Chapter 2c CNS Gross Anatomy
 Chris Rorden
University of South Carolina
Norman J. Arnold School of Public Health
Department of Communication Sciences and Disorders
University of South Carolina
1
What is a Fasciculi
 In anatomy, a Fasciculi refers to a
A.
B.
C.
D.
Volume of Cerebral Spinal Fluid
White matter fiber tract
Gray matter nuclei
Set of cells that support neurons
2
What is a Fasciculi
 What is a fascio?
A.
B.
C.
D.
A Flag
Bundle of rods, sometimes with an axe
A spoon
A shaft of wheat, used as an ancient straw
3
4
Spinal Cord
Same Meningeal Layers as the Brain
About 45cm long
Diameter of 1 cm.
Root filaments
Dorsal
Ventral
Pia mater
Arachnoid mater
Mixed spinal
nerve
Dura mater
5
Spinal Nerve Components
Dorsal Division: sensory part of nerve, sensory
information enters spinal cord through dorsal
root fibers
Ganglion: cell bodies of these nerves come
together to create the dorsal root ganglion
Dorsal Horn or Column: information enters the
spinal column at the dorsal horn
Spinal Nerve Components
Ventral Division: motor commands, leave the
ventral root and go to muscles
Ventral Horn or Column: information passed
from brain to spinal cord then from the ventral
root to the extremities
Transverse view of spinal cord
"Copyright © 2005 by Thompson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED"
Segmental Spinal Reflex Arc
 A stimulus/response system that maintains a constant state of muscular
tone
 Works by:
– muscles spindles sense stretching and send information through gamma
nerves to dorsal root of spinal cord
– a signal is sent back from the ventral root for the muscle to contract
Spinal Cord
Dorsal root fibers form ganglion
Connect to ventral fibers to form peripheral
spinal nerves.
Attached by Filum Terminale
10
Internal Spinal Cord
Gray Matter
Two Dorsal Horns (Sensory Info)
Two Ventral Horns (Motor Info)
White Matter
Three Myelinated Fasciculi
Dorsal, Lateral and Ventral
11
Spinal Cord Segments & Nerves
31 Spinal Segments and Nerves
Cervical
8
Lumbar
5
Thoracic
12
Coccygeal
1
Sacral
5
12
Ventricles
 Lateral Ventricles
 Connected by
interventricular foramen
 Collateral trigone area
 Posterior and inferior horns
 Connects to Third Ventricle
through Monro’s foramen
13
Ventricles
Birds Eye View
– Usually symmetrical in healthy people
14
Other ventricles…
 Third Ventricle
 Ventral to the corpora
quadrigemina
 Surrounded by central gray
area
 Connects to fourth ventricle
through Cerebral Aqueduct
 Fourth ventricle
– Near Pons / Medulla
15
Multiple choice
 You are in bed and hear a loud crash – your
heart pounds. What part of your CNS is
dominant?
A.
B.
C.
D.
Parasagittal
Sympathetic
Parasympathetic
Local
16
Ventricles
17
Ventricles in clinical setting
Hydrocephalus
– E.G. cyst
18
White matter fibers from the cortex
Brain stem connects to cortex
19
Medullary Centers
Interhemispheric (between) Connections
Intrahemispheric (within) Connections
Three types of fibers
– Projection: Project through internal capsule
– Association: Within a hemisphere
i.e. Arcuate fasciculus
– Commissural: Between hemispheres i.e. Corpus
callosum
20
Meninges
Three Basic Levels
Extensions of Dura mater
Falx Cerebri: Vertical partition dipping into
cranial space (Refection)
Tentorium Cerebri: Houses the cerebellum
Falx Cerebelli: Separates two cerebellar
hemispheres
21
Multiple choice
 What view of the brain is this?
A.
B.
C.
D.
Sagittal
Axial
Coronal
Sympathetic
22
Meninges
Arachnoid Trabeculae
– Connects Pia and Arachnoid
– Inside subarachnoid space
Arachnoid Villi
– Specialized protrusions through
which Cerebrospinal Fluid (CSF)
leaves the brain
23
Peripheral Nervous System (PNS)
 12 pairs of cranial nerves– Sensory, motor, or mixed
“On Old Olympus Towering Top A
Famous Vocal German Viewed
Some Hops.”
 31 pairs of spinal nerves
Cranial Nerves (12 pair)
I.
II.
III.
IV.
V.
Olfactory: sensory for smell
Optic: sensory for vision
Oculomotor: motor for vision
Trochlear: motor for vision
Trigeminal: sensory to eyes, nose, face and
meningies; motor to muscles of mastication
and tongue
Cranial Nerves
I.
II.
Abducen: motor to lateral eye muscles
Facial: sensory to tongue and soft palate,
motor to muscles of the face and stapes
III. Vestibulocochlear: sensory for hearing and
balance (aka Acoustic)
IV. Glossopharyngeal: sensory to tongue,
pharynx, and soft palate; motor to muscles
of the the pharynx and stylopharyngeus
Cranial Nerves
I.
Vagus Nerve: sensory to ear, pharynx,
larynx, and viscera; motor to pharynx,
larynx, tongue, and smooth muscles of the
viscera, 2 parts: superior laryngeal branch
and recurrent laryngeal branch
II. Spinal Accessory Nerve: motor to
pharynx, larynx, soft palate and neck
III. Hypoglossal Nerve: motor to strap
muscles of the neck, intrinsic and extrinsic
muscles of the tongue