Introduction to Behavioral Neuroscience Instructor Answer Guide
Multiple Choice
10.1 The physiological actions implementing movement – Contraction of muscles
1. A skeletal muscle is composed of many multi-nucleated ________ which each contain
bundles of ________, where contractile proteins are organized into ________.
a. sarcomeres / myofibrils / muscle cells (fibers)
b. muscle cells (fibers) / sarcomeres / myofibrils
c. myofibrils / muscle cells (fibers) / sarcomeres
d. muscle cells (fibers) / myofibrils / sarcomeres
Answer: d
2. The thin filament base attachment points that also demarcate the borders of each
sarcomere in a myofibril are called:
a. M-lines.
b. Z-discs.
c. A-bands.
d. I-bands.
Answer: b
3. Which contraction-associated protein is considered a “thick filament” and contains the
globular heads within a myofibril?
a. actin
b. myosin
c. troponin
d. tropomyosin
Answer: b
4. Which contraction-associated protein initially covers binding sites expressed by the thin
filaments that the globular heads of thick filaments bind to, and is moved away by another
protein to initiate contraction?
a. actin
b. myosin
c. troponin
d. tropomyosin
Answer: d
, Introduction to Behavioral Neuroscience Instructor Answer Guide
5. Which contraction-associated protein starts the cross-bridge cycle with its globular
heads bound with adenosine diphosphate (ADP)?
a. actin
b. myosin
c. troponin
d. tropomyosin
Answer: b
6. Which ion is primarily involved in the initiation of massive muscle depolarization called a
muscle action potential following the opening voltage-gated channels?
a. calcium
b. sodium
c. potassium
d. chloride
Answer: b
7. Which of the below neuron types would synapse directly onto a muscle cell/fiber?
a. lower motoneuron
b. upper motoneuron
c. pyramidal cell in motor cortex
d. interneuron in spinal cord
Answer: a
10.2 Eliciting Contractions from Lower Levels – Lower Motoneurons and Reflex Arcs
8. A motor unit consists of:
a. a muscle cell/fiber.
b. a motoneuron and all the muscle cells/fibers with which it synapses.
c. an anatomically defined muscle bundle such as the triceps muscle.
d. all motoneurons that connect to muscle cells/fibers pulling a limb in the same
direction.
Answer: b
9. Neurons that make up the hypoglossal cranial nerve (#12), and a motoneuron from the
ventrolateral spine, are both lower motoneurons because (by definition) they:
a. are involved in motor control.
b. reside in motoric-associated regions of the nervous system.
c. project directly to muscles.
d. release acetylcholine as their neurotransmitter.
2
Updated October 2024
Multiple Choice
10.1 The physiological actions implementing movement – Contraction of muscles
1. A skeletal muscle is composed of many multi-nucleated ________ which each contain
bundles of ________, where contractile proteins are organized into ________.
a. sarcomeres / myofibrils / muscle cells (fibers)
b. muscle cells (fibers) / sarcomeres / myofibrils
c. myofibrils / muscle cells (fibers) / sarcomeres
d. muscle cells (fibers) / myofibrils / sarcomeres
Answer: d
2. The thin filament base attachment points that also demarcate the borders of each
sarcomere in a myofibril are called:
a. M-lines.
b. Z-discs.
c. A-bands.
d. I-bands.
Answer: b
3. Which contraction-associated protein is considered a “thick filament” and contains the
globular heads within a myofibril?
a. actin
b. myosin
c. troponin
d. tropomyosin
Answer: b
4. Which contraction-associated protein initially covers binding sites expressed by the thin
filaments that the globular heads of thick filaments bind to, and is moved away by another
protein to initiate contraction?
a. actin
b. myosin
c. troponin
d. tropomyosin
Answer: d
, Introduction to Behavioral Neuroscience Instructor Answer Guide
5. Which contraction-associated protein starts the cross-bridge cycle with its globular
heads bound with adenosine diphosphate (ADP)?
a. actin
b. myosin
c. troponin
d. tropomyosin
Answer: b
6. Which ion is primarily involved in the initiation of massive muscle depolarization called a
muscle action potential following the opening voltage-gated channels?
a. calcium
b. sodium
c. potassium
d. chloride
Answer: b
7. Which of the below neuron types would synapse directly onto a muscle cell/fiber?
a. lower motoneuron
b. upper motoneuron
c. pyramidal cell in motor cortex
d. interneuron in spinal cord
Answer: a
10.2 Eliciting Contractions from Lower Levels – Lower Motoneurons and Reflex Arcs
8. A motor unit consists of:
a. a muscle cell/fiber.
b. a motoneuron and all the muscle cells/fibers with which it synapses.
c. an anatomically defined muscle bundle such as the triceps muscle.
d. all motoneurons that connect to muscle cells/fibers pulling a limb in the same
direction.
Answer: b
9. Neurons that make up the hypoglossal cranial nerve (#12), and a motoneuron from the
ventrolateral spine, are both lower motoneurons because (by definition) they:
a. are involved in motor control.
b. reside in motoric-associated regions of the nervous system.
c. project directly to muscles.
d. release acetylcholine as their neurotransmitter.
2
Updated October 2024
