Victims and survivors
John C. Gunn, Pamela J. Taylor in Forensic Psychiatry, 2014
The infant’s psychophysiological response to a state of ‘fear without solution’ in relation to their caregiver may elicit two separate responses.A ‘fight–flight response’, mediated by the sympathetic nervous system. This blocks reflective symbolic processing with the result that traumatic experiences are stored in sensory, somatic, behavioural and affective state, and is manifest in hyperarousal (Perry et al., 1997).If this ‘fight and flight response’ is not possible, a parasympathetic dominant states takes over, and the infant ‘freezes’ to conserve energy. In this state, endogenous opiates are released to produce numbing of pain, and a loss of vocalisation (Nijenhuis et al., 1998); this phenomenon may be seen under the PET scanner (Rauch et al., 1996).
Basic medicine: physiology
Roy Palmer, Diana Wetherill in Medicine for Lawyers, 2020
The external parts of the body (skin and muscles) are controlled mostly by the somatic nervous system. Somatic nerves, therefore, control movement of the trunk and limbs, as well as sensations such as touch, pain and temperature. By contrast, the viscera or internal organs of the body (heart, lungs, gut) are controlled by the autonomic nervous system. Autonomic nerves are either sympathetic or parasympathetic. Sympathetic nerves help the body to respond to sudden danger; they mediate the ‘fright, flight or fight’ response characterized by widening of the pupil, quickening of the heartbeat (tachycardia) and diversion of blood to the muscles. This process is assisted by liberation of the hormones adrenaline and noradrenaline into the bloodstream. The parasympathetic nervous system is concerned with vegetative processes such as swallowing and intestinal secretion, which are carried on during calmer times. Many viscera have a dual autonomic innervation, each with opposing functions. Thus, adrenaline makes the heart race, while stimulation of the vagus (parasympathetic) nerve causes the pulse to slow.
Anatomy and Physiology of the Autonomic Nervous System
Kenneth J. Broadley in Autonomic Pharmacology, 2017
Generally, the organs are innervated by both divisions of the autonomic nervous systems, which have opposing effects. However, because the parasympathetic nerves are less widely distributed and limited to the thoracic, abdominal and pelvic viscera, some organs receive only a sympathetic innervation. The physiological effects of sympathetic nerve activity to an organ can be anticipated by considering its role in preparing the body for flight or fight. So, for example, the rate and force of cardiac contractions increase to improve the blood flow to skeletal muscle where vascular smooth muscle is dilated. Sympathetic activity is generally more widespread which is reflected in the greater branching of sympathetic fibres in the sympathetic chain. The origins of sympathetic fibres supplying a particular organ are therefore often difficult to identify since there is considerable overlap between adjacent ganglia. A general scheme is presented in Figure 1.3.
An evaluation of empagliflozin and it’s applicability to hypertension as a therapeutic option
Published in Expert Opinion on Pharmacotherapy, 2020
Lakshini Y Herat, Vance B Matthews, Aaron L Magno, Marcio G Kiuchi, Revathy Carnagarin, Markus P Schlaich
As shown by the Hypertension Optimal Treatment (HOT) trial [13,14] and the UK Prospective Diabetes Studies (UKPDS) [15,16], patients assigned to lower BP targets have demonstrated improved outcomes in both micro and macrovascular complications, especially in preventing strokes. However, achieving adequate BP control is difficult in patients with diabetes [17], thus combination therapy is often required [18,19]. The regulation of BP is complex due to the involvement of several interrelated factors and mechanisms. Currently, numerous facets of BP regulation have been extensively studied, including: i) the sympathetic nervous system (SNS); ii) the renin–angiotensin–aldosterone system; iii) renal pathways involved in the regulation of sodium and volume balance; iv) mechanisms in regulating peripheral resistance and v) endothelial dysfunction [20,21].
Cardiovascular and metabolic consequences of the association between chronic stress and high-fat diet in rats
Published in Stress, 2018
Bruna B. Simas, Everson A. Nunes, Carlos C. Crestani, Guilherme F. Speretta
Interestingly, while the food and energy intake was similar among control and CVS rats fed with SD, the rats exposed to CVS and fed with SD decreased body weight gain. The increased sympathetic nervous system activity and hypertrophied adrenals found in these rats may be involved in this response. For instance, the sympathetic nervous system directly targets peripheral organs and stimulate the adrenal medulla to increase circulating catecholamines, so allowing an immediate “fight-or-flight” response to the threat. Besides, the increase in circulating concentrations of corticosterone modifies tissue metabolism to inhibit energy storage and increases glucose availability to muscle and brain (Harris, 2015). Moreover, brown adipose tissue thermogenesis seems to be activated by CRF and the sympathetic nervous system (Harris, 2015), which could also increase energy expenditure. Indeed, a recent study demonstrated increased interscapular brown adipose tissue accumulation, increased energy expenditure and lipid oxidation, and lower body weight in a mouse model of chronic psychosocial defeat, even with high food intake (Coccurello et al., 2017).
Anterior cervical discectomy and fusion is more effective than cervical arthroplasty in relieving atypical symptoms in patients with cervical spondylosis
Published in British Journal of Neurosurgery, 2022
Giovanni Grasso, Fabio Torregrossa, Brian A. Karamian, Jose A. Canseco, Alexander R. Vaccaro
Cervical disc herniation,45 inflammatory mediator release (including IL-1, IL-6, PGE2 and NO) resulting from cervical disc degeneration,46 and abnormal cervical mobility associated with age related degeneration47 have all been implicated in the stimulation of sympathetic fibers within the PLL. When sympathetic nerves within the PLL are excited, a reflex spreads through the sympathetic center located in the thoracic spinal cord.16 From here, the reflex reaches the postganglionic sympathetic fibers innervating the target organs resulting in sympathetic symptoms.45 However, sympathetic symptoms are not present in all the patients with cervical spondylosis which may be attributed to the differences in the sensitivities and/or stimulation of sympathetic nerves within the PLL.48
Related Knowledge Centers
- Autonomic Nervous System
- Enteric Nervous System
- Thoracic Vertebrae
- Spinal Cord
- Vertebral Column
- Ganglion
- Parasympathetic Nervous System
- Fight-Or-Flight Response
- Homeostasis
- Neuron