Components of nervous tissue. Components of Nervous Tissue and ANS Review Flashcards 2022-11-01
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Nervous tissue is a type of tissue found in the central and peripheral nervous systems of animals. It is responsible for transmitting, processing, and integrating sensory information, as well as controlling and coordinating the body's responses to stimuli. Nervous tissue is made up of two main types of cells: neurons and glial cells.
Neurons are the primary cells of the nervous system. They are responsible for transmitting nerve impulses, or electrical signals, throughout the body. Neurons have three main parts: the cell body, dendrites, and axons. The cell body contains the nucleus and other organelles, and is responsible for the synthesis and maintenance of the neuron. Dendrites are short, branching processes that extend from the cell body and receive signals from other neurons. Axons are long, slender processes that extend from the cell body and transmit signals to other cells, either through chemical synapses or electrical synapses.
Glial cells, also known as neuroglia or glia, are non-neuronal cells that provide support and protection for neurons. There are several types of glial cells, including astrocytes, oligodendrocytes, and microglia. Astrocytes are star-shaped cells that provide structural support for neurons and help to regulate the chemical environment of the brain. Oligodendrocytes are responsible for insulating axons with myelin, a fatty substance that helps to speed up the conduction of nerve impulses. Microglia are small cells that act as the immune system of the brain, protecting it from infection and injury.
In addition to neurons and glial cells, nervous tissue also contains various types of extracellular matrix, or non-cellular components. These include axons, dendrites, and myelin, as well as various neurotransmitters and other signaling molecules. Neurotransmitters are chemical messengers that are released by neurons and bind to receptors on the surface of other cells, transmitting signals across the synapse.
Overall, the components of nervous tissue play critical roles in the functioning of the nervous system. Neurons transmit electrical signals throughout the body, while glial cells provide support and protection for neurons. The extracellular matrix contains various signaling molecules that help to coordinate and regulate the activity of the nervous system. Together, these components work together to enable the body to sense, think, and respond to its environment.
It is made of dense irregular connective tissue and usually contains multiple nerve fascicles as well as blood vessels which supply the nerve. Astrocytes, in particular, 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. Other Neuron Classifications Neurons can also be classified on the basis of where they are found, who found them, what they do, or even what chemicals they use to communicate with each other. Multipolar Multipolar neurons are all of the neurons that are not unipolar or bipolar. They hypertrophy when the cell is injured create supportive framework for neurons create "blood-brain barrier" monitor and regulate interstitial fluid surrounding neurons secrete chemicals for embryological neuron formation stimulate the formation of scar tissue secondary to CNS injury The epineurium is the outermost layer of connective tissue surrounding a peripheral nerve. Despite overlap between adjacent spinal nerves, the innervation pattern is presented as evenly spaced horizontal or longitudinal patterns across the entire body, as illustrated in the following dermatome map: Dermatomes and myotomes Explore study unit Similar to dermatomes, the group of muscles supplied by the motor ï¬bers of a single spinal nerve can also be mapped. These are found housed within the The brain is made of four parts; The spinal cord continues from the brainstem.
Components of Nervous Tissue and ANS Review Flashcards
The autonomic nervous system seems to be the only thing that can act without your free will. Cortical pyramidal neurons and inhibitory interneuron subtypes are discussed together with examples of specialized neurons from subcortical regions. It is responsible for coordinating and controlling many body activities. Glial Cells of the PNS The PNS has satellite cells and Schwann cells. It is important to note that a single neuron does not act alone—neuronal communication depends on the connections that neurons make with one another as well as with other cells, like muscle cells. This is where the name of the disease comes from; sclerosis means hardening of tissue, which is what a scar is. Interestingly, both exercise and some antidepressant medications also promote neurogenesis in the hippocampus.
This chapter provides general information on the various types of cells that compose nervous tissues and serves as an introduction to cellular neuroscience. Astrocytes have many processes extending from their main cell body not axons or dendrites like neurons, just cell extensions. . Neurons The nervous system of the common laboratory fly, Drosophila melanogaster, contains around 100,000 neurons, the same number as a lobster. The synapse doesn't connect to the next cell directly. The PNS is a vast network of spinal and cranial nerves that are linked to the brain and the spinal cord.
Oligodendrocytes form the myelin sheath around axons. The function of myelin will be discussed below. Oligodendrocytes, shown in Figure 8b form myelin sheaths around axons in the CNS. Glial Cells Glial cells, or neuroglia or simply glia, are the other type of cell found in nervous tissue. An axon is a tube-like structure that propagates the integrated signal to specialized endings called axon terminals.
They do so by potentiating the activity of different organs under various circumstances; for example, the PSNS will stimulate higher Autonomic nerves synapse within autonomic ganglia before reaching their target organ, thus all of them have presynaptic and postsynaptic parts. One interesting difference between the nervous systems of invertebrates and vertebrates is that the nerve cords of many invertebrates are located ventrally whereas the vertebrate spinal cords are located dorsally. Most sensory neurons are pseudounipolar and have an axon that branches into two extensions: one connected to dendrites that receive sensory information and another that transmits this information to the spinal cord. The components are: 1. Nevertheless, even if they cannot be easily seen, and one specific process is definitively the axon, these neurons have multiple processes and are therefore multipolar. Neuroanatomy through clinical cases. Dendrites from a single neuron may receive synaptic contact from many other neurons.
These organelles include dendrites, presynaptic terminals, sex-chromatin, nissl granules, and neurofribillae etc. These white and grey rami communicantes establish a connection between spinal nerves and the two sympathetic trunks of the If you want more detail about spinal nerves take a look below: Somatic nervous system The somatic, voluntary, nervous system is responsible for providing sensory and motor innervation to Both cranial and spinal nerves contribute to the somatic nervous system. Each gap is called a node of Ranvier and is important to the way that electrical signals travel down the axon. Which organ is formed by nervous tissue? Disorders of the Nervous Tissue Several diseases can result from the demyelination of axons. This information is sent to the CNS via afferent sensory nerves.
It is the axon that propagates the nerve impulse, which is communicated to one or more cells. Identify the two primary parts of the nervous system and describe the function and structure of neurons and glial cells The nervous system is made up of neurons, specialized cells that can receive and transmit chemical or electrical signals, and glia, cells that provide support functions for the neurons by playing an information processing role that is complementary to neurons. ADVERTISEMENTS: c Axoplasm also contains mitochondria, nissl granules, neurofibrillae running parallel to the long axis of the axon. There is an amazing diversity of neuron shapes and sizes found in different parts of the nervous system and across species , as illustrated by the neurons shown in Figure 4. Components of the Nervous Tissue. One is the axon and one the dendrite. For example, carpal tunnel syndrome affects the median nerve, and occurs when the nerve is compressed within the tunnel.
Nervous systems vary in structure and complexity. The somatic has voluntary control of skin, bones, joints, and skeletal muscle. In: Texture of the Nervous System of Man and the Vertebrates. Cite this chapter y Cajal, S. Nervous tissue is composed of two types of cells, neurons and glial cells. Provided by: OpenStax CNX.
Where the axon emerges from the cell body, there is a special region referred to as the axon hillock. Neurons contain organelles common to many other cells, such as a nucleus and mitochondria. Roper, and Michael J. The Process of Myelination. Although glia have been compared to workers, recent evidence suggests that also usurp some of the signaling functions of neurons. While most of the new neurons will die, researchers found that an increase in the number of surviving new neurons in the hippocampus correlated with how well rats learned a new task. These splanchnic nerves synapse closer to their target organs in prevertebral ganglia called celiac, aorticorenal, and mesenteric superior and inferior.
They travel with the Are you searching for the best way to revise the peripheral nervous system anatomy? Â White and gray matter Synonyms: Brain cortex, Cortical grey matter The white color of myelinated axons is distinguished from the gray colored neuronal bodies and dendrites. This process is called as salutatory conduction and is helpful in the higher velocity of nerve transmission in myelinated fibres than that in un-myelinated fibres. However, there is one caveat; all autonomic nerves synapse with a sympathetic or preganglionic and carries the impulse towards the cluster of cell bodies. These ganglia can control movements and behaviors without input from the brain. The edges of this loose enclosure extend toward each other, and one end tucks under the other.
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