Transcript PSYC465 - neuroanatomy

The Anatomy of the
Nervous System
Why study Neuroanatomy?
Major divisions of the nervous system
Major divisions of the nervous system
Central
nervous
system
Brain
Spinal
cord
Somatic
nervous
system
Nervous
System
Peripheral
nervous
system
Autonomic
nervous
system
Afferent
nerves
Sensory  CNS
info
Efferent
nerves
CNS  Skeletal
muscles
Afferent
nerves
Efferent
nerves
Parasympathetic
nervous system
Sympathetic
nervous system
Terminology
CNS
PNS
Myelinproviding glia
Oligodendrocytes
Schwann Cells
Clusters of
cell bodies
Nuclei
Ganglia
(singular nucleus)
(singular ganglion)
Bundles of
axons
Tracts
Nerves
The spinal cord
Cross section through the spinal cord
Ventral
horn
Sympathetic & Parasympathetic Divisions
Cranial Nerves
I. Olfactory (smell)
II. Optic (vision)
III. Oculomotor (eye movement)
IV. Trochlear (eye movement)
V. Trigeminal (facial sensation
and chewing)
VI. Abducens (eye movement)
VII.Facial (taste and facial
expression)
VIII.Auditory (hearing and
balance)
IX. Glossopharyngeal (taste,
salivation swallowing)
X. Vagus (abdominal organs,
throat muscles)
XI. Spinal accessory (neck,
shoulders, head)
XII.Hypoglossal (tongue)
http://www.wnyc.org/shows/radiolab/episodes/2006/05/05
The body-brain
connection
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Radio Lab 2006
Where Am I?
Mind and body are in constant communication
(neuroscientists call this the brain-body loop), but the
loop can get out-of-sync-- even broken. This hour:
stories of people whose brains and bodies have lost each
other. We begin with a century-old mystery: why do
many amputees still feel their missing limbs? We speak
with a neuroscientist who solved the problem with a
magician's trick: an optical illusion. We continue with the
story of a butcher who suddenly lost his entire sense of
touch, and how, after many years, he managed to grow
a new sense. And we hear from pilots who lose
consciousness and suffer out-of-body experiences while
flying fighter jets.
The Anatomy of the
Nervous System
Neuroanatomy cont.
9
Anatomical Directions
Rostral
Caudal
Sagittal plane
(midsagittal
section)
Horizontal plane
Frontal plane
(coronal section)
Cross section
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11
12
The Five Major divisions of the Brain
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14
Five Major divisions of the Brain
Brainstem
1.
2.
3.
4.
5.
Telencephalon
Diencephalon
Mesencephalon
Metencephalon
Myelencephalon
] Forebrain
]
]
Midbrain
Hindbrain
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The Five Major divisions of the Brain
16
The Hindbrain

Myelencephalon
(medulla)
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Tracts
Small nuclei
Reticular formation
(RT)
Metencephalon

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
Cerebellum (little
brain)
Pons (bridge)
Neural tracts
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Mesencephalon - The Midbrain
Tectum


Superior collicui
(visual relay) #2
Inferior collicui
(auditory relay) #3
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Mesencephalon - The Midbrain
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Mesencephalon - The Midbrain
Tegmentum

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RF & tracts of
passage
Periaqueductal
gray
Substantia nigra
Red nucleus
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Mesencephalon - The Midbrain

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Periaqueductal gray mediates the analgesic
effects of opiate
drugs.
Substantia nigra (black
substance) – neurons
project to striatum;
degenerate in PD.
Red nucleus – motor
pathways from cortex
and cerebellum.
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Diencephalon

Thalamus – large twolobed structure; is the
top of the brain stem.
Contains many
different nuclei, most
of which project to the
cortex
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Sensory relay nuclei
Massa intermedia
White lamina
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Diencephalon

Hypothalamus – Below
the anterior thalamus.
Regulates several
motivated behaviors.
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Pituitary gland
Optic chiasm
Mammillary bodies
Other nuclei
LH
VMH
LH (lateral H.)
 VMH (ventromedial H.)
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Hypothalamus
(with other structures)
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Telencephalon
Cerebral cortex
 Major fissures
 Major gyri
 Four lobes
 Limbic system
 Basal ganglia
 Cerebral
commissures
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Telencephalon

Cerebral cortex
 Major fissures
 Lateral
fissure
 Central fissure
 Longitudinal fissure
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Telencephalon
Cerebral cortex
Rat brain
(Lissencephalic)
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Telencephalon
Cerebral cortex of human, chimpanzee and rat
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Telencephalon

Cerebral cortex
 Major fissures
 Major gyri
 Four lobe
 Frontal
 Parietal
 Temporal
 Occipital
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Telencephalon

90% of the cortex in
Humans is neocortex,
which has 6 distinct
cell layers. As the
name implies, Neocortex is a more
recent development
of brain evolution.
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Telencephalon

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Hippocampus – it is
cortex, but not neocortex (it only has 3
layers). It is
sometimes called
Archicortex.
Can you see the Sea
Horse?
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Telencephalon – Subcortical parts
Limbic System
Basal Ganglia
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Telencephalon – Limbic system

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Hippocampus
Amygdala
Fornix
Septum
Cingulate cortex
Mammilary bodies
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Telencephalon – Basal Ganglia
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Caudate nucleus
Putamen
Globus pallidus
Amygdala
Substantia nigra
Subthalamic n.
thalamus
cortex
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Telencephalon – Basal Ganglia
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Caudate nucleus
Putamen
Globus pallidus
Amygdala
Substantia nigra
Subthalamic n.
thalamus
cortex
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Telencephalon – Basal Ganglia

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Caudate nucleus
Putamen
Globus pallidus
Amygdala
Substantia nigra
Subthalamic n.
thalamus
cortex
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Name the brain region
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Mid-saggital
1. Type of section?
Cingulate
7.
Corpus
callosum
Pons
2.
Temporal
Cerebellum
3.
9.
Parietal
10.
Occipital
12.
Frontal
13.
14. 11.
Thalamus
Tegmentum
5.
Tectum
4.
Hypothalamus
Mammillary
bodies
8.
6.
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Memorize the chart on page 72
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Meninges

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Dura mater (tough mother) outer membrane.
Arachnoid membrane (web-like) a thin
membrane.
Subarachnoid space – contains large blood
vessels and CSF.
Pia mater (pious or gentle mother) adheres to
the surface of the CNS.
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Ventricles & CSF

Cerebral Ventricles Four large internal
chambers of the brian.
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Lateral ventricles, 3rd ventricle, & 4th ventricle.
Central canal – a small canal that runs the
length of the spinal cord.
Choroid plexuses are a network of capillaries
that protrude into the ventricles and produce
cerebrospinal fluid (CSF).
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Ventricles & CSF
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Ventricles and Choroid Plexus
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A. Lateral
ventricles
B. Third ventricle
C. Cerebral
aqueduct
D. Fourth Ventricle
E. Arachnoid villi
F. Choroid plexus
G. Choroid plexus
H. Subarachnoid
space
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Protecting the Brain
Physical protection
Skull & Vertebrae
 Meninges
 Cerebrospinal fluid (CSF)
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Chemical protection

Blood-brain barrier (BBB)
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Blood-brain barrier
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Results from the special structure of cerebral
blood vessels.
Cells in the walls of cerebral blood vessels are
tightly packed.
This provides a barrier for the passage of
some large-molecules and proteins into the
brain.
Not all large molecules are impeded (e.g.,
glucose).
Sex hormones readily pass through to certain
brain areas where the BBB is weak.
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Two basic cells of the nervous system
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Neurons – cells specialized for the
reception, conduction and transmission of
electrochemical signals.
Glial cells – classic view - support cells that
a) provide nutrients
b) clear waste
c) provide a physical matrix (glia means
“glue”)
But recent evidence suggests that they do
even more…
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Two basic cells of the nervous system
Glial cells also –
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Participate in neurotransmission by
sending signals to neurons and
receiving signals from them.
Control the establishment and
maintenance of synapses
Form circuits and may contribute to
synaptic plasticity.
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External Anatomy of the Neuron
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Cell body (soma)
Cell membrane
Dendrites
Axon
Axon hillock
Myelin
Nodes of Ranvier
Terminal boutons
Synapses
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External Anatomy of the Neuron
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Structural classes of Neurons
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Multipolar
Unipolar
Bipolar
Interneurons
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Structural Classes of Neurons
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Types of Glial Cells
Oligodendrocytes – myelinate axons
of the CNS.
 Schwann Cells – myelinate axons of
the PNS.
 Astrocytes – large star-shaped glia
 Microglia – respond to injury
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Suggested Websites for Chapter 3:
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Autonomic Nervous System: http://www.ndrf.org/ans.htm
The National Dysautonomia Research Foundation site; good overview of function and disorders like
Shy-Drager Syndrome, Guillain Barre Syndrome, and more well-known disorders like diabetes and
Parkinson's Disease.
Neurons and Glia: http://faculty.washington.edu/chudler/introb.html
From Dr. Eric Chudler at the University of Washington; scroll down to "Neurons" to find information
about neurons, glia, and a photo gallery of cells.
Neuroanatomy Quiz: http://psych.hanover.edu/Krantz/neural/struct3.html
A quick quiz on the anatomy of the neuron; part of Dr John Krantz's study aids and tutorials for
biopsychology.
The Ventricles: http://www.epub.org.br/cm/n02/fundamentos/ventriculos_i.htm
From the Brain & Mind site; more information about ventricles, cerebrospinal fluid, and hydrocephalus.
Interactive Brain Atlas: http://www9.biostr.washington.edu/da.html
From the Digital Anatomist project at the University of Washington, select the “BRAIN” icon for a
fabulous collection of images in many different planes of section, digital recreations of different
functional systems in the brain, and a good section on cerebrovasculature.
Brain Anatomy:
http://www.thebrain.mcgill.ca/flash/d/d_01/d_01_cr/d_01_cr_ana/d_01_cr_ana.html
From McGill University, a wonderful introduction to neuroanatomy, with different levels of complexity
(beginner to advanced) and levels of organization (from social aspects to molecular aspects of
neuroanatomy).
Word Roots: http://faculty.washington.edu/chudler/neuroroot.html
A good source for the Greek and Latin roots of many neuroanatomical terms.
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NPR website: http://www.npr.org/
Search for “brain”
 Other Links
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Gray Matters, the brain radio program and its archives
http://www.dana.org/books/archives/radiotv_archiveinde
x.cfm
Irvine Health Foundation Lecture series
http://www.ihf.org/lecture/2004lectures.html
Infinite Mind http://www.lcmedia.com/mindprgm.htm
Biopsychology news http://www.biopsychology.com/
PubMed http://www.ncbi.nlm.nih.gov/entrez/
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http://www.pbs.org/wgbh/nova/mind/
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