Written Exam Study Flashcards
______regulates blood flow through the skin and controls secretions of sweat glands to conserve or dissipate heat.
hypothalamus of the brain
Name the modified epidermal structures
Hair, Nails, and Skin glands
__________is a surface epithelium derived from ectoderm and it is a self-regenerating stratified squamous epithelium composed primarily of keratinocytes that produces a protective layer of keratin and lipids and other cells for pigmentation, sensation and immunity.
Epidermis
________ is the underlying layer of loose connective tissue and dense irregular connective tissue derived from mesoderm that contains many collagen fibers, hair follicles, sweat glands, blood vessels, lymphatic vessels, sensory receptors, nerves, and connective tissue cells.
Dermis
Adipocytes are located here
Hypodermis
The stratum basale, also known as the
stratum germinativum
________are touch receptors associated with nerve fibers found in the stratum basale.
Tactile Cells (Merkel Cells)
_______are from bone marrow and migrate into the stratum spinosum and help protect against pathogens by engulfing them then presenting characteristic parts of the antigens to lymphocytes.
Dendritic Cells (also called Langerhans cells)
_________can be involved in delayed-type hypersensitivity reactions like contact dermatitis
Dendritic (Langerhans) Cells
In the common skin disease,___________, dermal neutrophils invade the epidermis. This inflammation stimulates keratinocytes in the stratum basale to proliferate abnormally fast so cells move from the stratum basale to the stratum corneum in about 7 days resulting in a thicker stratum corneum that forms plaques or flakes (dandruff).
psoriasis
An Autoimmune Blistering Disease targets Desomosomes
Pemphigus Foliaceus/vegetans
Three Immigrant Cells of the Epidermis
Melanocytes, Langerhans cells, Merkel cells
is a mixed polymer of tyrosine and cysteine that ranges in color from yellow to brown to reddish.
phaeomelanin
The key enzyme in the production of melanin is
tyrosinase
Each melanocytes produces and transfers melanin pigment granules called _________into about 36 adjacent keratinocytes by the process of _______ _______
melanosomes
cytocrine injection
Tanning involves gene activation______ in keratinocytes in response to UVR-induced DNA damage, leading to an upregulation of ____________
(p53)
proopiomelanocortin (POMC).
Posttranslational cleavage of POMC produces
β-endorphin and α-MSH
MSH stimulates receptor __________ on adjacent melanocytes.
(MC1R)
is blueness resulting from deficiency of oxygen in the circulating blood. Hemoglobin becomes a bluish color when it is not bound to oxygen.
Cyanosis
Is redness due to dilated cutaneous vessels which can be caused by anger, sunburn, heat, allergy, embarrassment.
Erythema
is a patterned albinism thought to be caused by an autoimmune disorder that attacks melanocytes.
Vitiligo
Is a bruise caused by visible clotted blood in the dermis and hypodermis. Color change during healing is due to the breakdown of hemoglobin.
Hematoma
discolored skin caused by benign tumors of dermal blood capillaries
Hemangiomas
_______are composed of a fibrous capsule around a nerve ending. These sense light touch, shapes and texture and are located in dermal papillae in fingers, hand, foot, forearm, tongue and are particularly abundant in the vermillion zone of the lips.
Meissner’s (Tactile ) Corpuscles
_______are sensitive, high resolution tactile receptors in the epidermis used for sensing textures, edges and shapes. They
are derived from the neural crest.
in basal layer of epidermis.
Merkel’s cells
penetrate into the epidermis are bare dendrites that lack a Schwann cell covering and are sensitive to pain (nociceptors) and change in temperature (hot and cold).
Free Nerve endings
sense pressure, stretch, tickle and vibration. A nerve ending is wrapped with many layers of flattened cells that increase the sensory field. Found in hypodermis of hands, feet, breasts and genitals.
Pacinian Corpuscles
look similar to pacinian corpuscles, and are sensitive to displacement of surrounding collagen fibers due to slow, sustained mechanical stress (stretch or compression) of skin, ligaments, tendons and joint capsules.
Ruffini’s Corpuscles
is composed of a vascular, sensitive, loose
connective tissue arranged into dermal papillae. Meissner’s
corpuscles are found in the papillary layer. Dermal papillae are
upward extensions of the dermis that interdigitate with down
growths of the epidermis and correspond to the ridges of the
fingerprints.
Papillary Layer of the dermis
is the deeper part of dermis and is composed of
dense irregular connective tissue.
Reticular Layer of the dermis
is also called
the subcutaneous tissue or the
superficial fascia.
The hypodermis
Fine fetal hair is called?
Lanugo
fine, unpigmented hair of children and adults.
Vellus
At the base of each hair bulb there is a
Dermal Papilla
is
vascular tissue that
provides nutrients to the
hair bulb
outermost layer of a hair shaft.
Cuticle of a Hair Shaft
Hair grows on average about
0.3mm/day in young adults
Stages of hair growth are?
growth stage (anagen): at any point in time, about 90% of
scalp follicles are in the growth stage.
– shrinking stage (catagen) lasts 2-3 weeks follicle shrinks
– resting stage (telogen) lasts 1-3 months
__________ is baldness that can occur in
patches or across the entire body.
Alopecia
Hairloss that is is under genetic and hormonal control.
Pattern Baldness
_________ is excessive hair growth
usually caused by a hormone imbalance
(excessive ovarian or adrenal cortex
testosterone secretion).
Hirsutism
Nail root grows out of the
- *nail matrix**, which is
- *equivalent** to the stratum basale of the epidermis.
millions all over the body open directly onto the surface of the skin and function to cool the skin
Eccrine Glands
_______is sebum collected from lamb
wool and is used in skin creams to
soften the stratum corneum, lip balms
like Carmex and leather conditioners.
Lanolin
\_\_\_\_\_\_\_\_\_\_\_are only found in the skin of the external auditory meatus (ear canal).
Ceruminous
– arises from stratum basale and invades
dermis – treated by surgical removal and radiation
basal cell carcinoma
– arises from melanocytes
– ABCD: asymmetry, border irregular, color
mixed, diameter over 6 mm
Melenoma
______is called “tanning rays” and _______
“burning rays” but both can burn as well as
tan depending upon exposure conditions.
UVA
UVB
Cutaneous wound healing involves release of
numerous growth factors from a variety of cells
including…….
fibroblasts, macrophages, platelets and
keratinocytes.
Some growth factors attract cells into the wound
and other factors stimulate growth of the cells in
the epidermis and dermis.