Lecture 9 - Types Of Movement

Question 0

Which regions are responsible for planning of movement?

Answer 0

Basal ganglia

Question 1

Differentiate between reflex, voluntary and rhythmic movement, giving examples of each

Answer 1

Reflex: subconscious, happens immediately. Eg. Knee jerk

Voluntary: cortical decision to move. Eg. Reaching

Rhythmic: cortical decision to initiate the movement, but pattern generator controls the movement eg. Running

Question 2

Which region is deals with initiation of movement?

Answer 2

Motor cortex

Question 3

Which region is responsible for execution of movement?

Answer 3

Muscles

Question 4

Which movements require cortical integration, and which don’t?

Answer 4

Do: voluntary

Don’t: postural, reflex, pattern

Question 5

What is the role of the cerebellum in movement?

Answer 5

Optimisation of movement

Question 6

Describe how maintenance of posture requires feed forward information

Answer 6

Before a movement is effected, the body alters posture so that when the movement occurs, one is not unbalanced.

Think of the pulling on a fixed bar at the sound of a tone experiment:

• when the tone is heard, the muscles in the calves adjust before the biceps contract.
• this is to stabilise movement

Question 7

Describe the role of muscle spindle

Answer 7

Detects stretch in muscle
Sends information to the spinal cord
Alpha motor neuron is activated
The muscle in question contracts

Question 8

Describe the role of the gamma motor neuron

Answer 8

It innervates the muscle spindle, causing it to contract as the extrafusal muscle fibres contract. This maintains the firing rate of the spindle, making sure it doesn’t slacken

Question 9

In addition to the muscle spindle, what also controls the alpha and gamma motor neuron pathways?

Answer 9

Descending control from the brain

Question 10

What is the role of the Golgi tendon organs?

Answer 10

Detecting force in a muscle

Question 11

What is the structure of the Golgi tendon organs?

Answer 11

Diffuse nerve endings embedded in collagen of the tendon

Question 12

Describe what happens in the muscle spindle reflex. Eg, holding a glass and water is poured in

Answer 12

Q

Question 13

Describe the Golgi tendon reflex. Eg. Holding a load that is too heavy

Answer 13

1. When more weight is added, the Golgi tendon organ detects that the force of the muscle is high.
2. This sends information to the spinal cord
3. Motor neuron inhibited, muscle relaxes
4. Load is dropped, protecting the muscle

Question 14

Describe the patellar tendon reflex

Answer 14

1. Hammer hits the patella, stretching the muscle
2. Spindle detects stretch and sensory afferent delivers this information to the spinal cord
3. Alpha motor neuron for extensor activated, flexor motor neuron inhibited
4. Extensor Muscle contracts, flexor muscle is relaxed
5. Leg extends

Question 15

Describe the crossed extension reflex

Answer 15

1. Tread on a pin with the right leg
2. Nociceptor afferent sends information to the spinal cord
3. Alpha motor neurons activated or inhibited
4. Leg that trod on pin flexes, other leg extends to support the person