Obj 2.84

2.84 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses

Your nervous system sends electrical messages along nerves to and from different parts of your body and they tell your body what to do.

Sense organs are our RECEPTORS (detect the change). They send messages to the central nervous system telling it what has happened. These messages are sent along sensory neurons.

Nerve cells are different from other cells. They do have a cell membrane; cytoplasm and nucleus by they are a different shape. Part of the cell is stretched out to form the AXON. The axon can be over a metre long.

The messages that nerves carry are called NERVE IMPLUSES.
They are electrical signals
They pass very quickly along the axon of the neuron.

Each impulse in separate from the next and they travel along one after another.

Some axons have a fatty sheath around them, which insulated the axon and make the impulse travel along faster.