Practice Set 3B

Question 1

Which is a quick cycle of contraction in a whole muscle that occurs when a threshold level stimulus is reached?

Answer 1

Twitch

Question 2

What does the latent period on a myogram indicate?

Answer 2

The time period between the stimulus and the twitch

Question 3

On a myogram, how does the relaxation phase compare to the contraction phase?

Answer 3

The relaxation phase is longer.

Question 4

Which affects the strength of a muscle twitch?

Answer 4

How stretched the muscle was before stimulation

Question 5

True or false: A twitch is a sustained contraction in a whole muscle that occurs when a threshold level stimulus is reached.

Answer 5

False

Question 6

On a myogram, the time between the stimulus and the twitch is known as the _____ period.

Answer 6

latent

Question 7

The movement of an object or load results from the development of what kind of tension?

Answer 7

External

Question 8

As the myosin head releases the thin filament, muscle tension declines during what is referred to as the ______ phase of a muscle twitch.

Answer 8

relaxation

Question 9

Which affect twitch strength?

Answer 9

Stimulation frequency

Muscle fatigue

Temperature of the muscle

How stretched the muscle was just before it was stimulated

Question 10

Which is a quick cycle of contraction in a whole muscle that occurs when a threshold level stimulus is reached?

Answer 10

Twitch

Question 11

What type of tension develops during the latent period of muscle contraction?

Answer 11

Internal

Question 12

A muscle fiber shortens and generates force during the ______ period of a muscle twitch.

Answer 12

contraction

Question 13

A muscle fiber shortens and generates force during the ______ period of a muscle twitch.

Answer 13

contraction

Question 14

Temporal summation leads to a state of fluttering contraction known as what?

Answer 14

Incomplete tetanus

Question 15

Complete (fused) __________ is the continuous forceful contraction in a muscle with no relaxation between stimuli.

Answer 15

tetanus, tetany, or Tetanus

Question 16

Stimulus frequency affects the sarcoplasmic concentration of which of the following?

Answer 16

Calcium

Question 17

True or false: A twitch is a sustained contraction in a whole muscle that occurs when a threshold level stimulus is reached.

Answer 17

False

Question 18

When lifting something heavy, which type of contraction occurs first?

Answer 18

Isometric

Question 19

What produces incomplete tetanus?

Answer 19

Temporal summation

Question 20

Which is not naturally seen in the muscles of the body?

Answer 20

Complete tetanus

Question 21

Which type of contraction maintains joint stability and posture?

Answer 21

Isometric

Question 22

In what type of contraction does the internal tension build until it overcomes resistance and the muscle moves the load?

Answer 22

Isotonic

Question 23

Which describes slow-twitch fibers?

Answer 23

They have a rich blood supply.

Question 24

Temporal summation leads to a state of fluttering contraction known as what?

Answer 24

Incomplete tetanus

Question 25

Which fibers contain a fast-acting ATPase and phosphagen enzymes?

Answer 25

Fast-twitch

Question 26

In which condition are stimuli are so frequent that the muscle cannot relax, and the muscle twitches fuse into a smooth prolonged contraction?

Answer 26

Tetanus

Question 27

Skeletal muscles contain which of the following?

Answer 27

Both slow oxidative and fast glycolytic fibers

Question 28

A muscle shortens as it maintains tension in a what type of contraction?

Answer 28

Concentric

Question 29

Slow-twitch fibers are also known as ______ fibers.

Answer 29

red

Question 30

Fast-twitch fibers are also known as ______ fibers.

Answer 30

white

Question 31

Which fascicle arrangement produces the weakest muscle?

Answer 31

Circular

Question 32

Fatigue resistance is improved by ______ exercise which enhances the delivery and use of oxygen.

Answer 32

endurance

Question 33

What are muscles that contain mainly slow oxidative fibers called?

Answer 33

Red

Question 34

Fibers that are well adapted to aerobic respiration are called ______ -twitch fibers.

Answer 34

slow

Question 35

Which types of muscle tissue are considered involuntary?

Answer 35

Cardiac and smooth

Question 36

Muscle that are larger can generate ______ strength than those that are smaller.

Answer 36

more

Question 37

Which of the following is true of endurance exercise?

Answer 37

It increases oxygen transport in the blood.

Question 38

The thighs of a chicken are composed mostly of ______ fibers.

Answer 38

slow-oxidative

Question 39

Cardiac and smooth muscle are both considered which of the following?

Answer 39

Involuntary

Question 40

Which describes cardiac muscle tissue?

Answer 40

Striated, usually uninucleate, branching

Question 41

Intercalated discs contain which of the following that prevent cardiac cells from pulling apart during contraction?

Answer 41

Mechanical junctions

Question 42

Resistance exercise causes muscle growth by stimulating which of the following?

Answer 42

An increase in myofibril size

Question 43

Cardiac muscle tissue is autorhythmic but the ______ can increase or decrease the heart rate and contraction strength.

Answer 43

autonomic nervous system

Question 44

Where is cardiac muscle found?

Answer 44

In the heart wall only

Question 45

In the heart, what triggers the wave of electrical excitation that causes the heart to contract?

Answer 45

Pacemaker

Question 46

The thickened notched ends of cardiac muscle cells which contain gap junctions are called __________ discs.

Answer 46

intercalated

Question 47

Why are gap junctions important?

Answer 47

They allow the cells to contract in a coordinated fashion.

Question 48

What does it mean that cardiac cells are autorhythmic?

Answer 48

They contract rhythmically and independent of nervous stimulation.

Question 49

Choose all that are characteristics of cardiac muscle.

Answer 49

It uses aerobic respiration almost exclusively. It has large stores of glycogen. It is rich in myoglobin.

Question 50

Which muscle type is resistant to fatigue, contracts with a regular rhythm, and functions 24 hours a day?

Answer 50

Cardiac

Question 51

What is the function of the cardiac pacemaker?

Answer 51

It triggers contraction in the heart muscle.

Question 52

Which muscle type is striated, uninucleate, and branched?

Answer 52

Cardiac

Question 53

Cardiac muscle cells are considered ___________ because they contract rhythmically and independently.

Answer 53

autorhythmic or Autorhythmic

Question 54

Which muscle tissue is rich in myoglobin, mitochondria, glycogen and uses aerobic respiration almost exclusively for its energy needs?

Answer 54

Cardiac

Question 55

Which are the characteristics of cardiac muscle cells?

Answer 55

They are resistant to fatigue. They contract with regular rhythm. They contract nearly in unison.

Question 56

The muscle tissue that is typically slow to contract and slow to relax is _________ muscle.

Answer 56

smooth

Question 57

Which tissue can propel contents of a digestive organ?

Answer 57

Smooth muscle

Question 58

Which describes cardiac muscle tissue?

Answer 58

Striated, usually uninucleate, branching

Question 59

In smooth muscle cells, what binds the dense bodies to the membrane?

Answer 59

Intermediate filaments

Question 60

What does it mean that cardiac cells are autorhythmic?

Answer 60

They contract rhythmically and independent of nervous stimulation.

Question 61

What regulatory protein is associated with the thick filament of smooth muscle and activates myosin light-chain kinase?

Answer 61

Calmodulin

Question 62

Which describes smooth muscle?

Answer 62

It is slow to contract and slow to relax.

Question 63

What are the functions of smooth muscle?

Answer 63

To constrict or dilate blood vessels to control blood pressure To move material through the digestive tract To regulate pupil diameter

Question 64

What is the function of intermediate filaments in smooth muscle cells?

Answer 64

They bind the dense bodies to the sarcolemma.

Question 65

What is the immediate trigger for the contraction of smooth muscle?

Answer 65

Calcium ions

Question 66

In smooth muscle, which protein does calcium bind to?

Answer 66

Myosin

Question 67

The sarcolemma of smooth muscle cells has pockets called ______ that contain calcium channels.

Answer 67

caveolae