What is the function of the synaptic knob?

Based on the number of axons and dendrites, neurons are divided into three types: multipolar (with one axon and two or more dendrites), bipolar (with one axon and one dendrite), and unipolar (cell body with one axon only).Nissl’s granules are granular bodies in the cell body of a neuron. They are composed of typical cell organelles and are also present in the dendrites. The synaptic knob is a bulb-like structure at the distal end of the axon of a neuron. It possesses synaptic vesicles containing neurotransmitters. Dendrites are short fibres that branch repeatedly and project out of the cell body

The synaptic knob is a bulb-like structure at the distal end of the axon of a neuron. It possesses synaptic vesicles containing neurotransmitters. Dendrites are short fibres that branch repeatedly and project out of the cell body. They contain Nissl's granules and transmit impulses towards the cell body. Axons are long fibres that transmit nerve impulses away from the cell body to a synapse or to a neuro-muscular junction