Anatomy Flashcards
7 cards from real USMLE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Anatomy flashcards as text
A patient sustains a fibular neck fracture and subsequently develops foot drop with loss of sensation over the dorsum of the foot. Which nerve was most likely injured?
Answer: Common fibular (peroneal) nerve
The common fibular nerve winds superficially around the fibular neck, making it highly susceptible to injury; it innervates dorsiflexors and evertors of the foot, and its injury produces foot drop.
Which of the following structures correctly passes through the inguinal canal in males?
Answer: Ilioinguinal nerve and spermatic cord
In males, the inguinal canal transmits the spermatic cord along with the ilioinguinal nerve; in females, the round ligament of the uterus passes through instead of the spermatic cord.
When performing a lumbar puncture at L4-L5, which sequence of structures does the needle correctly traverse from superficial to deep?
Answer: Skin → supraspinous ligament → interspinous ligament → ligamentum flavum → epidural space → dura mater → subdural space → arachnoid mater → subarachnoid space
A lumbar puncture needle traverses in order: skin, supraspinous ligament, interspinous ligament, ligamentum flavum, epidural space, dura mater, subdural space, and arachnoid mater before entering the subarachnoid space.
A patient develops a 'winged scapula' following a radical mastectomy with axillary dissection. Which nerve was most likely damaged during the procedure?
Answer: Long thoracic nerve
The long thoracic nerve innervates the serratus anterior; its injury during mastectomy or axillary dissection causes winging of the scapula as the medial border protrudes from the thoracic wall.
The sinoatrial (SA) node receives its arterial supply from the SA nodal artery, which arises from which vessel in approximately 60% of individuals?
Answer: Right coronary artery
In approximately 60% of individuals, the SA nodal artery arises from the right coronary artery; in the remaining ~40%, it arises from the left circumflex artery.
A patient presents with inability to initiate arm abduction—unable to abduct beyond 15 degrees—after an anterior shoulder dislocation. Which muscle was most likely injured?
Answer: Supraspinatus
The supraspinatus initiates the first 15 degrees of arm abduction by stabilizing the glenohumeral joint; injury prevents initiation of abduction even though the deltoid remains intact.
A patient develops a Pancoast tumor at the apex of the right lung and presents with ptosis, miosis, and anhidrosis on the right side of the face. Which structure is most likely being compressed?
Answer: Cervical sympathetic chain
Pancoast tumors compress the cervical sympathetic chain, interrupting the sympathetic pathway and causing ipsilateral Horner's syndrome (ptosis, miosis, anhidrosis).