Neurophysiology 4

Question 1

These are rapid reproducible automatic responses
- employs simple neural circuits involving peripheral nerves and spinal cord
- does not require involvement of higher brain centres

Answer 1

Reflex movements

Question 2

These are variable complex and voluntary responses
- typically involves complex patterns of sensory and motor processing
- initiated on demand in brain and higher centres involved in control

Answer 2

Voluntary movements

Question 3

This modifies the voluntary and reflexive motor patterns at the subconscious level

Answer 3

Basal nuclei

Question 4

This plans and initiates voluntary motor activity *keyword VOLUNTARY / plan and initiates!

Answer 4

Cerebral cortex

Question 5

This controls reflex motor patterns related to eating, drinking, sexual activity.

It can also modify respiratory reflexes.

*keyword: CONTROLS reflex motor pattern

Answer 5

Hypothalamus

Question 6

This controls balance reflexes and more complex respiratory reflexes

Answer 6

Pons and medulla oblongata

Question 7

This part of the brain is mainly involved in executive functions (such as cognitive function, social behaviour, active recall, and planning)

• it also organises thoughts and actions

Answer 7

Prefrontal cortex

Question 8

Where is the primary motor cortex found?

Answer 8

Precentral gyrus

Question 9

Where does the desire to initiate a movement arise?

Answer 9

Prefrontal cortex

Question 10

How are skeletal muscles activated during voluntary movement?

Answer 10

Spinal cord motoneurons

Question 11

Why are motor neurons modulated when sensory information is fed back into the system? (for voluntary movement)

Answer 11

To modify and control the movement according to what you specifically want to do

Question 12

What motor-related regions of the cortex are activated during voluntary movement?

Answer 12

The descending pathways, motoneurons in the spinal cord (for skeletal muscles)

Question 13

The basal nuclei adjust patterns of movement by:

Answer 13

• altering the sensitivity of pyramidal cells (so that they can travel along the corticospinal tract)
• change the excitatory/inhibitory output of the medial/lateral pathways

Question 14

This helps plan, execute and learn motor programs. It integrates sensory information with planned events.

• organises timing of muscle contraction
• compares result of planned movement with actual result (crucial for error correction)
• modifies on going activity to make movement smooth and accurate

Answer 14

Cerebellum

Question 15

What disorder comes as a result of having an “abnormal” cerebellum?

Answer 15

Ataxia - affects coordination

Question 16

What is the voluntary motor control loop?

Answer 16

Prefrontal cortex – premotor cortex –primary motor cortex (with modifications from basal nuclei and cerebellum) – lower motor neurons

Question 17

This encodes the direction of movement. Or where the AP will go

Answer 17

Primary motor cortex