Satellite glia provide nutrients and structural support for neurons in the PNS. Microglia scavenge and degrade dead cells and protect the brain from invading microorganisms. Oligodendrocytes , shown in Figure One axon can be myelinated by several oligodendrocytes, and one oligodendrocyte can provide myelin for multiple neurons.
This is distinctive from the PNS where a single Schwann cell provides myelin for only one axon as the entire Schwann cell surrounds the axon.
Radial glia serve as scaffolds for developing neurons as they migrate to their end destinations. Ependymal cells line fluid-filled ventricles of the brain and the central canal of the spinal cord.
They are involved in the production of cerebrospinal fluid, which serves as a cushion for the brain, moves the fluid between the spinal cord and the brain, and is a component for the choroid plexus. The nervous system is made up of neurons and glia. Neurons are specialized cells that are capable of sending electrical as well as chemical signals.
Most neurons contain dendrites, which receive these signals, and axons that send signals to other neurons or tissues. There are four main types of neurons: unipolar, bipolar, multipolar, and pseudounipolar neurons. Glia are non-neuronal cells in the nervous system that support neuronal development and signaling.
There are several types of glia that serve different functions. Skip to content Chapter The Nervous System. Learning Objectives By the end of this section, you will be able to: List and describe the functions of the structural components of a neuron List and describe the four main types of neurons Compare the functions of different types of glial cells. Concept in Action. Parts of a Neuron. Neurons contain organelles common to many other cells, such as a nucleus and mitochondria.
They also have more specialized structures, including dendrites and axons. The soma is the cell body of a nerve cell. Myelin sheath provides an insulating layer to the dendrites. Axons carry the signal from the soma to the target. Dendrites carry the signal to the soma. Types of Neurons. Neurogenesis At one time, scientists believed that people were born with all the neurons they would ever have.
This micrograph shows fluorescently labeled new neurons in a rat hippocampus. Cells that are actively dividing have bromodoxyuridine BrdU incorporated into their DNA and are labeled in red.
Cells that express glial fibrillary acidic protein GFAP are labeled in green. Microglia scavenge and degrade dead cells, protecting the brain from invading microorganisms. Oligodendrocytes form myelin sheaths around axons in the CNS. One axon can be myelinated by several oligodendrocytes; one oligodendrocyte can provide myelin for multiple neurons.
This is distinctive from the PNS where a single Schwann cell provides myelin for only one axon as the entire Schwann cell surrounds the axon. Radial glia serve as bridges for developing neurons as they migrate to their end destinations. Ependymal cells line fluid-filled ventricles of the brain and the central canal of the spinal cord. They are involved in the production of cerebrospinal fluid, which serves as a cushion for the brain, moves the fluid between the spinal cord and the brain, and is a component for the choroid plexus.
Images of glial cells : a Astrocytes and b oligodendrocytes are glial cells of the central nervous system. Glial cells : Glial cells support neurons and maintain their environment. Glial cells of the a central nervous system include oligodendrocytes, astrocytes, ependymal cells, and microglial cells. Oligodendrocytes form the myelin sheath around axons.
Astrocytes provide nutrients to neurons, maintain their extracellular environment, and provide structural support. Microglia scavenge pathogens and dead cells. Ependymal cells produce cerebrospinal fluid that cushions the neurons. Glial cells of the b peripheral nervous system include Schwann cells, which form the myelin sheath, and satellite cells, which provide nutrients and structural support to neurons. Privacy Policy. Skip to main content. The Nervous System.
Search for:. Neurons and Glial Cells. Learning Objectives Recall the differences in structure and function between the central and peripheral nervous systems. Key Takeaways Key Points The central nervous system contains the brain and spinal cord; the peripheral nervous system consists of nerves, motor neurons, the autonomic nervous system, and the enteric nervous system.
The nervous system coordinates the voluntary and involuntary actions of the body by transmitting signals from the brain to the other body parts and listening for feedback. Nervous systems vary across different animals; some invertebrates lack a true nervous system or true brain, while other invertebrates have a brain and a system of nerves. Unlike vertebrates, not all invertebrates have both a CNS and PNS; their nerve cords are located ventrally rather than dorsally. The functions of the nervous system are performed by two types of cells: neurons, which transmit signals between them and from one part of the body to another, and glia, which regulate homeostasis, providing support and protection to the function of neurons.
Neurons Four major types of neurons transmit signals through the body via specialized structures such as dendrites, axons, and synapses. Learning Objectives Describe the functions of the structural components of a neuron. Key Takeaways Key Points Dendrites are the tree-like structures in neurons that extend away from the cell body to receive messages from other neurons at synapses; not all neurons have dendrites.
Synapses enable the dendrites from a single neuron to interact and receive signals from many other neurons. Axons are tube-like structures that send signals to other neurons, muscles, or organs; not all neurons have axons. Purkinje Cells. Trending Popular articles on BrainFacts. The Neuron.
Proteins That Balance Our Moods. Educator Resources Explain the brain to your students with a variety of teaching tools and resources. Find a Neuroscientist Engage local scientists to educate your community about the brain. Like Subscribe Follow Follow Subscribe. About BrainFacts. Some pages on this website provide links that require Adobe Reader to view. Nucleolus - produces ribosomes necessary for translation of genetic information into proteins Nissl Bodies - groups of ribosomes used for protein synthesis.
Endoplasmic reticulum ER - system of tubes for transport of materials within cytoplasm. Can have ribosomes rough ER or no ribosomes smooth ER. With ribosomes, the ER is important for protein synthesis. Golgi Apparatus - membrane-bound structure important in packaging peptides and proteins including neurotransmitters into vesicles. Mitochondria - produce energy to fuel cellular activities. Happy st Birthday to the Golgi apparatus!
In , the famous neuroanatomist Camillo Golgi reported his discovery of a ribbon-like apparatus inside neurons of the cerebellum. This structure now bears his name as the "Golgi apparatus. Color a neuron or several neurons online! Try the Neuron Review Test. Requires the Adobe Acrobat Reader. Answers to the Neuron Review Test. Build a Neuron - you must have the Shockwave plug-in for your browser.
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