Outline the importance of the junctions between neurones in the functioning of the nervous system

DEFINE: Key words What is a junction, what is a neurone and what is the nervous system? So, the nervous system connects all the nerve cells and fibres which transmit nerve impulses from one part of the body to another, in order to elicit a response to a stimulus; for example, they enable you to retract your hand when you touch a hot plate. Neurones are a specialised cell that enable the transmission from one part to another part of the body. A junction is just a gap. The question is specifically asking why these junctions are important in this whole network. A diagram of a synaptic junction would be very helpful in explaining the role of junctions. So, in forming an exam style answer we need key points taken from the mark scheme and our understanding to form a model answer. This is a 3 mark question, so we need to make several 1 mark points or half mark points to get the full amount.

1. Junctions ensure that an impulse only moves in one direction. Important to relay information to the central nervous system so that an output action can be produced to the sensory input i.e. take your hand away from a hot plate.
2. This information moves across the junction using acetylcholine. The impulse arrives at the pre synaptic membrane and releases acetylcholine into the synaptic cleft. Ach receptors are on the post synaptic membrane; the impulse is then transmitted to the second neurone.
3. The impulse in transmitted because acetylcholine causes depolarisation in the second neurone.