The Discovery Of Chemical Neurotransmission
Andrew P. Wickens in A History of the Brain, 2014
The somatic nervous system is the peripheral system of nerves responsible for carrying motor input to, and sensory information from, the musculature. By focusing their attention on the nerves innervating the skeletal muscles, both Bernard and Kühne had been examining part of this system. They were also helped by the fact that the somatic nervous system was reasonably well understood at the end of the nineteenth century. Indeed, Charles Bell and Francois Magendie had shown that the anterior roots of the spinal cord give rise to its outgoing motor neurons, while the posterior roots received the incoming sensory fibres. In addition, Sherrington had meticulously mapped the areas of the body innervated by each motor nerve. However, the body also contains a second system of nerves called the autonomic nervous system, which regulates activities normally beyond our conscious control such as heart rate, breathing, gastrointestinal activity, blood pressure and energy mobilisation (to name a few). Consequently, this system consists of a different set of motor neurons, which project to the smooth muscle of the body (this includes the blood vessels and bronchioles), as well as cardiac muscle and various glands. In addition, the autonomic nervous system also monitors visceral organs and blood vessels with sensory neurons that provide input information to the lower areas of the brain including the pons and medulla. Thus, the somatic and autonomic systems are completely independent from each other.
Neurophotonics for Peripheral Nerves
Yu Chen, Babak Kateb in Neurophotonics and Brain Mapping, 2017
The PNS consists of two major components, autonomic and somatic (Horch and Dhillon, 2004). The autonomic nervous system is mainly concerned with functions not normally under voluntary control. It consists of a preganglionic component (with nerve cells originating in the spinal column or skull) and a postganglionic component (with nerve cells lying wholly outside the axial skeleton). The somatic system is concerned with voluntary control of muscles. It consists of nerve cells with somata located within or near the spinal column or skull. The autonomic nervous system is further subdivided into sympathetic and parasympathetic components on the basis of anatomical, biochemical, and functional features. On the same basis, the somatic nervous system is divided into sensory and motor components.
Neuromuscular Physiology
Michael H. Stone, Timothy J. Suchomel, W. Guy Hornsby, John P. Wagle, Aaron J. Cunanan in Strength and Conditioning in Sports, 2023
Fundamentally, the nervous system is a network of nerve cells and its supporting connective tissue. The nervous system can be evaluated in two basic ways: based on its anatomical characteristics or based on functional characteristics. Anatomically, there are two parts: the central nervous system (CNS), consisting of the brain and spinal cord, and the peripheral nervous system (PNS) consisting of 43 pairs of peripheral nerves (12 cranial and 31 spinal). The function of the CNS is either autonomic or somatic. The autonomic nervous system is responsible for involuntary actions involved in “housekeeping” and homeostasis maintenance, such as peristalsis and regulation of heart rate and blood pressure. The somatic system innervates skin, muscles, joints and provides the CNS with environmental information. The primary function of the somatic nervous system is working in an integrative fashion with the muscular system, thus forming the neuromuscular system. The neuromuscular nervous system’s primary function is in producing voluntary movement and reflex arcs.
Autoimmune gastrointestinal dysmotility: the interface between clinical immunology and neurogastroenterology
Published in Immunological Medicine, 2021
Shunya Nakane, Akihiro Mukaino, Eikichi Ihara, Yoshihiro Ogawa
The human nervous system controls voluntary and involuntary actions via the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and the spinal cord and acts as the main control center. The PNS consists of the associated nerve networks, which connect parts of the body to the CNS. The PNS is divided into the autonomic nervous system, which controls involuntary activities such as digestion and breathing, and the somatic nervous system, which controls voluntary actions by transmitting stimuli information to the CNS and sending back response signals to striated muscles. The autonomic nervous system is further divided into the sympathetic, parasympathetic, and enteric nervous system (ENS). The sympathetic nervous system deals with fight-or-flight signals, the parasympathetic system maintains body conditions, and the enteric nervous system regulates GI functions. The ENS is a large division of the PNS that can control GI behavior independent of CNS input (Figure 2). The ENS may affect the effector systems in the gut directly or indirectly via its action on intermediate cells, which include the epithelium, smooth muscles, blood vessels, endocrine cells, and the interstitial cells of Cajal [9].
Tending to painful sex: applying the neuroscience of trauma and anxiety using mindfulness and somatic embodiment in working with genito-pelvic pain and penetration disorders
Published in Sexual and Relationship Therapy, 2023
Cyndi Darnell
Furthermore the relationship between the brain and the body via the ANS, the somatic nervous system (SomNS) responsible for relaxation of the muscles (Rothschild, 2000), informs us that visceral responses to trauma (in this case prolonged emotional torment and neglect) can be reactivated when a certain posture is resumed, even in a non-threatening context (Rothschild, 2000). For example consensual sexual activity produces involuntary genital arousal, but such sensations send information bi-directionally, first to the brain from the body via the ANS and SomNS, (fast moving System 1), the brain immediately recalls that such sensations are unwelcome, unacceptable and become a source of stress and anxiety ultimately, resending information back to the body and involuntarily contracting the pelvic floor muscles at an unconscious level, even though sexual pleasure is very much wanted ‘consciously’. Such unresolved emotional trauma results in persistent chaos and rigidity (Siegel, 2010a) creating ongoing sexual problems for people longing for pleasure but finding themselves unable to physically ‘relax’ or enjoy the experience, despite a psychological/emotional willingness to do so.
Neurotoxic responses of rainbow trout (Oncorhynchus mykiss) exposed to fipronil: multi-biomarker approach to illuminate the mechanism in brain
Published in Drug and Chemical Toxicology, 2022
Arzu Uçar, Fatma Betül Özgeriş, Veysel Parlak, Aslı Çilingir Yeltekin, Esat Mahmut Kocaman, Gonca Alak, Muhammed Atamanalp
Amino-aminobutyric acid (GABA) receptors are a class of receptors that respond to the neurotransmitter GABA, the inhibitory compound in the central nervous system of vertebrates (Wang et al.2016). FP interferes in the nervous system by selectively binding to gamma-aminobutyric acid (GABA)-gated chloride channels and antagonizing the effect of GABA (Stehr et al.2006, Qu et al.2016). Stimulation of the nervous system results in neuronal hyper-excitation, stroke, and death due to the accumulation of GABA in synaptic connections (Gunasekara et al.2007). GABA-mediated neurotransmission takes part in the modulation of several neural pathways in fish development. It has been reported that the affinity of FP to fish GABA receptors is similar to that found in insects and can be highly toxic to fish (Zhang et al.2018, Dallarés et al. 2020). Acetylcholine is one of the most common neurotransmitters in the body. It is released from various parts of the central nervous system, motor neurons of the somatic nervous system, pre-post ganglionic parasympathetic neurons and preganglionic sympathetic neurons in the autonomic nervous system (Ganong 2003). The biomarker evaluated in our study is Acetylcholinesterase (AChE), a crucial enzyme in the nervous system. AChE ends the nerve impulses by supplying hydrolysis of the neurotransmitter acetylcholine (Lionetto et al.2013). In accordance with research, the effect of insecticides is relavent to reversible or irreversible neutralization of AChE and lead to cholinergic poisoning (Silva et al.2013, Serafini et al.2019), acetylcholine accumulation and hyper-stimulation of receptors (Colovic et al.2013). It can be said that FP administration destroys the brain tissue cholinergic neurons (Tian et al.2018), reduces hydrolysis of ACh, crucial neurotransmitter for synaptic cleft (Baldissera et al.2017), and as a result, inhibits AChE activity. Inhibition of AChE activity may have been caused by the direct effect of FP on the active sites of the AChE enzyme and destroyed its connecting to acetylcholine.
Related Knowledge Centers
- Central Nervous System
- Muscle Contraction
- Peripheral Nervous System
- Spinal Nerve
- Skeletal Muscle
- Cranial Nerves
- Nerve
- Afferent Nerve Fiber
- Efferent Nerve Fiber
- Mixed Nerve