Solution :A typical synapse consists of a bulbous expansion of a nerve terminal called a pre-synaptic KNOB lying close to the membrane of a dendrite.The cytoplasm of the synaptic knob CONTAINS mitochondria, smooth endoplasmic reticulum, microfilaments and numerous synaptic vesicles. Each vesicles contains neurotransmitter (CHEMICAL substance) responsible for the TRANSMISSION of the nerve IMPULSE across the synapse.