Brainstem nuclei — Flashcards

Flashcard 41: Which cranial nerves (4) are located in the medulla? _____

Answer: IX, X, XI*, and XII

Flashcard 42: Which brainstem nucleus receives visceral sensory information (e.g., taste, baroreceptors, chemoreceptors) from cranial nerves VII, IX, and X?

Answer: Nucleus solitarius (Solitary nucleus)

Extra: The nucleus solitarius is located in the medulla and serves as the primary relay for visceral sensory information. It receives input from: - **CN VII (Facial):** Taste (anterior 2/3 of tongue) - **CN IX (Glossopharyngeal):** Taste (posterior 1/3), Baroreceptors/Chemoreceptors (carotid sinus/body) - **CN X (Vagus):** Taste (epiglottis), Baroreceptors (aortic arch), Visceral sensory (gut distension, etc.)

Flashcard 43: Light reflex: Cells in the pretectal area send axons to the _____ nucleus, bilaterally

Answer: Edinger-Westphal

Flashcard 44: Which medullary nucleus provides motor innervation to the muscles of the pharynx, larynx, and soft palate via cranial nerves IX, X, and XI?

Answer: Nucleus ambiguus

Extra: The nucleus ambiguus contains motor neurons that contribute to the glossopharyngeal (CN IX), vagus (CN X), and accessory (CN XI) nerves. It innervates the muscles of the soft palate, pharynx, and larynx. Lesions characteristically cause dysphagia and hoarseness.

Flashcard 45: Which brainstem nuclei are responsible for mediating the pupillary light reflex?

Answer: Pretectal nuclei

Extra: The pretectal nuclei receive bilateral input from the optic tracts and project to the Edinger-Westphal nuclei (parasympathetic part of CN III), mediating the direct and consensual pupillary light reflexes.

Flashcard 46: Identify the cranial nerve nucleus based on the following anatomical features: - Located in the **rostral midbrain** - **Anterolateral** to the cerebral aqueduct - **Anterior** to the Edinger-Westphal nucleus

Answer: Oculomotor nucleus (CN III)

Extra: The oculomotor nucleus is located at the level of the superior colliculus (rostral midbrain). The Edinger-Westphal nucleus (parasympathetic) lies dorsal (posterior) to the somatic motor nucleus.

Flashcard 47: The _____ colliculi are auditory structures

Answer: inferior

Flashcard 48: Which brainstem nucleus is located just lateral to the inferior cerebellar peduncle?

Answer: Cochlear nucleus

Flashcard 49: Which cranial nerve(s) does the dorsal motor nucleus contribute to? _____

Answer: CN X (Vagus)

Flashcard 50: Which brainstem nucleus is located near the midline in the floor of the fourth ventricle, just lateral to the medial longitudinal fasciculus (MLF)?

Answer: Abducens nucleus (CN VI)