Myotomes

Dr. Morton explains the brachial plexus, focusing on myotomes and peripheral nerves. The tutorial covers the motor deficits from injuries to spinal roots versus peripheral nerves, detailing the C5 to T1 spinal levels and their associated actions. Practice questions help reinforce understanding of nerve injuries and their effects on motor function. The video concludes with tracing sensory and motor neurons, emphasizing the importance of understanding myotomes and peripheral nerves.

What is the primary function of a myotome?

• To supply sensory neurons to the skin

• To transport blood to the muscles

• To supply motor neurons to a group of muscles

• To connect the brain to the spinal cord

Which nerve is responsible for shoulder abduction?

• Radial nerve

• Median nerve

• Axillary nerve

• Ulnar nerve

What would happen if the ulnar nerve is injured?

• No change in wrist flexion

• All wrist flexion would be lost

• Complete loss of elbow extension

• Some wrist flexion would be affected

Which spinal cord level is primarily responsible for wrist flexion?

• C8

• C7

• C6

• C5

If the C6 spinal cord level is injured, which reflex would be lost?

• Brachioradialis reflex

• Biceps reflex

• Triceps reflex

• Patellar reflex

Which nerve is primarily responsible for sensation in the thumb?

• Ulnar nerve

• Musculocutaneous nerve

• Median nerve

• Radial nerve

What is the impact of injuring a peripheral nerve?

• Loss of strength in all associated muscles

• Loss of strength in a specific myotome

• Complete paralysis of the limb

• No impact on muscle strength