Which of the following is NOT a visceral motor brainstem nucleus?

Which of the following is NOT a visceral motor brainstem nucleus?

• A. Edinger-Westphal nucleus
• B. Salivatory nuclei
• C. Dorsal motor nucleus
• D. Spinal trigeminal nucleus

Answer: (D)

Visceral motor nuclei in the brainstem are those that give rise to preganglionic parasympathetic neurons, coordinating autonomic functions like pupil constriction, salivation, and gut motility. Edinger-Westphal is the midbrain center for oculomotor parasympathetic output, driving pupil constriction and lens focusing. The salivatory nuclei (superior and inferior) provide parasympathetic signals to the lacrimal and salivary glands via cranial nerves VII and IX. The dorsal motor nucleus of the vagus contains preganglionic parasympathetic neurons that innervate thoracic and abdominal organs. The spinal trigeminal nucleus, however, is a somatic sensory nucleus handling pain, temperature, and touch from the face, not autonomic control. That’s why it’s not a visceral motor nucleus.

Visceral motor nuclei in the brainstem are those that give rise to preganglionic parasympathetic neurons, coordinating autonomic functions like pupil constriction, salivation, and gut motility. Edinger-Westphal is the midbrain center for oculomotor parasympathetic output, driving pupil constriction and lens focusing. The salivatory nuclei (superior and inferior) provide parasympathetic signals to the lacrimal and salivary glands via cranial nerves VII and IX. The dorsal motor nucleus of the vagus contains preganglionic parasympathetic neurons that innervate thoracic and abdominal organs. The spinal trigeminal nucleus, however, is a somatic sensory nucleus handling pain, temperature, and touch from the face, not autonomic control. That’s why it’s not a visceral motor nucleus.