614 PATHOLOGICAL CONDITIONS OF THE VAGUS. 



diminished, and ultimately the respiration ceases, the diaphragm being relaxed : while, with 

 the most intense stimulation, there may be spasmodic expiratory arrest of the respiration with 

 closure of the glottis, which may last for fifteen seconds. Paralysis of the laryngeal nerves, 

 which causes disturbances of speech, has been referred to in 313. In bilateral paralysis of the 

 recurrent nerves, in consequence of tension upon them due to dilatation of the aorta and the 

 subclavian artery, a considerable amount of air is breathed out, owing to the futile efforts which 

 the patient makes in trying to speak; expectoration is more difficult, while violent coughing is 

 impossible (v. Ziemssen). Attacks of dyspnoea occur just as in animals, if the person make 

 violent efforts. Some observers (Salter, Bergson) have referred the paroxysms of nervous 

 asthma, which last for a quarter of an hour or more, and constitute asthma bronchiale, to 

 stimulation of the pulmonary plexus, causing spasmodic contraction of the bronchial muscle ( 

 106). Physical investigation during the paroxysms reveals nothing but the existence of some 

 rhonchi ( 117). If this condition is really spasmodic iu its nature (? of the vessels), it must be 

 usually of a reflex character ; the afferent nerves may be those of the lung, skin, or genitals (in 

 hysteria). Perhaps, however, it is due to a temporary paralysis of the pulmonary nerves 

 (afferent), which excite the respiratory centre (excito-respiratory). 



Stimulation of the cardiac branches of the vagus may cause attacks of temporary suspension 

 of the cardiac contractions, which are accompanied by a feeling of great depression and of 

 impending dissolution, with occasionally pain in the region of the heart. Attacks of this sort 

 may be produced refiexly, e.g., by stimulation or irritation of the abdominal organs (as in the 

 experiment of Goltz of tapping the intestines). Hennoch and Silbermann observed slowing of 

 the action of the heart in children suffering from gastric irritation. Similarly, the respiration 

 may be affected refiexly through the vagus, a condition described by Hennoch as asthma 

 dyspepticum. In cases of intermittent paralysis of the cardiac branches of the vagus, we rarely 

 find acceleration of the pulse above 160 (Ricgcl), 200 (TuczeTc, L. Langer); even 240 pulse-beats 

 per minute have been recorded (Kuppcrt), and in such cases, the beats vary much in rhythm 

 and force, and they are very irregular. These cases require to be more minutely analysed, as it 

 is not clear how much is due to paralysis of the vagus and how much to the action of the 

 accelerating mechanism of the heart. Little is known of affections of the intra-abdominal 

 fibres of the vagus. It seems that the sensory branches of the stomach do not come from the 

 vagus. If the trunk of the vagus or its centre be paralysed, there are laboured, deep, slow 

 respirations, such as follow the section of both vagi (Guttmann). 



353. XI. NEEVUS ACCESSORIUS WILLISII. Anatomical. This nerve arises by two 

 completely separate roots ; one from the accessorius nucleus of the medulla oblongata 

 (fig. 427, 11), which is connected with the vagus nucleus ; while the other root arises between 

 the anterior and posterior nerve-roots from the spinal cord, usually between the 5th and 6th 

 cervical vertebra?. In the spinal cord, its fibres can be traced to an elongated nucleus lying on 

 the outer side of the anterior cornu, as far downwards as the 5th cervical vertebra. Near the 

 jugular foramen both portions come together, but do not exchange fibres (Holl) ; both roots 

 afterwards separate from each other to form two distinct branches, the anterior (inner), which 

 arises from the medulla oblongata, passing en masse into the plexus gangliiformis vagi. This 

 branch supplies the vagus with most of its motor fibres (compare 352, 3), and also its cardio- 

 inhibitoi-y fibres (fig. 433). [The upper cervical metameres or segments give origin not only to 

 the anterior and posterior roots of the corresponding nerve-roots, but between these roots arise the 

 roots of the spinal accessory nerve. This nerve contains large medullated nerve-fibres, and fine 

 medullated fibres such as characterise the visceral branches of the thoracic and sacral regions 

 ( 356). The nerve passes by the jugular ganglion of the vagus, then divides into the external and 

 internal branch. All the large fibres pass into the external branch, which, along with branches 

 from the cervical plexus, supply the sternomastoid and trapezius. The internal branch, com- 

 posed of small fibres, passes into the ganglion of the trunk of the vagus. Gaskell therefore 

 regards the internal branch "as formed by the rami viscerales of the upper cervical and vagus 

 nerves. " These fine medullated nerve-fibres probably arise from the cells of the posterior vesicular 

 column of Clarke. The motor fibres to the trapezius and sternomastoid arise from the cells 

 of the lateral horn of grey matter. ] 



If the accessorius be pulled out by the root in animals, the cardio-inhibitory 

 fibres undergo degeneration. If the trunk of the vagus be stimulated in the neck 

 four to five days after the operation, the action of the heart is no longer arrested 

 thereby [owing to the degeneration of the cardio-inhibitory fibres] ( Waller, Schiff, 

 Daszkiewicz, Heidenhain) ; according to Heidenhain, the heart-beats are accelerated 

 immediately after pulling out the nerve. 



The external branch arises from the spinal roots. This nerve communicates 

 with the sensory branches of the posterior root of the 1st, more rarely of the 2nd 

 cervical nerve, and these fibres supply sensibility to the muscles ; it then turns 



