Neural Circuits

Question 1

Pyramidal (corticospinal) tract

Answer 1

Main pathway for voluntary movement control

Question 2

Upper Motor Neurons

Answer 2

Originate in the cerebral cortex or brainstem with lower motor neurons
Voluntary movement

Question 3

Corticobulbar Tract

Answer 3

Connects the cerebral cortex to the brainstem nuclei of cranial nerves
Controls voluntary movements of muscles in the face, head and neck.

Question 4

Lower Motor Neurons

Answer 4

Connect UMNs to skeletal muscles, forming motor units
Voluntary and involuntary

Question 5

Reflex Arc

Answer 5

Bypasses the brain
Involves sensory neurons, spinal cord and motor neurons
Produces rapid, automatic responses
Involuntary

Question 6

Neural Circuit

Answer 6

Network of interconnected neurons that process specific types of information to carry out particular functions when activated

Question 7

Functions of neural circuits

Answer 7

• process various types of information
• adapt to new experiences
• coordinate complex behaviors

Question 8

Neural pathways in motor control

Answer 8

Pyramidal tracts
Extrapyramidal tracts

Question 9

Pyramidal and Extrapyramidal tracts transmit motor commands from the _ to the _ to the _

Answer 9

Brain, spinal cord, muscles

Question 10

How are neural circuits laid out?

Answer 10

Multiple layers of neurons with feedback loops.
Allows for dynamic interactions and adjustments

Question 11

What are neural circuits involved in?

Answer 11

Processing and integrating information
Allowing for complex responses

Question 12

Are neural circuits specialised or do they serve broader functions?

Answer 12

Each neural circuit is often specialised for a particular task.
Adapting its output based on the context

Question 13

What happens if there is dysfunction in neural circiuts?

Answer 13

Various neurological conditions

Question 14

Layout of Neural Pathways

Answer 14

More linear than circuits
Consisting of direct connects that do not typically involve feedback mechanisms

Question 15

What is the primary focus of neural pathways?

Answer 15

Transmitting signals between different regions without significant processing

Question 16

Are neural pathways specialised or do they serve broader functions?

Answer 16

Serve broader functions related sensory input or motor input without being dedicated to specific tasks

Question 17

What happens if there is damage to neural pathways?

Answer 17

Damage to specific pathways can lead to sensory deficits.

Question 18

The neural circuits responsible for the control of movement can be divided into …

Answer 18

Four distinct, highly interactive subsystems:
* Local circuits
* Upper motor neurons circuit
* Cerebellar circuits
* Basal ganglia circuits

Question 19

Location of local circuits

Answer 19

Within the grey matter of the spinal cord

Question 20

Components of local circuits

Answer 20

Lower motor neurons
Local circuit neurons

Question 21

Function of local circuits

Answer 21

Responsible for reflex actions and basic motor control, coordinating movements at the level of the spinal cord

Question 22

Pathways used by local circuits

Answer 22

Spinal reflex pathways
They receive inputs from sensory pathways and descending pathways from upper motor neurons

Question 23

Diseases associated with local circuits

Answer 23

Multiple sclerosis
Cervical spondylotic myelopathy
Traumatic spinal cord injury

Question 24

Location of upper motor neurons circuit

Answer 24

Primarily in motor cortex, premotor cortex and brainstem nuclei

Question 25

Components of upper motor neurons circuit

Answer 25

Neurons with cell bodies in brainstem or cerebral cortex axons descending to synapse with local circuit neurons

Question 26

Function of upper motor neurons circuit

Answer 26

Initiation of voluntary movements, control of complex movement

Question 27

Pathways connected to upper motor neurons circuit

Answer 27

Corticospinal Tract Corticobulbar Tract Corticorubal, Corticotectal and Corticoreticular Tracts

Question 28

Corticospinal tract

Answer 28

Directly connects the primary motor cortex to spinal cord lower motor neurons.

Question 29

Corticobulbar Tract

Answer 29

Connects the motor cortex to cranial nerve nuclei in the brainstem for facial and neck muscle control.

Question 30

Corticorubral, Corticotectal, and Corticoreticular Tracts

Answer 30

Modulate other pathways like rubrospinal, tectospinal, and reticulospinal tracts

Question 31

Diseases associated with upper motor neurons circuit

Answer 31

Amyotrophic Lateral Sclerosis (ALS) Primary Lateral Sclerosis (PLS) Stroke

Question 32

Location of cerebellar circuits

Answer 32

In the cerebellum at the back of the brain

Question 33

Function of the cerebellar circuits

Answer 33

Detects and corrects motor error between intended and performed movements

Question 34

Circuit of the cerebellar circuits

Answer 34

Acts via afferent pathways to upper motor neurons

Question 35

Pathways connected to the cerebellar circuits

Answer 35

Receives inputs from various sensory systems (via pontine nuclei) and sends outputs to upper motor neurons via thalamic relay nuclei

Question 36

Diseases associated with Cerebellar circuits

Answer 36

Cerebellar ataxia Some symptoms in Parkinson's disease Huntington's disease

Question 37

Location of basal ganglia circuits

Answer 37

Embedded in the depths of the forebrain

Question 38

Function of basal ganglia circuits

Answer 38

Regulates initiation and inhibition of movement Involved in action selection and learning motor skills Suppresses unwanted movements Primes upper motor neuron circuits for movement initiation

Question 39

Pathways connected to the Basal ganglia circuits

Answer 39

The striatum sends output to both the direct pathway (facilitating movement) and indirect pathway (inhibiting unwanted movements) affecting thalamic activity that influences upper motor neurons. Corticostriatal pathway is interconnected with the cortex for feedback loops

Question 40

Diseases associated with the basal ganglia circuits

Answer 40

Parkinson's Huntington's

Question 41

Myotatic Reflex Mechanism:

Answer 41

Neural circuit where muscle spindle afferents detect stretch and directly activate alpha motor neurons, resulting in muscle contraction. This rapid response is crucial for maintaining posture and balance, demonstrating the efficiency of spinal reflex pathways in motor control.

Question 42

Baroreceptor Reflex Functionality:

Answer 42

Integration of sensory input and autonomic motor output Baroreceptors in blood vessels detect pressure changes and modulate heart rate and vascular resistance. This reflex is vital for cardiovascular stability, ensuring adequate blood flow during physical activity and stress