Download 大腦神經解剖與建置

普通生物學 -神經系統與應用
Chapter 49
神經系統
Nervous System
(中樞神經系統CNS)
柯立偉 老師
交通大學生物科技學系
Outline

Nervous System 神經系統 (review)
 Organization of Vertebrate Nervous System
 Five Different Neurons in Nervous System
 Glia Cell in the Nervous System

Central Nervous System (CNS)
 Neuroanatomy and Development (大腦神經解剖與建置)
 Brain and Spinal Cord
 Overview (大腦,小腦,間腦,腦幹)
 大腦
 間腦
 腦幹
 小腦
 脊隨
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※ Organization of Vertebrate Nervous System※

In vertebrates
 The CNS is composed of the brain and spinal cord
 The peripheral nervous system (PNS) is composed
of nerves and
Central nervous
Peripheral nervous
system (CNS)
system (PNS)
ganglia.
Brain
Spinal cord
Cranial nerves
Ganglia outside
CNS
Spinal nerves
Figure 49.4
Organization of Vertebrate Nervous System


The spinal cord conveys information from and to the brain
and also produces reflexes independently of the brain
A reflex 反射動作 is the body＇s automatic response to a
stimulus
 For example, a doctor uses a mallet to trigger a kneeCell body of
Gray
jerk reflex
sensory neuron in
Quadriceps
muscle
matter
dorsal root
ganglion
White
matter
Hamstring
muscle
Spinal cord
(cross section)
Figure 49.3
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Sensory neuron
Motor neuron
Interneuron
2
※ Different Neurons in Nervous System※
※ Glia in the Nervous System※
CNS
VENTRICLE
Cilia
PNS
Neuron
Astrocyte
Oligodendrocyte
Schwann cell
Microglial
Capillary
Figure 49.6
Glia have numerous functions to nourish 滋養, support, and regulate
neurons.
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Glia in the Nervous System
Astrocyte (星形膠質細胞)
It induce cells lining capillaries in the CNS to form tight
junctions, resulting in a blood-brain barrier and restricting the
entry of most substances into the brain.
Microglia (小膠質細胞)
Immune cells that protect against pathogen 病原體.
Oligodendrocyte (少突膠質細胞)
Generating myelinate 髓鞘 axon in the CNS, greatly
increases the conduction speed of action potentials.
Schwann cell
Generating myelinate髓鞘 axons in the PNS.
Central Nervous System (CNS)
Neuroanatomy and Development
大腦神經解剖與建置
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Motivation
The relationship between brain anatomy (解剖學) and
cognition has been the source of fascination (魅力) and
puzzlement (迷惑) for hundreds of years.
舉例來說，許多研究認為大腦組織功能與智慧是有關聯的。
ex. Albert Einstein
To identify unique anatomical features of Einstein’s brain that
might explain his genius.
 When he died in 1955 at the age of 76, his brain was extracted
and saved.
 weighed, perfused with formalin, measured and photographed
 sectioned and embedded in a material that permitted it to be
thinly sliced to make histological slides for microscopic analysis
To compare with the brains from a few dozen normal persons
that had been donated for scientific research.
IQ vs. Brain Organization
我的腦哪裡不一
樣？？
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Two Prominent Features of Einstein’s Brain
First: the Sylvian fissure (大腦側裂溝) (the division that separates
the temporal lobe from the frontal and parietal lobes), in
Einstein’s brain had an unusual anatomical organization.
 Unlike the control brains, Einstein’s brain showed a strange confluence
(匯集處) of the Sylvian fissure with the central sulcus on the brain’s
lateral surface.
 The Sylvian fissure in most brains projects posteriorly (後面) to end in
an area surrounded by the supramarginal gyrus (腦回邊界之上).
Second: Einstein’s inferior parietal lobe (下頂葉) was actually
larger, and indeed thicker (較厚的) in lateral to medial extent.
 The increased size of Einstein’s inferior parietal cortex might have
been related to his intellectual capacity. (Hypothesis, not conclusion)
From such investigations, hypotheses can be generated and then
tested in brains removed at autopsy or, in the modern age of
neuroimaging, in brains in the living human.
Neuroanatomy
the branch of anatomy that studies the anatomical
organization of the nervous system
• Gross neuroanatomy : the focused is on general structures and
connections visible to the naked eyes (裸眼)
• Microscopic neuroanatomy (fine neuroanatomy) : to describe
the organization of neurons and their connections and subcellular
structure
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Methods in Neuroanatomy
How to view the brain?
?
Removing the brain from the head and
put it in a container filled with
preservative (防腐劑) such as formalin
(福馬林)
Meninges (腦膜)
a dense layers of collagenous
fibers (膠原纖維)
硬腦膜
蛛網膜
軟腦脊膜
動脈
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Meninges
Both the brain and spinal cord are protected by
a tough protective tissue called meninges
consisting of three layers:
• Dura matter
• Arachnoid membrane
• Pia matter
15
The photograph of the human brain
Cerebrum
Brain stem
cerebellum
Spinal cord
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Cerebrum
Cerebrum
gyrus (gyri)
sulcus (sulci)
Gyri (腦回): the protruding (突出) rounded surface
Sulci (溝): the numerous smaller invaginations (堆疊) seen as creases
(皺摺)
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Cerebrum
Three main anatomic planes
冠狀切
水平切
箭狀切
20
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Navigating in the Brain
• The front is the rostral end, toward the
frontal lobes.
• The posterior end is the caudal end, toward
the occipital lobe.
• The top and bottom are, respectively, the
dorsal and ventral surfaces of the brain.
1.5kg average
腦
gyrus (gyri複):凸處迴轉
sulcus (sulci複):皺褶
ventricular:腦室
國立交通大學生物科技學系 柯立偉老師
20%氧在腦
缺氧10分即死
身體動/不動腦中
血液變化小
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Different View of the Brain
dorsal view
( horizontal axial section)
front
右
左
lateral view
(sagittal section)
dorsal
Interhemispheric
fissure
(longitudinal
fissure)
frontal
occipital
occipital
ventral
sylvian fissure(裂溝)
→區分temporal lobe from
frontal lobe 及parietal
Central Nervous System (CNS)

Brain

Spinal Cord
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Human Brain Development
Brain structures in child and adult
Embryonic brain regions
Cerebrum (includes cerebral cortex, white
matter, basal nuclei)
Diencephalon (thalamus, hypothalamus,
epithalamus)
Telencephalon
Forebrain
Diencephalon
Midbrain
Mesencephalon
Midbrain (part of brainstem)
Metencephalon
Pons (part of brainstem), cerebellum
Myelencephalon
Medulla oblongata (part of brainstem)
Hindbrain
Midbrain
Hindbrain
Diencephalon
Cerebrum
Mesencephalon
Metencephalon
Diencephalon
Myelencephalon
Forebrain
Telencephalon
Embryo at 1 month
Embryo at 5 weeks
Midbrain
Pons
Medulla
oblongata
Cerebellum
Spinal cord
Spinal
cord
Figure 49.9b
Child
※ Overview of Our Brain※
Left cerebral
hemisphere
Right cerebral hemisphere
Cerebrum
大腦
Cerebral cortex 大腦皮層
Corpus callosum 胼胝體
Basal nuclei 基底核
Figure 49.9d
Cerebellum
小腦
Figure 49.9c
間腦 Diencephalon
視丘 Thalamus
松果體 Pineal gland
下視丘 Hypothalamus
腦下垂體 Pituitary gland
腦幹
Brainstem
Spinal cord 脊髓
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Midbrain
Pons 橋腦
Medulla
oblongata
延腦
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※ Cerebrum 大腦※



The cerebrum is divided into right and left cerebral
hemispheres, which receive information and control
movement of the left and right body.
A thick band of axons known as the corpus callosum 胼胝體
enables the right and left cerebral cortices to communicate.
Basal nuclei 基底核 serve as centers for planning and
learning movement sequences, deep within the white matter.
Left cerebral hemisphere
Right cerebral hemisphere
Cerebrum
Cerebral cortex
Corpus callosum
Basal nuclei
Figure 49.9c
Adult brain viewed from the rear
Four Lobes:
sylvian sulcus
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Gray matter and White matter
Gray matter and White matter
The brain and spinal cord contain
Gray matter, which consists of neuron cell bodies,
dendrites, and unmyelinated axons
White matter, which consists of bundles of myelinated
axons
Gray matter
White
matter
Ventricles
Figure 49.5
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Primary sensory cortex for vision
•
•
•
•
Brodmann area 17, BA 17
Striate cortex (cytoarchitectonic name)
Calcarine cortex (gross anatomical name)
Primary visual cortex (functional name),
V1 (for “visual area 1”)
不同命名不一定都有一對一的對應區域
Ex. BA18 of the visual system, is not
synonymous with V2.
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Functions of Human Cerebral Cortex
Figure 49.15
Frontal lobe
Motor cortex
(control of
skeletal muscles)
Somatosensory cortex
(sense of touch)
Parietal lobe
Prefrontal cortex
(decision making,
planning)
Sensory association
cortex (integration of
sensory information)
Visual association
cortex (combining
images and object
recognition)
Broca’s area
(forming speech)
Temporal lobe
Occipital lobe
Auditory cortex (hearing)
Wernicke’s area
(comprehending language)
Cerebellum
Visual cortex
(processing visual
stimuli and pattern
recognition)
Motor Areas of the Frontal Lobe
 Frontal lobe: planning / execution of movements
a. motor cortex : precentral gyrus =Motor strip
primary motor cortex (M1): BA4
b. prefrontal cortex
a* precentral gyrus：primary motor cortex之前有2個more main
motor areas (within BA6).
premotor cortex (lateral surface)
supplementary motor cortex (dorsal to premotor area)
* Axons in motor neurons extend to the spinal cord and brainstem
* Synapse on motor neurons in the spinal cord
2部分
b. prefrontal cortex (high-order association areas):
higher aspects of motor control planning / execution of behaviors
that require the integration of information over time分3 more areas:
1.dorsal lateral prefrontal cortex → working memory
2.orbitofrontal cortex
3.anterior cingulate and medial front regions
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Somatosensory Areas of the Parietal Lobe
Parietal Lobe
somatosensory cortex : central sulcus (posterior) and
postcentral gyrus and adjacent areas. (BA 1, 2, and 3)
1.receive inputs from the somatosensory of the thalamus
2.represent information: touch, pain, 溫度, 四肢姿態的信息(limb), 本體
感受(proprioception)
分為SⅠ (primary somatosensory cortex )
SⅡ (secondary somatosensory cortex )
Two pathways:
外界sensory signal
Thalamus
anterolateral system
(pain, 溫度)
dorsal column – medial lemniscal system
(touch, proprioception, movement)
SⅠ
SⅡ
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Frontal lobe
Parietal lobe
Jaw
Tongue
Leg
Hip
Trunk
Neck
Head
Knee
Hip
Genitalia
Toes
Tongue
Pharynx
Primary
motor cortex
Abdominal
organs
Primary
somatosensory
cortex
Figure 49.17
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Direct Stimulation on the Cortex
Visual Processing Areas in the Occipital Lobe
Retina
Thalamus
Lateral
geniculate
nucleus
V1: primary visual cortex
(≡striate cortex)
埋在occipital lobe的
(Bradmann Area 17)
calcarine fissure中
Colors/亮度/空間
primary visual pathway cortical projector (retina頻率/orientation
geniculo-striate pathway)
/movement
(Details in Ch5 & 6)
subcortical brain region
Retina
superior colliculus of
midbrain
visuomotor functions
(如眼動, eyemovents)
secondary(2nd)visual pathway (subcortical projection)
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Auditory Processing Areas in the Temporal Lobe
and Association Cortex
Temporal Lobe (TL)
BA 22 (surrounds the auditory cortex)
 Primary Auditory cortex: aids in the perception of auditory inputs
(1) superior part of Temporal Lobe (BA 41 & 42)
(2) buried (埋) in sylvian (lateral) fissure (tonotopic organization)
cochlea
耳蝸
subcortical relay
medial
geniculate of
thalamus
supratemporal
cortex
(Heschl’s gyri)
Association Cortex
Cortex 中非sensory / motor區(Audio/video/ somatosensory等),
皆為association cortex ,如 front cortex / temporal cortex
Ex:(1)visual association cortex (在parietal及temporal lobes)
(2)parietal-temporal-occipital junction
在左腦:language processing
在右腦:attentional orienting
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Playing a Music
動覺
味覺
體感覺
嗅覺
視覺
聽覺
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Language and Speech

Studies of brain activity have mapped areas responsible for language
and speech

Broca＇s area in the frontal lobe is active when speech is generated

Wernicke＇s area in the temporal lobe is active when speech is heard

These areas belong to a larger network of regions involved in language
Max
Hearing
words
Seeing
words
Speaking
words
Generating
words
Min
Figure 49.16
Review - Brain and its Functions
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新皮質
細皮質
基底核
間腦
Cingulate gyrus
扣帶迴
Hippocampus
海馬迴
(allocortex)
Limbic lobe
邊緣葉(系統)
Limbic Lobe (邊緣葉)
Limbic Lobe
mesocortex → 6層 (如cingulate gyrus)
allocortex → 1~4層 (如hippocampus)
temporal / frontal /parietal / occipital lobes≡6層neocortex (新皮質)
• 人類的新皮質
(neocortex)佔整個腦
的76%。
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穹窿
(拱型空間)
前聯合喉
• Classical Limbic Lobe:
1. cingulate Gyrus (扣帶迴)
2. hypothalamus (下視丘)
3. anterior thalamic nuclei (前丘腦核)
4. hippocampus (海馬迴)
• Papez Circuit:
1930 James Papez first
suggested these structures
were organized into a system
for emotional behavior.
• Two key components of the Limbic system (today): amygdala (杏仁核), a group
of neurons anterior to the hippocampus (orbitofrontal cortex + parts of basal
ganglia + medial dorsal nucleus of thalamus, not shown here).
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Limbic Lobe
 Hippocampus(海馬迴)
-inferior and media of temporal lobe
-分為4 CA (cornu ammonis 大角) fields CA1~CA4
dentate gyrus
Entorhinal
cortex 嗅皮質
cingulate
cortex

pyramidal nervous
hippocampus
fornix
與memory 及emotional processing(由於hippocampus與
cingulate mammillary bodies 與limbic system互連 )
papez circuit → emotional behavior
Amygdala(核心)+orbitofrontal cortex+(parts of) basal ganglia
+medial dorsal nucleus of thalamus

Limbic Lobe :演化史上neo cortex老原始
與emotional processing, learning, and memory 有關
Emotions


Generation and experience of emotions involve many brain
structures including the amygdala 杏仁核, hippocampus
海馬迴, and parts of the thalamus視丘, are grouped as the
limbic system .
The limbic system also functions in motivation, olfaction,
behavior, and memory.
Thalamus
Hypothalamus
Olfactory
bulb
Figure 49.13
Amygdala
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Hippocampus
27
Emotions


Generation and experience of emotion also require
interaction between the limbic system and sensory areas of
the cerebrum.
The structure most important to the storage of emotion in
the memory is the amygdala, a mass of nuclei near the
base of the cerebrum.
Nucleus accumbens
Happy music
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Amygdala
Sad music
Figure 49.14
28
Basal Ganglia
Basal Ganglia (腦部基底核)
-subcortical structures (在側腦室 (lateral ventricles)之前)
-在control of movement 扮演重要的角色
-細分成3部分：(Fig 3.20, p80)
globus pallidus (蒼白球)
corpus
caudate nucleus (尾狀核)
striatum
Putamen (硬核)
neostriatum
basal ganglia + subthalamic nucleus + substantia nigra
≡ (i) motor control [somatic motor and oculomotorsystems]
(ii) cognitive functions :
short-term memory process (dorsolaternal prefrontal cortex)
execution functions (behaviors)
• The subthalamic nucleus (丘腦
底部) and the substantia nigra
(黑質) are considered part of
the basal ganglia.
• Parkinson與位於中腦(midbrain)
的substantia nigra有密切關係，
因substantia nigra中生產
dopamine的細胞大量死亡所致。
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※ Diencephalon (間腦)※
Diencephalon
Thalamus
Pineal gland
Hypothalamus
Pituitary gland
Figure 49.9d
Diencephalon (間腦)




Incoming information from all the senses is sorted in the thalamus 視丘
and sent to the appropriate cerebral centers for further processing.
Through the hypthalamus 下視丘 control of the pituitary gland 腦下垂
體, it regulates hunger and thirst, plays a role in sexual and mating
behavior, and controls the fight-or-flight response.
It is also the source of posterior pituitary hormones and of releasing
hormones that act on the anterior pituitary.
The epithalamus includes the pineal gland 松果體 the source of
melatonin.
Diencephalon
Thalamus
Pineal gland
Hypothalamus
Pituitary gland
Spinal cord
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Figure 49.9d
30
Diencephalon (間腦)
 Diencephalon (間腦)
含thalamus (inner chamber含意) 及hypothalamus (下視丘)
Massa intermedia
左右連接
左thalamus
右thalamus
 Thalamus (視丘)
座落於brainstem 最前端(蛋形)
gateway to the cortex for the sensory systems (雙間)亦參與
brainstem projection system (嗅覺olfactory除外)
• Fig. 3.24 Gross anatomy of the thalamus. This diagram shows the thalamus of the
left and right hemispheres in a see-through brain. The thalamus is egg shaped. It
serves as the gateway to the cortex for the sensory systems and contains
reciprocal loops with all cortical regions, organized according to subdivisions of the
thalamus. The thalamus also is innervated by brainstem projection systems.
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※ Brainstem (腦幹)※
Brainstem
Midbrain
Pons 橋腦
Medulla
oblongata
延腦
Figure 49.9d
Brainstem (腦幹)




The brainstem consist of the midbrain, the pons 橋腦 and the medulla
oblongata 延腦.
The midbrain coordinates visual reflexes, such as the peripheral vision
reflex.
A major function of the pons and medulla is to transfer information
between the PNS and the midbrain and forebrain, also helping
coordinate large-scale body movements, such as running and climbing.
An additional function of the medulla is the control of several automatic,
homeostatic functions, including breath, heart and blood vessel activity,
swallowing 吞嚥, vomiting 嘔吐, and digestion 消化.
Brainstem
Midbrain
Pons
Medulla oblongata
Figure 49.9d
Spinal cord
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Brainstem (腦幹)
cerebral cortex
Diencephalon
(間腦)
midbrain
hindbrain
pons
medulla
spinal cord
控制:
(1)respiration(呼吸)
(2)consciousness (sleep/ wakeness)
Components of the Brainstem
The pons 橋腦: the upper segment of
the brain stem
 It contains nerve fibers that
connect the two halves of the
cerebellum.
 It is vital in coordinating
movements involving right and
left sides of the body.
The medulla oblongata 延腦: the
lower part of brain stem
 It transmits ascending and
descending nerve fibers between
the spinal cord and the brain.
 It also directly controls many
involuntary muscular and
glandular activities, including
breathing, heart contraction, artery
dilation, salivation, vomiting, and
probably laughing.
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※ Cerebellum (小腦)※


The cerebullem coordinates movement and balance and
helps in learning and remembering motor skills.
Receiving and integrating sensory information from the
muscles and also monitors motor commands issue by the
cerebrum during motor and perceptual functions.
Left cerebral hemisphere
Right cerebral hemisphere
Cerebrum
Cerebellum
Figure 49.9c
Adult brain viewed from the rear
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Cerebellum (小腦)
 Cerebellum(小腦)包括: (1)cerebellum cortex
(2)4對deep nuclei
(3)internal white matter
=I/O
 功能:
維持posture (姿態), walking, coordinated movement
 小腦不直接控制movements而整合body & motor commands
去modify motor flow 產生smooth而協調的行為動作.
Process of Movement
Inputs
(1)brain中處理
motor/sensory資料
(描述body position)
(2)vestibular
projection(平衡)
(3)audiory/visual
inputs
spinal cord
國立交通大學生物科技學系 柯立偉老師
cerebellum
I/P
Deep
nuclei
O/P
Thalamus
I/P
brainstem
brainstem nucleus
motor premotor cortex
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※ Spinal Cord (脊椎神經)※
 在medulla到末梢神經(全身)之間
Ventral root →傳遞final motor signal 到muscles
Dorsal root →傳遞peripheral sensory info到brain
Ventral Horn: contains the large
motor neurons that project to
muscles
Dorsal Horn: contains sensory
neurons and interneurons.
at each level of spinal cord
存在reflex pathway
(如knee-jerk reflex)
國立交通大學生物科技學系 柯立偉老師
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