terms

Question 1

plasma membrane of muscle fiber

Answer 1

sarcolemma

Question 2

cytoplasm of muscle fiber

Answer 2

sarcoplasm

Question 3

smallest contractile unit of muscle fiber, composed of thick and thin myofilaments made of contractile proteins

Answer 3

sarcomere

Question 4

network of smooth endoplasmic reticulum surrounding each myofibril, functions in regulation of intracellular CA2+ levels

Answer 4

sarcoplasmic reticulum

Question 5

continuations of sarcolemma, lumen continuous with extracellular space, increase muscle fiber’s surface area

Answer 5

t-tubule

Question 6

what myosin binds to for sliding action

Answer 6

actin

Question 7

heads bind to actin, pivots and pulls thin filament toward m line, ATP attaches to myosin head and cross bridge detaches, energy from hydrolysis of ATP cocks myosin head into high-energy state

Answer 7

myosin

Question 8

densely packed, rodlike elements, most of cell volume, exhibit striations

Answer 8

myofibril

Question 9

skeletal muscle cells increase in size but not number

Answer 9

hypertrophy

Question 10

smooth muscle cells can divide and increase in numbers

Answer 10

hyperplasia

Question 11

pouchlike infolding, sequester CA2+, most calcium influx from outside cell; rapid

Answer 11

calveoli

Question 12

binding messenger protein, intracellular target of the secondary messenger CA2+

Answer 12

calmodulin

Question 13

a multinucleate mass of cytoplasm resulting from fusion of cells

Answer 13

syncytium

Question 14

major responsibility for producing specific movement (agonist)

Answer 14

prime mover

Question 15

opposes or reverses particular movement

Answer 15

antagonist

Question 16

helps prime movers, adds extra force to same movement, reduces undesirable or unnecessary movement

Answer 16

synergist

Question 17

synergist that immobilizes bone or muscle’s origin, gives prime mover stable base on which to act

Answer 17

fixator