Neuroanatomy & physiology

Question 1

What 3 factors affect movement, according to the systems theory, and give examples of each

Answer 1

Interaction of task, individual and environment.
Many systems, subsystems and multiple connections within the nervous system working in parallel and hierarchy to produce movement

1. nature of task
   - functional, mobility task
2. resources of the individual
   - perception, cognition
3. characteristics environment
   - temperature, light

Question 2

What is a reflex?

Answer 2

The most elementary of motor co-ordination

Stereotyped response to a specific sensory stimulus

Question 3

What are spinal reflexes and what is the role of them?

Answer 3

Spinal reflexes are those which act through the spinal cord.
Neural circuitry is responsible and occurs entirely within the spinal cord
Receives sensory information from muscles, joints and skin
Essential in voluntary action.

Question 4

What is a stretch reflex and what is its role?

Answer 4

A simple monosynaptic reflex

Has a role in regulating muscle tone and posture and producing smooth movement

Question 5

What is motor learning?

Answer 5

Motor learning is how we learn new movement patterns in healthy people
Many brain structures involved

Question 6

What are 2 types of learning?

Answer 6

1. Habituation – learned suppression of a non-noxious response
   Decrease in synaptic activity
   E.g learning not to respond to a previously meaningful stimulus
2. Sensitisation – increased response to one stimulus that is consistently preceded by a noxious stimulus
   Increase in synaptic activity
   E.g. a dog getting really excited about going for a walk when you pick up your coat

Question 7

What are the 3 stages of motor skill learning as proposed by Fitts and Posner (1967)

Answer 7

1. Cognitive phase
2. Associative phase
3. Autonomous phase

Question 8

What factors enhance motor learning?

Answer 8

1. Practice
   - More is better
   - Massed v distributed practice
2. Specificity
   - Be task specific
3. Transferability
   - Whole v part training
4. Feedback
   - External focus but move from external to internal feedback
   - Knowledge of results rather than knowledge of performance
5. Mental Practice

Question 9

What is neuroplasticity?

Answer 9

The ability of the brain to adapt and re-learn.
This applies to both normal nervous systems and those affected by injury or disease
It gives us the ability to learn and to adapt to changing environments and also the possibility of recovery following injury or disease.

Question 10

What is Wallerian Degeneration?

How long does it last and how quickly does it repair?

Answer 10

process of degeneration that results when a nerve fiber is cut or crushed and the part of the axon distal to the injury degenerates.
Lasts for3-4 days
Regenerationbegins to occur at7 days
Growth occurs at1-4mm a day

Question 11

Explain what diaschisis and oedema are

Answer 11

Diaschisis is a sudden change of function in a portion of the brain connected to a distant but damaged brain area.
Oedema is a condition characterized by an excess of watery fluid collecting in the cavities or tissues of the body.
They both cause a temporary disruption of neural function due to shock of injury or disease.
Oedema is common around the brain following injury.
Again can be local or remote

Question 12

Name the 6 mechanisms of plasticity

Answer 12

Denervation Supersensitivity
Unmasking of silent synapses
Synaptogenesis
Collateral sprouting
Short and long term potentiation
Cortical remapping

Question 13

Explain what denervation supersensitivity is and when it occurs

Answer 13

Denervation refers to the loss of nerve supply.
Occurs when there is a loss of input from another area of the brain
The post synaptic membrane becomes more sensitive to the release of neurotransmitter

Question 14

How can the unmasking of silent synapses affect plasticity?

Answer 14

During recovery, previously unused synapses are recruited

Question 15

Explain what Synaptogenesis (Regenerative) is.

Answer 15

Synaptogenesis is the formation of synapses between neurons in the nervous system.
This occurs within 3 to 7 days of injury

Question 16

What is Collateral Sprouting (reactive synaptogenesis)

Answer 16

Neighbouring, uninjured axons sprout to innervate synaptic sites previously activated by the injured neuron

Question 17

What is Short term potentiation?

Answer 17

A change in the performance or output of a synapse in the short term – minutes to hours
An increase in synaptic strength due to increase in neurotransmitter production

Question 18

What is Long term potentiation?

Answer 18

Change in the performance or output of a synapse in the long term – weeks, months, years
Related to increase in pre-synaptic neurotransmitter release and structural change of the post-synaptic structure

Question 19

What is Cortical Remapping?

Answer 19

A process by which an existing cortical map is affected by a stimulus resulting in the creating of a ‘new’ cortical map.

Question 20

What factors enhance/effects neuroplasticity?

Answer 20

Repetition or practice (1000 reps)
Early intervention
Salience
Motivation
Feedback
Attention

Question 21

What are the most common causes of Peripheral Nerve injury?

Answer 21

Stretch related – e.g. Erb’s palsy
Lacerations – e.g. knife injury
Compressions – e.g. Saturday night palsy

Question 22

What are peripheral nerve injuries?

Answer 22

Peripheral nerve injuries re where one or more peripheral nerves are damaged, leading to neurological deficits distal to the level of the lesion

Question 23

What are some signs and symptoms of peripheral nerve injury?

Answer 23

Numbness
Tingling
Pins and needles
Weakness
Total loss of sensation (anaesthesia)

Question 24

What are the best methods to treat a peripheral nerve injury?

Answer 24

Maintain range – exercise and splinting
Education – loss of sensation
Monitoring recovery