What is the primary function of the synapse in the nervous system?

The primary function of the synapse in the nervous system is to transmit signals between neurons. Synapses are specialized junctions where the axon terminal of one neuron comes into close proximity with the dendrite or cell body of another neuron. When an electrical signal, or action potential, reaches the end of the axon, it triggers the release of neurotransmitters from the presynaptic neuron into the synaptic cleft. These neurotransmitters then bind to receptors on the postsynaptic neuron, allowing the signal to be passed along the neural circuit.

The efficient transmission of signals at synapses is crucial for communication within the nervous system, enabling everything from reflex responses to complex behaviors. This process of neurotransmission also plays an important role in learning, memory, and mood regulation.

The other options present functions that are not related to synapses. For example, hormones are produced by endocrine glands rather than synapses. Filtering blood is a function associated with the kidneys and other organs, while the connection of muscles to bones pertains to the musculoskeletal system, not neuronal connections.