nerve impulses

What is a synapse?

A functional connection between two neurons where an impulse is transmitted

What is the synaptic cleft?

The tiny gap between the axon terminal of one neuron and the dendrite of the next

Why don't neurons touch each other?

There is always a small gap (the synaptic cleft) between them, requiring neurotransmitters to carry the signal

What carries the nerve impulse across a synapse?

Neurotransmitters

Where are neurotransmitters stored?

In vesicles in the synaptic knobs of the presynaptic neuron

What happens when an impulse reaches the synaptic knob?

It stimulates vesicles to release neurotransmitters

How do neurotransmitters move across the synaptic cleft?

They diffuse across the gap

What happens when neurotransmitters reach the postsynaptic neuron?

They bind to receptors on the dendrites and trigger a new electrical impulse

What is the function of the postsynaptic neuron?

It generates a new electrical impulse that travels toward its cell body

Why are synapses important?

They ensure impulses travel in one direction, prevent continuous stimulation, and allow communication between different types of neurons

What is the sequence of neurons in signal transmission?

Sensory neuron → Interneuron → Motor neuron

Figure 1: Diagram of a synapse.