Brain Stem Anatomy and Function Overview

Brainstem

Central processing center for the CNS.

Cranial Nerves

Nerves 3-12 located in the brainstem.

Midbrain

Upper section of the brainstem; involved in vision and hearing.

Red Nucleus

Midbrain structure involved in motor coordination.

Superior Colliculus

Midbrain structure for visual reflexes.

Inferior Colliculus

Midbrain structure for auditory reflexes.

Substantia Nigra

Produces dopamine; involved in movement control.

Pons

Middle section of the brainstem; regulates breathing.

Pontine Respiratory Center

Regulates rhythm and pattern of breathing.

Medulla

Lower section controlling autonomic functions.

Vagus Nerve

Cranial nerve 10; controls parasympathetic functions.

Pyramids

Structures in the medulla for motor pathways.

Pyramidal Decussation

Crossing of motor fibers in the medulla.

Fasciculus Cuneatus

White matter for upper body sensory pathways.

Fasciculus Gracilis

White matter for lower body sensory pathways.

Medial Lemniscus

Pathway for sensory information to thalamus.

Medial Longitudinal Fasciculus

Coordinates eye movements and vestibulo-ocular reflex.

Basilar Section

Contains motor structures and descending axons.

Tegmentum

Contains reticular formation and sensory nuclei.

Reticular Formation

Regulates arousal, consciousness, and motor activity.

Tectum

Controls eye muscle movements and head orientation.

Horner's Syndrome

Caused by midbrain infarct; leads to sweating loss.

Locked-in Syndrome

Due to basilar artery occlusion; paralysis occurs.

Medial Medullary Syndrome

Infarct at anterior spinal artery; motor loss results.

Wallenberg's Syndrome

Infarct of PICA; causes vertigo and ataxia.

Weber's Syndrome

Midbrain infarct causing oculomotor nerve palsy.

Dysphagia

Impaired swallowing function.

Dysarthria

Impaired motor function of speech.

Diplopia

Double vision due to eye muscle dysfunction.

Dysmetria

Impaired control of movement distance and speed.

Motor Deficits

Weakness or paralysis from brainstem lesions.

Speech Therapy

Rehabilitation for dysarthria and dysphagia.

Cognitive Impairments

Altered sensation and attention deficits from lesions.

Cardiovascular Monitoring

Essential for patients with autonomic control issues.