OTHER PULSATILE PHENOMENA. 



115 



may be found communicating a movement to the contained air. The curves obtained are 

 relatively small, and closely resemble the curve of the carotid. A similar pulse is obtained in 

 the tympanum with intact membraua tympani, and when the soft parts of the tympanum are 

 congested (Schwartze, Trbltsch). 



2. Entoptical Pulse. After violent exercise, an illumination, corresponding to each pulse- 

 beat, occurs on a dark optical field. When the optical field is bright, an analogous darkening 



Curves of the carotid and posterior tibial taken simultaneously with Brondgeest's pansphygmo- 

 graph writing upon a vibrating-plate attached to a tuning-fork. The arrows indicate the 

 identical moment of time in each curve. 



occurs. The ophthalmoscope occasionally reveals pulsation of the retinal arteries (Jager), 

 which becomes marked in insufficiency of the aortic valves. 



3. Pulsatile Muscular Contraction. The orbicularis palpebrarum muscle contracts under 

 similar conditions synchronously with the pulse ; and it is perhaps due to the pulse-beat 

 exciting the sensory nerves reflexly. The Brothers Weber found that not unfrequently, while 

 walking, the step and pulse gradually and involuntarily coincide. 



4. When the legs are crossed as one sits in a chair, the leg which is supported is raised with 

 each pulse-beat, and it gives also a second or dicrotic elevation. 



5. If, while a person is quite quiet, the incisor teeth of the lower jaw be made just to touch 

 the upper incisors very lightly, we detect a double beat of the lower against the upper teeth, 

 owing to the pulse-beat in the external maxillary artery raising the lower jaw. The second 

 elevation is due to the closure of the semi-lunar valves, and not to a dicrotic wave. 



6. Brain and Fontanelles. The large arteries at the base of the brain communicate a 

 movement to it, while similar movements occur with respiration rising during expiration and 

 falling during inspiration. These movements are visible in the fontanelles of infants. The 

 respiratory movements depend upon variations in the amount of blood in the veins of the 

 cranial cavity, and also upon the respiratory variations of the blood-pressure. 



7. Amongst pathological phenomena are (a) the beating in the epigastrium, e.g., in hyper- 

 trophy of the right or left ventricle, caused, it may be, by deep insertion of the diaphragm, and 

 it may be, partly, by the beating of a dilated abdominal aorta or eceliac axis. 



(b) Aneurisms or abnormal dilatations of the arteries cause an abnormal pulsation, while they 



III. 



Fig. 98. 

 I. Elastic support for registering the molar motions of the body K, wooden box ; B, feet of 

 patient ; p, cardiograph ; a, b, elastic tubing. II. Vibration curves of a healthy person. 

 III. Curve obtained from a patient with insufficiency of the aortic valves and great 

 hypertrophy of the heart. 



produce a slowing in the velocity of the pulse-wave in the corresponding artery. Hence the 

 pulse appears later in such an artery than in the artery on the healthy side. Hypertrophy alitt 



