Module 5

Question 1

Match the correct type of motor neuron (α and γ) with the type of muscle fiber
(extrafusal and intrafusal).

Question 2

Describe the anatomical location, function, and afferent neurotransmission of
muscle spindle and Golgi tendon organs.

Answer 2

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Question 3

Discuss the types of efferent innervation of muscle fibers and their functions.

Answer 3

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Question 4

Trace the neuronal activity initiated by striking the patellar tendon with a
percussion hammer (patellar tendon reflex) that leads to contraction of a muscle.
Contrast this reflex with the inverse myotatic reflex (Golgi tendon reflex).

Answer 4

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Question 5

Describe the role of the γ efferent system in the stretch reflex and explain the
significance of α-γ co-activation. Contrast the actions of static and dynamic γ
motor neurons.

Answer 5

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Question 6

Describe the properties of the flexor reflex initiated by touching a hot stove.
Identify when pain is sensed, when flexor contraction occurs, and the neuronal
connections and role of the crossed extensor reflex.

Answer 6

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Question 7

Explain the overall transmembrane signaling steps whereby increases in cytosolic
calcium initiate cross-bridge cycling.

Answer 7

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Question 8

Identify the multiple sources, localization, and roles of calcium in muscle
contraction and relaxation.

Answer 8

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Question 9

Draw a myosin molecule and label the subunits (heavy chains, light chains) and
describe the function of the subunits.

Answer 9

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Question 10

Diagram the structure of the thick and thin myofilaments and label the constituent
proteins.

Answer 10

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Question 11

Diagram the chemical and mechanical steps in the cross-bridge cycle, and explain
how the cross-bridge cycle results in shortening of the muscle.

Answer 11

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Question 12

Draw and label a skeletal muscle at all anatomical levels, from the whole muscle to
the molecular components of the sarcomere. At the sarcomere level, include at
least two different stages of myofilament overlap

Answer 12

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Question 13

List the steps in excitation-contraction coupling in skeletal muscle, and describe
the roles of the sarcolemma, transverse tubules, sarcoplasmic reticulum, thin
filaments, and calcium ions.

Answer 13

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Question 14

List the steps in excitation-contraction coupling in skeletal muscle, and describe
the roles of the sarcolemma, transverse tubules, sarcoplasmic reticulum, thin
filaments, and calcium ions.

Answer 14

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Question 15

Draw the structure of the neuromuscular junction

Answer 15

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Question 16

List in sequence the steps involved in neuromuscular transmission in skeletal
muscle and point out the location of each step on a diagram of the neuromuscular
junction.

Answer 16

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Question 17

Define a motor unit and describe the order of recruitment of motor units during
skeletal muscle contraction of varying strengths.

Answer 17

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