PATHOLOGICAL VARIATIONS OF RESPIRATORY MOVEMENTS. 171 



while at the same time the inspiratory dilatation of the chest precedes the elevation of the 

 abdominal wall (Mosso). It is not determined whether the costal type of respiration in the 

 female depends upon the constriction of the chest by corsets or other causes (Sibson), or whether 

 it is a natural adaptation to the child-bearing function in women {Hutchinson). Some observers 

 maintain that the difference of type is quite distinct, even in sleep, when all constrictions are 

 removed, and that similar differences are noticeable in young children. This is denied by 

 others, while a third class of observers hold that the costal type occurs in children of both 

 sexes, and they ascribe as a cause the greater flexibility of the ribs of children and women, 

 which permits the muscles of the chest to act more efficiently upon the ribs. 



111. PATHOLOGICAL. Examination of the Lungs. The same methods that are applicable 

 to the heart, viz., I., Inspection; II., Palpation; III., Percussion; and IV., Auscultation, 

 apply here also.] 



[By inspection we may determine the presence of symmetrical or unilateral alterations in the 

 shape of the chest, the presence of bulging or flattening at one part, and variations in the 

 movement of the chest-walls. By palpation, the presence or absence, character, seat, and 

 extent of any movements are more carefully examined. But we may also study what is called 

 vocal fremitus ( 117). Percussion ( 114), Auscultation ( 116).] 



[In investigating the respiratory movements, we should observe (1), the frequency ( 109) ; 

 (2), the type ( 110) ; (3), the nature, character, and extent of the movements, noting also 

 whether they are accompanied by pain or not ( 110) ; (4), the rhythm.] 



I. Changes in the mode of Movement. In persons suffering from disease of the respiratory 

 organs, the dilatation of the chest may be diminished (to the extent of 5 or 6 cm. ) on both sides 

 or only on one side. In affections of the apex of the lung (in phthisis), the sub-normal 

 expansion of the upper part of the wall of the chest may be considerable. Retraction of the 

 soft parts of the thoracic wall, the xiphoid process, and the parts where the lower ribs are 

 inserted, occurs in cases where air cannot freely enter the chest during inspiration, e.g., in 

 narrowing of the larynx ; when this retraction is confined to the upper part of the thoracic 

 wall, it indicates that the portion of the lung lying under the part so affected is less extensile 

 and diseased. 



Harrison's Groove. In persons suffering from chronic difficulty of breathing, and in whom, 

 at the same time, the diaphragm acts energetically, there is a slight groove, which passes hori- 

 zontally outwards from the xiphoid cartilage, caused by the pulling in of the soft parts and 

 corresponding to the insertion of the diaphragm. 



The duration of inspiration is lengthened in persons suffering from narrowing of the trachea 

 or larynx ; expiration is lengthened in cases of dilatation of the lung, as in emphysema, where 

 all the expiratory muscles must be brought into action (fig. 137, II). 



II. Variations in the Ehythm. When the respiratory apparatus is much affected, there is 

 cither an increase or a deepening of the respirations, or both. When there is great difficulty of 

 breathing, this is called dyspnoea. 



Causes of Dyspnoea. (1) Limitation of the exchange of the respiratory gases in the blood due 

 to (a) diminution of the respiratory surface (as in some diseases of the lungs) ; (b) narrowing 

 of the respiratory passages ; (c) diminution of the red blood-corpuscles ; (d) disturbances of the 

 respiratory mechanism (e.g., due to affections of the respiratory muscles or nerves, or painful 

 affections of the chest-wall) ; (e) impeded circulation through the lungs due to various forms of 

 heart-disease. (2) Heat-dyspnoea. The frequency of the respirations is increased in febrile 

 conditions. The warm blood acts as a direct irritant of the respiratory centre in the medulla 

 oblongata, and raises the number of respirations to 30-60 per minute ("Heat-dyspncea"). If 

 the carotids be placed in warm tubes, so as to heat the blood going to the medulla oblongata, 

 the same phenomena are produced ( 368). [When a child sucks, it breathes exclusively 

 through the nose, hence catarrhal conditions of the nasal mucous membrane are fraught with 

 danger to the child.] 



[Orthopncea. Sometimes the difficulty of breathing is so great that the person can only 

 respire in the erect position, i.e., when he sits or is propped up in bed. This occurs frequently 

 towards the close of some heart affections, notably in mitral lesions ; dropsical conditions, 

 especially of the cavities, may be present.] 



Cheyne-Stokes' Phenomenon. This remarkable phenomenon occurs in certain diseases, 

 where the normal supply of blood to the brain is altered; or where the quality of the blood itself 

 is altered, e.g., in certain affections of the brain and heart, and in ursemic poisoning. Respir- 

 atory pauses of one-half to three-quarters of a minute alternate with a short period (- min.) of 

 increased respiratory activity, and during this time 20-30 respirations occur. The respirations 

 constituting this " series " are shallow at first ; gradually they become deeper and more dyspnceic, 

 and finally become shallow or superficial again. Then follows the pause, and thus there is an 

 alternation of pauses and series (or groups) of modified respirations. During the pause, the 

 pupils are contracted and inactive ; and when the respirations begin, they dilate and become 

 sensible to light ; the eyeball is moved as a whole at the same time. Hein observed that con- 

 sciousness was abolished during the pause, and that it returned when respiration commenced. 



