This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'Injury to radial nerve in lower part of spiral groove- \nSelect and explain. \nA. Spares nerve supply to extensor carpi radialis longus, B. Results in paralysis of anconeus muscle, C. Leaves extensions at elbow joint intact, D. Weakens pronation movement', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Radial nerve injury\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 High radial nerve palsy- Injury above the spiral groove.\n\n\xa0 \xa0Paralysis of all muscles supplied by radial nerve.\n\xa0 \xa0Clinical features\n\n§\xa0 Wrist drop, finger drop, thumb drop\n§\xa0 Extension affected of- elbow, wrist, thumb and fingers\n§\xa0 Sensation affected of- posterior surface of arm and forearm and lower lateral half of forearm.\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Low radial nerve palsy- Injury below the spiral groove.\n\n\xa0 \xa0Type I- Injury between spiral groove and elbow.\n\n§\xa0 Elbow extensors are spared- Triceps and Anconeus.\n§\xa0 Wrist, thumb and finger extensors paralysed- wrist drop, thumb drop, finger drop.\n§\xa0 Loss of sensation on dorsal side of first web space.\n\n\xa0 \xa0Type II- Injury below the elbow joint.\n\n§\xa0 Elbow and wrist extensors spared\n§\xa0 Thumb and finger extensors paralysed.(extensor digitorum, extensor digiti minimi, extensor indicis, extensor pollicis longus, extensor pollicis brevis)- Thumb drop and finger drop.\n\xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0 \xa0\xa0§\xa0Loss of sensation on dorsal side of first web space.', 'role': 'assistant'}]