7神经组织

brown
color
structure to form
a network.
EM: neurofilament: 10 nm in diameter microtubule: 25 nm in diameter
function: supporting involving in intracellular transportation
---function: receive the information
③ axon: ---thin, less branch
---structure: no Nissl body, but have microtubule, neurofilament, microfilament, mitochondria, SER and vesicle
more branch -less glial filament
/function: ⅰ.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
axon hillock: the beginning part of axon
axolemma
axoplasm
---function: initiate an impulse and conduct the impulse
* axonal transports:
slow anterograde: cytoskeletal
4. Glial cell(neuห้องสมุดไป่ตู้oglia)
1) Glial cell in CNS (central nervous system) a. Astrocyte:
/large stellate /round or ovoid nucleus, large and pale (euchromatin) /gliafilament: intermediate filament /end feet: to form glia limitans or vascular feet-constitute blood brain barrier
---dendrite: like branches of tree ---axon: long thin cord-liked
2) structure of
neuron ① cell body:
---cell membrane:
unit membrane-irritability, receive stimuli, initiate and conduct nerve impulse
there are synapsin I mito, SER, microtubule and microfilament /synaptic cleft: 15-30nm /postsynaptic element:
--postsynaptic membrane --receptors
Classification of chemical synapse: /According to function: excitatory synapse inhibitory synapse
3) classification: ---According to number of processes
multipolar neuron bipolar neuron pseudounipolar neuron ---According to length of axon Golgi type I neuron: long axon and large Golgi type II neuron: short axon
structural protein enzymes related to the production of neurotransmitters
b. Neurofibril:
LM: in silver
impregnation methods(silver
preparation),
there are many thread-liked dark
3. synapse
---definition: is the junctions between neurons or neuron and non-nerve cells
---classification:
chemical
synapse:
taking
neurotransmitter as communicating
---According to function sensory neuron motor neuron interneuron
---According to the neurotransmitter or neuromodulator release by the neuron cholinergic neuron aminergic neuron peptidergic neuron aminoacidergic neuron
membrane proteins-ions channel and receptor
---cell nucleus: large and round, centrallylocated, less heterochromatin, so pale stained, with a large, clear nucleolus
c. other organelle Golgi apparatus mitochondria pigment
② dendrite: ---many, short and more branches
---structure: similar to cell body
---dendritic spine( places for formation of synapse) and spine apparatus(structure formed by 2-3 layers SER)
b. Oligodendrocyte:
---structure: smaller, fewer process with a small round and dark stained N
---function:
i. their processes form myelin-sheath of NF in CNS
/According to structure:
type I: postsynaptic membrane is thicker than presynaptic membrane, with wide synaptic cleft(excitatory synapse)
type II: there are less electron dense material attached on synaptic membrane, the thickness of postsynaptic membrane is same to presynaptic membrane(symmetrical synapse)
protein:
microtubule,
microfilament and neurofilament
(0.1-0.4mm/d)
fast anterograde: synaptic vesicles, enzymes and proteins( 100-400mm/d)
fast retrograde: products of metabolism, intaking materials including protein or neurotrophic factors(100-400/d)
-neuromodulator: peptides- change the reaction of neuron to neurotransmitter, modulate neurotransmitter substance P enkephalin vasoactive intestinal polypeptide, VIP
EM: /presynaptic element: axonal terminal
presynaptic membrane synapse vesicle: -round or flattened, 40-60nm -clear or with electron dense core
-contain neurotransmitters: acetylcholine, Ach norepinephrine, NE dopamine, DA
/classification fibrous astrocytes:
-white matter, have long, thin and smooth processes -more glial filament- glial fibrillary acidic protein, GFAP
protoplasmic astrocyte: -gray matter, short, thick processes with
---cytoplasm: perikaryon a. Nissl body:
LM: basophilic spot-liked or granule-liked structure EM: parallelly-arranged RER and free ribosome function: synthesis of proteins