scholarly journals Anatomy and Physiology: Mechanisms of Nociceptive Transmission

Pain Medicine ◽  
2017 ◽  
pp. 3-5
Author(s):  
Daniel Vardeh ◽  
Julian F. Naranjo

Although efferent control of sensory transmission is a well-established concept, a specific network for nociceptive modulation has only recently been discovered. This network includes interconnected components at midbrain, medullary and spinal levels. At the midbrain level, electrical stimulation of the periaqueductal grey (p.a.g.) inhibits spinal neurons that respond to noxious stimuli as well as nociceptor-induced reflexes and escape behaviour in a variety of species. Midbrain stimulation also produces analgesia in patients with clinically significant pain. The rostral ventral medulla (r.v.m.) has similar behavioural and physiological effects and mediates midbrain antinociceptive actions at the level of the spinal cord. Endorphins are present at all levels of this nociceptive modulating network. Opiate microinjections at p.a.g., r.v.m. or spinal levels produce analgesia, presumably by mimicking the actions of the endorphins. The nociceptive modulatory system is diffusely organized, highly interconnected and appears to act as a unit whether activated by opiates or electrical stimulation. There are two classes of r.v.m. neurons the activity of which is correlated with the occurrence of reflexes induced by noxious stimulation. One class (the on-cell) accelerates, the other class (the off-cell) pauses just before tail flick. Both classes project to the spinal cord and are excited by electrical stimulation of the midbrain. However, when morphine is injected either systemically or into the p.a.g., the off-cell is excited and the on-cell stops firing. The off-cell is probably the r.v.m. output cell that inhibits nociceptive transmission at the level of the spinal cord. The function of the on-cell is not clear. The nociceptive modulatory system can be activated by a variety of stressful environmental factors, which are often, but not necessarily, noxious. The idea that the system acts as a simple negative feedback circuit is not consistent with its known properties.


2016 ◽  
Vol 1 (5) ◽  
pp. 4-12
Author(s):  
David P. Kuehn

This report highlights some of the major developments in the area of speech anatomy and physiology drawing from the author's own research experience during his years at the University of Iowa and the University of Illinois. He has benefited greatly from mentors including Professors James Curtis, Kenneth Moll, and Hughlett Morris at the University of Iowa and Professor Paul Lauterbur at the University of Illinois. Many colleagues have contributed to the author's work, especially Professors Jerald Moon at the University of Iowa, Bradley Sutton at the University of Illinois, Jamie Perry at East Carolina University, and Youkyung Bae at the Ohio State University. The strength of these researchers and their students bodes well for future advances in knowledge in this important area of speech science.


2018 ◽  
Author(s):  
Bernard Rousseau ◽  
RYAN BRANSKI

2019 ◽  
Vol 3 (6) ◽  

This article is about women and girls and the potential for major changes. I begin with two premises: first, the urethrovaginal gland (UVG) and its secretion, amrita, are critical elements of being a human female; and, second, there is a genetic underpinning to the robustness of UVG activity and its contribution to sexual satisfaction. The anticipation is that, in addition to facilitating women’s sexual satisfaction both through raising awareness and identifying geneticbased pharmaceuticals, we might also modestly enhance medical care and biomedical research endeavors relevant to human female sexual anatomy and physiology. However, there is substantial, almost uniform ignorance, reticence and untoward prejudice among medical professionals-both clinicians and researchers-that has compromised innumerable girls and women. Most important has been the ubiquitous incorrect presumption that the only fluid to pass through-or issue from-the female urethra is urine. The source of the other important urethral effluent, amrita, is the UVG (sometimes known as the Skene gland), but the UVG has most often been considered a fiction, a myth or irrelevant. Thus, its secretion, amrita, has similarly been considered a fiction, myth or irrelevant. Only one venue has openly acknowledged and exploited amrita: the adult movie industry. However, such endorsement predictably added to the rationales for making light of or ignoring this aspect of femininity.


2009 ◽  
Vol 4 (1) ◽  
pp. 76
Author(s):  
James Slater ◽  
Mark Fisch ◽  
◽  

William Harvey was the first scientist to describe the heart as consisting of separate right- and left-sided circulations. Our understanding of the heart’s anatomy and physiology has grown significantly since this landmark discovery in 1628. Today, we recognise not only the importance of these separate systems, but also the specific tissue that divides them. Our growing understanding of the inter-atrial septum has allowed us to identify defects within this structure and develop effective percutaneous devices for closure of these defects in the adult patient. This article discusses the formation of a patent foramen ovale (PFO) and atrial septal defect (ASD). In addition, we describe the medical illnesses caused by these defects and summarise the indications and risks related to percutaneous closure of these defects. We also report the most up-to-date transcatheter therapeutic options for closure of these common congenital defects in the adult patient.


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