Brain and Cranial Brain and Cranial NervesNerves

TerminologyTerminology

HemispheresHemispheres Gyrus (Gyri)Gyrus (Gyri) Sulcus (Sulci)Sulcus (Sulci) Longitudinal FissureLongitudinal Fissure VentriclesVentricles

– CSFCSF

Anatomy of the BrainAnatomy of the Brain

Cerebrum Cerebrum CerebellumCerebellum DiencephalonDiencephalon

– ThalamusThalamus– Hyothalamus Hyothalamus

Brain StemBrain Stem– MidbrainMidbrain– PonsPons– Medulla Medulla

oblongataoblongata

CerebrumCerebrum

AnatomyAnatomy– Frontal lobeFrontal lobe– Parietal lobeParietal lobe– Occipital lobeOccipital lobe– Precentral gyrusPrecentral gyrus– Postcentral gyrusPostcentral gyrus

FunctionsFunctions– Sensory cortexSensory cortex– Motor cortexMotor cortex– EmotionEmotion– Intellectual Intellectual

processesprocesses– AuditoryAuditory– VisualVisual– SpeechSpeech

CerebellumCerebellum

AnatomyAnatomy– HemispheresHemispheres

FunctionsFunctions– Compares Compares

intended intended movement with movement with what is actually what is actually happeninghappening

– Smooth, Smooth, coordinated coordinated movementsmovements

– Posture/balancePosture/balance

Brain StemBrain Stem

AnatomyAnatomy– Medulla Medulla

oblongataoblongata– PonsPons– MidbrainMidbrain

FunctionsFunctions– MedullaMedulla

Relays motor and Relays motor and sensory sensory informationinformation

Regulates Regulates heartbeat, heartbeat, breathing and breathing and blood vessel blood vessel dilationdilation

– PonsPons Control breathingControl breathing

Protective CoveringsProtective Coverings(Meninges)(Meninges) Dura materDura mater Dense connective tissueDense connective tissue

ArachnoidArachnoid Nonvascular connective tissueNonvascular connective tissue

Pia materPia mater Highly vascularHighly vascular

Covers surface of the brain and spinal cord Covers surface of the brain and spinal cord and invaginates along cortical surface to and invaginates along cortical surface to form perivascular spacesform perivascular spaces

Cerebral Spinal Fluid Cerebral Spinal Fluid

Formed in the choroid plexusFormed in the choroid plexus Reabsorbed into saggittal sinus Reabsorbed into saggittal sinus

by arachnoid villiby arachnoid villi Protects brain against concussive Protects brain against concussive

traumatrauma removes waste productsremoves waste products

Foramen of Monro

Cranial NervesCranial Nerves

I:I: OlfactoryOlfactory II:II: OpticOptic III:III: OculomotorOculomotor IV:IV: TrochlearTrochlear V:V: TrigeminalTrigeminal VI:VI: AbducensAbducens

VII: FacialVII: Facial VIII:VestibulocochlearVIII:Vestibulocochlear

– AcousticAcoustic IX:IX:

GlossopharyngealGlossopharyngeal X:X: VagusVagus XI:XI: AccessoryAccessory XII: HypoglossalXII: Hypoglossal

http://www.gwc.maricopa.edu/class/bio201/cn/cranial.htm

MnemonicMnemonic

OnOn OldOld Olympus’Olympus’ TowerTower TopTop AA

FinFin AndAnd GermanGerman ViewedViewed AA HopHop

MNEMONICMNEMONIC

OLFACTORYOLFACTORY OPTICOPTIC OCULOMOTOROCULOMOTOR TROCHLEARTROCHLEAR TRIGEMINALTRIGEMINAL ABDUCENSABDUCENS FACIALFACIAL VESTIBULOCOCHLEARVESTIBULOCOCHLEAR GLOSSOPHARYNGEALGLOSSOPHARYNGEAL VAGUSVAGUS ACCESSORYACCESSORY HYPOGLOSSALHYPOGLOSSAL

OHOH ONCEONCE ONEONE TAKESTAKES THE THE ANATOMYANATOMY FINALFINAL VERY VERY GOODGOOD VACATIONVACATION A-HEADA-HEAD

CN I: OLFACTORYCN I: OLFACTORY

Cranial nerve ICranial nerve I Function: Function:

– smellsmell Clinical test for Clinical test for

damage: damage: – determine determine

whether a person whether a person can smell can smell something something aromaticaromatic

CN II: OPTICCN II: OPTIC

Cranial nerve IICranial nerve II Function: Function:

– visionvision Clinical test for Clinical test for

damage: damage: – tests peripheral tests peripheral

vision and visual vision and visual acuityacuity

Effects of damage: Effects of damage: – blindness in part or blindness in part or

all of the visual fieldall of the visual field

CNIII: OCULOMOTORCNIII: OCULOMOTOR

Cranial nerve IIICranial nerve III Function: Function:

– eye movements, opening of eye movements, opening of eyelid, constriction of pupil, eyelid, constriction of pupil, focusing, proprioceptionfocusing, proprioception

Clinical tests for injury: Clinical tests for injury: – differences in pupil size; pupillary differences in pupil size; pupillary

response to light; eye trackingresponse to light; eye tracking Effects of damageEffects of damage

– dropping eyelid, dilated pupil, dropping eyelid, dilated pupil, double visiondouble vision

CNIV: TROCHLEARCNIV: TROCHLEAR

Cranial nerve IVCranial nerve IV Function: eye Function: eye

movements and movements and proprioceptionproprioception

Clinical test for injury: Clinical test for injury: ability to rotate eye ability to rotate eye inferolaterallyinferolaterally

Effects of damage – Effects of damage – double vision, patient double vision, patient tilts head toward affected tilts head toward affected sideside

CN V: TRIGEMINALCN V: TRIGEMINAL

Cranial nerve VCranial nerve V Function: sensory nerve of Function: sensory nerve of

the facethe face Clinical test for injury: Clinical test for injury:

– corneal reflex; sense of corneal reflex; sense of touch, pain, and touch, pain, and temperature; clench temperature; clench teeth; move mandible teeth; move mandible side to sideside to side

Effects of damage: Effects of damage: – loss of sensation and loss of sensation and

impaired chewingimpaired chewing

CN VI: ABDUCENS AND CN VI: ABDUCENS AND CN VII: FACIAL CN VII: FACIAL Cranial Nerve VICranial Nerve VI Function: Eye Function: Eye

movementsmovements Clinical test: lateral Clinical test: lateral

eye movementeye movement Effects of damage: Effects of damage:

inability to rotate eye inability to rotate eye laterally; at rest – eye laterally; at rest – eye rotates medially rotates medially because of action of because of action of antagonistic musclesantagonistic muscles

Cranial Nerve VIICranial Nerve VII Function: facial Function: facial

expression; sense of expression; sense of tastetaste

Clinical test: motor Clinical test: motor functions – close eyes, functions – close eyes, smile, whistle, frown, smile, whistle, frown, raise eyebrows; tasteraise eyebrows; taste

Effects of damage: Effects of damage: inability to control facial inability to control facial muscles; distorted muscles; distorted sense of tastesense of taste

CN VIII: CN VIII: VESTIBULOCOCHLEARVESTIBULOCOCHLEAR Cranial Nerve VIIICranial Nerve VIII Function: hearing and equilibriumFunction: hearing and equilibrium Clinical tests: test hearing, Clinical tests: test hearing,

balance, and ability to walk a balance, and ability to walk a straight linestraight line

Effects of damage: deafness, Effects of damage: deafness, dizziness, nausea, loss of balance, dizziness, nausea, loss of balance, and nystagmusand nystagmus

CN IX: CN IX: GLOSSOPHARANGEAL GLOSSOPHARANGEAL AND CN X: VAGUSAND CN X: VAGUS

Cranial Nerve IXCranial Nerve IX Function: swallowing, Function: swallowing,

salivation, gagging; salivation, gagging; touch, pressure, taste, touch, pressure, taste, and pain sensations and pain sensations from tongue, pharynx, from tongue, pharynx, and outer earand outer ear

Clinical tests: gag reflex, Clinical tests: gag reflex, swallowing, and swallowing, and coughingcoughing

Effects of damage: Effects of damage: difficulty swallowingdifficulty swallowing

Cranial Nerve XCranial Nerve X Function: swallowing; Function: swallowing;

taste; speech; taste; speech; respiratory, CV, and GI respiratory, CV, and GI regulation; sensations of regulation; sensations of hunger, fullness, and hunger, fullness, and intestinal discomfortintestinal discomfort

Clinical tests: test with Clinical tests: test with cranial nerve IXcranial nerve IX

Effects of damage: Effects of damage: hoarseness or loss of hoarseness or loss of voice; impaired voice; impaired swallowing and GI swallowing and GI motilitymotility

CN XI: ACCESSORY CN XI: ACCESSORY AND AND CN XII: HYPOGLOSSALCN XII: HYPOGLOSSAL Cranial Nerve XICranial Nerve XI

Function: swallowing; Function: swallowing; head, neck, and shoulder head, neck, and shoulder movementsmovements

Clinical tests: rotate head Clinical tests: rotate head and shrug shoulders and shrug shoulders against resistanceagainst resistance

Effects of damage: Effects of damage: impaired movement of impaired movement of head, neck, and head, neck, and shoulders; paralysis of shoulders; paralysis of sternocleidomastoidsternocleidomastoid

Cranial Nerve XIICranial Nerve XII Function: tongue Function: tongue

movements of speech, movements of speech, food manipulation, and food manipulation, and swallowingswallowing

Clinical test: tongue Clinical test: tongue functionfunction

Effects of damage: Effects of damage: difficulty in speech and difficulty in speech and swallowing; atrophy of swallowing; atrophy of tongue; inability to stick tongue; inability to stick out (protrude) tongueout (protrude) tongue