Symptoms Of GI Disease: Nausea, Vomiting And Pain

Question 1

What is the main aim of nausea and vomiting?

Answer 1

Poison defence system

Question 2

What physiological changes are associated with nausea?

Answer 2

Shaky, pale and clammy, decreased gut motility and hormone changes

Question 3

What does nausea trigger?

Answer 3

An aversion to a thing

Question 4

What is an aversion?

Answer 4

Strong dislike or disinclination which leads to behavioural changes

Question 5

What is the difference between vomiting and nausea?

Answer 5

Nausea is a sensation and vomiting is a physical act

Question 6

What is the scientific name for vomiting?

Answer 6

Emesis

Question 7

What happens in emesis?

Answer 7

Contents of upper GI tract expelled via mouth

Question 8

What is the relationship between nausea and vomiting?

Answer 8

Produced by the same stimulus

Nausea generally preempts vomiting but one may happen without the other

Question 9

What are the 13 emetic stimuli?

Answer 9

Poisining, GI infection, excessive alcohol, pregnancy, excessive eating, travel sickness, emotional upset, obstruction, raised intracranial pressure, metabolic disturbance, GI disease, IV drugs and other people being sick

Question 10

How does taste and smell protect against ingested toxins?

Answer 10

• prevent ingestion
• built in dislike of bitter flavours
• children don’t like trying new stuff

Question 11

What are the gastric and upper GI protection against ingested toxins?

Answer 11

• expel harmful agents before they can be absorbed

- associated with chemoreceptors cells

Question 12

What do the gastric chemoreceptive cells respond to?

Answer 12

Naturally occurring toxins, damaging chemicals and inflammatory mediators

Question 13

What is the chemoreceptor trigger zone?

Answer 13

The area postrema in the brainstem is where the blood-brain barrier is leaky and chemoreceptors can detect toxins in the blood

Question 14

What is the vestibular system?

Answer 14

Organ of balance but also a strong trigger for emesis

Question 15

Where is the nucleus tractus solitarius found?

Answer 15

In the medulla of the brainstem

Question 16

What does the nucleus tractus solitarius do?

Answer 16

Integrates cardiac, respiratory and GI functions

Question 17

What are the four types of warning inputs in the nucleus tractus solitarius?

Answer 17

• Visceral afferents in the stomach and duodenum
• area postrema
• vestibular system
• higher centres

Question 18

What happens to the area postrema if there is a raise in intercranial pressure?

Answer 18

Gets squeezed out of the bottom of the skull, causing vomiting

Question 19

What are the four types of visceral afferents in the stomach and duodenum?

Answer 19

Toxins, irritants, inflammation and distension

Question 20

What nerve are the vestibular systems signals sent through?

Answer 20

8th cranial nerve

Question 21

What are the three places the NTS can stimulate?

Answer 21

Higher centres, hypothalamus and autonomic efferents

Question 22

What are the higher centres the NTS stimulates and what does it cause?

Answer 22

Cerebral cortex/ limbic system -> nausea and future avoidance

Question 23

What does the NTS cause the hypothalamus to secrete?

Answer 23

ADH

Question 24

What does the NTS cause autonomic efferents to do?

Answer 24

Increase salivation and vasoconstriction in the GIT

Question 25

Why does the NTS make the body increase salivation?

Answer 25

More protection against acidic chyme as saliva is alkaline

Question 26

Why does the NTS cause vasoconstriction in GIT?

Answer 26

Reduce absorption of substance into bloodstream

Question 27

What are the 5 steps the NTS takes to trigger nausea and vomiting?

Answer 27

- reduces mixing and peristalsis - proximal stomach relaxes - giant retrograde contraction - retching - vomiting

Question 28

Why does the NTS reduce mixing and peristalsis?

Answer 28

Prevents toxins being carried through the system

Question 29

Why does the NTS relax the proximal stomach?

Answer 29

Means stomach is prepared to receive additional contents

Question 30

Why does the NTS cause a giant retrograde contraction?

Answer 30

Takes contents from mid-small intestine into the stomach

Question 31

What is the giant retrograde contraction controlled by?

Answer 31

Efferent vagal nerves

Question 32

What is retching?

Answer 32

Coordinated contractions of abdominal muscles and diaphragm

Question 33

Why is there no expulsion in retching?

Answer 33

Anti-reflux barriers intact

Question 34

What happens in the abdomen during retching?

Answer 34

Waves of high pressure- compresses stomach

Question 35

What happens when you vomit?

Answer 35

Oesophageal sphincters and crural diaphragm relaxes and further waves of contraction

Question 36

How are pain signals carried to the brain?

Answer 36

Visceral afferent nerves that converge on the greater and lesser splanchnic nerves at the thoracic vertebral level

Question 37

What do ‘pain’ receptors respond to?

Answer 37

Noxious stimuli

Question 38

What are ‘pain’ receptors actually called?

Answer 38

Nociceptors

Question 39

What do nociceptors respond to?

Answer 39

Distension, inflammation and muscle spasm

Question 40

What are noxious stimuli?

Answer 40

Things that have, are, or will cause damage to the body

Question 41

What inflammatory mediators do nociceptors respond to?

Answer 41

Injury, irritants, toxins, infection and autoimmunity

Question 42

What does inflammation do to nociceptors?

Answer 42

Depolarises them

Question 43

What do nociceptors do when depolarised?

Answer 43

Release proinflammatory chemicals

Question 44

What happens when positive nociceptor feedback increases?

Answer 44

Synapse potentiation

Question 45

What can the positive feedback synapse potentiation lead to?

Answer 45

Potentially self-sustaining activity that persists beyond the original cause

Question 46

How is somatic pain precisely localised?

Answer 46

Impulse taken to the somatosensory cortex, where there’s a map of the of the body

Question 47

What’s the map of the body in the somatosensory cortex called?

Answer 47

Somatosensory homonculus

Question 48

What is viscerosomatic convergence?

Answer 48

When an impulse synapses with a somatic nociceptor nerve at the spinal cord

Question 49

What does viscerosomatic convergence cause?

Answer 49

Referred pain

Question 50

What do the afferent nerve synapse segments match?

Answer 50

The embryonic origin of each organ

Question 51

Why can gallbladder infections refer their pain to C3-5?

Answer 51

Infection spreads to parietal peritoneum and diaphragm, and C3-5 is where their nerves come from

Question 52

What are the characteristics of visceral pain?

Answer 52

- referred to regions of the body wall - diffuse and poorly located - each organ has characteristic patterns of referral

Question 53

Why is visceral pain generally referred to regions of the body wall?

Answer 53

Viscerosomatic convergence

Question 54

Why is visceral pain diffuse and poorly localised?

Answer 54

There’s a relatively small number of afferents and imprecise wiring