Gross Anatomy and Embryology Flashcards
7 cards from real NBME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Gross Anatomy and Embryology flashcards as text
A patient presents with deviation of the uvula to the right, hoarseness, and dysphagia after a posterior inferior cerebellar artery stroke. Which nerve is most directly affected at the level of the medulla?
Answer: CN X (vagus)
Lateral medullary (Wallenberg) syndrome affects CN X nuclei, causing ipsilateral palatal and vocal cord paralysis with uvular deviation away from the lesion.
Branchial cleft cysts in the lateral neck most commonly arise from which pharyngeal cleft?
Answer: Second
The second pharyngeal cleft normally obliterates but may persist as a cyst along the anterior border of the sternocleidomastoid, which is the most common branchial cleft cyst.
A patient cannot wrinkle the forehead on the left side and has drooping of the left corner of the mouth. Which structure is most likely damaged?
Answer: Left CN VII at the stylomastoid foramen (lower motor neuron)
Lower motor neuron CN VII lesions (e.g., Bell palsy) affect all ipsilateral facial muscles including the forehead, unlike upper motor neuron lesions which spare forehead wrinkling due to bilateral cortical representation.
The thyroid gland descends from the foramen cecum to its final position. Remnants of this descent may persist as which structure?
Answer: Thyroglossal duct cyst
The thyroglossal duct normally obliterates after the thyroid descends; persistence creates a midline cyst that moves upward with swallowing and tongue protrusion.
After parotid gland surgery, a patient develops flushing and sweating over the cheek during meals. Which nerve is responsible for this Frey syndrome?
Answer: Auriculotemporal nerve (branch of CN V3)
Frey syndrome occurs when regenerating parasympathetic fibers from the auriculotemporal nerve aberrantly innervate sweat glands, causing gustatory sweating.
The cloacal membrane divides into the urogenital membrane and anal membrane at approximately which embryonic week?
Answer: Week 7
The urorectal septum divides the cloaca into the urogenital sinus and anorectal canal by the end of the 7th week, separating the urogenital and anal membranes.
A patient with a retropharyngeal abscess could have infection spread into the posterior mediastinum through which anatomical space?
Answer: Danger space (space 4)
The danger space (space 4) lies between the alar and prevertebral fascia layers and extends from the skull base to the posterior mediastinum, providing a direct path for infection spread.