Axon Terminal

The very end of the axon, where electrochemical signals are passed through the synapse to neighbouring cells by means of neurotransmitters and other neurochemicals. A collection of axons coming from, or going to, a specific brain area may be called a white matter fibre tract.

Autonomic Nervous System

Part of the central nervous system that controls internal organ functions (e.g., blood pressure, respiration, intestinal function, urinary bladder control, perspiration, body temperature). Its actions are mainly involuntary.

Auditory Cortex

Part of the brain’s temporal lobe, this region is responsible for hearing. Nerve fibres extending from the inner ear carry nerve impulses generated by sounds into the auditory cortex for interpretation