66 

 EXERCISE X 



DIUEESI'S 



I. See that the decapitate preparation provided is being properly 

 ventilated and is in good condition. 



II. Set the Einger-Locke fluid warming to 37° C, and see that you have 

 a cannula for the urethra, a 50 c.c. burette and a vertical stand for holding it, a 

 rubber tube and clamp attached to the burette, a cannula for the jugular vein, 

 and a beaker containing about 50 c.c. of aqueous 10 per cent. Na^SO^ solution. 

 Also a needle-syringe and a -5 c.c. capsule of pituitary extract (infundin). 

 Also a glass piston-syringe of about 30 c.c. capacity. 



III. Operation. A. Exposure of urethra and insertion of urethral cannula 



Obs. 42. (PI. V, figs. 1, 2, 3). Place preparation supine with all four limbs symmetrically 



Renal secretion extended by four clip-weights attached one to each foot. 



and venous at x xtl • • 



injection of ^^^^ *^^ position of the nipples of the inguinal mammae. Make out by 



saline. feeling through the skin and abdominal wall the anterior border of the symphysis 



pubis ; then of the pubic arch ; also the contour of the urinary bladder (PI. V, 

 fig. 1). Make a medial longitudinal skin incision, beginning in front nearly 

 as far forward as the cross-level between inguinal mammillae, and carried back 

 along the whole length of pubic symphysis. Expose through the subcutaneous 

 fat the linea alba of the abdominal wall and the crest of the symphysis pubis 

 throughout the length of the skin incision. Clear off the muscular attach- 

 ments (adductor femoris) from the symphysis and from the anterior ramus of 

 pubes for the extent shown in the figure (PI. V, fig. 1), taking care not to cut 

 the blood-vessels descending from abdomen over the pubic ramus r. and 1., but 

 turning them aside. Clear the abdominal edge of the pubes from the attach- 

 ments of the obliquus ext. abdominis and rectus abdominis. With the cutting 

 bone-pliers cut through the symphysis at junctions of its third and most posterior 

 fourths (PI. Y, fig. 2). Insert jaw of bone-pliers from abdominal edge deep to 

 pubic ramus, keeping close to deep face of ramus, and cut through rami in 

 positions marked in figure, allowing about 1-5 cm. width between the two 

 cuts. Cut OS pubis. Eemove the bone so freed by detaching carefully with 

 scalpel the obturator externus attachments r. and 1. from its sides and deep face. 

 With fine dissecting-forceps tear through fat tissue deep to symphysis in 

 mid-line, exposing the membranous urethra, which appears as a pale tough- 

 walled duct. Pass, with curved mounted needle, .a strong thread round 



