Neurons: Structure and Function

Importance of Neurons

• Neurons are among the most interesting cells in the human body.
• They make up the brain and nervous system.
• Responsible for thoughts, feelings, and sentience.

Structure of Neurons

Soma (Cell Body)

• Central part of the neuron.
• Contains the nucleus.

Dendrites

• Branch-like structures extending from the soma.
• Receive signals from other neurons.

Axon

• Tail-like extension from the soma.
• Transmits signals over long distances.

Axon Hillock

• Junction where the soma connects to the axon.

Axon Terminal

• End of the axon where it connects to other neurons or muscles.

Myelin Sheath

• Insulating layer around the axon.
• Made up of Schwann cells.

Nodes of Ranvier

• Gaps in the myelin sheath along the axon.

Signal Transmission

• Signals are received at dendrites.
• Signals are summed up at the axon hillock.
• Action potentials are triggered if the combined signal is strong enough.
• Signal travels down the axon to the axon terminal.
• Connections via synapses to other neurons or muscles.

Types of Neurons

• There are sensory neurons (e.g., taste buds) and other specialized types.
• Details on other neuron types will be discussed later.