A neuron, or nerve cell, is the fundamental unit of the nervous system, responsible for transmitting electrical and chemical signals. It has three main parts: the cell body (soma), dendrites, and axon. Dendrites receive signals, the cell body processes them, and the axon transmits signals away from the cell body.
Detailed Explanation:
Dendrites:
These are branched extensions of the cell body that act like antennae, receiving signals from other neurons or sensory receptors. They transmit these signals towards the cell body.
Cell Body (Soma):
This is the central part of the neuron that contains the nucleus, cytoplasm, and other organelles. It integrates the signals received by the dendrites and decides whether to transmit the signal further.
Axon:
A long, slender projection that extends from the cell body. It transmits signals away from the cell body to other neurons, muscle cells, or glands. The axon often has a myelin sheath, which insulates it and speeds up signal transmission.
Synapse:
The junction where an axon terminal of one neuron communicates with the dendrite of another neuron or a target cell. This communication involves the release of neurotransmitters, chemical messengers that transmit signals across the synaptic gap.
Axon Terminals:
The ends of the axon that form synapses with other cells.
Function:
1. Receiving signals:
Neurons receive signals from other neurons, sensory receptors, or other cells through their dendrites.
2. Processing signals:
The cell body integrates the received signals and decides whether to transmit them further.
3. Transmitting signals:
The axon carries signals away from the cell body, transmitting them to other neurons, muscles, or glands.
4. Communication at synapses:
At the synapse, neurotransmitters are released, and these chemicals bind to receptors on the target cell, causing a signal to be sent in the next cell.