Neuroanatomy Review: 2012

Dr J. Laprade

Studying Comprehensively: • There are basically 3 parts to doing this successfully.

• Start with a random structure….

1: Name everything you know about it: what it looks like, where it is located, what is it’s function, what is above/below/ to sides of it, what it connects to/is part of/is included with, what happens when it is damaged? 2: While you are naming everything above, take time to view the structure and all aspects from at least 2 different views, or look at 3D models/animations 3: Repeat the same steps above each time you introduce or name another new structure related to the original structure

Studying Comprehensively…an Example: • Let’s say the thalamus

1: What does it look like?

1. An egg-shaped structure comprised of a number of nuclei:

Anterior Group – limbic system

Ventral Group – proprioception (VP), movement planning & control (VA, VL)

Posterior Group – lateral genic (vision); medial geniculate (hearing)

Also: integrates sensory information; connects with association cortices

VA VL

VP LG

MG

Studying Comprehensively…an Example: Where is it? What is near it?:

2. Located near the midline of the brain; paired; joined by interthalamic adhesion

3. Is part of the DIENCEPHALON, comprised of: - HYPOTHALAMUS

-EPITHALAMUS

• Is located ANT and INF to thalamus • Function is to: regulate reproductive, autonomic and

instinctive functions, food & water intake; emotional behavior • Has pituitary attached to inferior portion

• Is located POST to thalamus • Function involved with puberty and circadian rhythms • Pineal gland is main part

Studying Comprehensively…an Example: What is beside it?:

4. In between both thalami, is the 3rd VENTRICLE - 3rd ventricle is attached to lateral ventricles (superiorly) by interventricular foramen ..lateral ventricles are located one in each hemisphere; each has 3 horns:

-anterior horn is in frontal lobe

-inferior horn is in temporal lobe

-posterior horn is in occipital lobe

-3rd ventricle is connected to 4th ventricle (inferiorly) via cerebral aqueduct. Cerebral aqueduct is located in midbrain; 4th ventricle is inbetween pons (ant) and cerebellum (post)

- All ventricles contain CSF which arises from CHOROID PLEXUS; CSF circulates around brain and spinal cord in the subarachnoid space from this system and returns to VENOUS SINUES via the arachnoid granulations

Studying Comprehensively…an Example:

Ventricles with Thalamus

Various animations: www.neuroanatomy.ca

Studying Comprehensively…an Example: What is around it?: 5. Superior to it is the CAUDATE NUCLEUS

– Above the head of caudate is anterior horn of lateral ventricle; tail of caudate is above the inferior horn of lateral ventricle (in temporal lobe)

6. Lateral to it is the INTERNAL CAPSULE & LENTIFORM – Lentiform has two parts: globus pallidus medially; putamen laterally – Lateral to putamen is the extension of the lateral fissure (separating frontal, parietal,

temporal lobes) – Caudate & Lentiform are both nuclei in cortex – Function of both nuclei is to refine normal voluntary mvt., not directly connected to

spinal cord; i.e. do not directly control movement – diseases of basal nuclei present with:

• hypokinesis (without paralysis) or hyperkinesis • altered posture and muscle tone • altered cognition, behavioural disturbances • eg. Parkinsonism

Relationship to X-Section

Slices

• Progressing through the Brain

Coronal

Horizontal

What is around it?: 6. Lateral to it is the INTERNAL CAPSULE & LENTIFORM

• INTERNAL CAPSULE – is one section of a long projection fiber tract; is comprised of motor (LCST) and sensory (STT & DCML) tracts traveling from brain spinal cord. Other portions include: corona radiata above the level of caudate/putamen (starting or ending in the pre and post central gyri); below it continues down to form

• cerebral peduncles in midbrain • and pyramids (LCST) in medulla • …ultimately contributing • to the posterior, lateral • and anterior funiculi of • spinal cord.

What does it connect to?: 7. All sensory information passes through here:

-VISION – from optic N (CN II) via lateral geniculate visual cortex (occipital lobe: what is blood supply of this lobe?)

-HEARING – from CN VIII via medial geniculate auditory cortex (temporal lobe, just inf to lateral fissure: what is blood supply of this cortex?)

-TOUCH, PRESSURE, PROPRIOCEPTION

- from face: via CN V to primary somatosensory cortex (specifically… lateral & inferior portion…what is blood supply to this region?)

- From body: via DCML tract (where does it pass through from spine, brainstem & end up in SSCortex?? …what is blood supplies of each of these regions)

-PAIN & PRESSURE

- from face: via CN V

- from body: via SST (where is it in the spinal cord, brainstem & where does it end up in SSCortex?)

-TASTE:

-ANT 2/3 of tongue: CN VII; POST 1/3 of tongue: CN IX …ends at very lateral aspect of SSCortex above lateral fissure

Blood Supply

ANTERIOR Cerebral Artery Deficits

• PARALYSIS OF CONTRALATERAL LEG, ARM AND FACE SPARED

• ANAESTHESIA OF CONTRALATERAL LEG, ARM AND FACE SPARED

Lateral Medial

Pharynx

Hip

Knee

Ankle

Toes

Middle Cerebral Artery Deficits

• MOTOR APHASIA

• PARALYSIS OF CONTRALATERAL FACE AND ARM, LEG SPARED

• ANAESTHESIA OF CONTRALATERAL FACE AND ARM, LEG SPARED

• RECEPTIVE APHASIA

Lateral Medial

Pharynx

Hip

Knee

Ankle

Toes

POSTERIOR Cerebral Artery

• Supplies: Midbrain (CN III, IV), inferior surface & occipital pole

• CONTRALATERAL PARALYSIS OF FACE AND BODY,

• ANAESTHESIA OF CONTRALATERAL FACE AND BODY,

• IPSILATERAL STRABISMUS, DIPLOPIA, DILATED PUPIL (CN III, IV)

• Visual Field deficit

Basilar Artery

• Supplies: PONS

• CNs here: V, VI, VII & VIII

• CONTRALATERAL PARALYSIS OF BODY

• IPSILATERAL PARALYSIS OF FACE (CN VII), CONTRALATERAL ANAESTHESIA OF BODY,

• POSSIBLY BILATERAL ANAESTHESIA OF FACE (IPSILATERAL CN V),

• STRABISMUS & DIPLOPIA DUE TO CN VI,

• IPSILATERAL DEAFNESS (CN VIII)

• DIZZINESS, VERTIGO, NAUSEA, VOMITTING (CN VIII)

Vertebral

• Supplies: Medulla • CN: IX, X, XI, XII • CONTRALATERAL PARALYSIS OF BODY (FACE

SPARED), • CONTRALATERAL ANAESTHESIA OF BODY (FACE

SPARED), • PARALYSIS OF IPSILATERAL TONGUE (CN XII), • ABSENT GAG REFLEX IPSILATERALLY (CN IX & X),

HOARSE VOICE (CN X) • WEAKNESS of MUSCLES supplies by XI

Thalamus

What is it?

Where is it?

Function?

What is close by?

Gray matter Group of

nuclei

Part of Dienceph.

Hypothal Epi-thal

Results of Damage?

Midline

Lateral to 3rd V 3rd V

4th

Lat

Superiorly Laterally

Medially

Caudate Int Capsule

Projection fibres & tracts

Function &

Damage

Lentiform

Function &

Damage

CSF

Connect Sensory Paths to Cortex B

loo

d S

up

ply

Special Senses

Cra

nia

l N

erv

es

Spinal Tracts

F’n

F’n

F’n

QUESTIONS??

Some Resources Online

http://library.med.utah.edu/WebPath/HISTHTML/NEURANAT/NEURANCA.html#4

http://faculty.washington.edu/chudler/flash/brainfly.html

http://www.getbodysmart.com/ap/nervoussystem/cns/brain/brainviews/tutorial.html

www.neuroanatomy.ca