01 cranial nerve overview
TRANSCRIPT
CRANIAL NERVES
Overview
Cranial NervesCranial Nerves NameName
II Olfactory NerveOlfactory Nerve
IIII Optic NerveOptic Nerve
IIIIII Oculomotor NerveOculomotor Nerve
IVIV Trochlear NerveTrochlear Nerve
VV Trigeminal NerveTrigeminal Nerve
VIVI Abducens NerveAbducens Nerve
VIIVII Facial NerveFacial Nerve
VIIIVIII Vestibulocochlear NerveVestibulocochlear Nerve
IXIX Glossopharyngeal NerveGlossopharyngeal Nerve
XX Vagus NerveVagus Nerve
XIXI Accessory NerveAccessory Nerve
XIIXII Hypoglossal NerveHypoglossal Nerve
Olfactory bulb
Olfactory tract
Cranial Nerves
Olfactory (I)Optic (II)Oculomotor (III)Trochlear (IV)Trigeminal (V)Abducens (VI)Facial (VII)Vestibulocochlear (VIII)
Glossopharyngeal (IX)
Vagus (X)Accessory (XI)Hypoglossal (XII)
Pituitary glandOptic tract
Cranial Nerves Cranial Exit
I Cribriform plate
II Optic canal
III Superior orbital fissure
IV Superior orbital fissure
V V1: Superior orbital fissure
V2: Foramen rotundum
V3: Foramen ovale
VI Superior orbital fissure
VII Internal acoustic meatusStylomastoid foramen
VIII Internal acoustic meatus (does not leave)
IX Jugular foramen
X Jugular foramen
XI Jugular foramen
XII Hypoglossal canal
Exit points
Cranial Nerves ComponentsCranial Nerves Components
Cranial Nerves Components
I sensory
II sensory
III motor
IV motor
V mix
VI motor
VII mix
VIII sensory
IX mix
X mix
XI motor
XII motor
& other
& other
1818
Sensory /Afferent
General Special
Motor/ Efferent
General Special
SomaticGSA
VisceralGVA
VisceralSVA
SomaticSSA
SomaticGSE
VisceralGVE
VisceralSVE
sensationfrom skin,
mucousmembrane
visceralsensation
frominternalorgans
smell &taste
vision,balance,
& hearing
innervateskeletalmusclesnot frombranchial
arches
innervatesmoothmuscles& glands
(autonomic)
innervateskeletalmuscles
frombranchial
arches
components
2020
Sensory /Afferent
General Special
Motor/ Efferent
General Special
SomaticGSA
VisceralGVA
VisceralSVA
SomaticSSA
SomaticGSE
VisceralGVE
VisceralSVE
sensationfrom skin,
mucousmembrane
visceralsensation
frominternalorgans
smell &taste
vision,balance,
& hearing
innervateskeletalmusclesnot frombranchial
arches
innervatesmoothmuscles& glands
(autonomic)
innervateskeletalmuscles
frombranchial
arches
components
2121
Sensory /Afferent
General Special
Motor/ Efferent
General Special
SomaticGSA
VisceralGVA
VisceralSVA
SomaticSSA
SomaticGSE
VisceralGVE
VisceralSVE
sensationfrom skin,
mucousmembrane
visceralsensation
frominternalorgans
smell &taste
vision,balance,
& hearing
innervateskeletalmusclesnot frombranchial
arches
innervatesmoothmuscles& glands
(autonomic)
innervateskeletalmuscles
frombranchial
arches
components
2222
Sensory /Afferent
General Special
Motor/ Efferent
General Special
SomaticGSA
VisceralGVA
VisceralSVA
SomaticSSA
SomaticGSE
VisceralGVE
VisceralSVE
sensationfrom skin,
mucousmembrane
visceralsensation
frominternalorgans
smell &taste
vision,balance,
& hearing
innervateskeletalmusclesnot frombranchial
arches
innervatesmoothmuscles& glands
(autonomic)
innervateskeletalmuscles
frombranchial
arches
components
Cranial Nerves
Components
I SVA
II SSA
III GSE, GVE
IV GSE
V SVE, GSA
VI GSE
VII SVE, GVE, SVA, GSA, GVA[?]
VIII SSA, SSA
IX SVE, GVE, SVA, GVA, GSA
X SVE, GVE, SVA, GVA, GSA
XI [Cranial]SVE, [Spinal]GSE
XII GSE
This slide is only for reference here; however you will memorize every detail of this slide in Med 3 – Neuroscience. So it is just matter of time!
3 kind of Motor/Efferent 3 kind of Motor/Efferent fibers:fibers:
1. GSE [somatic motor]1. GSE [somatic motor]
General Somatic efferent Cell bodies of these neurons lie in brainstem or spinal
cord and their axons innervate skeletal muscles These skeletal muscles are derived from Somites. CN – 3,4,6,11[spinal],12 Also note that all the 31 spinal nerves have GSE fibers.
2. SVE [bra2. SVE [brannchial motor]chial motor] Special Visceral efferent Functionally same as GSE and supply also
skeletal muscles Difference is, these skeletal muscles are
derived from Branchial arches and not from somites
Therefore also known as Branchial Motor Component
CN – 5,7,9,10,11[cranial] Logic behind using the term visceral here is that in lower animals the
muscles derived from branchial arches are not skeletal muscles but smooth muscles.
3. GVE [visceral motor]3. GVE [visceral motor]
General Visceral Efferent These fibers innervate Smooth Muscles or
Glands of internal organs[=viscera]. These fibers are part of Autonomic
nervous system [sympathetic and parasympathetic]
CN 3,7,9,10 In all these 4 cranial nerves fibers belong to parasympathetic
system. While sympathetic GVE fibers exist independent of cranial nerves.
4 kinds of Sensory fibers4 kinds of Sensory fibers::1.GSA [general sensory]1.GSA [general sensory]
General Somatic Afferent GSA fiber is one whose cell body [pseudounipolar
neuron] lies outside CNS in dorsal root sensory ganglion or sensory ganglions of cranial nerves.
Central limb of this neuron goes to CNS to specific nucleus in brainstem
Peripheral limb of this neuron goes to somatic receptors in skin, skeleton muscle, tendons or joints.
The sensory receptors responsible for sensations like, touch, pain, temperature, pressure, proprioception etc.
CN 5,7,9,10 Also note that all 31 spinal nerve have this GSA component.
2.GVA [visceral sensory]2.GVA [visceral sensory]
General Visceral Afferent Part of Autonomic nerves [sympathetic
and parasympathetic] Receptors are on mucus membrane and
wall of internal organs [viscera] Carry sensations like, burning, fullness,
pain [not specific and poorly localized], thirst, hunger, general unpleasantness etc. + chemoreception for cardio-respiratory regulation
CN 9,10
3.SSA [special sensory -1]3.SSA [special sensory -1]
Special Somatic Afferent Fibers associated with special senses
of Vision and Hearing+ Balance. Associated with highly specialized
somatic receptors stimulated by non-chemical changes like light or mechanical movements: Retina in eye and auditory receptors in ear
CN 2, 8
4.SVA [special sensory – 2]4.SVA [special sensory – 2]
Special Visceral Afferent Fibers associated with special senses
of Taste and Smell Receptors are highly modified special
receptors which detect CHEMICAL changes.
CN 1,7,9,10