Motor Control Hierarchy Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What represents the highest level of the motor control hierarchy?

Spinal cord

Motor cortex and cerebellum

Forebrain association areas and basal ganglia (correct)

Alpha motor neurons

Which part of the motor control hierarchy is responsible for the tactics of movement?

Spinal cord

Forebrain association areas

Alpha motor neurons

Motor cortex and cerebellum (correct)

What is the final common pathway for motor behavior?

Basal ganglia

Spinal interneurons

Sensory feedback

Alpha motor neuron (correct)

How does the brain influence the spinal cord's activity?

By commanding voluntary movements Signup and view all the answers

What role do spinal interneurons play in movement control?

They modulate the activity of alpha motor neurons Signup and view all the answers

What aspect of movement is NOT handled by the middle level of the motor control hierarchy?

Goal of the movement Signup and view all the answers

Which of the following is considered a part of the central motor system?

Basal ganglia Signup and view all the answers

Which statements about reflex movements are correct?

They reflect the complexity of spinal control systems. Signup and view all the answers

What is a common consequence of lesions in the parietal lobes?

Neglect of the side of the body opposite the lesion Signup and view all the answers

Which area works in conjunction with the posterior parietal cortex for motor control?

Prefrontal cortex Signup and view all the answers

What do areas 4 and 6 primarily contribute to?

Descending corticospinal tract Signup and view all the answers

At what point do actions transition from encoding to specification?

At cortical area 6 Signup and view all the answers

Which cognitive processes are thought to involve the anterior frontal lobes?

Decision making and abstract thought Signup and view all the answers

What did the studies by Per Roland and his colleagues primarily support?

The concept of higher order motor planning Signup and view all the answers

What is a possible effect of damage to the parietal lobes on spatial relations?

Confusion regarding spatial orientation Signup and view all the answers

Which function does cortical area 6 NOT directly relate to?

Regulating emotional responses Signup and view all the answers

Which areas of the brain are primarily known as the motor cortex?

Area 4 and Area 6 Signup and view all the answers

What is the significance of Wilder Penfield's work in relation to the motor cortex?

He demonstrated the function of the motor cortex through electrical stimulation. Signup and view all the answers

What is the first step in goal-directed movement according to the understanding of motor planning?

Selecting a plan to reach the intended location. Signup and view all the answers

Which of the following is NOT specifically localized to different regions of the cerebral cortex?

Emotional response to movement. Signup and view all the answers

What role does memory play in the planning of movement?

Memory is essential for holding the selected plan until it is executed. Signup and view all the answers

Where is area 4 of the motor cortex located?

Just anterior to the central sulcus on the precentral gyrus. Signup and view all the answers

Which aspect of motor control is crucial for understanding where the body intends to go?

The knowledge of body position in space. Signup and view all the answers

Which cortical area is immediately anterior to area 4?

Area 6 Signup and view all the answers

What does behavioral neurophysiology primarily involve?

Recording cellular activity in the brain of awake, behaving animals Signup and view all the answers

Which of the following can be investigated using behavioral neurophysiology techniques?

Learning and perception Signup and view all the answers

Why are some types of human neurosurgery performed with patients awake?

To accurately assess brain function and responses Signup and view all the answers

What technical development has advanced the field of behavioral neurophysiology?

The ability to insert large numbers of microelectrodes Signup and view all the answers

What is a major challenge in neuroscience as mentioned in the content?

Understanding the relationship between brain activity and behavior Signup and view all the answers

What type of information can be gathered from the methods used in behavioral neurophysiology?

Massive amounts of information about brain activity Signup and view all the answers

Which skill has been specifically studied through behavioral neurophysiology in humans?

Complex problem-solving abilities Signup and view all the answers

What enables the investigation of various neuroscientific topics through altered tasks in behavioral neurophysiology?

Flexibility of the methods employed in research Signup and view all the answers

What kind of synapses are marked with a plus (+)?

Excitatory Signup and view all the answers

What role does the direct pathway of the basal ganglia play in movement initiation?

Enhances the initiation of desired movements Signup and view all the answers

Which neurons are tonically active at rest and inhibit the VL?

GPi neurons Signup and view all the answers

What happens when cortical activation excites putamen neurons?

They inhibit GPi neurons Signup and view all the answers

What effect does activity in VLo have on the SMA?

Boosts its activity Signup and view all the answers

What type of connections initiate the motor loop through the basal ganglia?

Excitatory connections from the cortex Signup and view all the answers

Which structure is directly excited by cortical cells in the basal ganglia's motor pathway?

Putamen Signup and view all the answers

In the direct pathway of the basal ganglia, which type of synapse do putamen cells make?

Inhibitory synapses on globus pallidus neurons Signup and view all the answers

What role do the globus pallidus cells play in the motor pathway through the basal ganglia?

They inhibit the cells in VLo Signup and view all the answers

What is the connection called that is made from VLo to SMA in the basal ganglia's motor loop?

Thalamocortical connection Signup and view all the answers

Which of the following circuits are NOT primarily involved in the motor functions of the basal ganglia?

Sensory circuits Signup and view all the answers

What is the primary function of the direct pathway through the basal ganglia?

Facilitating movement Signup and view all the answers

What is a notable characteristic of the complexities of the basal ganglia?

Contains many parallel circuits Signup and view all the answers

Study Notes

Descending Spinal Tracts

Two major groups of pathways carry signals from the brain to motor neurons in the spinal cord
Lateral pathways are for voluntary movement of distal muscles, under direct cortical control
Ventromedial pathways are for posture and locomotion, under brainstem control
Lateral pathways crucial component is the corticospinal tract
Originates in the neocortex, the longest and one of the largest central nervous system (CNS) tracts
Two-thirds of axons originate in areas 4 and 6 of the frontal lobe, collectively called the motor cortex
Somatosensory areas of the parietal lobe also contribute, regulating the flow of somatosensory information
Axons pass through the internal capsule, cerebral peduncle, pons, and form the medullary pyramid in the medulla
The pyramidal tract's triangular cross-section gives it its name

Planning of Movement by the Cerebral Cortex

Motor cortex is a region of the frontal lobe (areas 4 and 6)
Area 4 is primary motor cortex (M1), anterior to the central sulcus on the precentral gyrus
Area 6 lies anterior to area 4, including the premotor area (PMA) and supplementary motor area (SMA)
These areas are involved in the control of voluntary movement
Penfield electrically stimulated the cortex to identify regions vital for movement
Somatotopic organization in M1, similar to sensory areas

The Basal Ganglia

Major subcortical input to area 6, located within the telencephalon
Consists of caudate nucleus, putamen, globus pallidus (internal/external segments), and subthalamic nucleus
Involved in selection and initiation of willed movements
Striatum (caudate and putamen) is the target of cortical input
Globus pallidus sends output to the thalamus
Subthalamic nucleus and substantia nigra participate in side loops that modulate the main direct pathway

Initiating Movement by Primary Motor Cortex

Motor pathway begins in cortical layer V, with large pyramidal neurons (Betz cells)
Neurons in layer V project to ventral horns of the spinal cord
Excite extensor motor neurons, inhibit flexor motor neurons
Major inputs to layer V pyramidal cells are from other cortical areas (especially those adjacent to area 4) and the thalamus, specifically the ventral lateral nucleus (VLc), which relays information from the cerebellum

Coding of Movement in M1

Motor cortex consists of a detailed mapping of individual muscles
More recent studies show many motor neuron pools are controlled by individual pyramidal cells
Activity precedes movement, encoding force and direction
Movement direction is encoded by the collective activity of a population of neurons (population coding)

The Cerebellum

Crucial for precise motor control
Responsible for coordinated movements and accurate timing
Damage results in ataxia (uncoordinated/inaccurate movements), dyssynergia, and dysmetria

Paresis, Paralysis, Spasticity, and Babinski

Paresis is weakness
Paralysis is complete loss of movement
Spasticity is excessive muscle tone and hyperreflexia
Babinski sign: upward flexion of the big toe when the sole of the foot is stroked, indicating upper motor neuron damage

Mirror Neurons

Some neurons in motor areas respond when movement is performed/imagined.
Neurons also respond when observing another individual perform the same action, even a human
May be involved in understanding others' actions and intentions, empathy, and autism

Basal Ganglia Disorders

Parkinson's disease is characterized by slowness of movement, rigidity, and tremor, often affecting people over 60
Damage to dopamine-producing neurons in the substantia nigra
Huntington's disease (hereditary, progressive) is characterized by hyperkinesia, dementia, and personality disorder (usually after adulthood)
Damage to neurons in the caudate nucleus, putamen, and globus pallidus

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the motor control hierarchy and its components, from the highest levels of motor planning to the role of spinal interneurons. This quiz covers essential concepts about brain function, movement control, and reflexes. See how well you understand the intricacies of motor behavior!