The vagus nerve plays a role in (amongst other things) controlling the pulse. The vagus reflex is a reaction which can reduce the pulse rate. Intentionally inducing a vagus reflex is sometimes used to treat tachycardia (racing pulse). The following stimuli may produce the vagus reflex:
- tensing the lower abdomen (similar to straining at stool)
- gentle pressure on the closed eyes
- a gulp of ice-cold water
- splashing ice-cold water on the face
- immersing the arms in ice-cold water
- finger stuck down the throat
- the insertion of an IV needle
- cough or sneeze (involuntary or autonomic works best)
- holding breath (after exhaling) - see Valsalva manoeuvre
- insertion of an object into the uterus such as an IUD
Famous quotes containing the word reflex:
“No sooner does a great man depart, and leave his character as public property, than a crowd of little men rushes towards it. There they are gathered together, blinking up to it with such vision as they have, scanning it from afar, hovering round it this way and that, each cunningly endeavouring, by all arts, to catch some reflex of it in the little mirror of himself.”
—Thomas Carlyle (1795–1881)