Exam 1 Flashcards
what are the layers of the skin from deep to superficial?
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
what layers of the epidermis are composed of living keratinocytes?
the first 3 layers
How many layers make up the stratum basale?
1 layer of cuboidal to low columnar cells
what are the 3 cell types found in the stratum basale
keratinocytes, melanocytes, and tactile cells
what are the most abundant cells in the epidermis?
keratinocytes
what is the function and location of keratinocytes
found in all layers, keratinocytes divide to regenerate new cells replacing old cells shed at surface, synthesizes keratin
what is the function of melanocytes
produce and store pigment in response to UV light, transfer pigment granules into keratinocytes
what is the function of tactile cells and what is another name for them
tactile (merkel) cells are scattered within stratum basale and are sensitive to touch. When compressed, chemicals are released that stimulate sensory nerve endings
how many layers make up the stratum spinosum
several layers of polygonal keratinocytes
what is the function of the stratum spinosum?
daughter cells from stratum basale are pushed in and begin to develop into specialized non dividing keratinocytes
what is the function of langerhans cells and where can they be found?
(epidermal dendritic cells) initiate immune response, found in spinosum and granulosum
how many layers make up the stratum granulosum
3-5 layers of keratinocytes
describe the steps of keratinization
(begins in granulosum)
- keratinocytes fill with keratin
- causes nucleus and organelles to disintergrate
- fully keratinized cell dead but structurally sound
- takes several layers to complete
how many layers is the stratum lucidum?
2-3 translucent layers
which layer of epidermis is only found in thick skin?
stratum lucidum
what is the protein found in thick skin that protects it from UV light?
eleidin
how many layers make up the stratum corneum?
20-30 layers of dead, interlocking keratinized cells
how long does it take the keratinocytes to migrate from the stratum basale to the stratum corneum?
about 2 weeks
what is the difference between thick skin and thin skin?
thick skin lacks hair follicles and sebaceous glands
true or false, those with darker skin have more melanocytes
false, everyone has the same number of melanocytes
where does carotene accumulate in the skin?
in subcutaneous fat and the keratinocytes of the stratum corneum
what causes albinism?
enzyme for melanin is nonfunctional and melanin can’t be produced
what is a nevus?
a localized overgrowth of melanocytes (a mole)
what do freckles represent?
localized areas of increased melanocyte activity
what is a hemangioma and what are the 2 types?
a skin discoloration due to benign blood vessel tumor, 2 types: capillary and cavernous
what are friction ridges?
small pegs in thin skin and complex arches and whorls in fingers, palms, soles, and toes
what is the function of friction ridges?
to increase friction on contact, also used for personal identification
what are the layers of the dermis?
papillary layer and reticular layer
what is the papillary layer composed of?
composed of areolar CT which forms dermal papillae
what part of the epidermis interacts with the dermis to interlock them and increase contact?
epidermal ridges
what is the reticular layer composed of?
dense irregular ct, large bundles of collagen fibers project
describe lines of cleavage
collagen and elastic fibers oriented in parallel bundles designed to resist stress during routine movement
how do the fibers of the dermis contribute to the characteristics of the skin?
the collagen fibers impart tensile strength while the elastic fibers allow stretch and recoil
what is the subcutaneous layer composed of?
areolar and adipose CT, CT fibers are interwoven with fibers of reticular dermis
what is the function of the subcutaneous layer?
pads and protects body, acts as energy reservoir, provides thermal insulation
which gender has a thicker subcutaneous layer
females
What are the functions of the integument
- protection
- prevention of water loss/gain
-secretion/absorption - immune protection
- temp regulation
- sensory reception
what is the function of sebaceous glands?
secrete sebum to lubricate skin and hair and make the integument water resistant
how does the integument regulate temperature
vasoconstriction decreases blood supply to peripheral structures
what are the 2 types of sweat glands
apocrine and merocrine
what type of sweat gland is most numerous
merocrine
what is the function of merocrine sweatglands
thermoregulation, secrete sweat composed of 99% water
where are merocrine glands most abundant?
palms, soles, and forhead
where are apocrine sweat glands found?
confined to axillary and anogenital areas
what do apocrine sweat glands secrete
sweat, fatty substances, and proteins
what are the two ways integumentary tissue can be repaired?
regeneration and fibrosis
describe the process of regeneration
replacement of damaged or dead cells with same cell type, restores function
describe the process of fibrosis
gaps are filled with scar tissue, functional activities not restored
Name the inputs and outputs of glycolysis
input: glucose, 2 ATP
output: 2 pyruvate, 2 NADH,2 ATP
Name the inputs and outputs of the intermediate stage
input: 2 pyruvate
output: 2 acetyl-CoA, CO2
Name the inputs and outputs of the citric acid cycle
input: 2 acetyl CoA
outputs: CO2, 6 NADH, 2 FADH2, 2 ATP
name the inputs and outputs of the electron transport chain
input: NADH,FADH2
output: H2O, 30 ish ATP
what is the final theoretical output from 1 glucose molecule
about 34 ATP
what is the final electron acceptor in cellular respiration?
oxygen
which process produces ATP in glycolysis and Citric Acid Cycle?
substrate level phosphorylation
what process produces ATP in the ETC?
oxidative phosphorylation
what type of gland lacks ducts?
endocrine glands
what are the two layers of serous membranes?
parietal layer: lines internal surface of body wall
visceral layer: covers external surface of organs
what is the function of serous fluid?
acts as a lubricant to reduce friction caused by movement of organs against body wall
what is the median space in the thoracic cavity?
the mediastinum
what serous membrane surrounds the heart?
the pericardium
what serous membrane is associated with the lungs?
the pleura
what serous membrane lines the abdominopelvic cavity?
the peritoneum
what are the three components of homeostatic systems
receptor, control center, effector
