NEET Medical PG 2014

Question 1

A 62-year-old woman has a neoplasm of the left coracoid process completely compressing the axillary artery. However, the left radial arterial pulse is normal. An anastomotic connection between which of the following arteries best explains this finding?

• Anterior and posterior humeral circumflex arteries
• Subscapular and brachial arteries
• Subscapular and posterior humeral circumflex arteries
• Suprascapular and subscapular arteries
• Thoracoacromial and supreme thoracic arteries

In this case, the axillary artery is being compressed in its second part. Therefore, the anastomotic connection must be between a branch from the first part of the axillary artery, or the subclavian artery, and a branch from the third part of the axillary artery, or the brachial artery. Answer 4 is the only one that fits this requirement. The suprascapular artery is a branch of the thyrocervical trunk of the subclavian artery. It would anatomose with branches of the circumflex scapular artery, which is a branch of the subscapular artery. The subscapular artery is a branch of the third part of the axillary artery.

Question 2

A 32-year-old woman has periods of numbness of the skin covering the proximal portion of her thenar eminence. Which of the following findings will confirm the most likely diagnosis?

• Atrophy of the dorsal interosseous muscles of the hand
• Decreased strength during extension of the thumb
• Loss of sensation to the skin covering the medial aspect of the hand
• Loss of sensation to the skin of the little finger
• Weakness on attempting to compress a marble between the thumb and little finger

The cutaneous deficit reported by this patient suggests a median nerve problem. If this is the case, the patient should also have weakness or inability in flexion and opposition of the thumb. Thus, the answer describing weakness on attempting to compress a marble between the thumb and little finger would be correct. Answers 1, 3, and 4 are ulnar nerve problems, and answer 2 is a radial nerve problem.

Question 3

A 42-year-old man has impingement of the ulnar nerve at the elbow. To repair this problem, he is undergoing a medial condylar osteotomy. During the procedure, the muscular attachments to the medial epicondyle are accidentally cut. Which of the following muscles has been damaged?

• Supinator
• Flexor carpi radialis
• Brachioradialis
• Extensor carpi ulnaris
• Flexor pollicis longus

Muscles in the superficial layer of the anterior compartment of the forearm attach to the medial epicondyle of the humerus. These include the flexor carpi radialis (correct answer), palmaris longus, flexor carpi ulnaris, and pronator teres muscles.

Question 4

A 17-year-old boy suffered a severe laceration of his distal forearm. To check the ulnar pulse, the emergency department physician would palpate in which of the following locations?

• Lateral to the tendon of the flexor carpi ulnaris
• Lateral to the tendon of the flexor digitorum superficialis
• Lateral to the tendon of the palmaris longus
• Medial to the tendon of the flexor carpi ulnaris
• Medial to the tendon of the palmaris longus

The ulnar pulse is palpated lateral to the tendon of the flexor carpi ulnaris, answer 1. The radial pulse is palpated lateral to the tendon of the flexor carpi radialis.

Question 5

A 17-year-old boy is unable to extend his hand after being struck on the posterior aspect of his arm with a lacrosse stick, and there is loss of sensation in a small area on the dorsum of his hand. An x-ray film of the arm shows a midhumerus fracture. Which of the following nerves is most likely damaged?

• Axillary
• Median
• Musculocutaneous
• Radial
• Ulnar

A fracture in the middle of the humerus usually involves the radial groove, which the radial nerve occupies as it moves around the lateral aspect of the humerus. Thus, the radial nerve can be injured. The physical findings in this patient of a loss of sensation on the dorsum of his hand suggests the radial nerve has been injured.