Contemporary Examples. 1  Cars have national attributes and GM wants their luxury line to grab the glitz of New York instead of the grime of Detroit. 2  Restorers completed a 12-year project in 1998 that cleaned decades of grime from the ceiling. 3  That grime came from the cigarette smoke of millions of commuters.
But one cell doesnât actually touch another, and the signals canât jump across the tiny spaces in between. To cross those tiny gaps, called synapses, they rely on chemical messengers. These chemicals are known as neurotransmitters. And their role in cell talk is called neurotransmission. When an electrical signal reaches the end of a neuron, it triggers the release of tiny sacs that had been inside the cells.
1 Sensory neurones carry signals from receptors receptors: organs which recognize and respond to stimuli to the spinal cord and brain. 2  Relay neurones carry messages from one part of the CNS CNS: Central Nervous System (brain and spinal cord). to another.here two neurones meet, there is a tiny gap called a synapse. Signals cross this gap using chemicals. One neurone releases the chemical into the gap. The chemical diffuses across the gap and makes the next neurone transmit an electrical signal.