The 23-minute educational film begins by comparing the simple nerve nets of the hydra and the segmented system of the earthworm to the far more complex human nervous system. Using clear animation ...

What Is the Nervous System? Your nervous system is your body's main communication system. It sends messages from your brain to the rest of your body and helps you respond to changes inside and ...

Muscles and glands are called effectors. The diagram summarises how information flows from receptors to effectors in the nervous system. Receptors are groups of specialised cells. They detect a ...

TThe fundamental unit of the nervous system is the neuron. Individual neurons are connected by synapses to form circuits. Evolution has driven the formation of ever more elaborate circuits to ...

“It suggests that some of the neuronal machinery was being packaged into cells and used for some form of communication prior to the advent of a nervous system.” Dr. Musser said he was looking ...