This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
Median nerve injury at the wrist leads to all except: 
Select and explain. 
A. Loss of function of the lumbrical to the index finger, B. Loss of function of the lumbrical to the middle finger, C. Effect on muscles on the thenar eminence, D. Loss of adduction of the thumb
D: Loss of adduction of the thumb
Answer: D: Loss of adduction of the thumb 
Explanation: Ans. D. Loss of adduction of the thumba. Adduction of thumb is carried out by the adductor pollicis, which is a deep muscle of the thumb and is supplied by the deep branch of ulnar nerve. Hence, in median nerve injury it remains functional and there is no loss of adduction of thumb.b. Lumbricals to the index and middle finger are supplied by the median nerve and have lost their function in this injury.c. Thenar muscles are mainly innervated by the median nerve and are paralyzed in this patient.