The midbrain or also known as
______, is a vital part of the
brain stem. It acts as a relay center
connecting the forebrain and
hindbrain.
mesencephalon
plays a role in vision, hearing,
and regulating mood.
MIDBRAIN
MAIN PARTS OF
THE MIDBRAIN
TECTUM
TEGMENTUM
the roof-like dorsal part of the midbrain,
which contains the superior and inferior
colliculi and is crucial for visual and auditory
reflexes.
TECTUM
the central core of the
midbrain containing many
important nuclei and white
matter tracts crucial for motor
control, sensory processing,
and consciousness
TEGMENTUM
STRUCTURAL COMPONENTS &
FUNCTION
TECTUM:
SUPERIOR COLLICULI
INFERIOR COLLICULI
STRUCTURAL COMPONENTS &
FUNCTION TEGMENTUM:
RED NUCLEUS
SUBSTANTIA NIGRA
reflex centres for visual
reflexes
SUPERIOR COLLICULI
lower auditory centres,
probably concerned with
reflexes involving auditory
stimuli
INFERIOR COLLICULI
motor control
,limb coordination,
relaying signals from the
cerebellum and cerebral cortex to
the spinal cord via the rubrospinal
tract
RED NUCLEUS
essential for motor control, reward,
and cognitive functions, producing
dopamine to modulate these
processes within the basal ganglia.
SUBSTANTIA NIGRA
two large bundles of nerve fibers on the front (ventral)
surface of the midbrain that act as a major pathway for
signals traveling between the cerebral cortex and the
brainstem and other parts of the central nervous
system.
CEREBRAL
PEDUNCLES
Ascending sensory
pathway
Carries fine touch,
vibration, and
proprioception
information from the body
to the thalamus.
MEDIAL
LEMNISCUS
Part of the auditory
pathway
Relays sound information
from the inner ear to the
auditory cortex via the
thalamus.
MEDIAL
GENICULATE
NUCLEUS
A fiber tract that
coordinates eye
movements.
Connects cranial nerves
controlling the eyes (III, IV,
VI) with the vestibular
system (CN VIII).
MEDIAL
LONGITUDINAL
FASCICULUS
A unique sensory nucleus
of the trigeminal nerve.
Relays proprioceptive
information from the jaw
and face (important for
chewing reflexes).
MESENCEPHALIC
NUCLEUS OF
CN V
Surrounds the cerebral
aqueduct.
Plays a role in pain
modulation and defensive
behaviors.
Can activate descending
pain-suppressing
pathways.
PERIAQUEDUCTAL
GRAY MATTER
Parasympathetic nucleus
associated with CN III.
Controls the pupil
constrictor muscle and
ciliary muscle (for
accommodation of the lens).
EDINGER–
WESTPHAL
NUCLEUS
A narrow channel connecting the
third and fourth ventricles.
Circulates cerebrospinal fluid (CSF).
Obstruction here causes
hydrocephalus (increased
intracranial pressure).
AQUEDUCT OF SYLVIUS
(CEREBRAL AQUEDUCT)
A narrow channel connecting the
third and fourth ventricles.
Circulates cerebrospinal fluid (CSF).
Obstruction here causes
hydrocephalus (increased
intracranial pressure).
AQUEDUCT OF SYLVIUS
(CEREBRAL AQUEDUCT)
