaline granules
stratum granulosum
sweat glands secrete product along with some cytoplasm; coiled tubular glands with large dilated lumina
apocrine
_______ consists of keratinized, stratified squamous epithelium; lacks blood vessels; do not penetrate basement membrane
epidermis
Milk production is both _____ and ______ (glands)
merocrine and apocrine
vascular plexus located at junction of papillary & reticular layers
Subpapillary plexus
Hair bulb lined by actively dividing epithelial cells homologous to what layer of epidermis?
Stratum basale
simple coiled tubular glands surrounded by myoepithelial cells that assist in secretion: 2 types
sweat glands
Desquamation and lifting of scab from periphery after 3 weeks is followed by ________ due to myofibroblasts
wound contraction
As epithelial cells of nail mature, they fill with _____ that form the nail plate
keratin
Cylindrical downgrowths of epithelium surrounded by collagen sheaths that produce hair shaft
hair follicles
____ lacks tyrosinase so DOPA and melanin don’t form; Premelanosomes form but do not mature
Albinos
What kind of glands are in areolar glands?
merocrine sweat and sebaceous glands
portion of nail that covers the lunula
cuticle/eponychium
Consist of afferent N fibers surrounded by highly modified Schwann cells—form concentric lamellae separated by fluid-filled spaces
Pacinian corpuscles
Proteins in apocrine glands secretions:
carbs, ammonia, lipids, and organic products
Is hair growth continuous or not continuous?
Not continuous
in first intention healing,in day 5 the incision fills with ________ tissue
granulation
_____ can be used as a marker, to differentiate melanocytes from keratinocytes containing phagocytosed melanin; Useful in distinguishing tumor types,
Tyrosinase
predominant cell product of stratum spinosum that form tonofilaments that aggregate into larger tonofibrils that anchor onto desmosomes
cytokeratin
_____ are responsible for the production of melanin
melanocytes
Thickened regions of smooth Mm in wall of arterioles, surrounded by connective tissue capsule; Bypass capillary bed, re-route blood from arterial to venous circulation
Glomus bodies
To produce melanin, a _____ precursor is oxidized to ______
tyrosine; DOPA
Fine body hair in women and children is referred to as
vellus hair
alkaline yellowish secretion with high protein and salt content with low lipids and carbs; large amounts of antibodies that is important in transfer of passive immunity to offspring
colostrum
Where are the 2 places the merocrine glands not found on the human body?
lips and genitalia
Growth phase of hair
anagen
The stratum corneum is primarily composed of
soft keratin
Keratinization of new cells leads to ______ and lifting of scab from periphery after 3 weeks
desquamation
Melanin synthesis is under control of a ____ hormone called ______
pituitary; melanocyte stimulating hormone
sweat glands that secrete only the product;
merocrine
Burn involving only epidermis
1st degree
most common form of hair loss affecting 30-40% of adults; genetic and androgen dependent
androgenic alopecia
Enzyme that converts testosterone to dihydrotestosterone leading to follicular atrophy
5-alpha-reductase
Inactive resting phase of hair
telogen
Smooth muscles responsible for piloerection are called
arrector pili muscles
skin layer that is highly vascular and contains many sensory receptors
dermis
skin function: ______ energy stored in SQ fat(1’ as triglycerides); Vit D synthesized in skin via hνMaintains homeostasis; excretory function (sweating); immune defense
metabolic functions
Glands in external auditory meatus
Ceruminous glands
Developing hair surrounded & protected by_____ and ______ —line hair follicle
internal and external root sheath
excessive secretion of sebum
seborrhea
Wound repair that occurs with more extensive loss of tissue, where wound edges do not approximate
Second intention healing
in second intention healing, Simultaneous proliferation/ maturation of _______ behind migrating front slowly restores multilayered, stratified epidermis
keratinocytes
red to yellow pigment present in individuals with red or blonde hair (ovoid)
pheomelanin
areola is made of what kind of epithelium?
stratified squamous epithelium with deep dermal ridges
flattened, enucleate, dead cell remnants in the stratum corneum
squames
____ glands are composed mainly of dense, irregular collagenous CT interspersed with adipose tissue and occasional smooth muscle; tubulo-acinar glands organized into secretory lobules
mammary glands
Which layer of the epidermis are exfoliated cervical epithelial cells that are routinely examined in PAP smear to detect cervical cancer
Stratum corneum
what 3 processes lead to the production of granulation tissue
neovascularization, fibroplasia, and re-epithelialization
Tyrosinase is located in cells called
premelanosomes
Protein secretion is primarily _____ (gland)
merocrine
As keratinocytes mature, they ____ and lose ____
die; nuclei
Sebaceous glands secrete sebum via the ______ canal which is high in lipid concentration and cell debris
pilosebaceous
unbranched, coiled, tubular glands with 1-2 layer of cuboidal to columnar epithelium with excretory ducts
merocrine sweat glands
T/F: In full thickness abrasion or 3rd degree burns, re-epithelializaion is not limited by size of wound
False
layer of dermis that is deeper and thicker
reticular layer
keratinization of cells in stratum granulosum represents interactions between what 2 things?
keratohyaline granules and tonofibrils
_________ are involved in contact allergic dermatitis; contact abundant cytoplasmic extensions
Langerhans cells
