dendrite树突：神经元细胞浆的线样伸展部分。单极及双极神经元的树突与轴突类似，而多极神经元的则呈树样突起。树突多由神经元的接受面构成
synapse突触：为神经元之间的功能性接触位点，神经冲动在此处以电的(见ephapse)或化学的方法由一神经元传递给另一神经元。在典型的突触中，神经冲动是由兴奋的突触前细胞的轴突末梢释放的神经递质(例如乙酰胆碱、去甲肾上腺素等)传递，这些递质扩散过突触间隙与突触后细胞膜上的受体结合，在突触后细胞中产生电的变化，引起突轴后神经元去极化(兴奋)或超极化(抑制)。突触也存在于神经末梢与效应器官之间的接合部位(例如神经肌肉接点)

Caption: Excitatory (asymmetric) synapses on a neuron dendrite (central nervous system). Two axon terminals (dark yellow) form excitatory synapses on a dendrite (green). Chemical synapses are specialized junctionsŒ through which nerve cells signal one another or other non-neuronal cells such as muscles. At a typical synapse an axon and a dendrite flank each other across a slender gap (synaptic cleft (purple and pink). Signaling molecules, known as neurotransmitters, are contained in tiny vesicles of the axon (light yellow). Neurotransmitters pass rapidly from axon to dendrite triggering an electrical impulse.
Magnification*: x16,245
Type: TEM
Keywords: 1962B.TIF asymmetric axon central nervous system CNS dendrite excitatory neuron synapse nerve cell TEM |

*(Magnifications are based on a 35mm slide image of 24mm in the narrow dimension.)