The somatic nervous system is NOT responsible for processing information about
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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.[1][2] The somatic nervous system consists of sensory nerves carrying afferent nerve fibers, which relay sensation from the body to the central nervous system (CNS), and motor nerves carrying efferent nerve fibers, which relay motor commands from the CNS to stimulate muscle contraction. The a- of afferent and the e- of efferent correspond to the prefixes ad- (to, toward) and ex- (out of). Structure[edit]There are 43 segments of nerves in the human body.[3] With each segment, there is a pair of sensory and motor nerves. In the body, 31 segments of nerves are in the spinal cord and 12 are in the brain stem.[3] Besides these, thousands of association nerves are also present in the body.[citation needed] Thus the somatic nervous system consists of two parts:
Function[edit]The somatic nervous system controls all voluntary muscular systems within the body, and the process of voluntary reflex arcs. The basic route of nerve signals within the efferent somatic nervous system involves a sequence that begins in the upper cell bodies of motor neurons (upper motor neurons) within the precentral gyrus (which approximates the primary motor cortex). Stimuli from the precentral gyrus are transmitted from upper motor neurons, down the corticospinal tract, to lower motor neurons (alpha motor neurons) in the brainstem and ventral horn of the spinal cord: upper motor neurons release a neurotransmitter called glutamate from their axon terminal knobs, which is received by glutamate receptors on the lower motor neurons: from there, acetylcholine is released from the axon terminal knobs of alpha motor neurons and received by postsynaptic receptors (nicotinic acetylcholine receptors) of muscles, thereby relaying the stimulus to contract muscle fibers. Reflex arcs[edit]A reflex arc is a neural circuit that creates a more or less automatic link between a sensory input and a specific motor output. Reflex circuits vary in complexity—the simplest spinal reflexes are mediated by a two-element chain, of which in the human body there is only one, also called a monosynaptic reflex (there is only one synapse between the two neurones taking part in the arc: sensory and motor). The singular example of a monosynaptic reflex is the patellar reflex. The next simplest reflex arc is a three-element chain, beginning with sensory neurons, which activate interneurons inside of the spinal cord, which then activate motor neurons. Some reflex responses, such as withdrawing the hand after touching a hot surface, are protective, but others, such as the patellar reflex ("knee jerk") activated by tapping the patellar tendon, contribute to ordinary behavior. Other animals[edit]In invertebrates, depending on the neurotransmitter released and the type of receptor it binds, the response in the muscle fiber could either be excitatory or inhibitory. For vertebrates, however, the response of a skeletal striated muscle fiber to a neurotransmitter – always acetylcholine (ACh) – can only be excitatory. See also[edit]
References[edit]
What is the somatic nervous system responsible for?The somatic nervous system is a component of the peripheral nervous system associated with the voluntary control of the body movements via the use of skeletal muscles.
Which of the following is not controlled by the somatic nervous system?Few examples of the somatic nervous system, or the voluntary movement controlled by the somatic nervous system are walking, running swimming and many more dejection is not controlled by the somatic nervous system betters it is controlled by the enteric nervous system.
What are the 3 parts of somatic nervous system?The sensory-somatic nervous system consists of the cranial and spinal nerves and the autonomic nervous system consists of sensory and motor neurons between the CNS and the internal organs.
Which of the following is regulated by the somatic nervous system?Abstract. The somatic nervous system provides control of skeletal muscle movement. Conscious control of movement originates in the motor cortex (both premotor and primary motor cortex).
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