12: Physiology and pharmacology of nausea and vomiting Flashcards
What is nausea?
The unpleasant urge to vomit
What is the medical term for vomiting?
Emesis
What is vomiting/emesis?
Forceful expulsion of stomach contents through mouth/nose
What muscles contract to produce vomiting?
Abdominal muscles
Diaphragm
Retching is the act of (normal / reverse) peristalsis.
reverse
What is regurgitation?
Effortless movement of stomach contents back to the mouth without nausea or retching
Where is the vomiting centre in the brain?
Medulla
Which cranial nerve, found in the ear, is associated with motion sickness vomiting?
Vestibulocochlear nerve CN VIII
Which cranial nerve supplies the stomach and sends the signals to trigger vomiting?
Vagus nerve CN X
The presence of ___ in the gut can trigger vomiting.
toxins
Which cells detect the presence of toxins in the gut?
Enterochromaffin cells
Which neurotransmitter is released by enterochromaffin cells in response to toxins?
Serotonin (5-HT)
Which receptors respond to serotonin (5-HT) to trigger vagal afferent discharge to the CNS?
5 HT receptors
What type of nerves produce the motor outputs of the oesophagus, stomach and small intestine in vomiting?
Vagal efferents
What type of nerves produce the contraction of the abdominal muscles and diaphragm in vomiting?
Somatic motor
