Question 1

In the myotatic knee-jerk reflex, what would happen if the α motoneurons to the hamstrings were severed?

Accepted Answer

A)  The lower leg would tremor. 
B)  The thigh would tremor. 
C)  The Golgi tendon organ would experience exaggerated stretch. 
D)  The intrafusal muscle fibers would extensively. 
E)  The extrafusal muscle fibers would stop firing. 
A)  The lower leg would tremor. 
B)  The thigh would tremor. 
C)  The Golgi tendon organ would experience exaggerated stretch. 
D)  The intrafusal muscle fibers would extensively. 
E)  The extrafusal muscle fibers would stop firing.

Question 2

One of the main hallmark clinical symptoms of Parkinson's Disease is uncontrolled tremors throughout the body. This strongly indicates that this disease involves the

Accepted Answer

A)  cerebellum. 
B)  motor cortex. 
C)  corticospinal tract. 
D)  basal ganglia. 
E)  red nucleus. 
A)  cerebellum. 
B)  motor cortex. 
C)  corticospinal tract. 
D)  basal ganglia. 
E)  red nucleus.

Question 3

Reciprocal innervation means that contraction of one muscle set is accompanied by

Accepted Answer

A)  relaxation of an antagonistic muscle. 
B)  stimulation of a downstream muscle. 
C)  stimulation of its downstream Golgi tendon organs. 
D)  inhibition of an antagonistic muscle. 
E)  stimulation of an antagonistic muscle. 
A)  relaxation of an antagonistic muscle. 
B)  stimulation of a downstream muscle. 
C)  stimulation of its downstream Golgi tendon organs. 
D)  inhibition of an antagonistic muscle. 
E)  stimulation of an antagonistic muscle.

Question 4

Explain what happens to a muscle when it stretches.

Accepted Answer

When a muscle stretches, not only are ex

Question 5

In the ubiquitous reaction, H2O + CO2 ↔ H2CO3 ↔ HCO3- + H+, found in the blood, explain how a build-up of protons in the blood leads to increased carbon dioxide in the CNS.

Accepted Answer

Protons cannot cross the blood-brain bar

Question 6

The muscles on which strength training (e.g., power-lifting, weight-lifting, resistance training) depends would

Accepted Answer

A)  be large. 
B)  have high endurance capacity. 
C)  be highly vascularized. 
D)  have high myoglobin content. 
E)  have relatively high oxidative capacity. 
A)  be large. 
B)  have high endurance capacity. 
C)  be highly vascularized. 
D)  have high myoglobin content. 
E)  have relatively high oxidative capacity.

Question 7

Which of the following represents a key feature of the reticulospinal tract?

Accepted Answer

A)  It controls locomotion, balance and posture. 
B)  It is one of the major lateral descending pathways. 
C)  It descends only as far as the cervical spinal cord. 
D)  It controls fine motor skills of the distal limbs. 
E)  It controls crude motor skills of the proximal limbs. 
A)  It controls locomotion, balance and posture. 
B)  It is one of the major lateral descending pathways. 
C)  It descends only as far as the cervical spinal cord. 
D)  It controls fine motor skills of the distal limbs. 
E)  It controls crude motor skills of the proximal limbs.

Question 8

Experiments by Georgopoulos showed that visually guided arm movements are initiated by corticospinal neurons that were selective for

Accepted Answer

A)  angle. 
B)  age. 
C)  activity. 
D)  proprioception. 
E)  direction. 
A)  angle. 
B)  age. 
C)  activity. 
D)  proprioception. 
E)  direction.

Question 9

In physical movements that require a lot of stretching (e.g., yoga), which of the following will respond more than the other (in terms of firing action potentials)?

Accepted Answer

A)  A (alpha) motoneurons will respond more than γ motoneurons. 
B)  Γ motoneurons will respond more than α motoneurons. 
C)  A (alpha) and γ motoneurons will respond to the same extent. 
D)  Neither α nor γ motoneurons will respond in this artificial setup. 
E)  It depends on how much stretch is employed. 
A)  A (alpha) motoneurons will respond more than γ motoneurons. 
B)  Γ motoneurons will respond more than α motoneurons. 
C)  A (alpha) and γ motoneurons will respond to the same extent. 
D)  Neither α nor γ motoneurons will respond in this artificial setup. 
E)  It depends on how much stretch is employed.

Question 10

The origin of the corticospinal tract is in the

Accepted Answer

A)  cerebral cortex. 
B)  visual cortex. 
C)  frontal cortex. 
D)  lateral spinal cord. 
E)  medial spinal cord. 
A)  cerebral cortex. 
B)  visual cortex. 
C)  frontal cortex. 
D)  lateral spinal cord. 
E)  medial spinal cord.

Question 11

If a skeletal muscle fiber is excised from the body, mounted between two immovable plates, and then concentrically stretched (lengthened), which will respond more than the other (in terms of firing action potentials)?

Accepted Answer

A)  A (alpha) motoneurons will respond more than γ motoneurons. 
B)  Γ motoneurons will respond more than α motoneurons. 
C)  A (alpha) and γ motoneurons will respond to the same extent. 
D)  Neither α nor γ motoneurons will respond in this artificial setup. 
E)  It depends on how much stretch is employed. 
A)  A (alpha) motoneurons will respond more than γ motoneurons. 
B)  Γ motoneurons will respond more than α motoneurons. 
C)  A (alpha) and γ motoneurons will respond to the same extent. 
D)  Neither α nor γ motoneurons will respond in this artificial setup. 
E)  It depends on how much stretch is employed.

Question 12

The flexor reflex is also often called the "withdrawal reflex". This is because it

Accepted Answer

A)  is a polysynaptic reflex arc. 
B)  is life-preserving or causes avoidance of an aversive stimulus. 
C)  causes the animal to withdraw into isolation. 
D)  involves each side of the body, one at a time. 
E)  involves both sides of the body, sequentially. 
A)  is a polysynaptic reflex arc. 
B)  is life-preserving or causes avoidance of an aversive stimulus. 
C)  causes the animal to withdraw into isolation. 
D)  involves each side of the body, one at a time. 
E)  involves both sides of the body, sequentially.

Question 13

Recordings of extrafusal muscle tension and accompanying sensory discharge from muscle spindles reveal that

Accepted Answer

A)  stimulation of α motoneurons is required to elicit a response from fusiform γ efferents. 
B)  fusiform efferents respond when extrafusal muscle fibers are relaxed. 
C)  fusiform efferents respond only if extrafusal muscle fibers are stimulated. 
D)  intrafusal muscle fibers' work load is proportional to that of the extrafusal muscle fibers. 
E)  intrafusal muscle fibers exhibit either maximum tension or none at all, depending on the tension experienced by the extrafusal muscle fibers. 
A)  stimulation of α motoneurons is required to elicit a response from fusiform γ efferents. 
B)  fusiform efferents respond when extrafusal muscle fibers are relaxed. 
C)  fusiform efferents respond only if extrafusal muscle fibers are stimulated. 
D)  intrafusal muscle fibers' work load is proportional to that of the extrafusal muscle fibers. 
E)  intrafusal muscle fibers exhibit either maximum tension or none at all, depending on the tension experienced by the extrafusal muscle fibers.

Question 14

Describe or draw the inter-relationships in how the motor cortex, pre-frontal cortex, basal ganglia, cerebellum, spinal cord and brainstem are involved a movement.

Accepted Answer

Thinking of initiating a movement begins

Question 15

Which projection from the cerebellum indicates that it is involved in fine motor control?

Accepted Answer

A)  To the motor cortex 
B)  To the vestibular nuclei 
C)  To the reticular nuclei 
D)  To the sensorimotor cortex 
E)  To the spinal cord 
A)  To the motor cortex 
B)  To the vestibular nuclei 
C)  To the reticular nuclei 
D)  To the sensorimotor cortex 
E)  To the spinal cord

Question 16

Central (CNS) awareness of muscle stretch occurs because of

Accepted Answer

A)  stimulation of α motoneurons. 
B)  stimulation of γ motoneurons. 
C)  relaxation of α motoneurons. 
D)  relaxation of γ motoneurons. 
E)  stimulation of both α and γ motoneurons. 
A)  stimulation of α motoneurons. 
B)  stimulation of γ motoneurons. 
C)  relaxation of α motoneurons. 
D)  relaxation of γ motoneurons. 
E)  stimulation of both α and γ motoneurons.

Question 17

One of the main benefits of α and γ motoneuron coactivation is to

Accepted Answer

A)  provide constant feedback to the brain regarding muscle tension and length. 
B)  prevent injury to the muscle because if stretched too much, it will resist stretch. 
C)  provide greater flexibility of the muscle. 
D)  provide the muscle with greater strength. 
E)  allow the muscle to hypertrophy. 
A)  provide constant feedback to the brain regarding muscle tension and length. 
B)  prevent injury to the muscle because if stretched too much, it will resist stretch. 
C)  provide greater flexibility of the muscle. 
D)  provide the muscle with greater strength. 
E)  allow the muscle to hypertrophy.

Question 18

Which of the following describes the action of dopamine on striatal neurons of the direct and indirect paths, respectively?

Accepted Answer

A)  Facilitates activity, suppresses activity 
B)  Facilitates activity, no effect on activity 
C)  Suppresses activity, facilitates activity 
D)  No effect on activity, facilitates activity 
E)  Suppresses activity, no effect on activity 
A)  Facilitates activity, suppresses activity 
B)  Facilitates activity, no effect on activity 
C)  Suppresses activity, facilitates activity 
D)  No effect on activity, facilitates activity 
E)  Suppresses activity, no effect on activity

Exam 26: Initiation and Control of Coordinated Muscular Movements

In the myotatic knee-jerk reflex, what would happen if the α motoneurons to the hamstrings were severed?

One of the main hallmark clinical symptoms of Parkinson's Disease is uncontrolled tremors throughout the body. This strongly indicates that this disease involves the

Reciprocal innervation means that contraction of one muscle set is accompanied by

Explain what happens to a muscle when it stretches.

In the ubiquitous reaction, H2O + CO2 ↔ H2CO3 ↔ HCO3- + H+, found in the blood, explain how a build-up of protons in the blood leads to increased carbon dioxide in the CNS.

The muscles on which strength training (e.g., power-lifting, weight-lifting, resistance training) depends would

Which of the following represents a key feature of the reticulospinal tract?

Experiments by Georgopoulos showed that visually guided arm movements are initiated by corticospinal neurons that were selective for

In physical movements that require a lot of stretching (e.g., yoga), which of the following will respond more than the other (in terms of firing action potentials)?

The origin of the corticospinal tract is in the

If a skeletal muscle fiber is excised from the body, mounted between two immovable plates, and then concentrically stretched (lengthened), which will respond more than the other (in terms of firing action potentials)?

The flexor reflex is also often called the "withdrawal reflex". This is because it

Recordings of extrafusal muscle tension and accompanying sensory discharge from muscle spindles reveal that

Describe or draw the inter-relationships in how the motor cortex, pre-frontal cortex, basal ganglia, cerebellum, spinal cord and brainstem are involved a movement.

Which projection from the cerebellum indicates that it is involved in fine motor control?

Central (CNS) awareness of muscle stretch occurs because of

One of the main benefits of α and γ motoneuron coactivation is to

Which of the following describes the action of dopamine on striatal neurons of the direct and indirect paths, respectively?

Principles of Signaling and Organization

Signaling in the Visual System

Functional Architecture of the Visual Cortex

Ion Channels and Signaling

Structure of Ion Channels

Ionic Basis of the Resting Potential

Ionic Basis of the Action Potential

Electrical Signaling in Neurons

Ion Transport Across Cell Membranes

Properties and Functions of Neuroglial Cells

Mechanisms of Direct Synaptic Transmission

Indirect Mechanisms of Synaptic Transmission

Release of Neurotransmitters

Neurotransmitters in the Central Nervous System

Transmitter Synthesis, Storage, Transport, and Inactivation

Synaptic Plasticity

The Molecular and Cellular Biology of Synaptic Plasticity

Mechanisms of Extrasynaptic Communication

Autonomic Nervous System

Walking, Flying, and Swimming: Cellular Mechanisms of Sensorimotor Behavior in Invertebrates

Sensory Transduction

Transduction and Transmission in the Retina

Touch, Pain, and Texture Sensation

Auditory and Vestibular Sensation

Constructing Perception

Development of the Nervous System

Critical Periods in Sensory Systems

Regeneration and Repair of Synaptic Connections After Injury

Appendix

Filters

In the ubiquitous reaction, H₂O + CO₂ ↔ H₂CO₃ ↔ HCO₃^- + H⁺, found in the blood, explain how a build-up of protons in the blood leads to increased carbon dioxide in the CNS.