![]() The pelvic viscera are innervated by nerves from the second through fourth sacral spinal segments. These four cranial nerves transmit visceral sensory information from the internal face and head (V) tongue (taste, VII) hard palate and upper part of the oropharynx (IX) and carotid body, lower part of the oropharynx, larynx, trachea, esophagus, and thoracic and abdominal organs (X), with the exception of the pelvic viscera. ![]() Cranial visceral sensory information enters the CNS by four cranial nerves: the trigeminal (V), facial (VII), glossopharyngeal (IX), and vagus (X) nerves. The cranial visceral sensory system carries mainly mechanoreceptor and chemosensory information, whereas the afferents of the spinal visceral system principally convey sensations related to temperature and tissue injury of mechanical, chemical, or thermal origin. Information on the status of the visceral organs is transmitted to the CNS through two main sensory systems: the cranial nerve (parasympathetic) visceral sensory system and the spinal (sympathetic) visceral afferent system ( Saper, 2002). When the spinal efferent nerves are interrupted, the denervated skeletal muscles lack myogenic tone, are paralyzed, and atrophy, whereas smooth muscles and glands generally retain some level of spontaneous activity independent of intact innervation. In vertebrates, somatic muscles include the striated muscles of the skeleton, which are innervated by the motoneurons of the anterior horns of the spinal cord and by some motor nuclei of the brainstem. Whereas motor nerves to skeletal muscles are myelinated, postganglionic autonomic nerves generally are nonmyelinated. the part of the nervous system that innervates the muscles of the body and makes sensory and motor functions possible. Many autonomic nerves form extensive peripheral plexuses, but such networks are absent from the somatic system. Somatic nerves contain no peripheral ganglia, and the synapses are located entirely within the cerebrospinal axis. These ganglia are small but complex structures that contain axodendritic synapses between preganglionic and postganglionic neurons. The most distal synaptic junctions in the autonomic reflex arc occur in ganglia that are entirely outside the cerebrospinal axis. The main difference between ganglia and nuclei is that ganglia are clusters of nerve cell bodies in the PNS whereas nuclei are clusters of nerve cell bodies in the CNS.The efferent nerves of the involuntary system supply all innervated structures of the body except skeletal muscle, which is served by somatic nerves. These functional units are present in both central nervous system ( CNS) and peripheral nervous system ( PNS). A spinal ganglion, for instance, is a cluster of nerve bodies positioned along the spinal cord at the dorsal and ventral roots of a spinal nerve. In vertebrates the ganglion is a cluster of neural bodies outside the central nervous system. The peripheral nervous system has two major partsthe somatic and autonomic systems. Then, what is a ganglion in the nervous system? Central Nervous System includes the brain and spinal cord Brain is control center for all activities in the body (made of billions of neurons) Spinal cord is made of bundles of neurons Sensory neurons send impulses to the brain or spinal cord. The somatic nervous system consists of afferent nerves or sensory nerves, and efferent nerves or motor nerves. One may also ask, what does the somatic nervous system control? The somatic nervous system (SNS or voluntary nervous system) is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles. The autonomic nervous system controls internal organs and glands, while the somatic nervous system controls muscles and movement. In the autonomic nervous system there are both sympathetic and parasympathetic ganglia which contain the cell bodies of postganglionic sympathetic and parasympathetic neurons respectively.Ĭonsidering this, what is the difference between the somatic nervous system and the autonomic nervous system?ĭifferences: The autonomic nervous system consists of two sub-components, whereas the somatic nervous system only has one. To summarize the different divisions of the nervous system: the parasympathetic nervous system controls rest and digest actions, and the sympathetic nervous system controls fight or flight actions. In the somatic nervous system this includes dorsal root ganglia and trigeminal ganglia among a few others. The somatic nervous system is one of the two great parties which divides the peripheral nervous system (which is the entire nervous system found outside of the brain and spinal cord). The PNS also includes the sympathetic nervous system and the somatic nervous system (SoNS), which controls voluntary body movements.
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