Muscle Physiology Practice Exam

Question 1

What chemical builds up in the muscles during anaerobic muscle movement?

Answer 1

lactic acid

Question 2

The neuromuscular junction is…

Answer 2

an interface (cleft) between a motor neuron and a skeletal muscle

Question 3

Muscle Terminology Matching: Synergists

Answer 3

smaller “stability” muscles that assist the prime mover to complete a contraction.

Question 4

Muscle Terminology Matching: Antagonists

Answer 4

muscle that oppose the movement of a agonist. Triceps:Biceps

Question 5

Muscle Terminology Matching: Prime Movers

Answer 5

Muscle that does the majority of the work during contraction

Question 6

Muscle Terminology Matching: Recruitment

Answer 6

Activation of additional motor units to increase contractile strength.

Question 7

Muscle Terminology Matching: Fixator

Answer 7

muscle that anchors a bone to keep it stable

Question 8

True or False: An isotonic exercise is one where tension is continually applied to a muscle but the insertion point does not move.

Answer 8

False

Question 9

Match the following components of the sarcomere with their coinciding descriptions: I-Band

Answer 9

only actin (thin filaments)

Question 10

Match the following components of the sarcomere with their coinciding descriptions: A band

Answer 10

both actin and myosin filaments overlap here.

Question 11

Match the following components of the sarcomere with their coinciding descriptions: H Zone

Answer 11

only myosin

Question 12

Match the following components of the sarcomere with their coinciding descriptions: M-Band (M-Line)

Answer 12

the midpoint of a sarcomere

Question 13

Match the following components of the sarcomere with their coinciding descriptions: Sarcomere boundary

Answer 13

Z-line to Z-Line (Z-Disc)

Question 14

In a muscle cell, the sarcolemma is equivalent to a [ ______ ] , but the [ _______ ] is equivalent to the muscle cell cytoplasm.

Answer 14

muscle membrane; sarcoplasm

Question 15

Tendons are important structures that link the muscular system with the skeletal system. They help to provide stability in your joints and have stretch receptors that let you know when you’ve met your maximum flexibility, so they do not rupture. They must be warmed up prior to rigorous exercise because they do not have a good blood supply. Therefore, tendons are constructed from ____________________________________________ tissue.

Answer 15

dense connective tissue

Question 16

Which of the following is not a characteristic of skeletal muscle?
contractility
excitability
reversibility
elasticity
extensibility

Answer 16

reversibility

Question 17

Which general characteristic of muscles is NOT true?
-there are 3 main muscle types that make up the human body
-muscles make up 65% of your body weight
-there are 600 muscles in the human body
-muscles are viewed as “the machines” of the body

Answer 17

muscles make up 65% of your body weight

Question 18

True or False: The prime mover causes the main muscle movement in an action while the antagonist opposes it.

Answer 18

true

Question 19

Which attachment point of the muscle is the part that moves the most?

Answer 19

insertion

Question 20

Which type of muscle increases the angle between parts?

Answer 20

extensor

Question 21

What does cardiac muscle look like?

Question 22

What does skeletal muscle look like?

Question 23

What does smooth muscle look like?

Question 24

Match the properties of skeletal muscles with the appropriate description: contractility

Answer 24

shortens with force

Question 25

Match the properties of skeletal muscles with the appropriate description: elasticity

Answer 25

will return to its original form

Question 26

Match the properties of skeletal muscles with the appropriate description: excitability

Answer 26

responds to a stimulus

Question 27

Match the properties of skeletal muscles with the appropriate description: extensibility

Answer 27

can be stretched

Question 28

What muscle type attaches to bones?

Answer 28

skeletal muscle

Question 29

What muscle type Controls the movement of food through the digestive tract?

Answer 29

smooth

Question 30

What muscle Contains tendons on either end?

Answer 30

skeletal muscle

Question 31

What muscle Has the most endurance out of any muscle.

Answer 31

cardiac muscle

Question 32

what muscle is Spindle-shaped and uninucleate?

Answer 32

smooth

Question 33

What muscle types Undergoes peristalsis?

Answer 33

smooth

Question 34

what muscle type Contains intercalated discs?

Answer 34

cardiac

Question 35

Match the following action with the correct muscle description: depressor

Answer 35

moves body parts downwards

Question 36

Match the following action with the correct muscle description: extensor

Answer 36

straightens body parts

Question 37

Match the following action with the correct muscle description: levator

Answer 37

moves body parts upwards

Question 38

Match the following action with the correct muscle description: abductor

Answer 38

moves body parts away from the midline

Question 39

Match the following action with the correct muscle description: adductor

Answer 39

moves body parts towards the midline

Question 40

The sarcoplasmic reticulum stores __________ when a muscle is relaxed and releases it for binding to ___________ during contraction.

Answer 40

calcium; troponin

Question 41

The energy for cross bridge cycling during muscle contraction is provided by

Answer 41

ATP

Question 42

Step 1 of sliding filament model

Answer 42

Myosin binds to crossbridge of actin (ADP + P form)

Question 43

Step 2 of sliding filament model

Answer 43

Myosin head initiates a "power stroke". (ATP used)

Question 44

Step 3 of sliding filament model

Answer 44

myosin detachment and "reset" (ATP Used)

Question 45

step 4 of sliding filament model

Answer 45

Myosin head initiates "recovery stroke" preparing to bind again.

Question 46

What does Troponin do

Answer 46

binds with calcium to allow sarcomere shortening.

Question 47

A motor unit refers to:

Answer 47

a single motor neuron plus all of the muscle fibers it activates.

Question 48

The transverse tubules (T-Tubules) in a muscle fiber...

Answer 48

provide a means of rapidly transmitting the action potential from the surface into the central portions of the muscle fiber.

Question 49

How many ATP are required to initiate a complete movement of the myosin head (power stroke - disengage – recovery stroke)?

Answer 49

two

Question 50

True or False: The term "Action Potential" is the correct name that refers to the wave-like energy that passes from the NMJ through the T-Tubules from the muscle to cause changes in the muscle initiating depolarization and the contraction process?

Answer 50

true

Question 51

The [ ______] mineral needs to be secreted from the [ _______ ] organelle in the muscle and bind to the [ _______ ] complex on the actin protein in order to expose the binding sites on the thin filament, so myosin can bind and from the cross-bridge.

Answer 51

calcium; sarcoplasmic reticulum; troponin

Question 52

SpongeBob’s skeletal muscle manager was running around frantically because myosin heads couldn’t bind to their actin crossbridges, so SpongeBob dropped his trusty spatula and collapsed to the Krusty Krab kitchen floor! There was a major ATP shortage. Which organelle was sleeping on the job?

Answer 52

mitochondria

Question 53

The molecule creatine phosphate is found only in muscle fibers. It has the unique function of transferring high-energy ___________ molecules to ADP therefore creating more ATP in a fraction of a second.

Answer 53

phosphate

Question 54

________-twitch muscular responses usually result in quick bursts of energy and involve easily fatigable muscles often during anaerobic activity.

Answer 54

fast

Question 55

Match the following components of the sarcomere with their coinciding descriptions: I-Band

Answer 55

only actin

Question 56

Match the following components of the sarcomere with their coinciding descriptions: A-Band

Answer 56

both actin and myosin filaments

Question 57

Match the following components of the sarcomere with their coinciding descriptions: H-Zone

Answer 57

only myosin

Question 58

Match the following components of the sarcomere with their coinciding descriptions: M-Line

Answer 58

the midpoint of a sarcomere

Question 59

Match the following components of the sarcomere with their coinciding descriptions: Sarcomere boundary

Answer 59

Z-line to Z-Line

Question 60

Step 1 of the NMJ process

Answer 60

Action potential travels the length of an axon of a motor neuron to the axon terminal

Question 61

Step 2 of the NMJ process

Answer 61

Voltage-gated Ca2+ channels open and Ca2+ ions diffuse into the terminal

Question 62

Step 3 of the NMJ process

Answer 62

Ca2+ entry causes the synaptic vesicle to release ACh via exocytosis

Question 63

Step 4 of the NMJ process

Answer 63

ACh diffuses across a synaptic cleft and binds to ACh receptors which contain ligand-gated cation channels

Question 64

Step 5 of the NMJ process

Answer 64

Ligand-gated channels open

Question 65

Step 6 of the NMJ process

Answer 65

Na+ ions enter the muscle fiber and K+ exit the muscle fiber; the greater inward flux of Na+ relative to the outward flux of K+ causes the membrane potential of the muscle to become less negative

Question 66

Step 7 of the NMJ process

Answer 66

Once the membrane potential reaches the threshold value the potential propagates along the sarcolemma

Question 67

What happens after the action potential (impulses) reaches the sarcolemma of the muscle cell? -step 1 of the sliding filament mechanism

Answer 67

“T” tubules carry impulses into the sarcoplasmic reticulum and releases Ca2+ ions

Question 68

What happens after the action potential (impulses) reaches the sarcolemma of the muscle cell? -step 2 of the sliding filament mechanism

Answer 68

Ca2+ ions enter the sarcomeres and binds to troponin on tropomyosin strands moving the strand and exposing myosin binding sites

Question 69

What happens after the action potential (impulses) reaches the sarcolemma of the muscle cell? -step 3 of the sliding filament mechanism

Answer 69

Myosin binds to actin forming crossbridges that ATP can bind to

Question 70

What happens after the action potential (impulses) reaches the sarcolemma of the muscle cell? -step 4 of the sliding filament mechanism

Answer 70

ATP breaks down, releasing energy, causing cross bridges to pull actin strand

Question 71

What happens after the action potential (impulses) reaches the sarcolemma of the muscle cell? -step 5 of the sliding filament mechanism

Answer 71

Another ATP binds to myosin cross bridge and causes myosin to bend, attach, and pull on the next actin strand

Question 72

What happens after the action potential (impulses) reaches the sarcolemma of the muscle cell? -step 6 of the sliding filament mechanism

Answer 72

When the action potential ends, Ca2+ ions are pumped back into the sarcoplasmic reticulum; tropomyosin returns to the original position covering the binding sites; muscle is at rest

Question 73

True or False: When there is no oxygen in the muscle cell due to strenuous activity, anaerobic respiration allows glycolysis to continue making ATP for energy use. In animal cells, this is called lactic acid fermentation.

Answer 73

True