neuroanatomy lab 3 '11

8/7/2019 Neuroanatomy LAB 3 '11

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CELL/NSCI 334/734 Neuroanatomy Lab Dr. Monique Cola

LAB 3

CRANIAL NERVES, BLOOD SUPPLY,

& VENTRICULAR SYSTEM

LAB OBJECTIVES

Cranial nerves:

A. Be able to locate attachment of CN to the brain/brainstem.

B. Review functions of CN

Blood Supply:

C. Be able to identify important vessels (Circle of Willis) of the CNS.

D. Understand major brain regions supplied by individual vessels.

Ventricular System:E. Be able to identify components of the ventricular system.

Cranial nerves

Number Name Function

Cranial nerves related

to the forebrain:

I Olfactory Smell

II Optic visionCranial nerves related

to the midbrain:

III Oculomotor Movement of the eye &

eyelid; constricts pupils;

accommodates

IV Trochlear Movement of the eye

Cranial nerves related

to hindbrain:

V Trigeminal Sensation of touch to the face;

movements of muscles of

mastication (chewing)VI Abducens Movements of the eye

VII Facial Moves the face, taste (ant. 2/3of tongue), salivates, and cries

VIII Auditory-vestibular Hearing and balance

IX Glossopharyngeal Taste (post. 1/3 of tongue),

salivates, swallows, detects blood pressure in aorta

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X Vagus Parasympathetic control of the

heart, lungs, and abdominalorgans; movement of muscles

in throat, sensation of pain in

viscera

XI Spinal Accessory Turns head, lifts shouldersXII Hypoglossal Moves tongue

There are 3 purely sensory nerves:

CN I -OlfactoryCN II Optic

CN VIII Auditory-vestibular

There are 5 purely motor nerves:

CN III - Oculomotor CN IV - Trochlear CN VI - Abducens

CN IX - Spinal accessory

CN XII - Hypoglossal

There are 4 "mixed" (sensory and motor) nerves:

CN V - trigeminal

CN VII - facialCN IX - Glossopharyngeal

CN X - Vagus

Blood Supply

Structure Relative location Function

Circle of Willis Ring of connected arteries at the base of brain; relates to optic nerve and chiasm,

pituitary stalks, CN III

Supratentorial blood supply to brain

Internal carotid a. Arises from the common carotid, courses

thru the carotid canal and cavernous

sinus; branches include the ophthalmic,posterior communicating, anterior and

middle cerebral arteries.

Anterior circulation

Middle cerebral a.(MCA)

Branch of the internal carotid; located inthe lateral sulcus

Supplies frontal, parietal, andtemporal lobes on the lateral

surface of the cerebrum

Anterior cerebral

a. (ACA)

Branch of the internal carotid; lies above

the corpus callosum

Supplies the medial surface of

the hemisphere, anteriorly

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Posterior cerebral

a. (PCA)

Branch of the basilar at the level of the

pons and midbrain

Supplies the occipital lobe and

the inferomedial aspect of thetemporal lobe.

Anterior Communicating a.

Short segment between two anterior cerebral arteries

Posterior communicating a.

Passes backwards to join the PCA; forms part of the Circle of Willis.

Basilar artery Formed by union of two vertebrals; lies

on the surface of the pons

Supplies pons and inner ear;

branches supply cerebellum

Superior cerebellar

a.

CN III surfaces thru the posterior cerebral

and superior cerebellar a.

Supplies superior surface of

the cerebellum

Ant. Inferior

cerebellar a.

Lies next to CN VII and VIII. Supplies anterior and inferior

cerebellum

Vertebral a. Enters cranial cavity thru the foramen

magnum; direct branches include the basilar and the post. inferior cerebellar a.

(PICA), and the anterior spinal

"posterior circulation"; direct

branches supply theventrolateral sector of the

medulla.Posterior inferior cerebvellar a.

(PICA)

Branches from the vertebral Supplies inferior aspect of thecerebellum

Anterior spinal a. From both vertebrals Supplies a ventral medial

sector of the medulla

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http://upload.wikimedia.org/wikipedia/commons/2/2e/Circle_of_Willis_en.svg




Ventricular System

The ventricular system consist of a series of interconnecting cavities originating from the centralcanal of the embryonic neural tube. In the spinal cord this is represented by the central canal.

In the brain, however, the enormous enlargement of this basic tube-like structure is paralleled by

the development of an elaborate system of ventricles. These cavities are lined with ependymalcells and contain cerebrospinal fluid (CSF), which is produced from specialized tissues

(choroid plexus) within the ventricles.

Structure Relative location Function

Lateral ventricles

• Anterior horn

• Body

• Posterior horn

• Inferior horn

• Atrium

-Frontal lobe-Parietal lobe

-Occipital lobe

-Temporal lobe-Base of the junction of

between temporal andoccipital lobes.

Septum pellucidum Thin sheet between the corpus

callosum and the fornix;separates the anterior horns

3rd ventricle Continuous from the cerebral

aqueduct; thalamus andhypothalamus forms the

lateral walls of 3rd vent.

Interventricular foramen

(Foramen of Monro)

Aperture lying in the rostral

portion of the 3rd ventricle

Provides communication with

the lateral ventricles

Choroid plexus Lining of ventricles;composed of ependymal cells

Produces CSF

Cerebral aqueduct Formed from the central canal

of the embryonic midbrain;

separates the tectum from the

tegmentum; opens posteriorlyinto the 4th ventricle

4th ventricle Formed in the embryonichindbrain

Foramen of Luschka Aperture lying at the tips of the lateral recesses in the

cerebellar hemispheres.Foramen of Megendie Lies in the midline toward the

posterior end of the 4 th

ventricle

Central canal of the spinal

cord

Formed from the embryonic

spinal cord canal.

Superior Medullary velum Forms the roof of the 4th

ventricle

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(From www.medfriendly.com)

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neuroanatomy lab 3 '11

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