BRS: Gross Anatomy Examination

BRS: Gross Anatomy Examination If a stab wound lacerated the posterior humeral circumflex artery passing through the quadrangular space on the shoulder region, which of the following nerves would be injured? A) Radial nerve B) Axillary nerve C) Thoracodorsal nerve D) Suprascapular nerve E) Accessory nerve - answer-B) The axillary nerve runs posteriorly to the humerous, accompanying the posterior humeral circumflex artery through the quadrangular space and innervating the teres minor and deltoid muscles - none of the other nerves pass through the quadrangular space A victim of an automobile absent is unable to abbduct her left arm. This indicated damage to which of the following parts of the brachial plexus? A) Middle trunk & posterior cord B) Middle trunk & lateral cord C) Lower trunk & lateral cord D) Upper trunk & posterior cord E) Lower trunk & medial cord - answer-D) Both upper trunk and posterior cord are damaged - abductors of the arm are deltoid (axillary nerve from posterior cord) and supraspinatus (suprascapular nerve from upper trunk) - middle and lower trunk give rise to no branches - lateral and medial cords supply no abductors of the arm In order for an engineer to construct a prosthetic arm, he will need to know that which of the following muscles flexes the elbow and is innervated by the radial nerve? A) Flexor digitorum longus B) Brachioradialis C) Brachialis D) Extensor digitorum longus