Anatomy Flashcards

A patient cannot dorsiflex or evert the foot after a fibular neck fracture. Which nerve is injured?

Answer: Common fibular (peroneal) nerve

The common fibular nerve winds around the fibular neck and innervates muscles responsible for dorsiflexion and eversion; its injury causes foot drop.

Which coronary artery most commonly supplies the sinoatrial (SA) node?

Answer: Right coronary artery

In approximately 60% of individuals the SA nodal artery is a branch of the right coronary artery.

The femoral triangle contains all of the following EXCEPT:

Answer: Obturator nerve

The femoral triangle contains the femoral nerve, artery, and vein (lateral to medial: nerve, artery, vein); the obturator nerve exits through the obturator foramen medially.

Which muscle forms the floor of the anatomical snuffbox?

Answer: Scaphoid bone

The scaphoid bone (and trapezium) forms the floor of the anatomical snuffbox, and tenderness there after a fall suggests a scaphoid fracture.

Which structure is at greatest risk when the long thoracic nerve is damaged?

Answer: Serratus anterior

The long thoracic nerve innervates the serratus anterior; its damage causes winging of the scapula because the muscle can no longer hold the scapula against the thoracic wall.

The calot triangle (cystohepatic triangle) contains the:

Answer: Cystic artery

The cystic artery is the key structure found within the triangle of Calot, formed by the cystic duct, common hepatic duct, and liver edge.

A lesion of the medial longitudinal fasciculus (MLF) produces which classic finding?

Answer: Internuclear ophthalmoplegia

An MLF lesion disrupts communication between CN VI and contralateral CN III nuclei, causing internuclear ophthalmoplegia with impaired adduction ipsilaterally and nystagmus contralaterally.