Examiners love this….
The Brain Stem – The Midbrain..
Ü Lies between the diencephalon and the pons
Ü Central cavity – the cerebral aqueduct
Ü Cerebral peduncles located on the ventral surface of the brain: Has pyramidal (corticospinal) tracts
Ü Superior cerebellar peduncles: Connect midbrain to the cerebellum
Ü Periaqueductal gray matter surrounds the cerebral aqueduct
Ü Involved in two related functions
o Fright-and-flight reaction
o Mediates response to visceral pain
ü Corpora quadrigemina – the largest nuclei
ü Divided into the superior and inferior colliculi
o Superior colliculi – nuclei that act in visual reflexes
o Inferior colliculi – nuclei that act in reflexive response to sound
Imbedded in the white matter of the midbrain
Ü Two pigmented nuclei
Ü Substantia nigra – neuronal cell bodies contain melanin
o Functionally linked to the basal nuclei
ü Red nucleus – lies deep to the substantia nigra
o Largest nucleus of the reticular formation
The Brain Stem – The Midbrain..
Ü Lies between the diencephalon and the pons
Ü Central cavity – the cerebral aqueduct
Ü Cerebral peduncles located on the ventral surface of the brain: Has pyramidal (corticospinal) tracts
Ü Superior cerebellar peduncles: Connect midbrain to the cerebellum
Ü Periaqueductal gray matter surrounds the cerebral aqueduct
Ü Involved in two related functions
o Fright-and-flight reaction
o Mediates response to visceral pain
ü Corpora quadrigemina – the largest nuclei
ü Divided into the superior and inferior colliculi
o Superior colliculi – nuclei that act in visual reflexes
o Inferior colliculi – nuclei that act in reflexive response to sound
Imbedded in the white matter of the midbrain
Ü Two pigmented nuclei
Ü Substantia nigra – neuronal cell bodies contain melanin
o Functionally linked to the basal nuclei
ü Red nucleus – lies deep to the substantia nigra
o Largest nucleus of the reticular formation
