Vomiting and Nausea

Question 1

The vomiting centre is located?

Answer 1

in the dorsal part of the medulla oblongata

Question 2

The chemo receptor trigger zone is located?

Answer 2

In the floor of the fouth ventricle (brain)

Lies OUTSIDE blood brain barrier

Question 3

Motion sickness and disease of the inner ear act on which nerve?

Answer 3

vestibulocochlear nerve

sends signals to the vomiting center

Question 4

Pathways to nausea emesis?

Answer 4

• Blood borne chemical stimuli via Chemoreceptor Trigger zone (morphine, digoxin, chemotherapy)

Question 5

Major central pathway to emesis/nausea is?

Answer 5

Vomiting center

Question 6

Which emesis receptors does the CTZ express?

Answer 6

Histamine (H1 !!! not 2!!)
M1
Dopamine (D2)
Serotonin (5HT3)
Opoid

Question 7

Which emesis receptor does the pharynx and GI tract express?

Answer 7

Serotonin (5HT3)

Question 8

Which emesis receptors do the vestibular nuclei express?

Answer 8

Mucarinic M1

Histamine H1

Question 9

Which emesis receptors does the VC express?

Answer 9

Muscarinic M1/M3
Serotonin 5HT3
Histamine H1

Question 10

In the gut ____ from e.g. bacteria, drugs or ethanol stimulate _____ cells. This leads to mediators such as _____. This leads to depolarization and AP of ____ afferent to ___ and ___

Answer 10

toxins, enterochromaffin like, serotonin (5HT3), Vagal, CTZ and nucleus trctus solaris

Question 11

What are the events in vomiting?

Answer 11

Suspension slow wave intestinal activity
Retrograde contractions from ileum to stomach
Relaxed sphincters! LOS
Close epiglottis
Contraction of diaphragm + abdominal muscles compress stomach
ejection + repeat

Question 12

Consequences sever vomiting?

Answer 12

• Dehydration
• HYPOCHLORAEMIC METABOLIC ACIDOSIS (loss gastric protons +chloride)
• hypokalaemia (reflex K+ excretion kidneys)
• mallory weiss tear
• aspiration

Question 13

Prochlorperazine, droperidol,trifluoperazine chlorpromazine, haloperidol, levomepromazine
are examples of WHAt

Answer 13

dopamine antagonists

Question 14

Dopamine antagonists act ___ by blocking _____

Answer 14

centrally, Chemoreceptor trigger zone

Question 15

Metoclopramide, Domperidone are examples of WHAT

Answer 15

prokinetic drugs

Question 16

What are the effects of prokinetic drugs?

Answer 16

• Increase gastric peristalsis
• Increase LOS tone

-BLOCKS D2 dopamine receptors in CTZ!!!!

Question 17

Granisetron, ondansetron, palonosetron

are examples of WHAT

Answer 17

5HT3-Receptor Antagonists

Question 18

5HT3-Receptor Antagonists block receptors in ___, ____ and ____

Answer 18

GIT and CNS, VC

Question 19

T/F

5HT3-Receptor Antagonists side effect is earache

Answer 19

F

HEADACHE

Question 20

Promethazine, cyclizine, cinnarizine

are examples of WHAT

Answer 20

H 1 ANTAGONISTS

Question 21

T/F

H1 antagonists cause CNS depression and sedation

Answer 21

T

Question 22

T/F

many H1 antagonists exert an additonal anti serotonin receptor effcet

Answer 22

F!

exert additional ANTIMUSCARINIC effect

Question 23

Hyosine (scopolamine), Dicyclomine

are examples of

Answer 23

anticholinergics

Question 24

Adjuvant antiemetics are?

Answer 24

group of drugs that are used with standard antiemetics to enhance its effects

Question 25

Examples of adjuvant antiemetics?

Answer 25

Corticosteroids Cannabinoids Benzodiazepines Neurokinin 1 receptor antagonists

Question 26

Treating chemotherapy induced nausea?

Answer 26

Triple therapy 1) Serotonin antagonist 2) dexamethasone corticosteroid 3) aprepitant neurokinin 1 receptor antagonist

Question 27

T/F Post-operative nausea and vomiting treatment is the same regardless of anaesthetic used and the type and duration of surgery

Answer 27

F | Varies !!

Question 28

T/F | Pregnancy associated Nausea and Vomiting is treated using Neurokinin 1 receptor antagonists

Answer 28

``` F change diet ginger wrist acupressure INTRACTABLE VOMITING MAY RESULT IN NUTRITIONAL AND IONINC IMBALANCES ```

Question 29

Hyperemesis gravidarum?

Answer 29

Fluid and electrolyte disturbances or nutritional deficiency develops from intractable vomiting in pregnancy

Question 30

First line Hyperemesis gravidarum?

Answer 30

antihistamine such as promethazine or cyclizine.