EXERCISE I 



ANNOTATION 



Ohs. 1. Ringer-Locke fluid is a ' normal 

 saline ' for mammalian tissues, isotonic with 

 and resembling in composition the saline con- 

 tents of mammalian blood plasma. S. Ringer 

 established (1884, Jnl of Physiol, iv, p. 20, 

 and subsequent papers) the importance of 

 adding certain minute quantities of Ca and 



K to the -6 per cent. NaCl saline fluid then 

 in use as normal for the frog's heart and 

 amphibian tissues. For mammalian tissues, 

 especially the heart, J. S. Locke (1901) 

 devised a saline having a content of Na, Ca, 

 and K in quantities normally present in 

 rabbit's blood-serum [Jnl. of Fhysiol. xxxvi, 



Text-fig. 5. Exsected piece of ileum (cat) in Kinger-Locke fluid at 35° C, 

 Pendular and ' tonic ' waves of contraction inhibited by adrenal extracts 

 (E. Woods). T, time in 4" intervals, s, signal indicating when adrenal extract 

 was added. 



p. 220, 1907), and this is now in general 

 use in physiological laboratories ; it is what 

 is here referred to as 'Ringer-Locke'. Its 

 composition is : — 



•015 p. cent, sodium bicarbonate 



•024 „ calcium chloride 



•042 „ potassium chloride ' 



•92 „ sodium chloride 



The water should be distilled in apparatus 



in dis- 



water. 



of glass, not metal, the merest traces of certain 

 metallic ions being poisonous to many living 

 tissues, e.g. heart. When used for perfusing 

 the heart, Locke has shown that the addition 

 of •I per cent, glucose is an improvement. 



Ohs. 2. ' Adrenalin ' is the name adopted 

 for the active principle extracted from the 

 medulla of the adrenal gland. The physio- 

 logical powers of such extracts were discovered 



