Upper GI tract Flashcards
(151 cards)
At what vertebrae does the trachea start and end?
C5 and T4
Where does the diaphragm sit?
T10
What is Stage 0 of swallowing?
Oral Phase
- chewing and saliva prepare bolus
- both oesophageal sphincters constricted
What is Stage 1 of swallowing?
Pharyngeal Phase
- pharyngeal musculature guides bolus towards the oesophagus
- upper oesophageal sphincter opens reflexively
- lower oesophageal sphincter opens due to vasovagal reflex (receptive relaxation reflex)
What is Stage 2 of swallowing?
Upper Oesophageal Phase
- upper sphincter closes
- superior circular muscles contract while inferior rings dilate
- sequential contractions of longitudinal muscle
What is Stage 3 of swallowing?
Lower Oesophageal Phase
- lower sphincter closes as food passes through
How is oesophageal motility measured?
pressure measurements (manometry)
What is the approximate pressure measurement of peristaltic waves?
around 40mmHg
What is the lower oesophageal sphincter’s resting pressure?
around 20 mmHg
What is the approximate change in the oesophageal sphincter’s pressure during receptive relaxation?
decreases by <5mmHg
What is the lower oesophageal sphincter mediated by?
inhibitory noncholinergic nonadrenergic (NCNA) neurons of the myenteric plexus
What is the absence of a stricture caused by?
- abnormal oesophageal contraction (hyper-motility, hypo-motility, disordered co-ordination)
- failure of protective mechanisms for reflux (GORD)
What are the different types of dysphagia?
- solids or fluids
- intermittent or progressive
- precise or vague
What is important when someone is complaining of dysphagia?
localisation
cricopharyngeal sphincter or distal
What is odynophagia?
pain on swallowing
What is regurgitation?
return of oesophageal contents from above an obstruction (functional or mechanical)
What may cause mechanical regurgitation?
obstructions eg: tumours
What is reflux?
passive return of gastroduodenal contents to the mouth
What is the biological characteristics of Achalasia?
loss of ganglion cells in Aurebach’s myenteric plexus in the lower oesophageal sphincter wall, leading to decreased activity of inhibitory NCNA neurones.
What is Achalasia?
the absence of peristalsis, and impaired relaxation of the lower oesophageal sphincter
What causes primary achalasia?
unknown aetiology
What causes secondary achalasia?
diseases that cause similar oesophageal motor abnormalities
- Chagas’ Disease
- Protozoa Infection
- Anyloid/Sarcoma/Eosinophilic Oesophagitis
What happens in the development of Achalasia?
- increased resting pressure of the lower oesophageal sphincter
- receptive relaxation sets in too late, and is too weak as the pressure in the LOS is much higher than the stomach, so food does not pass through
- swallowed food contents collects in the oesophagus causes increased pressure throughout with dilation of the oesophagus
- propagation of peristalic waves cease
What are the symptoms of Achalasia?
- weight loss
- dysplasia
- regurgitation
- oesophagitis
- pneumonia due to aspiration