Week 6 - Vomiting

Question 1

What is vomoting designed for?

Answer 1

A reflex designed to prevent the digestion of toxic substances
and is regulated by centres within the brain

Question 2

What are the areas involved in vomiting?

Answer 2

• Vestibular nuclei
• Chemoreceptor Trigger Zone
• Vomiting Centre

Question 3

What are the components and transmitters involved in vomiting within the Vestibular nuclei?

Answer 3

• responds to types of movement
• -motion sickness
• Histamine (H1)
• ACh (M)

Question 4

What are the components and transmitters involved in vomiting within the Chemoreceptor Trigger Zone?

Answer 4

• In the ‘area prostrema’ of the CNS
• Responds to signals from ingested material
• Dopamine (D2)
• Serotonin (5-HT3)

Question 5

What are the components and transmitters involved in vomiting within the Vomiting Centre?

Answer 5

ACh (M)

Question 6

What are some emetic stimulants?

Answer 6

– CNS stimuli such as pain, smells, emotions
– stimuli from the stomach
– chemicals and toxins in the blood (such as chemotherapeutic agents)
– motion sickness.

Question 7

What are the type of Anti-emetics?

Answer 7

H1 receptor antagonists
Muscarinic receptor antagonists
5-HT3 receptor antagonists
Dopamine receptor antagonists
Cannabinoids

Question 8

What are the uses and example of H1 antagonists?

Answer 8

• motion and morning sickness

- promethazine

Question 9

What are the uses and example of Muscarinic receptor antagonists?

Answer 9

• motion sickness and vomiting due to stimuli in stomach.

- hycosine

Question 10

What are the uses and example of 5-HT3 receptor antagonists?

Answer 10

• cytotoxic and chemotherapy associated vomiting

- ondansetron

Question 11

What are the uses and example of Dopamine receptor antagonists?

Answer 11

• vomiting due to gastrointestinal disorders, cytotoxic drugs.
• metaclopramide (maxalon)

Question 12

What are the uses of Cannabinoids?

Answer 12

• chemotherapy associated vomiting

- also orexigenic