What is the difference between unipolar and bipolar neurons

Pseudounipolar cells share characteristics with both unipolar and bipolar cells. A pseudounipolar cell has a single structure that extends from the soma like a unipolar cell , which later branches into two distinct structures like a bipolar cell. Most sensory neurons are pseudounipolar and have an axon that branches into two extensions: one connected to dendrites that receives sensory information and another that transmits this information to the spinal cord.

Types of Neurons : Neurons are broadly divided into four main types based on the number and placement of axons: 1 unipolar, 2 bipolar, 3 multipolar, and 4 pseudounipolar. While glia or glial cells are often thought of as the supporting cast of the nervous system, the number of glial cells in the brain actually outnumbers the number of neurons by a factor of ten.

Neurons would be unable to function without the vital roles that are fulfilled by these glial cells. Glia guide developing neurons to their destinations, buffer ions and chemicals that would otherwise harm neurons, and provide myelin sheaths around axons.

Scientists have recently discovered that they also play a role in responding to nerve activity and modulating communication between nerve cells. When glia do not function properly, the result can be disastrous; most brain tumors are caused by mutations in glia.

There are several different types of glia with different functions. Astrocytes make contact with both capillaries and neurons in the CNS. They provide nutrients and other substances to neurons, regulate the concentrations of ions and chemicals in the extracellular fluid, and provide structural support for synapses.

Astrocytes also form the blood-brain barrier: a structure that blocks entrance of toxic substances into the brain. They have been shown, through calcium-imaging experiments, to become active in response to nerve activity, transmit calcium waves between astrocytes, and modulate the activity of surrounding synapses.

Satellite glia provide nutrients and structural support for neurons in the PNS. 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.

Schematic cartoon of a ventral horn Somatic Efferent SE multipolar neuron. SE neurons have their cell bodies in the CNS; their axons join peripheral nerves and innervate skeletal muscle. As a multipoar neuron, a number of dendrites and one axon emanate from the cell body. The axon has few if any branches until its termination in a profusion of branches. The axon is specialized for conducting excitation from the input region to the output region of the neuron.

The cell body plus the dendrites of a mulltipolar neuron constitute a "dendritic zone" which receives synaptic input from other neurons. Axonal terminal branches telodendria make synaptic contact with other neurons or with effector organs neuromuscular synpases are shown above.

Go Top. Spinal Cord. So the multipolar neuron has one axon as you can see, extending from the cell body here, and its got several dendrites, which I've highlighted in red. One final type of neuron which you might hear mentioned, is the anaxonic neuron. The name again gives a clue, so "an" means without, so it's without axons. There are no axons in this type of neuron, it merely has a few projections from the cell body.

This type of neuron can't produce action potentials, but what happens is that it undergoes local potentials, or grades potentials. So it doesn't have any axons to send out action potentials. That's the basic classification of neurons. If you have found this video helpful, please click the like button, subscribe to our channel, and make sure you check out some more of our videos. Thank you for watching. Skip to content. Related Tutorials. Basic Parts of the Brain. Divisions of the Nervous System.

Glial Cells. Introduction to the Autonomic Nervous System. Neuron Structure. Parasympathetic Nervous System Anatomy. Sympathetic Nervous System Anatomy.

Synapse Structure. Transcription Hi this is Peter from AnatomyZone, and this is another neuroanatomy basics tutorials and in this short tutorial, we will take a look at the different types of neuron.

Unipolar Neuron We will begin by taking a look at the unipolar neuron. Pseudounipolar Neuron What humans have is something called a pseudo-unipolar neuron.