ANA124 N6: Brain stem and (some) Cranial Nerves

Girl, are you Cranial Nerve VII? Because every time I see you, I can’t help but smile.

Features of the midbrain

• Cerebral peduncles

• interpeduncular fossa

• pineal gland

• superior colliculi

• inferior colliculi

Cranial nerves that emerge from the midbrain

CNIII (occulomotor) and CNIV (trochlear)

features of the pons

• horizontal fibres

• basilar surface

• superior cerebellar peduncle

• middle cerebellar peduncle

• inferior cerebellar peduncle

cranial nerves that emerge from the pons

• CNV (trigeminal)

• CNVI (abducens)

• CNVII (facial

• CNVIII (vestibulocochlear)

• CNIX (glossopharyngeal)

Features of the medulla

• olive

• pyramids

• anterior median fissure

• decussation of pyramids

• tubercle of nucleus cuneatus

• tubercle of nucleus gracilis

Cranial nerves that emerge from the medulla

• CNX (vagus)

• CNXI (accessory)

• CNXII (hypoglossal)

Function of cerebellar peduncles

White fibers that travel to certain regions:

• superior: midbrain to cerebellum

• middle: right and left hemispheres of cerebellum

• inferior: up and down to medulla

features of the cerebellum

• 2 hemispheres

• vermis: the central region that connects hemispheres of cerebellum

• folia: cerebellar gyri that is gray matter

functions of the cerebellum

• regulates posture and balance

• large role in walking

• coordinates complex movements

sensory cranial nerves

• CNI (olfactory)

• CNII (optic)

• CNVIII (vestibulocochlear)

motor cranial nerves

• CNIII (occulomotor)

• CNIV (trochlear)

• CNVI (abducens)

• CNXI (accessory)

• CNXII (hypoglossal)

both motor and sensory cranial nerves

• CNV (trigeminal)

• CNVII (facial)

• CNIX (glossopharyngeal)

• CNX (vagus)

cranial nerve emerging from crista galli

• CNI

cranial nerve emerging from optic canal

• CNII

cranial nerve emerging from SOF

• CNIII

• CNIV

• CNV (V1)

• CNVI

Cranial nerve emerging from foramen rotundum

CNV (V2)

Cranial nerve emerging from foramen ovale

CNV (V3)

Cranial nerves emerging from IAM

• CNVII

• CNVIII

Cranial nerves emerging from jugular foramen

• CNIX

• CNX

• CNXI

Cranial nerve emerging from foramen magnum

CNXI

Cranial nerve emerging from hypoglossal canal

CNXII

Function of CNI

conveys smell from olfactory epithelium in roof of nasal cavity

Functions of CNV

• V1: opthalmic division, motor and sensory of forehead, eye, and tip of nose area

• V2: maxillary division, motor and sensory of maxilla, inferior side of nose, zygoma

• V3: mandibular division, motor to muscle of mastication and general sensory to anterior 2/3 of tongue

Function of CNVII

• innervates muscles of facial expression

• taste from anterior 2/3 of tongue

• innervation of salivary glands

• secretion of tears

function of CNVIII

• conveys auditory sensation from cochlea

• conveys balance info from vestibular apparatus

function of CNIX

• motor to muscle in pharynx

• general sensory and taste from posterior 1/3 of tongue and oropharynx

• parotid gland innervation

function of CNX

• general sensory to pharynx and larynx

• special sensory to pharynx and larynx

• parasympathetic innervation of thoracic and abdominal viscera

function of CNXI

• motor to sternocleidomastoid and trapezius

Function of CNXII

motor to muscles of tongue