Deck 7: The Muscular System

Question 1

When a muscle is stimulated before the muscle can fully relax, it can cause ________.

A) muscle twitch
B) summation
C) muscle failure
D) tendinitis

Answer 1

B

Question 2

Which of these structures is part of a muscle cell's plasma membrane that delivers signals to the sarcomere?

A) myosin head
B) actin fiber
C) endoplasmic reticulum
D) T tubule

Answer 2

D

Question 3

The arrangement of muscles so that the action of one muscle is opposite to that of its partner is referred to as ________.

A) synergistic
B) antagonistic
C) dual
D) insertion

Answer 3

B

Question 4

When a muscle is stimulated prior to full relaxation of a previous contraction and the second stimulus is added to the first contraction, this phenomenon is referred to as ________.

A) tetanus
B) twitch
C) fatigue
D) summation

Question 5

Which of the following is not a function of muscle?

A) destabilize joints
B) generate heat
C) move blood in veins
D) move lymph in lymphatic vessels

Question 6

Which of the following are protein filaments that function in muscle contraction and are shaped like a golf club with two heads?

A) intermediate filaments
B) myosin filaments
C) myofilaments
D) actin filaments

Question 7

Which structure delivers a signal from the motor neuron to all the sarcomeres of a muscle cell?

A) myosin filament
B) filaments-line
C) T tubule
D) sarcoplasmic reticulum

Question 8

When a myosin head binds to an actin molecule in order to contract a muscle, this is formed: ________.

A) myosin filament
B) actin filament
C) cross-bridge
D) troponin

Question 9

Which of these muscles would be most involved in a forcible exhalation, as in a sneeze?

A) rectus abdominis
B) sartorius
C) gastrocnemius
D) deltoid

Question 10

If it were possible to have antagonistic muscle pairs in an arm contract simultaneously, what movement would the arm make?

A) The arm would move away from the body.
B) The arm would move toward the body in a curling movement.
C) The arm would be locked in position.
D) The arm could move easily in each direction.

Question 11

Which of the following attaches the end of the muscle to a bone?

A) synergistic
B) tetanus
C) ligaments
D) tendons

Question 12

The attachment point of a muscle to a bone that can move is called the ________.

A) origin
B) insertion
C) synergistic
D) antagonistic

Question 13

The sarcoplasmic reticulum stores ions that are necessary for skeletal muscle contractions. Which of the following ions does it store?

A) magnesium
B) iron
C) sodium
D) calcium

Question 14

Which component of a muscle does the calcium ion combine with to allow a contraction to occur?

A) myosin head
B) actin
C) troponin
D) T tubule

Question 15

Muscle contraction results from the repeated cycle of interactions between myosin and actin. What is the last step of this cycle, after which the cycle starts over again?

A) New ATP molecules bind to the myosin heads, causing them to disengage from the actin.
B) The myosin heads split the ATP into ADP and Pi and store the energy.
C) The myosin head bends (the power stroke).
D) Myosin heads extend toward the Z lines at the ends of the sarcomere.

Question 16

Overuse, misuse, and age are some of the factors that contribute to excessive stress on a tendon, causing inflammation known as ________.

A) bursitis
B) tetanus
C) tendinitis
D) spasms

Question 17

Which of these junctions represents the connection between the tip of a neuron and a skeletal muscle cell from which acetylcholine diffuses?

A) neurotic
B) tight
C) neuromuscular
D) desmosome

Question 18

Which substance is released by motor neurons to stimulate a contraction?

A) myosin
B) acetylcholine
C) dopamine
D) calcium

Question 19

Why must tropomyosin cover the thin filament in just the right position before the muscle can relax?

A) It covers the myosin-binding sites and, if left exposed, will allow the myosin to bind and pull.
B) Without tropomyosin in the correct position, calcium cannot be released.
C) It is needed in the proper location, or ATP cannot be used.
D) It has a particular binding place that facilitates the removal of calcium.

Question 20

Which of these muscle types permit(s) voluntary movement?

A) cardiac
B) skeletal
C) smooth
D) All of the above permit voluntary movement.

Question 21

The myofibrils contain two protein filaments that contract the muscle. Of these, the ________ are the thinner filaments.

Question 22

The ________ is a modified form of endoplasmic reticulum that stores and releases calcium ions when a muscle contracts.

Question 23

All muscles share four traits. All are excitable, contractile, extensible, and ________.

Question 24

A band of connective tissue that aids in the attachment of muscle to bone is a(n) ________.

Question 25

________ is a condition in which there is an excessive stress on a tendon, causing inflammation.

Question 26

Someone who has broken an arm and has had a cast on it for months will notice a distinct shrinking of the arm once the cast is removed. Why does this happen?

A) The cast has reduced blood flow to the muscle tissue to reduce swelling.
B) Muscles that are not used will atrophy.
C) The other arm was used more to compensate for the unused one, and it has become stronger.
D) If the person was right-handed, he or she will become left-handed.

Question 27

What is the result of resistance exercise?

A) Existing muscle cells increase in diameter.
B) The number of muscle cells increases.
C) More mitochondria develop.
D) New blood vessels develop.

Question 28

A(n) ________ is the attachment point of a muscle to a bone that remains stationary during movement.

Question 29

A muscle will ________ if levels of calcium and potassium decrease in the blood.

Question 30

Some insecticides interfere with the removal of acetylcholine from the synaptic cleft. What effect will this have on muscle contraction?

A) The muscle cell will lose all of its supply of calcium.
B) The muscle cell will be unable to be stimulated again.
C) The muscle cell will be in a state of constant stimulation, leading to a tetany response.
D) The muscle cell will have a single twitch and will be unable to contract again.

Question 31

Why is ATP needed for muscle contraction?

A) It causes tropomyosin to slide off the myosin-binding sites of actin.
B) It's needed for calcium release from the sarcoplasmic reticulum.
C) It causes calcium to bind to troponin.
D) Myosin must contact the actin filament and move to pull it toward the midline of the sarcomere.

Question 32

Tetanus is a very serious disease caused by a toxin from a bacterium. Which of the following is the most obvious symptom?

A) excessive sneezing
B) dissolving bones
C) excessive weight gain
D) muscle paralysis

Question 33

After a period of exercise, a person will breathe heavily for some time after the activity has ceased. What is happening during this time as the oxygen debt is being paid?

A) Lactic acid is being removed.
B) Creatine phosphate is being regenerated.
C) Glycogen stores are being regenerated.
D) All of the above are true.

Question 34

The muscle that extends and rotates the thigh when walking is called the ________.

Question 35

Why does a person continue to breathe heavily after prolonged activity?

A) because of lack of water
B) to relieve fatigue
C) to relieve O2 debt
D) no reason

Question 36

What causes delayed onset muscle soreness?

A) exercise in which a muscle lengthens while it contracts
B) walking on level ground
C) running on level ground
D) gentle stretching

Question 37

A person may have a muscle injury that really affects the tendon and not the muscle tissue itself. Why is it that after a hard workout, muscle pain will go away in a few days at most, but tendinitis lasts so much longer?

A) Muscle cells are more elastic, so they are harder to damage.
B) Unlike a tendon, muscle tissue has an ample blood supply, so it's easier to repair.
C) Muscle cells can be rested, but tendons have to be used all the time.
D) The electrical signals that muscle cells generate are used to aid in healing.

Question 38

________ pairs up with troponin proteins to form a complex that blocks muscle contractions.

Question 39

Which muscle cells are designed for endurance?

A) slow-twitch cells
B) fast-twitch cells
C) myoglobin
D) hemoglobin

Question 40

Which of these cell types can be described as muscle cells that contract rapidly, are rich in glycogen deposits, and depend on anaerobic respiration to produce ATP?

A) slow-twitch cells
B) fast-twitch cells
C) myoglobin
D) hemoglobin

Question 41

A bundle of muscle cells is called a(n) ________.

Question 42

The type of exercise that creates new blood vessels and makes the heart pump more efficiently is ________.

Question 43

Myasthenia gravis is a disease caused by the immune system that attacks the acetylcholine receptors found on muscle cells. What effect would blocking these receptors have on muscle contraction?

Question 44

A(n) ________ consists of a motor neuron and all the muscle cells that it stimulates.

Question 45

Rigor mortis sets in after the death of humans and other animals because the supply of ATP decreases to the point at which calcium can no longer be removed from the cell. At this point, the myosin molecules attach to the thin filament. The muscles stiffen, and limbs cannot be moved. Why and for how long does the muscle then remain in this continuously contracted state?

Question 46

The release of acetylcholine into the neuromuscular junction is shortly followed by the release of ________ ions from the sarcoplasmic reticulum.

Question 47

________ is a sustained, powerful contraction of a muscle that results from frequent stimulation with no time between stimuli for relaxation.

Question 48

Muscle cells that contract slowly when stimulated but with enormous endurance are called ________.

Question 49

In former times, surgeons used small doses of curare to relax the patient's abdominal and other muscles during operations. Why did this compound work? What additional precautions do you think the medical staff needs to put into place when a patient is under anesthesia?

Question 50

________ provides the energy required for voluntary muscle contraction in an individual's body.

Question 51

Your skeletal muscles might make a lot of these fast contractions when you are cold:________.

Question 52

________ are the proteins that appear as dark bands that mark the ends of the sarcomeres.

Question 53

When the O2 in the muscles of an individual who has exercised for a long period of time is used up, this condition is known as ________.

Question 54

The striations (lines) of skeletal muscles are caused by the arrangement of many elongated ________.

Question 55

Explain the function of ATP in muscle contractions.

Question 56

Describe the four traits that all muscle types share.

Question 57

During muscle contraction, the heads of myosin filaments pull actin filaments toward the center of a ________ (the contractile unit of muscle).

Question 58

How do calcium ions affect muscle contractions?

Question 59

George liked to go for very long runs; we can assume that this chemical becomes depleted during those marathons: ________.

Question 60

Aerobic exercises do not increase skeletal muscle size, but they do cause various changes in the body. Explain what changes aerobic exercises initiate.

Question 61

Turkey is often served at Thanksgiving meals in which family members vie for portions of white or dark meat. Why is the breast meat of a turkey whiter in appearance than the darker meat found in the leg muscles?

Question 62

Steve decides to make a meal for some of his friends. He uses a variety of foods to prepare the meal, including some canned mushrooms. Unfortunately, he gives his friends a mild case of botulism food poisoning. His friends report blurred vision and trouble speaking due to a flaccid paralysis of the muscle cells by the botulinum toxin. Propose a mechanism by which this toxin would inhibit muscle contraction.

Question 63

Compare and contrast the physiological effects of steroid use to increase and improve performance in both genders.