Chapter 1 pt. 2

Question 1

Does a muscle contraction require energy?

Answer 1

Yes

Question 2

How is energy created for a muscle contraction?

Answer 2

ATPase, located on the myosin head, splits the ATP to yield ADP, inorganic phosphate (Pi), and energy

Question 3

What does the energy in a muscle contraction do?

Answer 3

It powers the tilting of the myosin head

Question 4

How is energy required for muscle relaxation?

Answer 4

Calcium is returned to the sarcoplasmic reticulum by an active calcium pumping system that requires ATP

Question 5

What happens after calcium is pumped back into the SR for muscle relaxation?

Answer 5

Troponin and tropomyosin return to the resting conformation by covering the active sites

Question 6

What are type 1 muscle fibers?

Answer 6

Slow twitch fibers

Question 7

What are type b/x muscle fibers?

Answer 7

Fast twitch fibers

Question 8

How long does it take type 1 fibers to reach peak tension when stimulated?

Answer 8

110 ms

Question 9

How long does it take type b/x fibers to reach peak tension when stimulated?

Answer 9

50 ms

Question 10

What muscle fibers make up 50% of muscles

Answer 10

Type 1

Question 11

What muscle fibers make up 25% of muscles?

Answer 11

Type 2a and 2x

Question 12

What muscle fibers make up 1-3% of muscles?

Answer 12

Type 2c

Question 13

How are muscle fiber types analyzed?

Answer 13

Muscle biopsy

Question 14

What is the function of muscle biopsy?

Answer 14

allows us to study muscle fibers and gauge the effects of acute exercises and chronic training on fiber composition

Question 15

What muscle fiber has a slow form of myosin ATPase?

Answer 15

Type 1

Question 16

What muscle fiber has a fast form of myosin ATPase?

Answer 16

Type 2

Question 17

What is gel electrophoresis?

Answer 17

A method for identifying fiber types by chemically separating the different types of myosin molecules

Question 18

Which muscle fiber has a more developed sarcoplasmic reticulum?

Answer 18

Type 2

Question 19

What determines whether a muscle fiber is type 1 or type 2?

Answer 19

The a-motor neuron

Question 20

How many muscle fibers does an a-motor neuron innervate in type 1 motor units?

Answer 20

less than or equal to a cluster of 300 muscle fibers

Question 21

How many muscle fibers does an a-motor neuron innervate in type 2 motor units?

Answer 21

more than or equal to 300 muscle fibers

Question 22

All muscle fibers reach peak at?

Answer 22

20% peak force

Question 23

What muscle has a very high percentage of type 1 fibers in everyone?

Answer 23

The soleus muscle (behind the gastrocnemius in the calf)

Question 24

What type of muscle fiber has a high level of aerobic endurance?

Answer 24

Type 1

Question 25

Type 1 fibers are efficient at producing ATP from the oxidation of?

Answer 25

Carbohydrates and fats

Question 26

Aerobic means?

Answer 26

presence of oxygen

Question 27

What type of muscle fiber performs better anaerobically?

Answer 27

Type 2

Question 28

Anaerobic means?

Answer 28

Without oxygen

Question 29

What type of muscle fiber fatigues the easiest and has limited endurance?

Answer 29

Type 2a

Question 30

Which type 2 fiber is used in shorter, higher-intensity endurance events like mile run or 400m swim?

Answer 30

Type 2a

Question 31

Which type 2 fiber is used in highly explosive events like the 100m dash or 50m sprint swim?

Answer 31

Type 2b

Question 32

What determines our individual muscle fibers?

Answer 32

The a-motor neuron

Question 33

How are muscle fibers differentiated?

Answer 33

Based on their neuron

Question 34

Endurance and resistance training reduce the percentage of what type of muscle fiber?

Answer 34

Type 2b

Question 35

Endurance and resistance training increases a fraction of what type of muscle fiber?

Answer 35

Type 2a

Question 36

As we grow older we tend to lose what type of muscle fibers?

Answer 36

Type 2

Question 37

What is the order recruitment of motor units?

Answer 37

Type 1, type 2a, type 2b

Question 38

What is the principle of orderly recruitment?

Answer 38

The ranking of motor units in a given muscle

Question 39

What type of muscle fiber has less force production?

Answer 39

Type 1

Question 40

What type of muscle fiber has more force production?

Answer 40

Type 2

Question 41

What is a static muscle contraction?

Answer 41

A muscle generates force without movement because the joint angle does not change

Question 42

Concentric means?

Answer 42

Shortening

Question 43

Eccentric means?

Answer 43

Lengthening

Question 44

What are considered dynamic contractions?

Answer 44

Concentric and eccentric contractions

Question 45

What is happening during a concentric contraction?

Answer 45

Thin filaments are pulled toward the center of the sarcomere

Question 46

What is happening during an eccentric contractions?

Answer 46

Force is exerted when extending the elbow

Question 47

What is rate coding?

Answer 47

The frequency of stimulation of the motor unit

Question 48

What are the 3 types of rate coding

Answer 48

Twitch, summation, tetanus

Question 49

What are the 4 things that generate force?

Answer 49

Motor unit recruitment, rate coding, length-tension relationship, and speed-force relationship