United States or Rwanda ? Vote for the TOP Country of the Week !
Anatomically, the auditory nerve not only goes to those parts of the brain whence the motor innervation emanates, and to the reflex centres in the cerebellum, but passes close by the vagus or pneumogastric nerve, which rules the heart and the vasomotor functions.
Literally, the tender mother; the innermost of the three coverings of the brain. It is thin and delicate; hence the name. External cartilaginous flap of the ear. Anything formed or moulded. The liquid part of the blood. A membrane covering the lung, and lining the chest. Pleurisy. An inflammation affecting the pleura. The chief nerve of respiration; also called the vagus, or wandering nerve.
Of his professional education he always speaks with scorn, claiming to have been his own teacher from first to last. His appointed teachers did not perceive that a new source of culture was within their hands. Homo vagus et inconstans! one of them pedantically reports of the future pilgrim to Rome, unaware on which side his irony was whetted.
The cell-bodies of the inhibitory fibers are located in the bulb, from where their fibers pass to the heart as a part of the vagus nerve. In addition to the fibers above mentioned, are those that convey impulses from the heart to the bulb.
Some of it will leak away into the nerves of his face and distort his features, some may set his tear-glands at work, some may travel down his vagus nerve and inhibit his heart's action so that he faints, or upset the blood-vessels in his head and give him a stroke.
Whoever has seen repeated, as we have, the experiment first performed by Weber, showing the consequence of irritating the vagus nerve, which connects the brain with the viscera whoever has seen the action of the heart suddenly arrested by irritating this nerve; slowly recommencing when the irritation is suspended; and again arrested the moment it is renewed; will have a vivid conception of the depressing influence which an over-wrought brain exercises on the body.
Unlike the other cranial nerves, which are concerned with the special senses or distributed to the skin and muscles of the head and neck, the vagus, as its name implies, strays downward into the chest and abdomen supplying branches to the throat, lungs, heart and stomach and forms an important connecting link between the brain and the sympathetic nervous system."
The tenth pair, the pneumogastric, also known as the vagus or wandering nerves, are the longest and most complex of all the cranial nerves. They are both motor and sensory, and are some of the most important nerves in the body. Passing from the medulla they descend near the oesophagus to the stomach, sending off, on their way, branches to the throat, the larynx, the lungs, and the heart.
It is also a well known fact that anything which inhibits or removes vagus control of the heart allows the heart to become more rapid, since these nerves act as a governor to the heart's contractions. Under the influence of atropin the heart rate is increased by paralysis of the vagi.
The drug increases the force and frequency of the respirations by stimulating the vagus roots in the lung. It paralyzes respiration finally by a secondary depressant action upon the respiratory center. It does not cause convulsions. It lessens and finally abolishes reflex action by a direct action upon the cord, and by a slight action upon the muscles and nerves.
Word Of The Day