i8 



EXERCISE YII 



Obs. 31. 

 Pituitary 

 extract and 

 arterial 

 pressure. 



Obs. 32. 

 Splanchnic n. 

 vasoconstric- 

 tion in kidney 

 and gut. 



Obs. 33. 

 Inspection of 

 chyle and 

 lacteals. 



Obs. 34. 

 Chromaffine 

 reaction of 

 adrenal 

 medulla. 



Obs. 35. 

 Time of the 

 lesser circula- 

 tion. 



Set the kymograph running, and induce asphyxia as in exerc. VI, § V. 

 Compare the effect on the arterial pressure with that obtained in exerc. VI.] 



X. Place 2 c.c. of Ringer-Locke in a watch-glass ; open the glass capsule 

 containing ' infundin ' by notching the stem with a file and then breaking it 

 across at the notch. Add the contents to the Ringer-Locke, and take up 1 c.c. 

 in the needle-syringe. Inject the syringeful per venam (saphena vein) while 

 the kymograph record is running, and while your co-worker marks with the 

 signal the time and duration of the injection. Observe the result (text-fig. 24). 

 Refill the syringe from the watch-glass. When the rise "of pressure 

 due to the injection has fully subsided, repeat the injection. Observe 

 the result ; it will probably be a fall of arterial pressure ; if a rise, the rise 

 will be very much smaller than on the first injection, thus differing from the 

 adrenal extract reaction. 



The kymographic part of the exercise finishes with this observation. 



XI. Lay bare the right kidney and note closely the colour of it and the 

 size of its venules. Stimulate the splanchnic nerve — no kymographic record 

 is necessary — and note the pallor which ensues in the kidney and any change 

 in size of venules. 



Repeat the observation on a loop of small intestine. 



XII. Note the milk-white lymphatic vessels in the mesentery ; they 

 might be mistaken for nerves. Prick one, and examine the escaped chyle 

 under the microscope. The animal was fed with milk a few hours before being 

 killed. (The minute semi-translucent oval seed-like bodies in the mesentery 

 near the vessels are Pacini end-organs.) 



XIII. Remove the left adrenal gland and place it in 2 per cent, potassium 

 bichromate solution. In an hour's time examine it by cutting it across and 

 inspecting the cross-section. Note the difference in colour between the cortex 

 and medulla. 



XIV. Place a cannula in the right external jugular vein, its nozzle 

 directed towards the heart. Fill the glass syringe provided for you with 

 Ringer-Locke strongly coloured with methylene-blue. Expose the right renal 

 artery freely and slip a piece of white card under it. Attach the syringe by 

 rubber tubing to the jugular cannula, avoiding air in the connexion. Have 

 stop-watch ready. Inject the methylene-blue solution into the vein and note 

 with the watch the time elapsing between the injection and the appearance of 

 blue in the renal artery. This affords a rough estimate of the time taken in 

 the transit of blood through the pulmonary circulation. 



