Brainstem Structures

Brainstem Tissue

has its own GM and WM

overall brainstem function

breathing, consciousness, BP, HR, sleep - anything under unconscious control

Brainstem & cranial nerves

10 of 12 originate from brainstem

Midbrain Location

intermediate to thalamus and pons

Midbrain connection to cerebellum

superior cerebellar peduncles

Crus Cerebri

lines along midbrain corresponding to tracts

Cerebral Aqueduct

connects 3rd and 4th ventricle

Corpora Quarigemina

both colliculi on both sides

Superior Colliculi

visual reflexes, output to lateral geniculate body

Inferior Colliculi

auditory processing, output to medial geniculate body

Midbrain Cranial Nerves

Trochlear and Oculomotor

Substantia Nigra

part of basal ganglia found in midbrain, produces dopamine and regulates movement

Red Nucleus

in midbrain, responsible for motor control and muscle tone

Ventral Tegmental Area

has dopaminergic neurons for rewards pathway

Pons Location

intermediate to midbrain and medulla oblongata

anterior distension

houses basilar groove on pons

Pons connection to cerebellum

via middle cerebellar peduncles (largest)

Pons & Ventricles

forms anterior wall of 4th ventricle

Pons-Medulla Junction

contains a ton of cranial nerve exit points

Cranial Nerve Nuclei

gives rise to according cranial nerves

Locus Coeruleus

synthesizes Norepinephrine, part of RAS

Reticular Activating System

responsible for arousal and attention

Pontine Nuclei

assist in coordinating movement, connect with cerebellum via middle peduncles

Medulla Oblongata Location

Inferior to pons, prior to foramen magnum

Medulla Oblongata Connection to cerebellum

via inferior cerebellar peduncles

Medulla Oblongata & Ventricles

forms bottom portion of floor of 4th ventricle

Dorsal Median Sulcus

on medulla oblongata, contains fibers

Pyramids

in medulla oblongata, contain motor fibers from M1 to spinal grey matter

Pyramidal Decussation

in medulla, where fibers cross to contralateral body

Olive

on medulla oblongata, aid in motor coordination through connection with cerebellum

Medulla Oblongata Cranial Nerves

Glossopharyngeal, Hypoglossal, Vagus, and Accessory

Medulla Oblongata Secondary Functions

Respiratory and vasomotor centers