Week 10 Quiz

Question 1

Which form of muscle contraction involves shortening of the sarcomeres?

a. Concentric
b. Isotonic
c. all listed options involve shortening of the sarcomeres
d. Isometric
e. Eccentric

Answer 1

a. Concentric

Question 2

What is another term for pivot point?

Answer 2

fulcrum

Question 3

which term applies to most of our joint movements where the contraction of the muscle generates not just a motion but specifically one that involves rotation about an axis?

Force
Torque

Answer 3

Torque

Question 4

General Review of muscles: Imagine a small group of workers within the muscle. If the initial effort to move a mass is insufficient, what would the foreman of the group request?

a. More food (ATP) for the workers.
b. More workers (motor units)
c. More oxygen
d. more food (lactic acid) for the workers

Answer 4

b. More workers (motor units)

Question 5

What term do we use to describe a massive number of action potentials in a row leading to unusual force production by the muscles?

Answer 5

Tetanus

Question 6

Which motor units are easiest to recruit?

a. Small motor units
b. Large motor units

Answer 6

a. Small motor units

Question 7

What term do we use to describe the phenomenon when a muscle receives multiple stimulating action potentials from the same motor neuron rapidly in a row allowing for normal motor behaviors.

Answer 7

Temporal summation

Question 8

Which type of muscle fiber will require the greatest density of blood vessels to support their metabolic activity?

a. Fast glycolytic
b. Slow oxidative
c. Fast oxidative

Answer 8

b. Slow oxidative

Question 9

Which muscle condition is characterized as an autoimmune disease where the immune system begins attacking acetylcholine receptors on muscle cells leading to muscle weakness?

a. Muscular dystrophy.
b. Delayed onset muscle soreness (DOMS).
c. Fybromyositis.
d. Myasthenia gravis

Answer 9

d. Myasthenia gravis

Question 10

.If you attempted a large muscle contraction to perform a given action and required even greater muscle force to achieve the goal what other category of muscles should your body recruit?

a. Antagonists.
b. Assistants.
c. Agonists.
d. Synergists.
e. Prime movers

Answer 10

d. Synergists

Question 11

Which muscle condition is a genetic sex-linked disease where muscle atrophies and is replaced by fat and connective tissue, and ultimately causing premature death due to respiratory failure?

a. Myasthenia gravic\s.
b. Fybromyositis.
c. Muscular dystrophy.
d. Delayed onset muscle soreness (DOMS)

Answer 11

c. Muscular dystrophy.

Question 12

Which muscle has the fastest muscle twitch observable with a myogram? (check the lecture slides for a visual to help).

a. Soleus.
b. Extraocular muscle.
c. Gastrocnemius.
d. Rectus femoris.
e. Biceps femoris.

Answer 12

b. Extraocular muscle.

Question 13

What phase of a muscle twitch measured by the myogram encapsulates the events that occur specifically at the synapse of a motor neuron with the muscle fiber?

a. Period of contraction.
b. Latent period.
c. Period of relaxation

Answer 13

b. Latent period.

Question 14

Which type of muscle fiber will produce lactic acid as a regular component of their metabolic activity?

a. Slow oxidative.
b. Fast glycolytic.
c. Fast oxidative

Answer 14

b. Fast glycolytic.

Question 15

At what sarcomere length do our skeletal muscle produce the greatest amount of muscle force?

a. When the sarcomeres are maximally shortened.
b. the sarcomeres are maximally lengthened.
c. When the sarcomeres are in their mid-length range.

Answer 15

c. When the sarcomeres are in their mid-length range.

Question 16

What does treppe refer to in muscle activity?

a. Muscle damage caused by eccentric contractions that forcibly rip the myosin heads away from actin active sites under heavy loads.

b. The first contraction after prolonged rest having low contractile strength and then increasing in subsequent contractions.

c. A genetic condition leading to malformed myosin proteins and therefore muscle structure.

d. Breakdown of acetylcholine in the synapse by acetylcholinesterase at an abnormally high rate due to excess concentration of the enzyme.

e. Muscle contraction exhaustion after extreme physical activity due to use of all available ATP.

Answer 16

b. The first contraction after prolonged rest having low contractile strength and then increasing in subsequent contractions.

Question 17

Results when contractions are sustained for a long time.

a. Muscle fatigue.
b. Refractory period.
c. Tetanic contractions.
d. Concentric contractions.
e. Latent period.

Answer 17

a. Muscle fatigue.

Question 18

What component of the human body is the lever facilitating motion about our joints?

a. The synovial joint itself.
b. The muscle force generated when muscles contract.
c. The bones associated with the synovial joint.
d. The muscles associated with the synovial joint.
e. The muscle attachment locations associated with the synovial joint.

Answer 18

c. The bones associated with the synovial joint.

Question 19

In which scenario will an individual be able to generate the motion that they choose to make voluntarily?

a. Te = Tr.
b. Te > Tr.
c. Te < Tr

Answer 19

b. Te > Tr.

Question 20

What is the appropriate definition of a motor unit?

a. A set of motor neurons and the set of muscle fibers that they innervate.
b. A single motor neuron and all the muscle fibers that it innervates.
c. A set of motor neurons and the single muscle fiber that they innervate.
d.mA single motor neuron and the single muscle fiber that it innervates

Answer 20

b. A single motor neuron and all the muscle fibers that it innervates.

Question 21

If you tried to lift a suitcase and it turned out to be heavier than you anticipated what physiological change would your body most likely perform to aid your lifting ability?

a. Increase the number of action potentials sent to the previously engaged motor neuron or neurons. WRONG
b. Increase the number of motor units being recruited to perform the action

Answer 21

b. Increase the number of motor units being recruited to perform the action

Question 22

How hard do our muscles have to work to create motion about our joints because of the way that they are organized in the human body?

a. Our muscles are organized about the joint so efficiently that we generate very little muscle force to yield normal body motion.
b. Our muscles are organized about the joint in a way that requires larger forces to create normal motions about the joint

Answer 22

b. Our muscles are organized about the joint in a way that requires larger forces to create normal motions about the joint

Question 23

Which form of muscle contraction produces muscle force without a change in sarcomere length.

a. Eccentric.
b. Isometric.
c. Concentric.
d. Isotonic.
e. All listed options involve muscle force production without changing the length of the sarcomeres.

Answer 23

b. Isometric.

Question 24

Which form of muscle activity or behavior is only observable in the laboratory setting?

a. Muscle tone.
b. Temporal summation.
c. Muscle twitch.
d. Isotonic contractions.
e. Isometric contractions

Answer 24

c. Muscle twitch.

Question 25

Identify the example of a second-class lever (effort and fulcrum on opposite sides and load in the middle).

a. Elbow.
b. Neck and head.
c. Ankle

Answer 25

c. Ankle

Question 26

General Review of Muscles: Puffer fish produce a toxin (tetrodotoxin) that binds to acetylcholine receptors but does not open the sodium ion channels. Its effects at the muscle would be to produce:

a. Tremors.
b. Cramps.
c. Increase ATP demand.
d. Paralysis

Answer 26

d. Paralysis

Question 27

General Review of Muscles: According to the sliding filament theory, muscle contraction occurs when:

a. Actin filaments slide over myosin filaments.
b. Actin filaments slide over other actin filaments.
c. Myosin filaments slide over other myosin filaments.
d. One sarcomere slides over other sarcomeres

Answer 27

a. Actin filaments slide over myosin filaments.

Question 28

Which example is the best fit for an eccentric contraction?

a. Lowering the bag of groceries onto the dining table slowly so that you do not crush the carton of eggs amongst the other heavy items.
b. Holding the bag of groceries steady and high as you enter the house to avoid your excited puppy trying to bite the bag.
c. Lifting a bag of groceries off the counter at the grocery store by grabbing the bags handle

Answer 28

a. Lowering the bag of groceries onto the dining table slowly so that you do not crush the carton of eggs amongst the other heavy items.

Question 29

We know that muscles have multiple functions, but how much of the energy we use leads to heat production?
a. 40%.
b. 20%.
c. 60%.
d. 50%.
e. 100%.

Answer 29

c. 60%.

Question 30

What muscle condition is characterized by inflammation of muscle connective tissue due to injury or strain, electrolyte imbalance which hyper-sensitizes the neuromuscular junction all leading to stiffness and soreness?

a. Muscular dystrophy.
b. Fybromyositis.
c. Delayed onset muscle soreness (DOMS).
d. Myasthenia gravis

Answer 30

b. Fybromyositis.

Question 31

Identify the joint that is organized with the effort and load on opposite ends and the fulcrum in the middle.

a. Neck and head.
b. Ankle.
c. Elbow

Answer 31

a. Neck and head.

Question 32

Identify the body example within the body that is controlled by a small motor unit.

a. Gastrocnemius.
b. Muscles of the hips.
c. Gluteus maximus.
d. Muscles of the eye.
e. Muscles of the legs

Answer 32

d. Muscles of the eye.