Nausea and Vomiting

Question 1

True or False: Nausea and Vomiting are part of the body’s defence system.

Answer 1

True

Question 2

How do toxic substances cause vomiting?

Answer 2

• Irritate the stomach/intestines
• Stimulate chemoreceptors
• Vomiting
  -> reduce absorption of toxin

Question 3

Does vomiting have memory?

Answer 3

Yes as it is a protective mechanism.

Question 4

What is the definition of nausea?

Answer 4

Feeling of wanting to throw up
Gastric dilation
Upper intestinal contractions by reverse peristalsis propel contents into stomach

Question 5

What is the definition of retching?

Answer 5

Involuntary, forceful contractions of the diaphragm and abdominal muscles. Pushes top of stomach into the chest.

Question 6

What is the definition of vomiting?

Answer 6

Inspiration followed by strong muscle contractions force stomach contents out. Involve reflexes to block the lungs/nose and relaxes the oesophageal sphincters.

Question 7

Give some physical causes of nausea and vomiting.

Answer 7

• Pain
• Motion
• Infection
• Disease
• Drugs
• Chemotherapy

Question 8

Give some physiological examples of Nausea and Vomiting.

Answer 8

• Sight
• Smell
• Thought

Question 9

Give some emotional causes of nausea and vomiting.

Answer 9

• Fear
• Anxiety
• Panic

Question 10

What are the technical term for vomiting?

Answer 10

Emesis

Question 11

What therapy is used for vomiting?

Answer 11

Anti-emetics

Question 12

What is Emesis controlled by?

Answer 12

Neuronal network in the medulla oblongata

Question 13

What is part of the Vomiting (emetic) centre?

Answer 13

Chemoreceptor trigger zone - senses emetic stimuli
Vestibular nuclei Detects motion and balance
GI system
CNS

Question 14

Why is it good that the chemoreceptor trigger zone is found outside the blood-brain barrier?

Answer 14

So that it can detect the emesis in the blood.

Question 15

What does the CTZ sense in the blood?

Answer 15

Chemicals

Question 16

What is the CTZ very sensitive to?

Answer 16

High levels of toxic substances in blood.

Question 17

CTZ has receptors for what?

Answer 17

• Serotonin
• Dopamine
• Opioid
• Substance P
• Chemicals

Question 18

Which receptors are found in the CTZ?

Answer 18

• Chemoreceptors
• D2 receptors
• NK1 receptor (neurokinin)
• 5-HT3 receptor

Question 19

How can we stop nausea when looking at the chemoreceptor trigger zone?

Answer 19

We can block the receptors.

Question 20

Where is the vestibular nuclei (apparatus) found?

Answer 20

In the inner ear.

Question 21

Which 2 neurotransmitters stimulate the vestibular nuclei?

Answer 21

• Histamine (H1)
• ACh (M1 muscarinic)

Question 22

Vestibular nuclei can be stimulated by which substance?

Answer 22

Alcohol

Question 23

Stimulation of the gut chemoreceptors trigger nausea and vomiting by which nerve?

Answer 23

Vagal nerve

Question 24

Fill in the gaps:
_____ cells in the GI tract respond to chemicals by releasing _____

Answer 24

1. Enterochromaffin
2. Serotonin (5-HT)

Question 25

True or False: Stomach irritation and distension can trigger serotonin receptors.

Answer 25

True

Question 26

What is the limbic system?

Answer 26

Emotional nervous system

Question 27

True or False: High corticol effects can stimulate nausea and vomiting.

Answer 27

False. High corticol effects can stimulate or suppress nausea and vomiting.

Question 28

Which two main drugs can cause nausea?

Answer 28

- Levadopa - Opioid analgesic

Question 29

What are the 5 things that the body does for the emesis reflex?

Answer 29

- Glottis closed - Upper and lower oesophageal sphincters relax - Abdominal muscles and diaphragm contract - Stomach relaxes - Intestines reverse peristalsis

Question 30

What are the general therapies to suppress nausea?

Answer 30

- Seratonin (5-HT3) antagonists - Histamine antagonists - Muscarinic antagonists - Dopamine antagonists - Cannabinoids - Benzodiazepines

Question 31

What is the main drugs used to target dopamine receptors?

Answer 31

Metoclopramide

Question 32

Antihistamines are antagonists to which receptors?

Answer 32

Histamine H1 receptors

Question 33

Give some examples of antihistamines used in vomiting?

Answer 33

- Cinnarizine - Promethazine - Promethazine teoclate

Question 34

What is the downside of using antihistamines for nausea and vomiting?

Answer 34

Weakly effective and rarely used for treatment unless last resort.

Question 35

What are some side effects of using antihistamines?

Answer 35

- Dizziness - Sedation - Dry mouth

Question 36

True or False: Promethazine can be used to treat vomiting in pregnancy.

Answer 36

True

Question 37

True or False: Hyoscine is an anticholinergic.

Answer 37

True

Question 38

How does hyoscine butylbromide help in nausea?

Answer 38

Relaxes GI smooth muscle contractions.

Question 39

What is a good thing about Hyoscine butylbromide?

Answer 39

Doesn’t cross the BBB so no side effects of sedation.

Question 40

What is the downside of using hyoscine butylbromide?

Answer 40

It is poorly absorbed so it is not very effective against vomiting.

Question 41

Give a brand for hyoscine butylbromide.

Answer 41

Buscopan

Question 42

Where do dopamine antagonists work?

Answer 42

On the dopamine receptors in the chemoreceptors trigger zone.

Question 43

Give some examples of dopamine antagonists.

Answer 43

- Chlorpromazine hydrochloride - Prochlorperazine - Trifluoperazine

Question 44

What is a side effect of using a dopamine antagonist?

Answer 44

Has a sedative effect

Question 45

Dopamine receptors are used to treat severe nausea and vomiting associated with which conditions?

Answer 45

- Cancer - Radiation therapy - Cytotoxic drugs - Opioids - Anaesthetics - Other drugs

Question 46

How does metoclopramide help in preventing nausea and vomiting?

Answer 46

Acts on the gastric smooth muscle which stimulates gastric emptying.

Question 47

Metoclopramide can also block which other receptor?

Answer 47

Serotonin 5-HT3 receptor

Question 48

What is another dopamine receptors antagonist?

Answer 48

Domperidone

Question 49

True or False: Domperidone can cause sedation.

Answer 49

False. It doesn’t cross the BBB so it doesn’t cause sedative effects.

Question 50

Why is Domperidone no longer used in children?

Answer 50

It is less effective.

Question 51

True or False: Serotonin blocks the vomiting centre.

Answer 51

False. Serotonin blocks the chemoreceptors trigger zone.