2 LAB OR A TORY G UIDE IN PH YSIOL OGY. 



minutes. Keep the web moist with normal saline 

 solution. 



(#) What change occurs in the diameter of the arteriole? 

 () What effect would you expect this to have on ar- 

 terial pressure ? 

 (V) Would its action on the arterioles help to account 



for its effect on arterial pressure? 



(4) Comparisons. Compare digitalis and atropin with 

 regard to (a) their effect on the rate of the heartbeat, 

 (b) Their effect on the irritability of the vagus. 



