Physiology: nausea & emesis

Question 1

what is nausea

Answer 1

a subjective, highly unpleasant sensation usually felt in throat or stomach as ‘sinking’ sensation

Question 2

what is acute nausea often preceded and relieved by

Answer 2

emesis(vomiting)

Question 3

what other symptoms are usually involved in nausea, retching or emesis

Answer 3

pallor, sweating, excessive salivation

Question 4

what GI changes are seen in nausea

Answer 4

relaxation of stomach + lower oesophagus, upper intestinal contractions, forcing intestinal contents by reverse peristalsis into stomach

Question 5

what is the difference between retching and emesis

Answer 5

retching = dry, no vomitus
emesis = forceful expulsion of gastric/intestinal contents out of the mouth

Question 6

what GI changes are experienced in emesis and retching

Answer 6

reverse peristalsis forcing intestinal contents into stomach, rhythmic reverse peristalsis of stomach and oesophagus

Question 7

describe the action of the abdominal muscles and diaphragm in emesis and retching

Answer 7

forceful, involuntary contractions of both

Question 8

where in the brain is emesis coordinated

Answer 8

the vomiting centre(VC) in the medulla oblongata of the brain stem

Question 9

what symptoms often follow vomiting

Answer 9

profuse salivation, sweating, elevated HR and sensation of nausea

Question 10

what are the consequences of vomiting

Answer 10

dehydration, loss of gastric H+ and Cl causes hypochloraemic metabolic acidosis, raising blood pH, hypokalaemia