What is the different of neuron to an odinary cells?
Neurons, also known as nerve cells, are the basic units of the nervous system. They are specialised cells that transmit information through electrical and chemical signals. Neurons are distinct from ordinary cells in several ways:
1. Structure: Neurons have a unique structure consisting of three main parts:
- Cell body (soma): This is the main part of the neuron where the nucleus and most of the organelles are located.
- Dendrites: These are branched extensions of the cell body that receive signals from other neurons.
- Axon: This is a long, slender projection that transmits signals away from the cell body to other neurons or muscles.
2. Electrical excitability: Neurons have the ability to generate and transmit electrical signals called action potentials. These signals are brief, all-or-nothing electrical impulses that travel along the axon.
3. Chemical signaling: Neurons communicate with each other by releasing chemical messengers known as neurotransmitters. Neurotransmitters are released from the axon terminals (the end of the axon) and bind to receptors on the dendrites of other neurons, triggering an electrical signal in those neurons.
4. Polarisation: Neurons have a resting membrane potential, which is a difference in electrical charge across their cell membrane. This difference in charge is maintained by the movement of ions (sodium, potassium, and chloride) across the membrane. When a neuron receives a signal, the membrane potential changes, which can either trigger an action potential or inhibit it.
5. Synapses: Neurons communicate with each other at specialised junctions called synapses. A synapse is formed between the axon of one neuron (the presynaptic neuron) and the dendrite of another neuron (the postsynaptic neuron). When an action potential reaches the axon terminal, it causes the release of neurotransmitters into the synaptic cleft (the space between the two neurons). The neurotransmitters bind to receptors on the postsynaptic neuron, which can either excite or inhibit that neuron.
6. Integration of signals: Neurons integrate the signals they receive from multiple other neurons. This integration determines whether the neuron will fire an action potential or not. The strength of the signal is influenced by the number and strength of the synaptic connections, as well as the activity of other neurons in the network.
In summary, neurons are specialised cells with unique structural and functional properties that allow them to transmit, process, and integrate information within the nervous system. These properties enable neurons to carry out their essential role in controlling bodily functions, receiving and processing sensory information, and mediating cognitive processes such as learning and memory.