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30 de oct. de 2023 · Learn about the structure and function of nerves, the functional and structural units of the peripheral nervous system. Find out the differences between afferent, efferent and mixed nerves, and the spinal and cranial nerves.
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- 13 min
Learn about the structure and function of nerves, the glistening white cords that connect the nervous system with other parts of the body. Find out how nerves are classified into sensory, motor, and autonomic, and how they are innervated by the brain and spinal cord.
- The Editors of Encyclopaedia Britannica
- Cell Body
- Dendrites
- Axons
- Axon Terminals
- Coverings
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The cell body holds the nucleus. It is the site of protein synthesis, which occurs on small granules of rough endoplasmic reticulum called nissl substance. In the nervous system, many neuronal cell bodies can group together to form a distinct structure. In the CNS, this is known as a nucleus, and in the PNS as a ganglion.
The dendritesare elongated portions of the cell body. They extend outwards, receiving input from the environment and from other neurones.
The axonis a long, thin structure down which action potentials (the nerve impulse) are conducted. Whilst neurones have many dendrites, most cells only have one axon. Each axon is coated in myelin – a layer of insulating lipid. Myelin is formed by cells wrapping themselves around the nerve axon. In the CNS, this is performed by oligodendrocyte cells...
Theaxon terminalis the most distal part of the axon. It is from here that the neurone sends chemical signals to other cells – usually via neurotransmitter release. To facilitate the secretion of neurotransmitters, the axon terminals contain a large number of mitochondria.
In the peripheral nervous system, the axons of neurons are grouped together to form nerves. The axons are enclosed by several connective tissue layers: 1. Endoneurium – Surrounds the axon of an individual neurone. 2. Perineurium – Surrounds a fascicle, which is a collection of neurones. 3. Epineurium – Surrounds the entire nerve, which is formed by...
Learn about the structure and function of neurones, the cells of the nervous system. Find out how they are classified, covered and affected by diseases.
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22 de mar. de 2022 · Learn about the different types of nerves, how they function and where they are located in your body. Find out how to keep your nerves healthy and what conditions can affect them.
Hace 3 días · Explore the anatomy and physiology of the nervous system, from the brain and spinal cord to the nerves and sense organs. Learn about neurons, neuroglia, afferent and efferent nerves, and more with 3D models and descriptions.
3 de nov. de 2023 · Learn about the nervous system, a network of neurons that sends, receives and modulates information between different body parts. Explore the cells, divisions, functions and clinical notes of the nervous system.
Learn about the anatomy and function of nerves, the bundles of axons in the peripheral nervous system. See illustrations of the layers, fluids, and fibers that make up a nerve and how they are affected by injury.
