Muscle Functions questions and answers

Question: Which of these are functions of muscles? You may select more than one option – choose all that apply.

Answer Options:
stabilize joints
generate blood cells
generate heat
create voluntary movements

Answer: stabilize joints
generate heat
create voluntary movements

Question: The muscle property of __ means that muscle cells can be excited by a stimulus.

Answer Options:
extensibility
elasticity
contractility
excitability

Answer: excitability

Question: Muscles have no striations.

Answer Options:
Skeletal
Cardiac
Smooth
Postural

Answer: Smooth

Question: Intercalated discs connect muscle cells with gap junctions and desmosomes. Which type of muscle contains intercalated discs?

Answer Options:
cardiac
skeletal
dense connective tissue
smooth

Answer: cardiac

Question: The less movable muscle attachment that remains relatively stable during contraction is called

Answer Options:
innervation
connection
insertion
origin

Answer: origin

Question: The smallest contractile unit of a muscle cell is the

Answer Options:
motor neuron
thick filament
sarcolemma
sarcomere

Answer: sarcomere

Question: The plasma membrane of a muscle cell is called the

Answer Options:
perimysium
sarcoplasmic reticulum
transverse tubule
sarcolemma

Answer: sarcolemma

Question: The connective tissue covering that encloses the entire muscle is called the

Answer Options:
periosteum
epimysium
endomysium
perimysium

Answer: epimysium

Question: This protein blocks the myosin-binding site on actin when the muscle is at rest.

Answer Options:
calcium
G-actin
titin
tropomyosin

Answer: tropomyosin

Question: The sarcomere relaxes when

Answer Options:
calcium
ATP
tropomyosin
ATPase

Answer: calcium (is removed)

Question: A motor unit is

Answer Options:
one muscle cell and all the myofibrils inside of it
one whole muscle and all the neurons that connect to it
one motor neuron and all the muscle cells it connects to

Answer: one motor neuron and all the muscle cells it connects to

Question: In a relaxed muscle fiber most of the intracellular calcium is found in the

Answer Options:
sarcoplasm
sarcoplasmic reticulum
axon terminal
transverse tubules

Answer: sarcoplasmic reticulum

Question: Which of the following is not true about the thick myofilament?

Answer Options:
contains troponin and tropomyosin
found in the center of the sarcomere
creates cross-bridges during contraction
primarily made of myosin

Answer: contains troponin and tropomyosin

Question: Choose the arrangement that lists the structures in correct order from the largest to smallest.

Answer Options:
muscle fiber, myofilament, myofibril, fascicle, whole muscle
whole muscle, muscle fascicle, muscle fiber, myofibril, myofilament
whole muscle, muscle fascicle, myofilament, muscle fiber, myofibril
myofilament, myofibril, muscle fiber, muscle fascicle, whole muscle

Answer: whole muscle, muscle fascicle, muscle fiber, myofibril, myofilament

Question: Which of the following statements about the structure of myofilaments is true?

Answer Options:
ATPase function occurs on the head of the myosin molecule
myosin head binds to tropomyosin during contraction
tropomyosin has a binding site for calcium
actin molecules have a hinge-like portion that bends during contraction

Answer: ATPase function occurs on the head of the myosin molecule

Question: Endomysium is the connective tissue covering of

Answer Options:
a muscle cell
a nerve cell
a whole muscle
a fascicle

Answer: a muscle cell

Question: Movement of an ion against its gradient requires energy and is called __ transport.

Answer Options:
active
deadly
facilitated diffusion
passive

Answer: active