LESSON XIV. ACTION OF ADRENALINE ON 



BLOOD VESSELS. STIMULATION OF VENTRICLE. 



1. Expose the heart of a pithed frog, and tie the sino- 

 auricular junction (Less. XI, 5). Tie one aorta a short 

 distance from the heart. Tie a small cannula, having a 

 short piece of rubber tubing on one end and containing 

 saline solution, in the other aorta facing the peripheral 

 vessels, and cut the aorta near the heart; by pinching 

 the tubing force saline solution into the neck of the 

 cannula in order to prevent blood clotting in it. Cut 

 out the heart and place it in saline solution for 2. 



Fill the cannula with Ringer's fluid by means of a 

 pipette* and connect it with a 3-way tube so that the 

 mid-branch is uppermost. Brush off any clots that may 

 have formed at the cut ends of the veins. Place the 

 frog on a disc in a funnel and fix the 3-way tube with 

 plasticine (p) to the edge of the funnel (cp. Fig. 24). 

 Connect the distal end of the 3-way tube with aMariotte's 

 bottle at a slightly higher level. Put a glass dish under 

 the funnel and open the clamp (Cl. Fig. 24). When the 

 tubes have been emptied of air through the tube (t) close 

 the latter with a small piece of glass rod. The fluid will 

 then be forced through the blood vessels. 



Count the drops which fall from the funnel in two or 

 more successive minutes. Then inject with a hypodermic 

 syringe Jc.c. 'OOlp.c. adrenaline into the tube T, and 

 count the drops in each successive minute ; the flow will 

 soon become very slow owing to the contraction of the 

 blood vessels caused by adrenaline. 



