Quiz #3 Motor Control & Mucles

Question 1

When the sympathetic nervous system is activated:

a) heart rate speeds up
b) pupils dilate
c) intestinal mobility is inhibited
d) the bladder contracts
e) A, B, and C only
f) all of the above

Answer 1

e) A, B, and C only

Question 2

Which of the following statement(s) describe(s) pace-maker potential?

a) Oscillations in membrane potential that depolarize to create a rhythm of contraction
b) Cardiac muscle cells that fire action potentials spontaneously
c) Resting membrane potential in cardiac muscle cells
d) A and B only
e) all of the above
f) none of the above

Answer 2

d) A and B only

Question 3

Which of the following correctly describes (1) the location where a muscle tendon connects to the distal end of a bone, and (2) the starting location of a muscle?

a) (1) insertion, (2) origin
b) (1) origin, (2) insertion
c) (1) beginning, (2) end
d) (1) end, (2) beginning
e) (1) tendon), (2) ligament

Answer 3

a) (1) insertion, (2) origin

Question 4

Which of the following statement(s) about cardiac muscle is/are FALSE?

a) Cardiac muscle cells have a single nucleus
b) Cardiac muscle cells are striated
c) Cardiac muscle cells are branched
d) Cardiac muscle cells are influenced by hormonal control
e) two of the above
f) none of the above

Answer 4

f) none of the above

Question 5

Which neurotransmitter is used in the neuromuscular junction?

a) acetylcholine
b) epinephrine
c) norepinephrine
d) dopamine
e) oxytocin

Answer 5

a) acetylcholine

Question 6

Which of the following statement(s) regarding the somatic nervous system is/are TRUE?

a) Cell bodies of neurons are located in the ventral horn
b) There is a single axon projecting to the target tissue
c) Neurons branch close to their targets
d) A single neuron can only innervate one muscle fiber
e) A, B and C only
f) all of the above

Answer 6

e) A, B, and C only

Question 7

What proteins are myofibrils composed of?

a) contractile
b) elastic
c) regulatory
d) accessory
e) three of the above
f) all of the above

Answer 7

e) three of the above

Question 8

Which of the following statement(s) is/are TRUE?

a) Sympathetic ganglia originate in the lumbar and thoracic regions of the spine
b) Sympathetic ganglia have long preganglionic neurons and short postganglionic neurons
c) All parasympathetic ganglia originate in the brain stem
d) Parasympathetic ganglia have short preganglionic neurons and long postganglionic neurons
e) three of the above
f) all of the above

Answer 8

a) Sympathetic ganglia originate in the lumbar and thoracic regions of the spine

Question 9

Why is calcium important in regard to muscle contraction?

a) It acts as a source of energy for the muscle
b) it binds with myosin to enable the power stroke
c) it binds with tropomyosin to allow it to rotate and expose the myosin binding sites
d) two of the above
e) none of the above

Answer 9

e) none of the above

Question 10

You are examining a muscle fiber under a microscope and notice the cell has a striped appearance. Which of the following statement(s) regarding this muscle fiber is/are TRUE? (select all that apply)

a) the muscle fibre is striated
b) the muscle fibre is either from skeletal muor cardiac muscle
c) the muscle fibre is definitely from skeletal muscle
d) the muscle fibre is arranged in sarcomeres
e) the muscle fibre must be innervated by somatic neurons
f) the muscle fibre could be arranged in multiple directions within the muscle itself

Answer 10

a) The muscle fibre is striated,
b) The muscle fibre is either from skeletal or cardiac muscle,
d) The muscle fibre is arranged in sarcomeres

Question 11

Which of the following filaments will block the crossbridge formation and limit the ability of muscles to contract?

a) troponin
b) tropomyosin
c) actin
d) myosin
e) nebula
f) titin

Answer 11

b) tropomyosin

Question 12

What of the following statements correctly describes a motor unit?

a) All the muscle fibres within a given muscle
b) All the neurons going into one unit of the body
c) A motor neuron and all of the muscle fibres it innervates
d) A muscle fibre and all of the neurons it is innervated by
e) A motor neuron and all of the muscles it extends through

Answer 12

c) A motor neuron and all of the muscle fibres it innervates

Question 13

Compared to skeletal muscle, cardiac muscle cells:

a) are smaller
b) have fewer mitochondria
c) contain a larger sarcoplasmic reticulum
d) have smaller, straighter t-tubules
e) all of the above
f) none of the above

Answer 13

a) are smaller

Question 14

Smooth muscle makes up a large portion of the muscles in several areas of the body. Which of the following is NOT an example of a smooth muscle?

a) urinary sphincter
b) lower esophagus
c) small intestine
d) myocardium
e) two of the above
f) none of the above

Answer 14

d) myocardium

Question 15

Which of the following are classifications of smooth muscle? (select all that apply)

a) location
b) contraction pattern
c) communication
d) striation
e) cell shape
f) arrhythimicity

Answer 15

a) location
b) contraction pattern
c) communication

Question 16

Which of the following statement(s) about the sarcoplasmic reticulum is/are TRUE?

a) Only present in skeletal muscle fibres
b) Specialized endoplasmic reticulum
c) stores Ca2+ for contraction
d) Provides energy for contraction
e) two of the above
f) three of the above

Answer 16

e) two of the above

Question 17

Which of the following statement(s) regarding smooth muscle is/are FALSE?

a) fatigues easily
b) does not use calcium for contraction
c) contracts through electrical and chemical signals
d) two of the above
e) all of the above

Answer 17

d) two of the above

Question 18

Which of the following statement(s) about myofilaments is/are FALSE?

a) Thick filaments are made up of both myosin and actin
b) Thick filaments create the dark bands in skeletal muscle
c) Thin filaments are made up of actin
d) Thin filaments create the light bands in skeletal muscle
e) Two of the above
f) None of the above

Answer 18

a) Thick filaments are made up of both myosin and actin

Question 19

Tyler took some medication for their flu symptoms. Later, Tyler began to feel a little faint because the medication caused their heart to beat more slowly and their blood pressure to fall. What system was likely activated by the medication?

a) parasympathetic
b) sympathetic
c) somatic
d) central
e) automatic

Answer 19

a) parasympathetic

Question 20

Which of the following is/are TRUE statement(s) regarding skeletal muscles as they compare to smooth muscles? (select all that apply)

a) Typically operate at shorter lengths
b) Arranged in a variety of directions
c) Controlled by the autonomic nervous system
d) Typically relax very quickly
e) Use more mitochondria and more ATP to contract

Answer 20

a) Typically operate at shorter lengths,
d) Typically relax very quickly,
e) Use more mitochondria and more ATP to contract

Question 21

Which of the following options has the correct organization of a muscle from largest to smallest?

a) Muscle → fascicle → muscle fibre → myofibrils → myofilaments
b) Muscle → fascicle → myofibrils → muscle fibre → myofilaments
c) Muscle → muscle fibre → fascicle → myofibrils → myofilaments
d) Muscle → muscle fibre → myofibrils → fascicle → myofilaments
e) Muscle → muscle fibre → myofibrils → myofilaments → fascicle
f) None of the above are correct

Answer 21

a) Muscle → fascicle → muscle fibre → myofibrils → myofilaments

Question 22

The biceps brachii muscle and triceps brachii muscle both act at the elbow joint. When the biceps brachii muscle contracts, the angle between the upper and lower arm decreases. When the triceps brachii muscle contracts, the angle between the upper and lower arm increases. Which of the following statement(s) is/are CORRECT
a) The biceps brachii and triceps brachii are antagonist muscle groups
b) The biceps brachii is an extensor muscle
c) The triceps brachii is a flexor muscle
d) The biceps brachii is a flexor muscle
e) The triceps brachii is an extensor muscle
f)When the biceps brachii contracts, the triceps brachii relaxes
When the biceps brachii contracts, the tricps brachiielaxes

Answer 22

a) The biceps brachii and triceps brachii are antagonist muscle groups,
c) The biceps brachii is a flexor muscle,
e) The triceps brachii is an extensor muscle,
f) When the biceps brachii contracts, the triceps brachii relaxes

Question 23

Why does a t-tubule support the action potential of an active muscle fibre?

a) The tubules allow for the action potential to dive deep into the muscle
b) The tubule lumen is directly connected with the extracellular fluid
c) The tubules allow for rapid repolarization around the perimeter of the muscle fibre
d) two of the above
e) all of the above are correct

Answer 23

d) two of the above are correct

Question 24

Which of the following statement(s) about the crossbridge cycle is/are TRUE?

a) When ATP attaches to myosin, the crossbridge is formed
b) When ATP attaches to myosin, the crossbridge detaches
c) When the power stroke occurs, actin slides towards the A-band
d) When the power stroke occurs, actin slides towards the M-line
e) A and D
f) B and D

Answer 24

B and D