Neurons can be quite large - in some neurons, such as corticospinal neurons from motor cortex to spinal cord or primary afferent neurons neurons that extend from the skin into the spinal cord and up to the brain stem , can be several feet long!
Types of Neurons Nerve Cells The human body is made up of trillions of cells. Neurons are similar to other cells in the body because: Neurons are surrounded by a cell membrane. Neurons have a nucleus that contains genes. Neurons contain cytoplasm, mitochondria and other organelles. Neurons carry out basic cellular processes such as protein synthesis and energy production.
However, neurons differ from other cells in the body because: Neurons have specialize cell parts called dendrites and axons. Dendrites bring electrical signals to the cell body and axons take information away from the cell body.
Neurons communicate with each other through an electrochemical process. Neurons contain some specialized structures for example, synapses and chemicals for example, neurotransmitters. The Neuron One way to classify neurons is by the number of extensions that extend from the neuron's cell body soma. Neurons can also be classified by the direction that they send information. Sensory or afferent neurons: send information from sensory receptors e.
Motor or efferent neurons: send information AWAY from the central nervous system to muscles or glands. Interneurons: send information between sensory neurons and motor neurons.
This molecule stimulates the second neuron creating a new wave of electrical impulse. In the end, the impulse reaches the required part. There are basically three types of neurons which are as follows:. Sensory Neurons - These are the nerve cells that are activated by sensory input from the environment.
Physical and chemical both inputs can activate sensory neurons that correspond to our five senses. Many sensory neurons have only one axon which is split into two branches called pseudounipolar. Motor Neurons - These are present in the spinal cord part of the central nervous system which connects to muscles, glands, and organs throughout the body. The impulse from the spinal cord to skeletal and smooth muscles is transmitted through these neurons. Interneurons - These are the ones that are present in between which connect the spinal motor and sensory neurons.
These form circuits of various complexity while communicating signals between sensory and motor neurons. Neurons are of different shapes and sizes depending on their location.
Whereas the cranial nerves distribute signals to different parts of the head brain, brainstem. Nerves are found in the peripheral nervous system.
A nerve is considered to be the basic unit of the peripheral nervous system. A nerve comprises of different types of axons, through which they transmit signals and information to the different body parts.
Each nerve is covered with three layers: — the inner endoneurium covering the nerve fibres, perineurium being the middle layer and the outer layer called epineurium. This is the basic structure of a nerve. A nerve is formed by a group of neurons. A neuron, on the other hand, is an individual specialized cell. This is the main difference between a nerve and a neuron. A neuron is also called a nerve cell or a neurone, but the latter spelling and usage has now become quite uncommon.
The main function of a neuron is also to convey information. A neuron transmits nerve impulses, in the form of electrical and chemical signals, also called electrochemical signalling. The functions of neurons can be specified based on the different types of neurons that exist. Common Health Topics. Somatic nervous system. Autonomic nervous system. Cranial nerves and spinal nerves. Biology of the Nervous System.
Test your knowledge. A brain abscess is a pocket of pus in the brain. Which of the following is NOT a common cause of a brain abscess? More Content. Click here for the Professional Version. The somatic nervous system. Typical Structure of a Nerve Cell A nerve cell neuron consists of a large cell body and nerve fibers—one elongated extension axon for sending impulses and usually many branches dendrites for receiving impulses.
Brachial plexus: Sorts and recombines nerve fibers traveling to the arms and hands. Lumbosacral plexus: Sorts and recombines nerve fibers going to the legs and feet. Was This Page Helpful? Yes No. Effects of Aging on the Nervous System.
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