The Central Nervous System
SPPA 2050 Speech Anatomy &
Physiology
1
Outline
I. Anatomy of the Nervous System
II. Afferent and Efferent Pathways
III. Centers and Circuits for the Neural
Control of Speech
SPPA 2050 Speech Anatomy &
Physiology
2
Outline
I.
Anatomy of the Nervous System
i.
ii.
iii.
Central Nervous System
Peripheral Nervous System
Nourishment and Protection
SPPA 2050 Speech Anatomy &
Physiology
3
Outline
I.
Anatomy of the Nervous System
i.
Central Nervous System
•
•
•
•
•
•
•
•
Basic Organization
Cerebral Hemispheres
Basal Ganglia (Nuclei)
Thalamus & Hypothalamus
Cerebellum
Limbic System
Brainstem
Spinal Cord
SPPA 2050 Speech Anatomy &
Physiology
4
Basic CNS Organization
I.
II.
Spinal cord
Brain
a.
Hindbrain



b.
c.
Medulla
Pons
Cerebellum
Midbrain
Forebrain




Thalamus
Hypothalamus
Basal ganglia
Cerebrum
SPPA 2050 Speech Anatomy &
Physiology
5
Basic CNS Organization
I.
II.
Spinal cord
Brain
a.
Hindbrain



b.
c.
Medulla
Pons
Cerebellum
brainstem
Midbrain
Forebrain




Thalamus
Hypothalamus
Basal ganglia
Cerebrum
SPPA 2050 Speech Anatomy &
Physiology
6
Basic CNS Organization
CNS is made up of gray matter and
white matter
SPPA 2050 Speech Anatomy &
Physiology
7
White matter
• Contains axons that communicate between CNS structures
• Why white?
• Contains myelin (which is fatty) which insulates axons
• When you think white matter, think connections between
brain regions.
SPPA 2050 Speech Anatomy &
Physiology
8
Gray matter
• contains cell bodies and synapses that allow
communication between neurons.
• Place of integration/modulation of CNS activity.
• Nucleus: collection of CNS cell bodies
• When you think gray matter, think cell bodies &
synapses between individual neurons.
SPPA 2050 Speech Anatomy &
Physiology
9
White and gray matter
Gray matter
White matter,
Transverse Section of Brain
SPPA 2050 Speech Anatomy &
Physiology
10
White and gray matter
Gray matter,
which stains light
White matter,
which stains dark
(Weigert stain)
Cross-Section of Caudal
Brainstem
SPPA 2050 Speech Anatomy &
Physiology
11
Basic CNS Organization
• The CNS is generally “symmetric”
sinistral
dextral
Cross-Section of Brainstem
(Level 3)
SPPA 2050 Speech Anatomy &
Physiology
12
Outline
I.
Anatomy of the Nervous System
i.
Central Nervous System
•
•
•
•
•
•
•
•
Basic Organization
Cerebral Hemispheres
Basal Nuclei (Basal Ganglia)
Thalamus & Hypothalamus
Cerebellum
Limbic System
Brainstem
Spinal Cord
SPPA 2050 Speech Anatomy &
Physiology
13
Cerebral Hemispheres
SPPA 2050 Speech Anatomy &
Physiology
14
Cerebral Hemispheres
• Largest part of the brain
• wrinkled surface or cortex (bark)
– ↑ ↑ ↑ surface area
– Principally gray matter (synapses)
– organized in layers
SPPA 2050 Speech Anatomy &
Physiology
15
Cerebral Cortex: Basic Structure
SPPA 2050 Speech Anatomy &
Physiology
16
Cerebral Cortex: Basic Structure
• Gyrus
– outfolding of cortex
• Sulcus/fissure
– infolding of cortex
SPPA 2050 Speech Anatomy &
Physiology
17
Cerebral Hemispheres
Longitudinal fissure
SPPA 2050 Speech Anatomy &
Physiology
18
Lobes of Cerebral Cortex
Figure 39.12
SPPA 2050 Speech Anatomy &
Physiology
19
Insula: Lobe or region?
SPPA 2050 Speech Anatomy &
Physiology
20
Sulci & Brodmann Areas
Figure 39.11
SPPA 2050 Speech Anatomy &
Physiology
21
Relation between anatomy
and function
Kent (1997)
SPPA 2050 Speech Anatomy &
Physiology
22
Communicating between brain
structures
• Performed by axonal fibers (i.e. white matter)
• Fasciculi – bundles of axonal fibers
SPPA 2050 Speech Anatomy &
Physiology
23
Communicating between brain
structures
Types of fibers
• Association fibers
– connect cortical areas in the same hemisphere
• short (i.e. gyrus to next gyrus)
• long (i.e. connecting lobes)
• Commissural fibers
– connect hemispheres
• Projection fibers
– Projects to/from the brainstem and spinal cord
SPPA 2050 Speech Anatomy &
Physiology
24
Some fasciculi of the cerebral cortex
(long association fibers)
Kent (1997)
SPPA 2050 Speech Anatomy &
Physiology
25
Commissural fibers of the cerebral
cortex
•
•
•
•
Figure 39.31
Corpus callosum
Anterior commissure
Middle commissure
Posterior commissure
SPPA 2050 Speech Anatomy &
Physiology
26
Corona radiata & internal capsule
Figure 39.8
SPPA 2050 Speech Anatomy &
Physiology
27
Outline
I.
Anatomy of the Nervous System
i.
Central Nervous System
•
•
•
•
•
•
•
•
Basic Organization
Cerebral Hemispheres
Basal Ganglia (Nuclei)
Thalamus & Hypothalamus
Cerebellum
Limbic System
Brainstem
Spinal Cord
SPPA 2050 Speech Anatomy &
Physiology
28
Basal ganglia (nuclei)
SPPA 2050 Speech Anatomy &
Physiology
29
Basal ganglia (nuclei)
A collection of nuclei including
• caudate nucleus
• putamen
• globus pallidus
• subthalamic nucleus
• substantia nigra
• putamen + globus pallidus = lentiform nucleus
• caudate nucleus + putamen = corpus striatum
SPPA 2050 Speech Anatomy &
Physiology
30
Basal ganglia (nuclei)
Caudate nucleus
body
head
tail
Lentiform nucleus
SPPA 2050 Speech Anatomy &
Physiology
Netter
31
Basal ganglia (nuclei)
Figure 39.9 Transverse
Figure 39.7 Coronal
SPPA 2050 Speech Anatomy &
Physiology
32
Basal ganglia (nuclei)
Function
• involved in movement control
• Does not directly connect to motorneurons
• Helps stabilize the motor system
Diseases
• Parkinson’s Disease
– reduced movement
• Huntington’s Chorea
– uncontrolled “dancing” like movement
• Hemiballismus
– Uncontrolled rapid movements
SPPA 2050 Speech Anatomy &
Physiology
33
Outline
I.
Anatomy of the Nervous System
i.
Central Nervous System
•
•
•
•
•
•
•
•
Basic Organization
Cerebral Hemispheres
Basal Nuclei (Basal Ganglia)
Thalamus & Hypothalamus
Cerebellum
Limbic System
Brainstem
Spinal Cord
SPPA 2050 Speech Anatomy &
Physiology
34
Thalamus
SPPA 2050 Speech Anatomy &
Physiology
35
Thalamus
Figure 39.9 Transverse
Figure 39.7 Coronal
SPPA 2050 Speech Anatomy &
Physiology
36
Thalamus
Figure 39.16
SPPA 2050 Speech Anatomy &
Physiology
37
Thalamus
Netter
SPPA 2050 Speech Anatomy &
Physiology
38
Thalamus
Basic Anatomy
• Is a collection of nuclei
• All sensory information (exception olfaction) passes through
thalamus en route to cerebral cortex
• Information from basal ganglia and cerebellum reaches cortex via
the thalamus
• “gateway to the cortex”
Function
• integration site for
–
–
–
–
Sensory information from different modalities
Complex behavior (language)
Motor processes
Emotional circuits
SPPA 2050 Speech Anatomy &
Physiology
39
Thalamic nuclei
• Anterior & mediodorsal nuclei
– Connected to emotional circuits
• Ventral anterior and ventral lateral nuclei
– input from basal ganglia and cerebellum
• Ventral posterior lateral (VPL) and medial (VPM)
– relays general sensory information from body (VPL) and
head (VPM)
• Medial geniculate body
– Relays/processes auditory information
• Lateral geniculate body
– Relays/processes visual information
SPPA 2050 Speech Anatomy &
Physiology
40
Hypothalamus
Figure 39.16
SPPA 2050 Speech Anatomy &
Physiology
41
Hypothalamus
Basic Anatomy
• Located inferior to the thalamus (hence “hypo”)
Function
• Controls ‘autonomic behavior such as
–
–
–
–
–
release of hormones
control of food and water intake
sexual behavior
sleep cycles
emotional responses
• Indirect role in speech (unless you include flirting)
SPPA 2050 Speech Anatomy &
Physiology
42
Outline
I.
Anatomy of the Nervous System
i.
Central Nervous System
•
•
•
•
•
•
•
•
Basic Organization
Cerebral Hemispheres
Basal Nuclei (Basal Ganglia)
Thalamus & Hypothalamus
Cerebellum
Limbic System
Brainstem
Spinal Cord
SPPA 2050 Speech Anatomy &
Physiology
43
Cerebellum
Figure 39.6
SPPA 2050 Speech Anatomy &
Physiology
44
Cerebellum & Brainstem
Figure 39.6
SPPA 2050 Speech Anatomy &
Physiology
45
Cerebellum
• Cerebellum ~ “little brain”
• Contains ~ ½ neurons in the entire brain
• Attached to dorsal brainstem by peduncles
– Inferior cerebellar peduncle
– middle cerebellar peduncle
– superior cerebellar peduncle
SPPA 2050 Speech Anatomy &
Physiology
46
Cerebellar peduncles
(new slide)
Figures 39.16,39.18
SPPA 2050 Speech Anatomy &
Physiology
47
Cerebellum
•
•
White matter
– Fibers going into and out of the cerebellum via
peduncles
Gray matter
– Cerebellar cortex
– deep cerebellar nuclei
SPPA 2050 Speech Anatomy &
Physiology
48
Cerebellar gray matter
(new slide)
SPPA 2050 Speech Anatomy &
Physiology
From Netter
49
Cerebellum
Cerebellar cortex
What is it?
– Primary information receiving area
How is information received?
– Inferior and middle cerebellar peduncles
Where does the information come from?
– other motor control centers
– vestibular system (balance)
– Information about body position via brainstem
and spinal cord
SPPA 2050 Speech Anatomy &
Physiology
50
Cerebellum
Deep Cerebellar Nuclei
What is it?
– Primary information sending area
How does it send information?
– superior cerebellar peduncle
Where does it send information?
– brainstem and spinal cord
– Cerebral cortex via thalamus
SPPA 2050 Speech Anatomy &
Physiology
51
Cerebellum
Function
• Coordinates muscles for smooth fluid motion
• Monitors “state” of body in space
• Monitors/adjusts motor commands
Cerebellar Disease/damage
• can result in “ataxia”
– Decomposition of movement
– Errors in timing and scaling of movement
– Tremor during movement activities
SPPA 2050 Speech Anatomy &
Physiology
52
Outline
I.
Anatomy of the Nervous System
i.
Central Nervous System
•
•
•
•
•
•
•
•
Basic Organization
Cerebral Hemispheres
Basal Nuclei (Basal Ganglia)
Thalamus & Hypothalamus
Cerebellum
Limbic System
Brainstem
Spinal Cord
SPPA 2050 Speech Anatomy &
Physiology
53
Limbic System
SPPA 2050 Speech Anatomy &
Physiology
54
Limbic System
Hippocampus
Fornix
Mammillary body
Amygdala
Figure 39.13
SPPA 2050 Speech Anatomy &
Physiology
55
Limbic System
Function
• Important in regulating emotional and
visceral responses
• role in speech/language unclear
– damage in the area can cause mutism
(lack of any speech)
SPPA 2050 Speech Anatomy &
Physiology
56
Outline
I.
Anatomy of the Nervous System
i.
Central Nervous System
•
•
•
•
•
•
•
•
Basic Organization
Cerebral Hemispheres
Basal Nuclei (Basal Ganglia)
Thalamus & Hypothalamus
Cerebellum
Limbic System
Brainstem
Spinal Cord
SPPA 2050 Speech Anatomy &
Physiology
57
Brainstem: ventral
Midbrain
Pons
Medulla
Figure 39.19
SPPA 2050 Speech Anatomy &
Physiology
58
Brainstem: Dorsal Lateral
Midbrain
Pons
Medulla
Figure 39.19
SPPA 2050 Speech Anatomy &
Physiology
59
Brainstem: dorsal
Midbrain
Pons
Medulla
Figure 39.19
SPPA 2050 Speech Anatomy &
Physiology
60
Brainstem
Basic Anatomy
• Contains
• Projection fibers (called tracts)
– To higher CNS structures from SC/BS
– To SC/BS from higher CNS structures
•
Nuclei
– Associated with cranial nerves
– Associated with basic bodily function
SPPA 2050 Speech Anatomy &
Physiology
61
Brainstem
Function
• Cranial nerve nuclei
–
–
•
Motor supply to muscles of speech
Sensory supply to head and neck
Regulates some essential life functions
–
–
–
–
Body temperature
Respiration
Swallowing
Digestion
SPPA 2050 Speech Anatomy &
Physiology
62
Figure 39.19
SPPA 2050 Speech Anatomy &
Physiology
63
Superior orbital fissure (CN V: ‘V1’)
Foramen rotundum (CN V: ‘V2’)
Foramen ovale (CN V: ‘V3’)
Internal auditory meatus (CN VII & VIII)
Jugular foramen (CN IX, X, XI)
Hypoglossal canal (CN XII)
SPPA 2050 Speech Anatomy &
Physiology
64
Cranial Nerve Nuclei
Figure 31.2
SPPA 2050 Speech Anatomy &
Physiology
65
Where do cranial nerves arise?
Pons
• CN V – sourced to a number of BS nuclei
• CN VII –motor portion from Facial nucleus
Medulla
• CN IX, X, XI – originate largely in nucleus ambiguus
• CN XII – originates in Hypoglossal nucleus
SPPA 2050 Speech Anatomy &
Physiology
66