THJ'. PELVIS. 285 



9. Explain tJic tecJinicjue of obtaining knee-jerk, or patcllar reflex movement. 



(i) Place the patient in the sitting posture on the table, with his legs hanging 

 at right angles to the thighs ; (2) blindfold the patient, and do not acquaint him 

 with the procedure ; otherwise, through nerve-influence from the obturator to the 

 sartorious muscle, phenomena of a voluntary nature on the part of the patient 

 might be observed which would cloud your diagnosis ; (3) tap the ligamentum 

 patellae with a ferrule, or, better still, gently prick the skin over the same with a 

 sharp instrument. Students should be encouraged to practice obtaining these 

 reflexes on one another. 



DIAPHRAGM. (Fie. 195.) 



Function. Partition between thorax and abdomen. 

 Superior Serous Relations. Pericardium and pleurae. 

 Inferior Serous Relations. The diaphragmatic peritoneum. 

 Structure. A musculo-membranous sheet. 

 Apertures. CEsophageal, aortic, and caval. 

 Ligamentum arcuatum inter tiiun, part of iliac fascia. 

 Ligamentum arcuatum cxternum, part of lumbar fascia. 

 Central tendon forms the summit of the dome. 

 CEsophageal opening transmits oesophagus and vagus nerves. 

 Aortic opening transmits aorta and thoracic duct. 

 Caval opening transmits the ascending vena cava. 

 Physiological Action. Deepens the chest. 

 Nerve-supply. The two phrenics and the sympathetic. 

 Source of Sympathetic Nerve-supply. Solar plexus. 

 Blood-supply. The phrenic arteries. 



Source of Plirenic Arteries. Aorta, renals, and intercostals. 

 Hoiv many origins lias the diaphragm ? 



1. Anterior or Sternal Portion. The lower border and back of the ensiform 

 cartilage and the adjacent part of the back of the anterior aponeurosis of the 

 transversalis abdominis. 



2. Lateral or Costal Portion. The lower border and inner surface of the 

 cartilages of the six lower ribs, and sometimes also from the adjacent part ot 

 the ribs. 



3. Posterior or Vertebral Portion. (i) The ligamentum arcuatum externum, a 

 fibrous thickening of the anterior layer of the lumbar fascia, which stretches 

 from the tip of the transverse process of the second lumbar vertebra to the tip 

 of the last rib ; (2) the ligamentum arcuatum internum a fibrous thickening of 

 the iliac fascia, which arches over the upper part of the psoas from the sick- of 

 the body of the second lumbar vertebra to the tip of its transverse process ; (3) 

 the cms of the diaphragm a strong vertical band, fleshy externally, tendinous 

 internally, arising on the right side from the front of the bodies of the first to 

 the third or fourth lumbar vertebra;:, from the intervening vertebral discs, and 

 the anterior common ligament ; on the left side, from the bodies of the first to 

 the second or third vertebrae only, as well as the discs and anterior common 

 ligament. 



Insertion. The front, sides, and back of the central tendon. 



The crura are perforated, and transmit structures as follows : The right, the 

 sympathetic and the splanchnics of the right side; the left, the splanchnics of 

 the left side and the vena azygos minor. 



