EXM 1 Skin Flashcards
Nails are made of_____.
Keratin
Hypooxygenation causes what in nails
clubbing
What layer of the skin does not have blood vessels?
Epidermis
Superficial most outer layer of skin
Epidermis
4 cell types that make up Epidermis
Keratinocytes, Melanocytes, Langerhan Cells, Merkel Cells
Which layer of skin does not contain blood vessels?
Epidermis
Protein sheet separating Epidermis from Dermis
Basement Membrane
Layer of skin that has thick connective tissue, nerves, blood vessels, and glands
Dermis
Layer of skin that has fat
Hypodermis
What does skin thickness vary by?
Location and age
Principle cell type of epidermis
keratinocyte
5 layers of strata
stratum germinativum stratum spinosum stratum granulosum stratum lucidum stratum corneum
Layer of strata that is surface of skin
stratum corneum
layer of strata only present in thick skin (palms, soles)
stratum lucidum
layer of strata with granular appearance, has 3-5 layer of flattened keratinocytes
stratum granulosum
cytoplasmic production of keratin begins in this strata layer. “prickle cells”
stratum spinosum
layer of strata that has cell division
stratum germinativum
Cells that produce pigment to protect us from radiation
melanocytes
What differs in melanocytes between light and dark complected people?
amount of melanin produced (larger melanosomes), melanocytes do not differ nor do the amount.
what is melanin synthesized by?
amino acid tyrosinase
Immune antigen presenting cells in epidermis
Langerhan/ Dendritic cells
epidermal cell that is derived from monocyte and generated in bone marrow
Langerhan/ Dendritic cells
cells involved in contact hypersensitivity reactions
Langerhan/ Dendritic cells
Epidermal cells that establish contact with somatosensory afferent neurons
merkel cells
epidermal cells that serve as receptors for LIGHT TOUCH, discrimination of shapes and textures
merkel cells
Where are Merkel cells most abundant?
in sensitive area of the skin - fingertips, lips, genitalia
where are Merkel cells located in the epidermis?
strata germinativum
Site of blister formation
Basement Membrane
Separates Epidermis from subcutaneous layer of fat
Dermis
Major component of connective tissue in Dermis
Collagen type 1
Why is scar tissue not flexible?
It is predominately cartilage
How are fibers arranges in the papillary dermis?
irregular
How are fibers arranges in the reticular dermis?
tightly bundles in a fascicle like pattern
orientation of reticular dermis collagen fibers results in _____.
Langer’s Lines
Incisions have the best cosmetic outcome when made ______ to langer’s lines
parallel
Function of lymphatic vessels in dermis
remove interstitial fluid, contribute to immune defense
What plexus is responsible for the pink color of your skin?
sub papillary plexus- perfuses the dermal papilla
mechanoreceptor that mediates LIGHT TOUCH and pressure
messier corpuscles
mechanoreceptor that mediates pressure, touch and vibration sensation
pacinian corpuscle
mechanoreceptor that responds to stretching and distortion of skin
ruffian’s corpuscles
mechanoreceptor located in the papillary dermis
messier corpuscles
mechanoreceptors located in the reticular dermis
ruffian’s corpuscles, pacinian corpuscle
sensory receptors that synapse with sensory neurons
mechanoreceptors
sensory nerve receptors that respond to potentially damaging stimuli
nociceptors
receptors that transmit temperature, pain, and itch sensations
nociceptors
How is a nociceptor signal sent?
by sensory nerve fibers to CNS through the dorsal root and trigeminal ganglia
lowest level of pain
itch
nociceptor signals are enhanced by what 3 substances?
prostaglandins, kinin system, substance p
where to nociceptors terminate?
in the papillary dermis and around hair follicles
dermal immune cells that have role in wound healing, blood clotting, and inflammation
dermal dendritic cells (langerhans cells)
in dermis, these cells stimulate hypersensitivity reactions/ allergic reactions
mast cells
mast cells secrete ______ in allergic response
histamine
histamine release causes what 3 things?
inflammation, swelling, and vasodilation
Sweat glands that open directly onto skin surface
Eccrine
Sweat glands that open into hair follicle
Apocrine
Why is body odor produced?
when bacteria metabolize fatty acid they cause body odor
purpose of apocrine glands
to prevent bacterial growth
Where are sebaceous glands not found?
palms, soles, side of feet
What is included in the pilosebaceous unit
hair, sebaceous gland, arrestor pili muscle- enclosed in collagen sheath
Hair is composed of _____.
keratin
fine, fetal hair
lanugo hair
fine, pre-pubertal body hair
Vellus hair
course, mature hair
Terminal hair
90% of hair follicles are in this hair cycle?
Anagen
hair cycle for active growth
Anagen
1% of hair in this cycle of hair growth, hair is loosely attached
Catagen
10% of hair in this cycle, no growth
Telogen
Losing more hair than normal can be sign of _____.
Hypothyroidism
layer of strata (epidermis) the cuticle is
stratum corneum
