Nausea and Vomiting and Diarrhea

Question 1

the 4 mechanisms the stimulate the vomiting center are

Answer 1

1. Chemoreceptor trigger zone (CTZ)
2. GI tract/Vagus nerve
3. Vestibular apparatus
4. Higher CNS:-cerebral cortex, -sensory organs

Question 2

what is the CTZ triggered by?

Answer 2

-drugs, hormones, toxins, metabolic abnormalities (actions of opiods, chemotherapy, pregnancy)

Question 3

the CTZ is affected by what neurotransmitters?

Answer 3

-serotonin (5HT), Dopamine, Acetylcholine

Question 4

visceral stimulation (Or GI/Vagus stimulation) is triggered by?

Answer 4

• triggered by afferent fibers mainly from our GI tract, but also cardiac nerves (direct visceral irritation or distention)
• (gastroenteritis, overeating, MI)
• triggered by mechanical or chemosensory receptors
• stimulated by both parasympatehtic and sympathetic fibers (primarly the Vagus nerve) some of which connect to the CTZ and some which directly stimulate the vomiting center

Question 5

visceral (GI/Vagus stimulation) affected by what neurotrasnmitters?

Answer 5

-serotonin, dopamine, neurokinin

Question 6

vestibular triggered by

Answer 6

• motion sickness

- some opiods exert some influence on this point

Question 7

vestibular affected by what neurotransmitters?

Answer 7

-Histamines, acetylcholine