Exam 1 flashcards.txt

From Iusmhistology

red stain; eosin

blue stain; hematoxylin

number of nuclei in skeletal muscle; many

location of skeletal muscle nuclei; periphery

name of a full length muscle cell contractile organelle; myofibril

sarc in greek; flesh

diameter of human RBC; 7-8 microns

thickness of lm sections; 5-7 microns

do skeletal muscle cells have a basement membrane?; yes

where is the skeletal muscle basement membrane?; on the outside of the sarcolemma

fasicles are a group of...; myofibers

individual muscle cells are held together by the; endomyesium

this layer runs into and throughout a fascicle; perimyseium

this is the outer-most layer of a fasicle; epimyseium

I bands occur where in the sarcomere; where there are not thick filaments

do I bands change orientation of light?; no

define the A band; where thick filaments exist

do A bands change orientation of light?; yes

what happens at the z line?; thin filaments attach to their backbone

at what line do thick filaments attach?; M line

define the H zone; where there is only thick filaments without thin filament overlap, centered around the m line

thin filaments made of actin or myosin?; actin

thick filaments made of actin or myosin?; myosin

where is the atpase unit of myosin; the head

what ion must be elevated to allow cross-bridge formation? to what concentration?; Ca, 1 mM

true or false: ADP and Pi are released upon ATP burning by myosin; false

what are the three domains of troponin and what do they do; C (senses Ca), I (inhibitory, binds actin), and T (interacts with tropomyosin)

this protein of the thin filament inhibits myosin from binding actin; tropomyosin

what two proteins binding causes myosin to release Pi?; myosin to actin

ADP release from myosin is triggered by what event?; the first 45 degree rotation of myosin on actin

troponinC binds calcium allowing this protein to move; tropomyosin

how far does tropomyosin move around actin to allow myosin binding?; about 5 minutes on a clock face (30 degrees)

t tubules are made of what; cell membrane

t tubules reach into the cell and touch what?; sarcoplasmic reticulum cisternae

what is a triad?; the junction of two terminal cisternae with a T tuble at the A-zone / I-zone junction

describe the a-zone / i-zone junction; the a zone is where there is no thick filament and the i zone is where there are only thick filaments so the junction is the end of the thick filament

does the basemement membrane outside the sarcolemma invaginate with the T tubule?; yes, a little

what is the difference between triads in mammals and other animals?; other animals have a triad in which the T tubule touches the sarcomere at the Z line

the nerve plate is a synonyme for the...; synapse

how many muscle fibers can one axon innervate?; one or many

define a motor unit; a neuron and all the muscles it innervates

can a neuron fire only a portion of it's motor unit?; no, it is all or nothing

in the eye, would you predict a large or small number of myofibers for each motor unit?; small because the eye requires very fine movement

which striated muscle type has branched myofibers?; cardiac

skeletal myofibers are joined physically, electrically, or both?; physically

cardiac myofibers are joined physically, electrically, or both?; physically, electrically

location of cardiac nuclei; centrally located

number of cardiac nuclei; 1 or 2

does cardiac or skeletal muscle have more vascularization?; cardiac

name the junctions found in an intercalated disk?; facial adherens, macula adherens, gap junctions

facial adherens are like what type of junction; zonula adherens

macula adherens are like what type of junction; desmosomes

what happens at each of the three junctions of the intercalated disk?; thin filaments connect at the facial adherens, thick filaments at the macula adherens, and electrical signals connect at the gap junctions

do gap junctions hold cells physically together?; no because they don't affect cytoskeleton

where along the myofiber are gap junctions located?; along the longitudinal membrane

the atria of the heart can release what hormone? what is its function?; atrial naturetic peptid, vasodilator, diuretic (water and Na loss at kidney)

diads are found in this type of muscle; cardiac

this type of muscle is spindle shaped; smooth muscle

location and number of smooth muscle nuclei; central, single

describe a smooth muscle cross-section in terms of cell diameter; there will be a variety of diameters because some cells will be cut toward their ends where they are tapered and some will be cut at the middle where they have a larger diameter

this muscle type does not have sarcomeres; smooth muscle

to what type of cytoskeletal fiber are actin and myosin attached in smooth muslce cells?; intermediate filaments

desmin and vimentin make up what type of cytoskeletal fiber?; intermediate filament

intermediate filaments are made of what two proteins?; desmin and vimentin

dense bodies connect what?; thin filaments of actin and intermediate filaments

membrane dense bodies connect what? thin filaments of actin and intermediate filaments

what two structures link thin and intermediate filaments?; dense bodies and membrane dense bodies

these structures of smooth muscle generate dark bodies on the membrane and cytoplasm; membrane dense bodies and dense bodies

this muscle type doesn't require T tubles; smooth muscle cells

this muscle type may use the state of intermediate filaments to regulate contraction

smooth muscle uses what cue to cause myosin to assemble into filaments?; phosphorylation of myosin

in smooth muscle, phosphorylation of myosin causes what?; myosin to form filaments

for smooth muscle contraction, must myosin be phosed or dephosed? phosphorylated

which muscle type may generate a corkscrewed nucleus upon contraction?; smooth muscle

which muscle types have gap junctions?; cardiac and smooth

what facilitates "unitary smooth muscle" activity?; electrical connectivity via gap junctions

multi-unit smooth muscle is controlled by gap junctions, neuronal stimulation, or both; neuronal stimulation, mostly

what cell is capable of regenerating skeletal muscle?; satellite cells

where to satellite cells live?; just below basement membrane next to skeletal cells

in a light microscope slide, what does a satellite cell look like?; a peripheral nucleus or a fibroblast

can smooth muscle regenerate?; yes, most smooth muscle cells can dedifferentiate and replicate

what are the steps in satellite cell regeneration of skeletal muscle (5)?; satellite cells -> myoblasts -> myotubles -> myofibrillogenesis -> myofiber

describe myofibrillogenesis (4 things) (one step in the regen of skeletal muscle); formation of myofibrils of myotubes, nuclei pushed outward, fusion, elongation

describe a myotubule (one step in the regen of skeletal muscle); long cells, multiple cells bound together

describe myoblasts; can fuse, don't look like muscle but do have similar expression pattern

describe myotubes; a syncitium of myoblasts

does hematoxylin bind acidic or basic particles?; acidic

is hematoxylin acidic or basic?; basic

H&E stands for...; hematoxylin and eosin

with what two elements does hematoxylin react to generate it's color?; Aluminum or iron

hematoxylin generates what color?; blue

what color does eosin generate?; red

does eosin stain acidic or basic particles?; acidic

chromatin and ribosomes are stained by what stain?; hemotoxylin

connective tissue, cytoplasm, collagen, muscle fibers, and mt. are stained by; eosin

connective tissue, cytoplasm, collagen, muscle fibers, and mt. are turned red by this stain; eosin

vacant areas on slides may have contained this type of tissue, dissolved during fixation; adipose

size of RBCs (in a slide and in real life); 7 micrometers, 10 micrometers

what type of muscle can be found in the uterus, appendix, bladder?; smooth

in the GI tract, what are the orientations of the inner and outer layers of smooth muscle?; circumferential and longitudinal

this organ has "interlaced" smooth muscle; uterus

this organ has disparate bundles of smooth muslce separated by connective tissue; bladder

what is the difference between the smooth muscle of the uterus and bladder?; bladder muscle is disparate while uterus muscle is interlaced

what color (and by which stain) does connective tissue stain?; red via eosin

the soft palate and tongue are made of what type of muscle?; skeletal

myofibers are surrounded by what layer?; endomyseium

perimysium surrounds what unit?; bundles

epimyseium surrounds what unit of muscle?; fasicle or gross muscle unit