Neurons
Neurons are cells that react and act in the process of receiving and transmitting information by signaling.
They are an important function of the Central Nervous System.
Neurons Can be Found in the Following Structures:
1.) Brain
2.) Spinal Cord
3.) Peripheral nerves
Important Information on Nerves:
– Neurons themselves can differ greatly – some allow for touch, visual, light, smell, sound, and many others.
– Neurons in limbs receive stimuli and transfer or send the signal to the spinal cord and to the brain.
– Chemical ions are the basic mechanism of response. Ions are released and “uptake” during stimuli. Ions cause an “electrical charge” that extends along the neuron. This charge is similar to dominoes falling in a pattern and along a shaped arrangement.
The Anatomy and Function of Neurons is as Follows:
1.) Nucleus
– Production of RNA
– Production of Proteins
2.) Dendrite
– Are branch-like prominences from the neuron
– They function to receive stimuli from an adjacent neuron
– They appear to collect the information and pass it to the axon in the appropriate speed and intensity.
3.) Soma
– This is referred to as the cell body of a neuron
– It houses the nucleus of the neuron
4.) Axon
– Is a long cord or fiber that allows the conduction of impulses
– The longest axon is the “sciatic nerve” – which runs from the spine to the big toe of each foot.
– It is sheathed or surrounded by myelin
5.) Myelin Sheath
– A layer that surrounds the axon
– Schwann cells surround those of the Peripheral nervous system
– Oligodendrocytes surround those of the Central nervous system
6.) Axon terminal
– This is the end of the neuron
– Action potentials or electrical impulses are generated here
– Chemicals or “neurotransmitters” are essential
Types or Classifications of neurons:
1.) Unipolar
– Dendrite and axon from the same portion – only one axon
– Cell body is typical in the central aspect of neuron
– Found in spinal cord and brain
2.) Bipolar
– Single axon
– Axon on one side and dendrite on other
– Found in eye, smell, and hearing locals
3.) Multipolar
– Single axon
– Multi-dendrites
– Found in the brain
Several separate but similar neuron types are seen:
1.) Anterior horn – found in the spinal cord
2.) Basket Cells – found in Cerebellum
3.) Betz Cells – are very large neurons that allow for motor movement
4.) Granule Cells – a type of Golgi II neurons
5.) Medium Spiny Neurons – found in the corpus striatum
6.) Purkinje Cells – found in the cerebellum
7.) Pyramidal Cells – a type of Golgi I neurons
7.) Renshaw Cells – linked to alpha motor neurons