Posterior Triangle of the Neck Practice Questions and Answers 100% Pass

Posterior Triangle of the Neck Practice Questions and Answers 100% Pass A muscular patient who regularly lifts weights presents with pain and weakness in his right upper limb that has been slowly developing over time. His limb is cool and there is an obvious vascular insufficiency in his upper extremity. Subsequent tests show that a large vessel passing between the anterior and middle scalene muscles is being occluded by hypertrophy (enlargement) of the muscles due to the excercise. The artery involved is the: - Answer- Subclavian The subclavian artery runs between the anterior and middle scalene muscles. Since this is the major artery supplying blood to the upper limb, occluding this artery might cause the symptoms of pain and weakness. This patient has a thoracic outlet syndrome, which means that one of the arteries or nerves that is passing from the thoracic outlet into the upper limb or or lower neck is being compressed. In repairing a damaged right subclavian artery, the surgeon notices and protects a large nerve passing around to the posterior surface of the artery. This nerve, which does not encircle the subclavian on the left side, is the: - Answer- Recurrent laryngeal The recurrent laryngeal nerves have different relationships to structures on the right and left sides of the body. On the right side, the recurrent laryngeal nerve loops around the right subclavian artery at approximately the T1/T2 vertebral level. On the left side, the recurrent laryngeal nerve loops around the arch of the aorta, behind the ligamentum arteriosum, at approximately the T4/T5 level. A stab wound just above the left clavicle, lateral to the sternocleidomastoid muscle, may be life-threatening because of the possibility of injury to the: - Answer- subclavian artery The subclavian artery crosses between the anterior and middle scalene muscles, which means that it is also posterior to the sternocleidomastoid muscle. Lateral to the sternocleidomastoid muscle, the subclavian artery runs just above the clavicle. Eventually, this artery descends toward the upper limb. So, it is in the right position to be injured in the stabbing. The question also mentions that the wound was life-threatening, so you should really be looking for an answer about an artery. The brachial plexus is also in the area of the stab wound, but a brachial plexus injury would not be life-threatening. A 27-year-old man who is a professional weight lifter comes to his physician complaining of recent weakness in his left arm and frequent tingling in his hand and fingers during exercise sessions which subsides with rest. He is diagnosed as having vasuclar insufficiency due to scalenus anticus syndrome and as a remedy it is decided to transect the anterior scalene muscle where it inserts on the first rib. During surgery, which structure in contact with the anterior surface of the muscle must the surgeon be careful of sparing? - Answer- Phrenic nerve The phrenic nerve is formed from contributions from the C3, 4, and 5 ventral primary rami. It lies on the anterior scalene muscle, which means that the surgeon would need to watch for this nerve while transecting the anterior scalene. A 60-year-old man with a previous history of right carotid endarterectomy, comes to his physician complaining of light-headedness and dizziness whenever he uses his right hand vigorously. He is diagnosed as having subclavian steal syndrome due to an atherosclerotic plaque at the point where his subclavian artery branches from the brachiocephalic trunk. The cerebral insufficiency is the result of blood being stolen from which artery? - Answer- Vertebral Subclavian steal syndrome occurs when there are abnormal blockages in vessels coming off of the aortic arch. Due to these blockages, there may be low blood flow to one arm through the subclavian artery. During high activity in the underperfused arm, the body needs to find a way to send blood to the arm to meet metabolic demands. It does this by shunting blood from the vertebral arteries.