Facial Nerve - USMLE - Neuroanatomy - Get 1 Year Online Access to 400+ Hours of videos on Basic Medical Sciences. Limited Time Offer: $99 ONLY! http://drnajeeblectures.com/
almost 7 years ago
This is the best online medical lectures site, providing high quality medical and nursing lectures for students across the globe. Our lectures are oversimplified for adequate learning, less memorization and proper understanding of difficult concept in clinical medicine.
about 7 years ago
http://www.handwrittentutorials.com - This tutorial looks at the ways in which the Nervous System is divided and categorised, both functionally and anatomically. Concepts such as the CNS, PNS and the Autonomic Nervous system are discussed in detail. For more entirely FREE tutorials and the accompanying PDFs visit http://www.handwrittentutorials.com
about 7 years ago
This question is about the somatic nervous system (SNS). I read that this the SNS part of the peripheral nervous system (PNS) and that it controls skeletal muscle. It is therefore thought to be voluntary. In contrast, the autonomic nervous system controls smooth muscle, under involuntary control. What I'm wondering is if reflex arcs (or reflexes) are controlled by the autonomic nervous system, why is it making use of skeletal muscle? Take the example of the reaction of moving your hand away when it is placed on something hot. These motor commands come from the autonomic nervous system but control the arm muscles that are normally controlled consciously. In other words things normally controlled voluntarily. The response was activated by the ANS, and was therefore automatic, but the muscles supplied by these motor commands were skeletal muscles? Can someone explain this (contradition) or perhaps correct my wrong thinking?
over 8 years ago
An edited version of my Friday Evening Discouse given to the Royal Institution on 11 April 2008. Abstract: The vagus nerves (cranial nerve X) connects our brainstem to the body, facilitating monitoring and control of many automatic functions; the vagus electrically links our gut, lungs and heart to the base of the brain in an evolutionarily-ancient circuit, similar between mammals and also seen in birds, reptiles, and amphibians. The vagus comprises a major part of the parasympathetic autonomic nervous system, contributing to the motor control of important physiological functions such as heart rate and gut motility. The vagus is also sensory, relaying protective visceral information leading to reflexes like cough and indication of lung volume. The vagus has been described as a neural component of the immune reflex. By monitoring changes in the level of control exerted by the vagus, apparent as beat by beat changes of heart rate, it is possible to indirectly view the effect of pharmaceuticals and disease on brainstem function and neural processes underlying consciousness. The paired vagus nerves of humans have different functions, and stimulation of the left vagus has been shown to be a therapeutic treatment for epilepsy, and may modulate the perception of pain.
over 12 years ago