IB Biology: C2.2-Structure of synapses

Front

What are synapses?

Back

Synapses are junctions between neurons and other neurons or receptors of effectors where neurons come in close contact but do not touch.

Front

Where are synapses found in the body?

Back

In the brain, synapses are between neurons. In muscles and glands, synapses are between neurons and muscle fibres and secretory cells.

Front

Why can't impulses cross synapses directly?

Back

Impulses cannot cross synapses because the neurons in a synapse do not touch each other, though they may be in close proximity.

Front

What role do neurotransmitter molecules play at synapses?

Back

Neurotransmitter molecules are released from one end of the synapse to stimulate the impulse in the other end of the synapse.

Front

In which direction do synapses transmit impulses?

Back

Synapses transmit impulses in only one direction, from the presynaptic towards the postsynaptic neuron.

Front

What are the three components of a synapse?

Back

A synapse is made up of the presynaptic neuron, the synaptic cleft, and the postsynaptic neuron.

Front

What is the presynaptic neuron?

Back

The presynaptic neuron is the neuron on one side of the synapse that releases neurotransmitter molecules.

Front

What is the synaptic cleft?

Back

The synaptic cleft is the tiny gap between the two neurons.

Front

What is the postsynaptic neuron?

Back

The postsynaptic neuron is the neuron on the other side that receives the neurotransmitter molecules.