6.1 Multiple Choice Questions
1) 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
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.1
Section: 6.1
2) 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
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.2
Section: 6.2
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: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.2
Section: 6.2
4) 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.
Answer: C
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 6.2
Section: 6.2
5) The attachment point of a muscle to a bone that can move is called the ________.
- A) origin
- B) insertion
- C) synergistic
- D) antagonistic
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.2
Section: 6.2
6) Which of the following attaches the end of the muscle to a bone?
- A) synergistic
- B) tetanus
- C) ligaments
- D) tendons
Answer: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.2
Section: 6.2
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
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
8) 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
Answer: A
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 6.3
Section: 6.3
9) 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
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
10) Which substance is released by motor neurons to stimulate a contraction?
- A) myosin
- B) acetylcholine
- C) dopamine
- D) calcium
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
11) 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: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
12) 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
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
13) 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
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
14) 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.
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
15) 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
Answer: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
16) 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 Piand 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.
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
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
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
18) Which of these muscle types permit(s) voluntary movement?
- A) cardiac
- B) skeletal
- C) smooth
- D) All of the above permit voluntary movement.
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.4
Section: 6.4
19) 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: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.4
Section: 6.4
20) 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
Answer: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.4
Section: 6.4
21) 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.
Answer: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.5
Section: 6.5
22) 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.
Answer: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.5
Section: 6.5
23) Why does a person continue to breathe heavily after prolonged activity?
- A) because of lack of water
- B) to relieve fatigue
- C) to relieve O2debt
- D) no reason
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.5
Section: 6.5
24) 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
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.6
Section: 6.6
25) Which muscle cells are designed for endurance?
- A) slow-twitch cells
- B) fast-twitch cells
- C) myoglobin
- D) hemoglobin
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.6
Section: 6.6
26) 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.
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.7
Section: 6.7
27) 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.
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.7
Section: 6.7
28) 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.
Answer: C
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 6.7
Section: 6.7
29) 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
Answer: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.7
Section: 6.7
30) 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.
Answer: B
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 6.7
Section: 6.7
31) 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
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.7
Section: 6.7
6.2 Fill-in-the-Blank Questions
1) All muscles share four traits. All are excitable, contractile, extensible, and ________.
Answer: elastic
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.1
Section: 6.1
2) A(n) ________ is the attachment point of a muscle to a bone that remains stationary during movement.
Answer: origin
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.2
Section: 6.2
3) A band of connective tissue that aids in the attachment of muscle to bone is a(n) ________.
Answer: tendon
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.2
Section: 6.2
4) ________ is a condition in which there is an excessive stress on a tendon, causing inflammation.
Answer: Tendinitis
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.2
Section: 6.2
5) The muscle that extends and rotates the thigh when walking is called the ________.
Answer: gluteus maximus
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
6) ________ pairs up with troponin proteins to form a complex that blocks muscle contractions.
Answer: Tropomyosin
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
7) A muscle will ________ if levels of calcium and potassium decrease in the blood.
Answer: cramp
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
8) The myofibrils contain two protein filaments that contract the muscle. Of these, the ________ are the thinner filaments.
Answer: actin filaments
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
9) The ________ is a modified form of endoplasmic reticulum that stores and releases calcium ions when a muscle contracts.
Answer: sarcoplasmic reticulum
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
10) The striations (lines) of skeletal muscles are caused by the arrangement of many elongated ________.
Answer: myofibrils
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
11) ________ are the proteins that appear as dark bands that mark the ends of the sarcomeres.
Answer: Z lines
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
12) A bundle of muscle cells is called a(n) ________.
Answer: fascicle
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
13) The release of acetylcholine into the neuromuscular junction is shortly followed by the release of ________ ions from the sarcoplasmic reticulum.
Answer: calcium
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
14) During muscle contraction, the heads of myosin filaments pull actin filaments toward the center of a ________ (the contractile unit of muscle).
Answer: sarcomere
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
15) Your skeletal muscles might make a lot of these fast contractions when you are cold:________.
Answer: twitches
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.4
Section: 6.4
16) A(n) ________ consists of a motor neuron and all the muscle cells that it stimulates.
Answer: motor unit
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.4
Section: 6.4
17) ________ is a sustained, powerful contraction of a muscle that results from frequent stimulation with no time between stimuli for relaxation.
Answer: Tetanus
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.4
Section: 6.4
18) George liked to go for very long runs; we can assume that this chemical becomes depleted during those marathons: ________.
Answer: glycogen
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.5
Section: 6.5
19) ________ provides the energy required for voluntary muscle contraction in an individual’s body.
Answer: ATP
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.5
Section: 6.5
20) 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 ________.
Answer: oxygen debt
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.5
Section: 6.5
21) Muscle cells that contract slowly when stimulated but with enormous endurance are called ________.
Answer: slow-twitch cells
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.6
Section: 6.6
22) The type of exercise that creates new blood vessels and makes the heart pump more efficiently is ________.
Answer: aerobic
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.7
Section: 6.7
6.3 Matching Questions
Match each definition in the first column to the correct term in the second column.
- A) T tubules
- B) Muscle twitch
- C) Testosterone
- D) Troponin
- E) Myosin
- F) Calcium ions
- G) Tropomyosin
- H) Slow-twitch muscle fibers
- I) Tendons
- J) Fast-twitch muscle fibers
- K) Actin
1) Anabolic steroids are chemically related to this type of hormone.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.7
Section: 6.7
2) A rapid, very brief muscle contraction.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.4
Section: 6.4
3) Delivers the signals from the motor neuron to every sarcomere of the muscle cell.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
4) Calcium binds to this protein to initiate a contraction.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
5) Covers the myosin-binding sites on actin.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
6) Protein that makes up the thin myofilament.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
7) Protein that makes up the thick myofilament.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
8) Functions in the attachment of muscle to bone.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.2
Section: 6.2
9) Muscle fibers designed for rapid and powerful responses.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.6
Section: 6.6
10) Muscle fibers that are designed for endurance, contract slowly, and have a steady supply of energy.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.6
Section: 6.6
11) Bind to troponin in the sarcomere to initiate muscle contraction.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Section: 6.3
Answers: 1) C 2) B 3) A 4) D 5) G 6) K 7) E 8) I 9) J 10) H 11) F
6.4 Short Answer and Essay Questions
1) Describe the four traits that all muscle types share.
Answer: Muscles have the ability to shorten and are contractile. Muscles are excitable and can respond to stimuli. Muscles are extensible and have the ability to stretch. Muscles are elastic and can return to their original length after being either lengthened or shortened.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.1
Section: 6.1
2) How do calcium ions affect muscle contractions?
Answer: The tropomyosin-troponin complex situates itself at the actin-myosin binding sites, preventing the formation of the cross-bridges. The tropomyosin-troponin complex can be moved once calcium ions bind to the troponin, exposing the myosin heads to the actin filaments and allowing the contraction to proceed.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Global LO: G8
Section: 6.3
3) 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?
Answer: Curare prevents acetylcholine from connecting to muscles. Since the diaphragm is likely to stop working, patients may stop breathing because of this, so assisted breathing devices are usually used.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 6.3
Global LO: G5|G7
Section: 6.3
4) Explain the function of ATP in muscle contractions.
Answer: ATP binds to the myosin heads, allowing the myosin heads to disengage from the actin. The myosin heads split the ATP molecules and store the energy, which allows the myosin heads to swivel in preparation to form the cross-bridges.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Global LO: G8
Section: 6.3
5) 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?
Answer: Acetylcholine is needed to initiate an action potential on the surface of a muscle cell. Without it, the muscle will not contract. If a diseased state destroys or blocks the receptors that acetylcholine normally binds to, the signal will not be sent, and the muscle will not contract.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 6.3
Global LO: G7|G8
Section: 6.3
6) 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?
Answer: If the myosin molecules cannot disengage from the actin filaments (i.e., the cross-bridges cannot be broken), the muscle cannot rebound back to its starting position, and the muscle will stay locked in that position. Eventually, the actin and myosin proteins themselves will break down, and the muscles will be moveable again.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.3
Global LO: G7|G8
Section: 6.3
7) 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.
Answer: If the muscles become flaccid, they cannot be stimulated to contract. The most likely cause would be that the toxin is somehow interfering with the action of acetylcholine. The toxin may be blocking acetylcholine release, or it may be blocking the binding of acetylcholine to the receptors on the muscle.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 6.3
Global LO: G5|G7|G8
Section: 6.3
8) 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?
Answer: The breast muscles of a turkey provide the force necessary for flight. Since turkeys are not exceptional fliers and do not migrate, the flight muscles are not frequently used. Therefore, the breast meat consists of fast-twitch fibers that lack much myoglobin. Turkeys rely instead on running to escape predators, so the leg muscles get far more exercise. These tend to be slow-twitch fibers containing lots of myoglobin and are thus darker in appearance.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 6.6
Global LO: G7|G8
Section: 6.6
9) Compare and contrast the physiological effects of steroid use to increase and improve performance in both genders.
Answer: Steroid use may promote a false sense of invincibility, increased aggression, and severe depression. Abuse of these drugs can severely affect the liver, cardiovascular system, and reproductive system. Males often have a reduction in natural testosterone production, causing atrophy of the testicles, which leads to sterility and impotence. Many females exhibit irreversible development of masculine traits, such as growth of body hair, deepening of the voice, loss of
scalp hair, smaller breasts, and enlarged clitoris.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.7
Global LO: G5|G7|G8
Section: 6.7
10) Aerobic exercises do not increase skeletal muscle size, but they do cause various changes in the body. Explain what changes aerobic exercises initiate.
Answer: Aerobic exercises initiate the development of new blood vessels to muscles and more mitochondria within muscle cells. Muscle coordination, digestive tract movement, and the cardiovascular and respiratory system will also benefit. The strength of the skeleton also increases because of the increased force on the bones.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 6.7
Global LO: G8
Section: 6.7
Biology of Humans: Concepts, Applications, and Issues, 6e (Goodenough)
Chapter 7 Neurons: The Matter of the Mind
7.1 Multiple Choice Questions
1) Which type of cell found in the nervous system is the most numerous?
- A) neuron
- B) neuroglial cell
- C) sensory cell
- D) Schwann cell
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.1
Section: 7.1
2) Leprosy destroys nerve tissue, so an afflicted person is likely to hurt his or her foot without even knowing it. Which types of neurons are likely to be affected?
- A) neuroglial cells
- B) motor neurons
- C) sensory neurons
- D) interneurons
Answer: C
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.1
Section: 7.1
3) Which type of neuron is found only in the brain and spinal cord?
- A) sensory neuron
- B) interneuron
- C) motor neuron
- D) glial cell
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.1
Section: 7.1
4) Which of the following parts of the nervous system is closest to a muscle?
- A) neuron
- B) interneuron
- C) motor neuron
- D) neuroglial cell
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.1
Section: 7.1
5) Muscle cells that are not exercised will atrophy, or shrink in size. Lou Gehrig’s disease affects nervous tissue but also causes muscle atrophy. What type of nerve cell must be affected to cause this muscle-wasting condition?
- A) interneurons
- B) sensory neurons
- C) neuroglial cells
- D) motor neurons
Answer: D
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.1
Section: 7.1
6) In saltatory conduction, nerve impulses jump from one exposed region of the axon to another. This exposed region is called the ________.
- A) motor end plate
- B) node of Ranvier
- C) Schwann cell gap
- D) interneurons
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
7) Inhaling or “huffing” is a way to achieve a high, usually by breathing in a fat-soluble substance. Which of the following structures would be most likely attacked first?
- A) myelin sheath
- B) axon
- C) neuron
- D) dendrite
Answer: A
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.2
Section: 7.2
8) Multiple sclerosis is a disease in which the myelin sheath is destroyed. What will happen to nerve conduction speed in affected neurons?
- A) It will slow down dramatically.
- B) It will speed up dramatically.
- C) It will speed up just a little bit.
- D) There will be no effect.
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
9) Infants require many nutrients early in life, including lipids such as fats. A low-fat diet for infants is not recommended because, among other things, it can affect the development of the nervous system. Why does the developing nervous system need lipids?
- A) Glial cells need lipids to produce the myelin sheath.
- B) Fats are needed for energy because infants are often on a low-carbohydrate diet.
- C) Lipids are needed to produce the polypeptide neurotransmitters used by neurons.
- D) Fats are required to generate action potentials on nerve cells.
Answer: A
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.2
Section: 7.2
10) When traveling down the neuron, which of the following parts of the neuron does the action potential pass through before the axon?
- A) glial cell
- B) dendrite
- C) synapse
- D) cell body
Answer: D
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.2
Section: 7.2
11) Which of these diseases involves the destruction of the myelin sheath on certain neurons within the brain and spinal cord?
- A) depression
- B) Alzheimer’s disease
- C) Parkinson’s disease
- D) multiple sclerosis
Answer: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
12) A new drug interferes with the function of the dendrites of a neuron. What will happen to this neuron?
- A) The neuron will continuously send signals.
- B) The neuron cannot be stimulated to send a signal along its axon.
- C) The neuron will die off.
- D) The neuron will sometimes send signals and will sometimes not send signals.
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
13) Which one of the following ions outside the neuron would make it very difficult for a depolarization to occur?
- A) potassium
- B) sodium
- C) chloride
- D) manganese
Answer: C
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.3
Section: 7.3
14) The specialized membrane proteins that actively transport sodium and potassium ions across the plasma membrane are known as the ________.
- A) sodium-chloride pump
- B) sodium-manganese pump
- C) sodium-potassium pump
- D) sodium pump
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
15) A nerve impulse does not vary in intensity with regard to the strength of the stimulus. What do we call this phenomenon?
- A) resting membrane potential
- B) refractory period
- C) all-or-nothing principle
- D) graded response
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
16) Sodium and potassium ions cross the neuron’s membrane to cause which of the following processes?
- A) action potential
- B) passive transport
- C) refractory period
- D) transmission
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
17) A neuron’s membrane that maintains a charge difference across its surface in which the inside is more negative than the outside is called ________.
- A) graded potential
- B) resting potential
- C) action potential
- D) summation
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
18) Some drugs modulate the activity of ion channels. For example, Novocain somewhat inhibits the opening of sodium channels. What happens to the threshold of a sensory neuron if this drug is used?
- A) It will take less stimulation to reach threshold.
- B) It will take more stimulation to reach threshold.
- C) Threshold will not change.
- D) The nerve will not function and will die off.
Answer: B
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.3
Section: 7.3
19) Ouabain is a chemical used on poison arrows in Africa. It works by inhibiting the sodium-potassium pump. What effect does this chemical have on an action potential?
- A) It prevents the stimulation of an action potential by removing sodium from the cell.
- B) It immediately causes an action potential to be generated.
- C) There is no direct effect because the pump is used to maintain ion distributions, not to cause an action potential.
- D) It causes the release of a neurotransmitter that causes an action potential.
Answer: C
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.3
Section: 7.3
20) Which of the following is a chemical signal that diffuses across the gap between adjacent neurons to convey a message to the next cell?
- A) neurotransmitter
- B) synapse
- C) dendrite
- D) action potential
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
21) The combined effects of inhibitory and excitatory effects on a postsynaptic cell will decide whether that cell generates an action potential. This principle is called ________.
- A) threshold
- B) internalization
- C) summation
- D) potentiation
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
22) Which of the following is a neurotransmitter that triggers a contraction of a voluntary muscle?
- A) synapse
- B) action potential
- C) sodium
- D) acetylcholine
Answer: D
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
23) Your classmate does not have much muscle strength. Her doctor says she has an autoimmune disease, but you didn’t quite catch the name the physician gave for the illness. Based on what you have learned, what do you think the diagnosis is?
- A) Alzheimer’s disease
- B) schizophrenia
- C) senility
- D) myasthenia gravis
Answer: D
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.4
Section: 7.4
24) Which neurotransmitter appears to be associated with an energizing “good” feeling and is essential in hunger, thirst, and sex drive?
- A) dopamine
- B) serotonin
- C) norepinephrine
- D) synapse
Answer: C
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
25) Which neurotransmitter may function to regulate emotions and is involved in pathways that control complex movements?
- A) dopamine
- B) serotonin
- C) norepinephrine
- D) synapse
Answer: A
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
26) Prior to their release, where are the special chemicals called neurotransmitters stored in a neuron?
- A) axon
- B) synaptic knob
- C) dendrites
- D) cell body
Answer: B
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
27) You might have been accidentally exposed to an insecticide while working in a citrus grove. What symptoms of poisoning would you watch for?
- A) depression
- B) Alzheimer’s disease
- C) muscle tremors
- D) excessive urination
Answer: C
Bloom’s Taxonomy: Synthesis/Evaluation
Learning Outcome: 7.4
Section: 7.4
28) Prescription drugs such as Prozac help maintain higher levels of serotonin in the brain. What effect will this have on an individual?
- A) It will act as an antidepressant because a lack of serotonin is considered a cause of depression symptoms.
- B) It will act to suppress impulsive behavior because too much serotonin causes children to act out.
- C) It will cause a patient to be sleepy because serotonin is essential to a good night’s sleep.
- D) It will cause tetany due to an overproduction of acetylcholine.
Answer: A
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.4
Section: 7.4
7.2 Fill-in-the-Blank Questions
1) ________ is the name given to the motor neurons that carry information away from the brain or spinal cord.
Answer: Efferent
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.1
Section: 7.1
2) A(n) ________, or afferent, neuron conducts information toward the brain and spinal cord.
Answer: sensory
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.1
Section: 7.1
3) ________ is the name of the cell that wraps around the axon, forming the myelin sheath.
Answer: Schwann cell
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
4) Axons and dendrites of individual neurons, arranged in bundles and covered by connective tissue, make up ________.
Answer: nerves
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
5) The jumping of a nerve impulse from one node of Ranvier to the next is known as ________.
Answer: saltatory conduction
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
6) ________ are numerous short, branching projections from the neuron that create a huge surface for receiving signals from other cells.
Answer: Dendrites
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
7) The neuron requires a certain level of depolarization of its membrane in order to generate an action potential. This level of depolarization is known as the ________.
Answer: threshold
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
8) During an action potential, the ________ ions rush into the axon.
Answer: sodium
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
9) Immediately after an action potential occurs, the sodium channels close and cannot be reopened. What is this period called?
Answer: refractory period
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
10) The neuron that releases neurotransmitters is known as ________, while the neuron that receives the neurotransmitters is knows as ________.
Answer: presynaptic; postsynaptic
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
11)
Look at the accompanying figure. In Step 1 ________ ions enter the neuron, while in Step 2 ________ ions leave the neuron.
Answer: sodium; potassium
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
12) ________ is a progressive brain disease in which the dopamine-producing neurons in the movement control center of the brain die.
Answer: Parkinson’s disease
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
13) ________ involves an insufficient amount of several neurotransmitters, such as serotonin, dopamine, and norepinephrine, for extended periods of time.
Answer: Clinical depression
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
14) The synaptic ________ is the narrow space between two neurons.
Answer: cleft
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
15) The enzyme that removes the neurotransmitter acetylcholine from synapses after it has been released is known as ________.
Answer: acetylcholinesterase
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
16) ________ is a neurotransmitter released at every neuromuscular junction (the junction of a motor neuron and a skeletal muscle cell), where it triggers contraction of voluntary (skeletal) muscles.
Answer: Acetylcholine
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
7.3 Matching Questions
Match each definition in the first column to the correct term in the second column.
- A) Inhibitory synapse
- B) Synapse
- C) Sensory neuron
- D) Synaptic knobs
- E) Dendrite
- F) Axon
- G) Motor neuron
- H) Interneurons
- I) Ion channels
- J) Excitatory synapse
1) Synapse in which neurotransmitters decrease the chance of an action potential on the postsynaptic cell.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.4
Section: 7.4
2) Synapse in which neurotransmitters allow sodium to enter the postsynaptic cell.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
3) A specific type of neuron that conducts information toward the brain and spinal cord from a sensory receptor.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.1
Section: 7.1
4) The junction between a neuron and another cell.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
5) The short branching projections of a neuron, which provide surface area for sending and receiving signals from other cells.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
6) Specific neurons that carry information away from the brain and spinal cord to an effector such as a muscle or a gland.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.1
Section: 7.1
7) Membrane proteins that allow specific charged molecules to pass through from one side of the membrane to the other.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.3
Section: 7.3
8) Part of the neuron where neurotransmitters are released.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.4
Section: 7.4
9) A single, long extension of a neuron’s cell body that functions to transmit an incoming message or impulse.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Section: 7.2
10) Association neurons that are located between the sensory and motor neurons, where they integrate or interpret the sensory signals.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.1
Section: 7.1
Answers: 1) A 2) J 3) C 4) B 5) E 6) G 7) I 8) D 9) F 10) H
7.4 Short Answer and Essay Questions
1) Compare and contrast the sensory neurons, motor neurons, and interneurons.
Answer: All three have the generalized components of a neuron, such as the cell body, dendrites, and so on. However, sensory neurons conduct information toward the brain and spinal cord from the sensory receptors that gather information within and around the body. By contrast, motor neurons carry information away from the brain and spinal cord to an effector. Association neurons, or interneurons, can be found between sensory and motor neurons within the brain or spinal cord. These neurons are responsible for the integration or interpretation of sensory signals and the response to these signals.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.1
Global LO: G8
Section: 7.1
2) Explain the anatomy of a typical neuron.
Answer: Dendrites are numerous short, branching projections from a neuron that receive information from other neurons or from the environment. The cell body controls the neuron’s metabolic activities and integrates input from other neurons. The axon conducts the nerve impulses away from the cell body. Neurotransmitters are released at synaptic knobs.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Global LO: G8
Section: 7.2
3) What is the function of the myelin sheath in the nervous system?
Answer: The myelin sheath serves to insulate axons of neurons in the brain and spinal cord along with axons outside the brain and spinal cord. It is composed of Schwann cells outside the central nervous system (CNS). The Schwann cells wrap around an axon many times to prevent messages from short-circuiting between neurons.
Bloom’s Taxonomy: Knowledge/Comprehension
Learning Outcome: 7.2
Global LO: G8
Section: 7.2
4) Some nerves are myelinated, and others are not. Myelinated nerves send signals faster than unmyelinated neurons. Draw two neurons of equal length, and wrap segments of myelin along one. Be careful to leave spaces for the nodes of Ranvier. Now, measure the exposed axons of each, and total up the distance. Describe why the myelinated neurons send signals faster.
Answer: It should be apparent from the drawing that myelinated neurons have less exposed axon length; thus, signals travel faster as they jump from one node to the next.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.2
Global LO: G4|G8
Section: 7.2
5) If a drug had the side effect of destroying dopamine-producing neurons, what effect would this have on a person?
Answer: The individual would probably start to show signs of Parkinson’s disease. Signs include a shuffling walk, hunched posture, and possible involuntary shaking.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.4
Global LO: G5|G8
Section: 7.4
6) What are some of the dangers associated with the use of organophosphate pesticides that might be of concern for humans? (Organophosphates inhibit acetylcholinesterase.) What are some ethical concerns related to their use?
Answer: There are many insecticides that prevent insect pests from damaging favorable plants or household foods. The organophosphate insecticides kill insects by inhibiting acetylcholinesterase, the enzyme that degrades acetylcholine. This causes acetylcholine to accumulate and continuously stimulate in the synapse. These pesticides have a similar effect on humans.
The following are some of the ethical concerns: (1) Organophosphates could be used against humans in warfare. (2) Organophosphates could pose a threat to wildlife, including “good” insects such as bees, if not applied carefully. (3) These toxins could be used in homicides and suicides. (4) Accidental poisoning of farm workers and others exposed to these pesticides kills 500,000 people annually worldwide.
Bloom’s Taxonomy: Synthesis/Evaluation
Learning Outcome: 7.4
Global LO: G2|G5|G7|G8
Section: 7.4
7) Tay-Sachs disease is a genetic disorder in which fat deposits build up in nerve cells of the brain, leading to a slow loss of function. Because this disease usually strikes children under 1 year of age, the symptoms are not immediately apparent. Think about the symptoms that this condition would cause. List some that you think are possible. What would be the inevitable end result as the disease progresses?
Answer: The disease would interfere with neuron function in the brain. Because very young children don’t speak, verbal communication is not a reliable measure of the illness. The most noticeable symptoms would be loss of motor function, difficulty swallowing, or inability to see or move around in response to stimuli. Eventually, motor function will be impaired to the point that the child will be unable to breathe. In the end, the disease is fatal.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.3
Global LO: G5|G7|G8
Section: 7.3
8) Potassium ions are important in the resting membrane potential and the action potential of the nerve and to the contraction of muscle cells. The concentration gradient of potassium ions is critical to both. An excess of potassium outside a neuron or muscle cell would negate the concentration gradient. What would happen if the heart were injected with massive amounts of potassium? Explain your answer.
Answer: Potassium ions added to the exterior of a cell would disrupt the resting membrane potential because they would not “leak” in the correct direction. During the resting potential, there are more potassium ions inside of the cell; during the action potential, potassium leaks out of the cell. An action potential could be initiated as sodium rushes into the cell, but another one could not be generated.
Bloom’s Taxonomy: Synthesis/Evaluation
Learning Outcome: 7.3
Global LO: G7|G8
Section: 7.3
9) In the disease myasthenia gravis, the immune system attacks the receptors for the neurotransmitter acetylcholine. A drug is used to inhibit the enzyme acetylcholinesterase, which normally removes the neurotransmitter. This improves the condition of the patient. How does this work?
Answer: If a person with this disease has fewer receptors for acetylcholine, it would help to inhibit the breakdown of the neurotransmitter in the synapse. Increasing the concentration of the neurotransmitter in the synapse could increase the likelihood that some of the neurotransmitter will bind with the receptors.
Bloom’s Taxonomy: Application/Analysis
Learning Outcome: 7.4
Global LO: G7|G8
Section: 7.4
