Upper GI Tract [Complete] Flashcards
Name the two main sphincters of the oesophagus.
Upper oesophageal sphincter
Lower oesophageal sphincter
Name the 5 regions of the oesophagus.
Cervical oesophagus
Upper thoracic oesophagus
Middle thoracic oesophagus
Lower thoracic oesophagus
Abdominal oesophagus
Different regions of the oesophagus have different types of muscles. Which type of muscle makes up the cervical muscle?
Skeletal
Which type of muscle makes up the upper thoracic oesophagus?
Smooth/Skeletal
Which type of muscle makes up the middle thoracic oesophagus?
Skeletal/Smooth
Which type of muscle makes up the lowerr thoracic oesophagus?
Smooth
An alternative name for the lower thoracic oesophagus is known as?
The esophagogastric junction (EGJ)
What are the average lengths of each component of the oesophagus?
Cervical: 5cm
Upper thoracic: 5cm
Middle thoracic: 5cm
Lower thoracic (EGJ): 10cm
Where does the cervical oesophagus begin and at what vertebral level?
Begins from the upper oesophageal sphincter at C5/6
What vertebral level does the oesophagus enter the diaphragm?
T10
What vertebral level does the oesophagus end at?
T11
What nearby structures are used as reference for the location of the begining of the oesophagus?
cricoid cartilage of the larnyx(oesophagus is located behind them)
What nearby structures are used as reference for the where the cervical oesophagus ends?
The sternal notch
What is the average length of the oesophagus?
20-25cm
The lower oesophageal sphincter does not have any sphincter related muscles to enable it to produce a closing effect. Instead there are nearby anatomical contributions which enable it to perform its function. List these 4 contributions.
Distal oesophagus 4-5cm within the abdominal cavity
Diaphragm sorrounding the LOS (right and left crux)
Oesophagus enters at an acute angle (Angle of His)
Phrenoesophageal ligament
The angle in which the oesophagus enters the stomach is known as?
Angle of His
What is the function of the angle of His?
Helps to prevents reflux of gastroduodenal contents from travelling back up the oesophagus.
What is the importance of the distal oesophagus being located within the abdominal cavity.
When there is positive intra-abdominal pressure, this enables the compression of this part of the oesophagus preventing regurgitation
What is the function of the right and left crux of the diaphragm?
Creates a pinch-cock effect
What is the purpose of the phrenoesophageal ligament?
Enables independant movement of the oesophagus and disphragm during respiration or swallowing.
Name the 4 main phases of swallowing?
Phase 0: Bolus phase
Phase 1: Pharyngeal phase
Phase 2: Upper oesophageal phase
Phase 3: Lower oesophageal phase
Summarise the bolus phase of swallowing
Chewing & saliva prepare bolus
Both oesophageal sphincters constricted during this
Summarise the pharyngeal phase of swallowing
Pharyngeal musculature guides food bolus towards oesophagus
Upper oesophageal sphincter opens reflexly
lower oesophageal sphincter is opened by vasovagal reflex (receptive relaxation reflex)
Summarise the upper oseophageal phase of swallowing
Upper sphincter closes
Circular muscle rings superior to bolus constrict to prevent regurgitation and inferior rings dilate to enable entry further down the oesophagus.
Sequential contractions of longitudinal muscle occurs to help guide bolus down the the oesophagus easier.
Summarise the lower oesophageal phase of swallowing
As food passes through the lower oesophageal sphincter, it begins to close
The opening of the lower oesophageal sphincter is triggered by which reflex?
The vasovagal reflex
Which of the sphincters stays open the most during the swallowing process?
The lower oesophageal sphincter (Opens at the same phase as the upper but continues to stay open for later phases.
What medical test can be performed to determine oesophageal motility?
A manometry
What is manometry?
Measure of changes in pressure and movement within the oesophagus to help determine any abnormality.
What is the average pressure generated from peristaltic waves?
40mmHg
What is the avergae resting pressure of the lower oesophageal sphincter
20mmHg
During receptive relaxation of the LOS, what happens to the pressure?
Pressure decreases to less than 5mmHg
relaxation of the LOS is mediated by which neurones?
Mediated by inhibitory noncholinergic nonadrenergic (NCNA) neurons of myenteric plexus
In order for dysphagia to be caused by a functional disorder of the oesophagus, what must there be an absence of?
A stricture
What is an oesophageal stricture?
A abnormal narrowing of the oesophagus
What are the two main pathological causes for the diagnosis of a functional oesophageal disorder?
Abnormal oesophageal contractions
Failure of protective mechanisms for reflux
Give an example of a functional oesophageal disorder characterised by failed protective mechanisms for reflux.
GERD (Gastrooesophageal reflux disorder)
Give 3 examples of types of abnormal oesophageal contractions.
Hypermotility (e.g. achlasia)
Hypomotility (e.g. scleroderma)
Disordered coordination (e.g. corkscrew oesophagus)
Diffculty in swallowing is known as?
Dysphagia
Dysphagia can present itself in different ways. What characteristics must be considered when distinguishing differences?
Location
Whether its intermittent or progressive
Whether it occurs when swallowing liquids or fluid
Whether its precise or vague in apprecitation (detection)
What are the two main locations where dysphagia can occur in?
Cricopharyngeal sphincter
Distal oesophagus
Pain in swallowing is known as?
Odynophagia
Define regurgitation
Regurgitation refers to return of oesophageal contents from above an obstruction