OSMT (Ontario Society of Medical Technologists) Practice Exam

Where do neurotransmitters cross?

1. Node of the Ranvier

2. Synaptic cleft

3. Ganglion

4. None of the above

The correct answer is: Synaptic cleft

Neurotransmitters cross the synaptic cleft, which is the small gap between two communicating neurons at a synapse. When an action potential reaches the end of a presynaptic neuron, neurotransmitters are released from vesicles into this cleft. They then bind to specific receptors on the postsynaptic neuron, which allows for the transmission of signals between neurons. This process is essential for neuronal communication and influences various physiological functions. The other options mentioned do not involve the crossing of neurotransmitters. The Node of Ranvier is a gap in the myelin sheath of an axon that facilitates the rapid propagation of action potentials but does not participate in neurotransmitter activity. A ganglion refers to a cluster of neuronal cell bodies in the peripheral nervous system and is not a site for the crossing of neurotransmitters. Thus, the synaptic cleft is the critical area where the action of neurotransmitters occurs, making it the correct choice.