OSMT (Ontario Society of Medical Technologists) Practice Exam

What is the space where neurotransmitters cross?

1. The axon of one neuron and the dendrite of the other

2. Adjacent Schwann cells on the axon

3. Sensory receptors and the efferent nerve

4. The myelin sheath and the cellular sheath

The correct answer is: The axon of one neuron and the dendrite of the other

The space where neurotransmitters cross is known as the synapse, which is found between the axon terminal of one neuron and the dendrites of another neuron. This area is crucial for communication within the nervous system. When an electrical impulse reaches the axon terminal, it triggers the release of neurotransmitters into the synaptic cleft, the gap that exists between the two neurons. These neurotransmitters then bind to receptor sites on the dendrites of the receiving neuron, facilitating the transmission of signals. The other options do not accurately represent the location where neurotransmitter action occurs. Schwann cells are involved in myelination of the peripheral nervous system but do not function in the synaptic transmission of signals. Similarly, sensory receptors and efferent nerves are part of different pathways that do not describe the synaptic interaction between neurons. The myelin sheath serves to insulate axons and improve the speed of electrical transmission but does not involve the crossing of neurotransmitters. Thus, the first choice accurately represents the essential site of chemical communication in the nervous system.