tectum

(roof of the midbrain)

part of the midbrain that is superior/posterior to the mesecephalic aqueduct - contains the 4 colliculi (corpora quadrigemina)

function of the medullary velum 

separate the CSF that is inside the 4th ventricle from the CSF in the subarachnoid space surrounding the brainstem - there are 2 the superior medullary velum is attached to the superior pons the inferior on the medulla

Reticular Formation

loose bundle of neurons and nuclei at the core of the brainstem - extend from the diencephalon through the medulla

not heavily mylinated - generally identified as the "stuff" that isn't something else

Very old/basic part of the brainstem 

Functions of the Reticular Formation 

alerting the cortex and supporting consciousness

focusing attention on specific stimuli

some autonomic functions (cardiac and respiratory)

descending pain modulatory pathways

origin of some upper motor neuron pathways 

Cranial Nerve I

Olfactory Nerve 

Where does Cranial Nerve I arise from?

Olfactory bulb - in the cerebrum 

Cranial Nerve I exits the skull from 

the cribriform plate

Cranial Nerve II

Optic Nerve

Cranial Nerve II arises from 

the diencephalon

Cranial Nerve II exits via the 

Optic foramen

Cranial Nerve III

Oculomotor

Cranial Nerve III arises from 

the mesencephalon

Cranial Nerve III exits via 

the superior orbital fissure

Cranial Nerve IV

Trochlear

Cranial Nerve IV arises from 

posterior mesencephalon

Cranial Nerve IV exits via

the superior orbital fissure 

Cranial Nerve V

Trigeminal 

Cranial Nerve V arises from 

the pons

Cranial Nerve V exits via 

(V1) trigeminal opthalamic - superior oribital fissure

(V2) trigeminal naxillary - foramen rotundum

(V3) trigeminal manibular - foramen ovale

Cranial Nerve VI

Abducent Nerve

Cranial Nerve VI arises from 

pons 

Cranial Nerve VI exits via 

superior oribtal fissure 

Cranial Nerve VII

Facial Nerve

Cranial Nerve VII arises from 

the pons

Cranial Nerve VII exits via

the internal acoustic meatus

and

stylomastoid foramen

Cranial Nerve VIII

Vestibulocochlear

Cranial Nerve VIII arises from 

medulla

Cranial Nerve VIII exits via 

the internal acoustic meatus 

Cranial Nerve IX

Glossopharyngeal

Cranial Nerve IX arises from 

medulla

Cranial Nerve IX exits via

jugular foramen

Cranial Nerve X

Vagus 

Cranial Nerve X arises from 

medulla

Cranial Nerve X exits via

jugular foramen

Cranial Nerve XI

Accessory

Cranial Nerve XI arises from 

medulla

Cranial Nerve XI exits via 

jugular foramen

Cranial Nerve XII

Hypoglossal

Cranial Nerve XII arises from 

medulla

Cranial Nerve XII exits via

Hypoglossal Canal