# Biological comparisons

Go to [[Week 2 - Introduction]] or back to the [[Main AI Page]]
Part of the page on [[Deep Learning]]

Artificial Neural Network neurons are based on human neurons — though there are thought to be 100 billion neurons in the human brain, with each one connected to 10,000 other neurons through *synapses* between *axons* and *dendrits*. This far exceeds any machine-learning model currently in use.

- **Synapse**: A structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. 
- **Axon**: (nerve fibre) A long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body.
- **Dendrite**: Branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project.

![A graphical representation of a biological neuron](https://i.imgur.com/VLwTmTo.png)