Motor pathways

Question 1

3 categories of skeletal motor system

Answer 1

Locomotion, manipulation and communication

Question 2

The musculoskeletal system

Answer 2

Complex set of interacting elements (joints, anchorages, levers and actuators)

Question 3

Motor nerves

Answer 3

• Run from SC to muscles
• Control actions
• Cervical and lumbar enlargements which help to move the arms and legs

Question 4

Neuromuscular junction

Answer 4

Specialised synapse transferring signals from the CNS to muscles. Sits in a pit on the surface of the muscle cell.

Question 5

What is the primary motor complex?

Answer 5

• Strip of tissue anterior to the central sulcus
• Can also be called pre-central gyrus, area 4 or M1
• Causes activation of muscles
• Areas of M1 are devoted to hands, fingers, face and throat

Question 6

The corticospinal tract

Answer 6

Output of the human motor system controlling skilled movements. Forms part of the internal capsule, cerebral peduncles and pyramids.

Question 7

How much of each area contributes to the corticospinal tract?

Answer 7

• M1 controls 30%
• Supplementary and pre-motor also control 30%
• Somatosensory (S1) controls 60%

Question 8

Corticospinal motoneurons

Answer 8

Control forearm and hands

Question 9

Motor cortex

Answer 9

Codes for movement, force and direction

Question 10

Basal ganglia

Answer 10

Associated with movement disorders (Parkinson’s disease) and modulates voluntary movements

Question 11

Cerebellum

Answer 11

Generates smooth, co-ordinated sequences of muscle interactions and damage to the cerebellum can affect these movements

Question 12

Brainstem

Answer 12

Nuclei involved in control of innate behaviour (posture) and controls speed of locomotion

Question 13

Spinal cord (SC)

Answer 13

Contains circuits that generate patterns for locomotion