Oesophagus Flashcards
what is the oesophagus?
a fibromuscular tube, about 25cm in length
what is the function of the oesophagus?
transports food from the pharynx to the stomach
where does the oesophagus originate from?
inferior border of the cricoid cartilage (C6 vertebrae)
where does the oesophagus extend to?
to the cardiac orifice of the stomach (T11)
what can the oesophagus be divided into anatomically?
thoracic and abdominal parts
what does oesophagus contain which helps contribute to its function?
upper and lower oesophageal sphincter
what is the oesophagus continuous with?
the laryngeal part of the pharynx
where does the oesophagus descend down into?
superior mediastinum of the thorax
where is the oesophagus situated as it descends down into the superior mediastinum of the thorax?
between trachea and the vertebral bodies T1-T4
what happens after the oesophagus has descended down pass T1-T4?
enters the abdomen by piercing the muscular right crus of the diaphragm, through the oesophageal hiatus
where is the oesophageal hiatus and what is it?
a hole in the diaphragm at the T10 level
what does the phrenicoesophageal ligament connect?
connects oesophagus to border of the oesophageal hiatus
what does the phrenicoesophageal ligament permit?
independent movement of the oesophagus and diaphragm during respiration and swollowing
how long is the abdominal part of the oesphagus
approximately 2cm long
where does the abdominal part of oesophagus terminate?
by joining the cardiac orifice of the stomach at level of T11
what are the muscular layers contained within the oesophagus?
internal circular
external longitudinal
what is the external longitudinal layer comprised of?
different muscle types in each 1/3 of the oesophagus
what are the muscles in the different 1/3s of the oesophagus?
superior: voluntary straited
middle: voluntary straited and smooth muscle
inferior: smooth muscle
what transports food through the oesophagus?
peristalsis
what is peristalsis?
a rhythmic contraction of the muscles, which propagates down the oesophagus
what does hardening of the muscular layers interfere with? result?
interfere with peristalsis and cause dysphagia
what is dysphagia?
difficulty in swallowing
what do the upper and lower oesophageal sphincters act to prevent?
prevent the entry of air and the reflux of gastric contents respectively
where is the upper oesophageal sphincter located and the type of muscle??
anatomical, straited muscle sphincter at the junction between the pharynx and oesophagus
what is the upper oesophageal sphincter made of?
produced by the cricopharyngeus muscle
normally, what does the upper oesophageal sphincter prevent? how?
upper oesophageal sphincter constricted to prevent the entrance of air into the oesophagus
what is the lower oesophageal sphincter and where is it located?
a physiological sphincter located in the gastro-oesophageal junction
what is the gastro-oesophageal junction?
junction between the stomach and oesophagus
where is the gastro-oesophageal junction
situated to the left of the T11 vertebrae
what is the gastro-oesophageal junction marked by?
the change from from oesophageal to gastric mucosa
why is the lower oesophageal sphincter classified as a physiological (or functional) sphincter?
it doesn’t have any specific sphincteric muscle
how does the lower oesophageal sphincter function?
a number of forces act
how does the oesophagus enter the stomach?
at an acute angle
when are walls of intra-abdominal section of the oesophagus compressed?
when there is a positive intra-abdominal pressure
why are the folds of mucosa present?
folds of mucosa present aid in occluding the lumen at the gastro-oesophageal junction
what is the function of the right crus of the diaphragm?
a ‘pinch-cock’ effect
what happens during oesophageal peristalsis?
the sphincter is relaxed to allow food to enter the stomach
what is the function of the sphincter at rest?
prevent the reflux of acidic gastric contents into the oesophagus
