Brainstem MCQs

The pattern of the arrangement of cranial nerve nuclei from the ventral to dorsal aspect is: Somatic Afferent > Visceral Afferent > Visceral Efferent > Somatic Efferent Reference: Langman's Medical Embryology 14th edition, Page number - 326

Each nucleus ambiguus innervates the ipsilateral side of the palate and each cerebral hemisphere projects corticonuclear fibers to each nucleus ambiguus, but the predominance of fibers go to the contralateral nucleus. The fibers from the nucleus ambiguus emerge through the postero-lateral sulcus of the brainstem Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Head and neck, Page number - 311

The metencephalon differentiates into the cerebellum, the coordination center for posture and movement and the pons, which serves as a neural relay center. Reference - Textbook of Langman's, 12th Edition, Central Nervous System Embryology Page number - 287

Explanation: The medulla oblongata is the direct upward continuation of the spinal cord, extending from the foramen magnum to the lower border of the pons. It forms the lowest part of the brainstem and lies vertically in the anterior posterior cranial fossa between the clivus and cerebellar vallecula. Because medulla is shaped like truncated cone- a bulb like structure, it is also called the bulb.

The facial nerve fibers, which cover the abducent nucleus, lie deep to the facial colliculus. Reference : Textbook of Gray's Anatomy for students, 3rd Edition, Head and neck, Page number - 901

The Posterior inferior cerebellar artery (PICA) is an arterial branch of the vertebral system that supplies the brain. It is responsible for providing blood flow to the posterior inferior cerebellum, as well as other areas of the brainstem Reference : Textbook of Gray's Anatomy for students, 3rd Edition, Head and Neck, Page number - 879

Explanation: On the ventral part of pons bands of fibres made up (from medial to lateral side) Medial lemniscus Spinal lemniscus Trigeminal lemniscus Lateral lemniscus The lateral lemniscus is the only one that forms a major component of the auditory pathway, carrying fibres from the cochlear nuclei via trapezoid body and superior olivary complex up to the inferior colliculus. Medial, spinal and trigeminal lemnisci carry touch, pain temperature, and trigeminal sensory fibres respectively, and are not a part of hearing.