Chapter 7
nervous tissue
(神经组织)
Objective:
To understand
Which tissue can receives, transmits, and
integrates information from outside and inside
the body to control the activities of the body?
Which kind of cell can perceive and think
and dream?
What structure and function of the nerve cell ?
nervous tissue
nervous system
CNS
PNS
Peripheral Nervous System
Central Nervous System
brain and spinal cord. outside the brain and spinal cord
Components:
neuron—receive,
transmit and integrate
information .conduct the nerve impulse
neuroglia—support , protect and insulate ,
nourish neurons
Neuron (神经元)
The structural and functional basic unit of NS
1. The Structure of neuron
consists of cell body, dendrite and axon
1) cell body (perikaryon)
(1) cell membrane:
proteins-ions channel(离子通道)
receptor (受体)
receive stimuli, initiate and conduct nerve impulse
(2).nucleus:
large,round, light (euchromatic )with clear nucleolus
(3).Cytoplasm：
LM: Nissl bodies(尼氏体）
(basophilic masses)
EM：RER and free ribosome
synthesize
structural proteins
enzymes
(酶)
neurotransmitters
(神经递质)
图3
尼氏体电镜图
other organelle
Golgi bodies
SER
Mitochondria.
pigment
Neurofibril(神经原纤维):
o
LM: dark brown thread network (silver preparation)
EM:microtubules and filaments
cytoskeletal elements (C骨架) support
transportation
2). processes
（突起）
dendrite
axon
（树突） （轴突）
图
6
运
动
神
经
元
结
构
模
式
图
(1)dendrite（树突）each with numerous
branches.
structure: similar to cell body
dendritic spines, (树突棘)
(each the site of one synapse)
function: receive the information
Nerve signals travel along dendrites toward
the cell body.
Characteristics of The Dendrites
1 A nerve cell typically has several dendrites,
each with numerous branches.
2. The diameter of dendrites typically decreases
away from the cell body, so that dendrites tapering
gradually to fine twigs.
3. Dendrites typically receive synaptic contacts
from axons of many other nerve cells.
4.Nerve signals travel along dendrites toward the
cell body.
(2).axon(轴突 ) few branches
The axon is the "transmitting" process of
the neurone
axon hillock (轴丘) : the beginning part of axon
lacks Nissl body
axolemma (轴膜)
axoplasm
have microtubule, neurofilament, microfilament, Mito,
SER and vesicle (transportation)
function: conduct the impulse
axonal transports: (轴突运输)：
（1） slow anterograde:(慢速)：
perikaryon （ microfilament, neurofilament,microtubule）
the ends of axon (轴突终末)
（2） fast anterograde:(快速顺向）
perikaryon Pr,E,synaptic vesicles
axonal terminal
（3） fast retrograde:(快速逆向)：
axonal terminal (metabolic products, intaking materials ）
perikaryon
Characteristics of The axon
The axon is a process which is specialized for
conducting signals from one nerve cell to another.
The diameter of an axon is uniform along its entire
length.
The terminal branches of an axon make synaptic
contacts onto other nerve cells (or with peripheral
effectors, i.e. muscles and glands).
Nerve signals travel along axons away from the cell
body and toward synapses at the axonal terminal.
Each nerve cell has one and only one axon. Typical axons
have relatively few branches, except near the terminal end.
2. Classification of neuron
1)According to number of processes
① multipolar neuron 多极神经元
② bipolar neuron
双极神经元
③ pseudounipolar neuron假单极神经元
2).According to function
①sensory neuron 感觉神经元（Afferent ）
Convey sensory information into the CNS
② motor neuron运动神经元（efferent ）
convey information out from the central
nervous system to muscles or glands.
③ interneuron中间神经元:(Association neuron联络)
信息加工和传递
●Reflex arc
sense receptors
motor neuron
sensory neuron
Effector
CNS
(interneuron)
3)According to length of axon
① Golgi type I neuron: long axon and large c
高尔基Ⅰ型神经元：有长轴突(1米以上) 大N元
② Golgi type II neuron: short axon
高尔基Ⅱ型神经元：有短轴突(几微米)的小N元
4) According to the neurotransmitter or
neuromodulator release by the neuron
按神经递质和调质的化学性质分类：
① cholinergic neuron胆碱能神经元（乙酰胆碱）
②去甲肾上腺素能神经元（去甲肾上腺素）
③ aminergic neuron胺能神经元（多巴胺、5-羟
色胺）
④ aminoacidergic neuron氨基酸能神经元（Υ-氨
基丁酸、甘氨酸、谷氨酸）
⑤ peptidergic neuron肽能神经元（神经肽：脑啡
肽、Ｐ物质、神经降压素）
一氧化氮（NO）也是一种神经递质
3. synapse 突触
· are points of contact between nerve cells ( between
axon terminals and dendrites), where signals are
transmitted from one cell to another.
synapse
between neurons or neuron and non-nerve cells
axon terminals dendrites ,axon terminals spines
axon terminals
cell body
classification:
chemical synapse(化学性突触)
electrical synapse电突触
gap junction
电信号
图10
神经元胞体表面的突触小体 (镀银染色)
突触高倍（银染）
Synapse
structure of chemical synapse:化学性突触
based on neurotransmitters, secreted by one cell
and binding to another.
(以神经递质作为传递信息的媒介)
图14 不同形状的突触小泡电镜图
EM：presynaptic element 突触前成分
presynaptic membrane 突触前膜
synapse vesicle:( neurotransmitters）突触小泡（N递质）
synapsin
Mito
(小泡面Pr—突触素)
microtubule, microfilament
synaptic cleft: 15-30nm 突触间隙
Postsynaptic element
突触后成分
postsynaptic membrane突触后膜,
Receptors 受体
Classification of
chemical synapse:
According to function:
excitatory synapse
inhibitory synapse
微管
微丝
线粒体
本章重点
The components of the nerve tissue
•NT的构成
The characteristics of neuron
• 神经元的LM与EM结构特点,功能及分类
The structures of the chemical synapse
•化学性突触EM结构.
Practice Quiz
Each slide will be shown for 1 minute.
There will be two questions per slide.
Identify structures at the green arrows
Nissl bodies
Identify structures at the red arrows
axon hillock
Name the stain used to visualize the structures
in question silver
silver
Identify structures at the green arrows
Neurofibril
Identify the tissue
Nervous
Identify the granules at the blue arrows.
pigment granules
Identify the structures at the green arrows.
synapse
Describe the tissue stain method
神经胶质细胞
（neuroglial cell）
绝缘，信息传递的专一性
oligodendrocyte
少突胶质细胞
microglia
小胶质细胞
Astrocyte:
星形胶质细胞：
（一）CNS的神经胶质c
1、
Astrocyte 脚板
end feet
胶质界膜（在脑和脊髓表面）
胶质膜(Cap表面)
form glia limitans or vascular feet-constitute
blood brain barrier
fibrous astrocytes
纤维性…: 位于白质.
protoplasmic astrocyte
原浆性…: 位于灰质
function:
supporting, insulating and repairing
ii. regulate the environment and movement of
neuron
iii. secret neurotrophic factor: nerve growth
factor, NGF, ciliary neurotrophic factor, CNTP
and glial cell line-drived neurotrophic factor,
GDNF
功能： 支持和绝缘
分泌神经营养因子
构成血脑屏障
（blood-brain barrier）血脑屏障：
血液与脑组织间的屏障，阻止血液中某些物质
进入脑组织。选择性允许营养和代谢产物通过，
维持脑内环境稳定.
组成：连续Cap内皮
基膜
神经胶质膜
2、 oligodendrocyte少突胶质细胞
小、核卵圆形、突起少
是CNS的髓鞘形成C
髓轴
轴突
少突胶质细胞
3、 microglia小胶质细胞 ：最小
具有吞噬作用
NS的巨噬C
4、室管膜细胞：
产生脑脊液
三种胶质细胞光镜图 (镀银染色)
左图为少突胶质细胞,右上为小胶质细胞,右下示星形胶质细胞
室管膜
细胞
小胶质
细胞
神经元
星形胶
质细胞
毛细血管
有髓神经纤维
内皮细胞
少突胶质细胞
胶质
界膜
有髓神
经纤维
（二）PNS的神经胶质C
1、施万细胞（Schwann cell)
是PNS的髓鞘形成C
分泌神经营养因子,
修复.
促进受损伤的神经元
存活及其轴突再生
2、卫星细胞
（satellite cell）
神经纤维（nerve fiber）和神经
组成： 神经元的长轴突+神经胶质C
分类：
有髓Nf （myelinated nerve fiber）
无髓Nf （unmyelinated nerve fiber）
郎飞结
轴突
髓鞘
有髓Nf:N冲动呈跳跃式传导，传导速度快
PNS: 神经元的长轴突+施万C.

CNS: 神经元的长轴突+少突胶质C.

1、有髓神经纤维的结构：轴突 、髓鞘 、郎飞结
神经纤维的构成
轴突
郎飞结
施万细胞
图31 有髓神经纤维束横切面光镜图
（绿:轴突 蓝:髓鞘 红:神经束膜细胞）
有髓神经纤维横切面电镜图
周围神经纤维髓鞘形成
及其超微结构模式图
少突胶质细胞与中枢有髓神经纤维关系模式图
PNS的Nf集合在一起
神经（nerve）
•神经外膜（epineurium）：
•神经束膜（perineurium）起屏障作用
•神经内膜（endoneurium）：
四、神经末梢
1.

感觉神经末梢
(Nerve ending)
PNF的终末，遍布全身
游离神经末梢
触觉小体（tactile corpuscle）
环层小体
肌梭
1.游离神经末梢
感觉Nf终末分支，分布于表皮、角膜、ct
感受温度、应力和某些化学物质的刺激
参与产生冷、热、轻触和痛觉
2、触觉小体（tactile corpuscle）
分布：真皮乳头
功能：感受应力刺激
产生触觉
3.环层小体（lamella corpuscle）
分布：皮下组织、腹膜、肠系膜、韧带、关节囊
功能：感受较强的应力，
产生压觉和振动觉