Hormones and Nerves

Hormones and Nerves

Hormones

Hormones are chemical messengers which travel the blood to activate target cells.
Hormones are released directly into the blood stream and are carried around the body until they reach their target organ/cells.
The target cells have the right receptors to respond to the hormone. Similarly, organs being affected are called target organs.
Hormones travel at “the speed of blood”. Their effects are long lasting.

Neurones

The Dendrons connect with other neurones to enable electrical impulses to be passed along.
Neurones are very long which also speeds up the impulse. Connecting with other neurones slows the impulse down, so it is faster to have one long neurone instead.
The gap/connection between two neurones is called a synapse.
The nerve impulse is transmitted by chemicals called neurotransmitters. These diffuse across the synapse.
When the neurotransmitters reach the next neurone, they set off a new electrical impulse.

Differences between hormones and nerves