Quiz for Week 30 - Questions
Question 1. Sketch the brachial plexus.
Question 2. A rigger falls from a platform and catches himself by his right hand on a
beam. The traction ruptures T1 nerve root. What disability will result?
Question 3. A drunk sleeps with his arm over a park bench and compresses his
radial nerve on the posterior aspect of his humerus. What will be his symptoms on
awakening?
Question 4. Identify the structures normally visible and palpable at the wrist.
Question 5. Describe the different types of nerve fibres.
Question 6. Define the terms neurapraxia, neurotmesis and axonotmesis, and
describe how they arise.
Question 7. Identify the major impacts which alcohol abuse has on the health care
system.
Question 8. What are the options to support a patient who has lost earning capacity
due to an accident or injury? How do these differ when the injury occurs in private
time versus work time?
Question 9. What principles underlie the rehabilitation by physiotherapists and
occupational therapists of a patient with a nerve palsy which may recover in time?
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DON’T TURN THE PAGE UNTIL YOU HAVE WORKED ON THESE QUESTIONS
IN MONDAY’S PBL TUTORIAL, OR ATTEMPTED WRITTEN ANSWERS
YOURSELF.
Quiz for Week 30 – Answer Guide
Question 1. Sketch the brachial plexus.
This is one of the basic tasks in learning the anatomy of the nerve supply to the upper limb.
The nerve roots need to be correctly identified, as well as the major nerves emerging from
the plexus.
Question 2. A rigger falls from a platform and catches himself by his right hand on a
beam. The traction ruptures T1 nerve root. What disability will result?
T1 is distributed to the intrinsic muscles of the hand, through the ulnar nerve. Sensory
supply to the skin through T1 to the medial aspect of the arm and forearm will be affected.
Question 3. A drunk sleeps with his arm over a park bench and compresses his
radial nerve on the posterior aspect of his humerus. What will be his symptoms on
awakening?
This can be deduced from the knowledge that the radial nerve supplies the triceps,
brachioradialis, supinator and extensor muscles of the digits. It supplies sensation to the
posterior arm and forearm, plus the lateral two thirds of the dorsum of the hand.
Question 4. Identify the structures normally visible and palpable at the wrist.
On the flexor surface, flexor carpi radialis, palmaris longus, flexor digitorum superficialis and
flexor carpi ulnaris are conspicuous cords. The relations of these landmarks to the arteries
and nerves should be identified. On the lateral surface, the abductor pollicis longus, extensor
pollicis brevis and extensor pollicis longus are seen.
Question 5. Describe the different types of nerve fibres.
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•
•
Group A fibres include the largest myelinated somatic afferent and efferent fibres and
have the highest conduction velocity.
Group B fibres are myelinated pre-ganglionic fibres
Group C fibres are thin, non-myelinated, visceral and somatic pain fibres
Question 6. Define the terms neurapraxia, neurotmesis and axonotmesis, and
describe how they arise.
•
•
Neurapraxia is failure of conduction of a nerve in the absence of structural damage
resulting in numbness, tingling and weakness. It is usually caused by compression of the
nerve.
Neurotmesis is the complete severance of a peripheral nerve and is associated with
degeneration of the nerve fibre distal to the point of severance and slow nerve
regeneration.
•
Axonotmesis is the rupture of nerve fibres (axons) within an intact nerve sheath as a
result of prolonged pressure or crushing. It is followed by degeneration of the nerve
beyond the point of rupture but the prognosis for nerve regeneration is good.
Question 7. Identify the major impacts which alcohol abuse has on the health care
system.
Alcohol abuse is a major factor in or cause of:
• Domestic violence;
• Family and other personal relationships
• Employment–related performance
• Street- and pub-brawls
• MVAs
• Liver disease (cirrhosis)
• Neuropsychiatric impairment
Question 8. What are the options to support a patient who has lost earning capacity
due to an accident or injury? How do these differ when the injury occurs in private
time versus work time?
This is an opportunity for the students to review the social security system and the relativities
between disability benefits and worker’s compensation payments.
Question 9. What principles underlie the rehabilitation by physiotherapists and
occupational therapists of a patient with a nerve palsy which may recover in time?
The central principle is to maintain mobility: if the limb is neglected while waiting for
regeneration, the stiffness of joints due to capsule tightening may become so severe that
mobility cannot be restored later, even though the nerve has regenerated. OTs are skilled in
application of splintage and other aids, which prevent contractures and maximise function,
as well as reorganising the environment and possibly the patient’s work around their
disability.