Muscle 2

Question 1

a motor neuron and all of the muscle fibers it innervates

Answer 1

motor unit

Question 2

specialized domain of the sarcolemma
highly excitable
responsible for initiating the AP that propagates across the myofibers causing muscle contraction

Answer 2

motor end plate

Question 3

junction of the axon terminal of a motor neuron with a motor end plate
specialized area of the sarcolemma of the skeletal myofiber to be innervated

Answer 3

neuromuscular junction

Question 4

genetic diseases
caused by mutations in the dystrophin gene located in the X chromosome
wasting of muscles/mental retardation

Answer 4

muscular dystrophies

Question 5

link between acting cytoskeleton and basal lamina caused by…

Answer 5

no dystrophin

Question 6

found only in heart where it forms thick layer called myocardium
involuntary muscle
short/branched striated fibers
one central nucleus

Answer 6

cardiac muscle

Question 7

junctional complexes found b/t 2 adjacent cardiac fibers

step-like pattern

Answer 7

interclated discs

Question 8

runs across the fibers @ right angles
zonula adherens - anchor
desmosomes - bind fibers together

Answer 8

transparent part

Question 9

runs parallel to the myofilaments

gap junctions - rapid flow of info b/t fibers

Answer 9

lateral part

Question 10

involuntary
non-straited fibers
one central nucleus per fiber
no T-tubules
fibers communicate via gap junctions

Answer 10

smooth muscle

Question 11

tunica media made up of smooth muscle cells and elastic tissues
smooth muscles control vessel diameter

Answer 11

smooth muscle of arteries and veins

Question 12

longitudinal layer:muscle fibers run parallel to the long axis of the organ
circular layer: muscle fibers run around the circumferences of the organ

Answer 12

smooth muscle of intestine

Question 13

consist of myosin/actin filaments attached to dense bodies in the sarcoplasm or plasma membrane

Answer 13

contractile units

Question 14

arranged obliquely in cell
some attach to dense bodies in the cytoplasm
other attache to dense plaques of the plasma membrane

Answer 14

thin filaments