1. Functions of the Nervous System

2. NERVOUS SYSTEM CENTRAL NS PERIPHERAL NS GRAY MATTER WHITE MATTER
BRAIN SPINAL CORD CRANIAL SPINAL AUTONOMIC
NERVES NERVES NERVES
(12 pairs) (31 pairs)
SYMPATHETIC PARASYMPATHETIC
NERVES NERVES
GRAY MATTER WHITE MATTER

3. Section 1 General Function of Neuron and Neuroglia 1. Neuron
The structure and function unit of nervous system, including the soma, axon and dendrites

4. Classification of neuron by function

5. Function and Classification of Nerve Fiber
Nerve Fiber: Axons or Dendrites
Function
Conducting AP
Nerve impulse

6. Characteristics of Excitement Conduction
Intact
Bidirectional conduction
Not easy to be fatigue
Insulation

7. The affecting factors of conduction velocity
Diameter of the axon
myelin sheath or no myelin sheath
Thickness of myelin sheath
Temperature

8. Erlanger /Gasser classification of nerve fibers
Fiber types
Function
Avg. fiber diameters (μm)
Avg. cond. Velocity (m/s) Aα
Primary muscle spindle afferents, motor to skeletal muscle 15
100 (70-120) Aβ
Cutaneous touch and pressure afferents 8
50 (30-70) Aγ
motor to muscle spindle 5
20 (15-30) Aδ
Cutaneous temperature and pain afferents
<3
15 (12-30) B
Sympathetic preganglionic 3
7 (3-15) C
Cutaneous pain afferents sympathetic postganglionic 1
1 (02-2)

9. Lloyd/Hunt classification of nerve fibers
Group
Function
Avg. fiber diameters (μm)
Avg. cond. Velocity (m/s)
Ia,Ib
Primary muscle spindle afferents and afferents from tendon organs 13
75 (70-120) II
Cutaneous mechanoreceptors 9
55 (25-70)
III
Deep pressure sensors in muscle 3
11(10-25) IV
Unmyelinated pain fibers 1

10. Axoplasmic transport of nerve fiber
Conception:: Axoplasm in axon often keep flow, the flow of axoplasm play the role to transport material, it is called axoplasmic transport.
Anterograde axoplasmic transport
~ fast
~ slow
Retrograde axoplasmic transport

11. Fig. Axopasmic transport
dynein
kinesin
Fig. Axopasmic transport
Fig. The method of horseraidish peroxidase

12. Trophic action of nerve
Conception: Nerve endings often release some trophic factors, continuously to regulate metabolic activity of the tissue that controlled by the nerve, then affecting its the structure, biochemical and physiological changes, this effect is called trophic action of nerve.
Mechanism: anxoplasmic transport
Phenomenon:

13. Neurotrophin
Conception: a kind of protein molecules that produced by the tissue( such as muscle ) and astrocytes, and is the necessary substance to the neuron survival and growth.
Action mode: Neurotrophin enter into the terminal of axon by endocytosis, then reach to cell body by retrograde axoplasmic transport.
Significance: to promote protein synthesis in the cell body. so play important roles in supporting neuron growth, development and functional integrity.
Types:

14. Types of Neuroglia CNS Astrocyte Microglia Oligodendrocyte
Ependymal Cell
CNS
Astrocyte
Microglia
Oligodendrocyte

15. Characteristics of Neuroglia
Quantity
Protrusion:
Gap junction:
Membrane receptor
Membrane potential:

16. Function of Neuroglia 1.Supporting and inducting neuron migration:
2. Repair and.
3: Immune response.
4. Insulation and barrier：
5. Metabolism and nutrition
6. Keeping the stability of potassium concentration
7.Uptaking and secreting the neurotransmitter

17. Section 2 synaptic transmission
1. Several important synaptic transmission
*Classical synaptic transmission
*Non-directed synaptic transmission
*Electrical synaptic transmission
2. Neurotransmitter and receptor
*Neurotransmitter
*Receptor
*The main transmitter and receptor system

18. Classical synaptic transmission
Synaptic microstructure
Presynaptic membrane
Voltage-gated Ca2+ channels
Transmitter vesicles
Synaptic cleft
Postsynaptic membrane
Receptors

19. Classical synaptic transmission
Classification of Synapse
Main: A-D、A-S、A-A
Other: D-D、D-S、D-A、S-D、S-S、S-A

20. Classical synaptic transmission
Process of synaptic transmission
1. AP
2. Ca2+ channel open
3. Neurotransmitter release
Exocytosis
4. Neurotransmitter + receptor
5. Postsynaptic potential (AP)
Electric - Chemical - Electric

21. Synaptic Transmission
AP travels down axon to bouton.
VG Ca2+ channels open.
Ca2+ activates calmodulin, which activates protein kinase.
Protein kinase phosphorylates synapsins.
Synapsins aid in the fusion of synaptic vesicles.

22. Synaptic Transmission (continued)
NTs are released and diffuse across synaptic cleft.
NT (ligand) binds to specific receptor proteins in postsynaptic membrane.
Chemically-regulated gated ion channels open.
EPSP: depolarization.
IPSP: hyperpolarization.
Neurotransmitter inactivated to end transmission.

23. Classical synaptic transmission
Postsynaptic Potential
Excitatory postsynaptic potential(EPSP)
Inhibitory postsynaptic potential(IPSP)
depolarization
hyperpolarization

24. Excitatory postsynaptic potential (EPSP)
No threshold.
Decreases resting membrane potential.
Closer to threshold.
Graded in magnitude.
Have no refractory period.
Can summate.

25. Inhibitory postsynaptic potential (IPSP)
No threshold.
Hyperpolarize postsynaptic membrane.
Increase membrane potential.
Can summate.
No refractory period.

26. Summation of EPSP or IPSP
The processes by which the multiple EPSPs (IPSPs) from presynaptic neurons summate over time and space are called temporal and spatial summation

27. Classical synaptic transmission
Excitation and inhibition of postsynaptic neuron

28. Classical synaptic transmission
Modulation of synapse
Regulating NT release
Ca2+ inflow, AP frequency or amplitude, presynaptic receptor.
Regulating the uptake and inactivation
Regulating the receptors
Synaptic Plasticity

29. Classical synaptic transmission
The types of synaptic plasticity
Posttetanic potentiation
Habituation
sensitization
long-term potentiation( LTP)
long-term depression(LTD)

30. Non-directed synaptic transmission
The postganglionic autonomic neuron innervate the smooth muscle and cardiac muscle .
The multiple branches are beaded with enlargements (varicosity) that are not covered by Schwann cells and contain synaptic vesicles;
Fig. : Ending of postganglionic autonomic neurons on smooth muscle

31. Electrical synaptic transmission
Structure: Gap junctions:
Each gap junction is composed of 12 connexin proteins.
The 12 connexin proteins form a water channel.
the charged small molecules and the local current are allowed through.
Distribution

32. Electrical synaptic transmission
Functional characteristics:
the charged small molecules and the local current are allowed through the channel.
low resistance
Rapid
Bidirectional transmission
significance:

33. Electrical Synapse
Chemical Synapse

34. Neurotransmitter
Conception: small molecules that synthesized by the neurons, can be released from presynaptic terminals into the synaptic cleft and combined with the receptor of postsynaptic membrane, cause postsynaptic potential.

35. Conception of neuromodulator:
In addition to neurotransmitter, neuron can synthesize and release some chemical substances, they are not directly transmit information between neurons, but can enhance or impair neurotransmitter effects, this kind of substance is called neuromodulator.
Neurotransmitter coexistence :
Two or more than two (including neuromodulator) have been found in the same neuron, this phenomenon is called neurotransmitters coexistence.

36. Neurotransmitter Neurotransmitter metabolism: Synthesis Storage
Release
Degradation
Reuptake

37. Receptor Subtype of receptor: each receptor has multiple subtypes
Cholinergic receptor：muscarinic receptor (M receptor) and nicotinic receptor (N receptor), N1 and N2
Adrenergic receptor: α (α1, α2) and β (β1, β2, β3)

38. Receptor Presynaptic receptor: also called autoreceptor
Usually, the presynaptic receptor activation can inhibit neurotransmitter release, realize the negative feedback control.
noradrenergic receptor
noradrenalin

39. Receptor Mechanism of receptor : Classification of receptor :
Activation : Binding with the neurotransmitter
Signal transduction pathways
Biological effects(changing postsynaptic neuron activity or making target cells to produce effects
Classification of receptor :
Ion channel receptors
G protein-coupled receptor : most

40. Main neurotransmitter and receptor system
Acetylcholine(Ach) :
Cholinergic neuron: widely distributed in the CNS
Somatic motor nerve fibers
All autonomic preganglionic fibers
Most parasympathetic postganglionic fibers
A few sympathetic postganglionic fibers
Cholinergic fiber

41. The Life Cycle of Acetylcholine
Choline acetyltransferase
Acetylcholinesterase

42. Acetylcholine(Ach) receptor:
According to pharmacological properties, acetylcholine receptor can be divided into two categories
Muscarinic receptors(M receptor):
M1 to M5, G protein-coupled receptor
Nicotinic receptors(N receptor):
N1 and N2, ion channel receptor

43. G protein-coupled receptor
M receptor

44. Ion channel receptor
N Receptor

45. Acetylcholine(Ach) receptor:
Distribution
Antagonist M
Autonomic effector
(cardiac muscle，smooth muscle）
Atropin N1
Autonomic ganglion
Curare, hexamethonium N2
Endplate membrane of skeletal muscle
Curare, decamethonium

46. Noradrenaline(NA) or norepinephrine(NE):
Noradrenergic neuron: In both PNS and CNS
PNS: Smooth muscles, cardiac muscle and glands.
CNS: General behavior.
Adrenergic fibers: most sympathetic postganglionic fibers
Adrenergic receptors: G protein-coupled receptor

47. Distribution and antagonist of adrenergic receptor in the peripheral nervous system
Distribution Antagonist 1
Most sympathetic effector(excitation)
Phentolamine, Prazosin 2
Presynaptic receptor (regulate neurotransmitter release)
Phentolamine,Yohimbine 1
cardiac muscle(excitation)
Propranolol, Practolol 2
Most sympathetic effector(inhibition)
Propranolol, Butaxamine

48. Mechanism of Action ( receptor)

49. Dopamine and receptor:
Dopaminergic neuron:
Distributed in the CNS:
Dopaminergic receptors:
1.Nigrostriatal system, participate in the movement regulation.
2.Mesolimbic system,participate in the mental activities.
3.Tuberoinfundibular system, involved in neuroendocrine regulation.

50. Serotonin and receptor:
Serotonergic neuron :
mainly in the raphe nucleus of the lower brainstem
Receptors:
There are 7 types of serotonin receptor: Serotonin1-7.
There are 14 subtypes of Serotonin receptors:
Histamine and receptor:
Histaminergic neuron :
mainly in the tuberomammillary nucleus of posterior hypothalamus, its fiber projection is very wide, almost reach all parts of CNS.
Receptors:
Histamine system has three kinds of receptors, H1,H2, and H3
All receptors are a G- protein-coupled receptor

51. Amino acid neurotransmitter and receptor:
Excitatory amino acid:
Mainly include the glutamate and aspartate, and glutamate is the major excitatory neurotransmitter in the brain and spinal cord
Inhibitory amino acid:

52. Changeable and high-class
Section 3 The basic rule of reflex activity
What is Reflex?
Reflex refers to the regularity response of body to various stimulus from internal and external environment under
the central nervous system involvement.
Classification of reflex
Classification
Obtain
Quantity
Form
Unconditioned reflex
innate
limited
fixed and low-class
Conditioned reflex
acquire
infinite
Changeable and high-class

53. Section 3 The basic rule of reflex activity
Central Control of Reflex
Reflex arc: Receptor→Afferent neuron→CNS→ Efferent neuron→ Effector
Monosynaptic reflex: only a synaptic transmission in the central. This is the simplest reflected, only monosynaptic reflex in vivo is tendon reflex.
Polysynaptic reflex: Multiple synaptic transmission in the central. This is the simplest reflected, Most reflexes are polysynaptic reflex.

54. The basic process of reflex

55. Contact Ways of Central Neurons
Single line connection
Divergent connection

56. Contact Ways of Central Neurons
Convergent connection
Chain connection
Recurrent connection

57. Characters of Central Excitation Conduction
One-way conduction
Central delay
Summation of excitation .
Change of excitatory rhythm
After discharge
Susceptibility & Fatigue

58. Nerve fiber conduction Synaptic transmission Environmental factors
Characteristics of and nerve fiber conduction and synaptic transmission
Nerve fiber conduction
Synaptic transmission
Conduction direction
Bidirectional
monodirectional
Time delay no
have
Potential change
all or nothing
changes of Summation and rhythm
After discharge
Integrity
requirement
Fatigue
not easy
easy
Environmental factors
insulation
susceptible

59. Central Inhibition and Facilitation
Postsynaptic inhibition
*afferent collateral inhibition
After afferent nerve to the central, not only can excite a interneuron though synaptic connection, but can excite a inhibitory interneuron through its collateral branch, further inhibit another neuron, this kind of inhibition is called afferent collateral inhibition.
*recurrent inhibition
When the central neuron is excited, the efferent impulse is conducted outward along the axon, at the same time, also can excite a inhibitory interneuron though its collateral branch, then cause the release of inhibitory neurotransmitter, which inhibit the previously excited neurons, this kind of inhibition is called recurrent inhibition.

60. Central Inhibition and Facilitation
Presynaptic inhibition
Postsynaptic facilitation
Presynaptic facilitation