Miscellaneous
Bobby Krishnachetty, Abdul Syed, Harriet Scott in Applied Anatomy for the FRCA, 2020
This chapter is intended to cover the anatomical knowledge of nerves that helps trainee anesthetists who are revising for the Primary and Final FRCA exams. The topics of importance to anesthetists are presented under 'structures', 'circulation' and 'nervous system'. The chapter includes a wide range of questions of clinical relevance that are asked in the exam. Peripheral nerves are formed of axons of neurons with cell bodies that reside in the central nervous system. The autonomic nervous system is the unconscious nervous system that deals with a series of involuntary functions controlling a number of actions within organs in the body. The sympathetic nervous system consists of a chain of fused ganglia that lie adjacent to the spinal cord bilaterally. The parasympathetic nervous system consists of preganglionic fibers originating from the brain stem of the motor nuclei of cranial nerves III, VII, IX and X and from the ventral rami of sacral nerves two, three and four (cranio-sacral outflow).
General Organization of the Nervous System
Jean-Pierre Monnet, Yves Harmand in Pediatric Regional Anesthesia, 2019
The nervous system is made up of highly differentiated tissues, the function of which is the transmission of information. The nervous system is divided into two subsystems: the central nervous system, including the cortex, brain stem, cerebellum, and spinal cord, and the peripheral nervous system, consisting of the spinal roots, ganglia and nerves, and the peripheral nerves. With vertebrates, a further increase in the differentiation of nerve cells gives rise to a system specifically devoted to communication with the surroundings. A similar organization can still be found in olfactory cells in humans, but in the higher animals a nerve cell usually mediates the propagation of excitatory stimuli applied to other nerve or muscle cells. Thus a system of nerves is created and it is called the autonomic nervous system. This system is subdivided into two antagonist parts: the sympathetic and parasympathetic nervous systems.
John Newport Langley (1852–1925)
Andrew P. Wickens in Key Thinkers in Neuroscience, 2018
A Cambridge physiologist John Newport Langley who more than any other person mapped out the functional neuroanatomy of the sympathetic and parasympathetic nervous systems and who first proposed the concept of pharmacological receptors in 1905. Langley had examined the specific physiological functions of the three major spinal outflows and begun to use a new nomenclature to describe this system of nerves. In 1889, Langley, with the help of Dr William Lee Dickinson, turned their attention to the array of nerves that leave the length of the spinal cord and control the automated or vegetative functions of the body. The fibres of the cranial and sacral outflows passed further out into the body, where they terminated in ganglia closer to their target organs. Langley had extended his work with nicotine to the neuromuscular junction and found it also caused the skeletal muscles to contract.
Moderate Pressure Massage Elicits a Parasympathetic Nervous System Response
Published in International Journal of Neuroscience, 2009
Miguel A. Diego, Tiffany Field
Twenty healthy adults were randomly assigned to a moderate pressure or a light pressure massage therapy group, and EKGs were recorded during a 3-min baseline, during the 15-min massage period and during a 3-min postmassage period. EKG data were then used to derive the high frequency (HF), low frequency (LF) components of heart rate variability and the low to high frequency ratio (LF/HF) as noninvasive markers of autonomic nervous system activity. The participants who received the moderate pressure massage exhibited a parasympathetic nervous system response characterized by an increase in HF, suggesting increased vagal efferent activity and a decrease in the LF/HF ratio, suggesting a shift from sympathetic to parasympathetic activity that peaked during the first half of the massage period. On the other hand, those who received the light pressure massage exhibited a sympathetic nervous system response characterized by decreased HF and increased LF/HF.
Negative Peer Status and Relational Victimization in Children and Adolescents: The Role of Stress Physiology
Published in Journal of Clinical Child & Adolescent Psychology, 2015
Nicole Lafko, Dianna Murray-Close, Erin K. Shoulberg
The purpose of the current investigation was to determine the unique associations between two subtypes of low peer status, peer rejection and unpopularity, and changes in relational victimization over time. This study also investigated if these associations were moderated by sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) reactivity to peer stress. Sixty-one girls attending (Mage = 11.91 years, SD = 1.62; predominantly Caucasian) a residential summer camp were followed across 1 calendar year. Participants' skin conductance and respiratory sinus arrhythmia were assessed during a laboratory stress protocol. Peer rejection and unpopularity were measured using peer nomination techniques and counselors reported on relational victimization. Both unpopularity and rejection were associated with increased relational victimization over time among girls who exhibited reciprocal SNS activation (i.e., high SNS reactivity coupled with PNS withdrawal). Rejection was also associated with subsequent victimization among girls exhibiting reciprocal PNS activation (i.e., low SNS reactivity, PNS activation). Findings underscore the biosocial interactions between low peer status and physiological reactivity in the prediction of peer maltreatment over time.
Prostate cancer progression attributed to autonomic nerve development
Published in Cancer Biology & Therapy, 2013
Elena V Fernández, Douglas K Price, William D Figg
In a study recently published in Science, Magnon et al. show that both the sympathetic and parasympathetic components of the autonomic nervous system play an integral part in the development and dissemination of prostate cancer (PCa). Inhibition of the sympathetic nervous system (SNS) and disruption of the adrenergic receptors, specifically Ardβ2, resulted in the prevention of primary PCa tumor development in mice. The authors found that inhibition of the SNS is only successful in preventing murine tumor development if completed early enough, and the parasympathetic nervous system (PNS) predominates in later stages of PCa. Inhibition of the PNS by way of the cholinergic receptor, muscarinic 1 (Chrm1), caused mice to develop less metastases to the pelvic lymph nodes, intestines, and bones. A PCa progression scheme has been outlined where initial tumor engraftment is controlled by the SNS but then becomes less prominent than the PNS, which promotes metastasis. The investigators showed the dependence of the autonomic nervous system on development of PCa and present opportunities for prevention; further studies are needed to confirm these results in humans.
Related Knowledge Centers
- Enteric Nervous System
- External Ear
- Nervous System
- Sympathetic Nervous System
- Salivary Glands
- Visceral Afferents
- Tongue