Oesophagus, Stomach and Duodenum Flashcards
What is the function of the oesophagus?
transport food and fluid to stomach by peristaltic waves
What are the borders/margins of the oesophagus
starts in the midline as the continuation of the pharynx at C6; inferior border of cricoid cartilage
Where does the oesophagus descend between?
between trachea and vertebral column
Where does the oesophagus enter the thorax?
behind trachea, with the arch of the aorta to its left in the superior mediastinum
Where does the oesophagus enter the abdominal cavity?
T10, slightly left of the midline
What are the 4 non-pathological constrictions of the oesophagus?
- upper oesophgeal sphincter - level C6
- Arch of aorta - T4
- Left main bronchus
- Diaphragm - T10
What feature is related to the oesophagus anteriorly but not a constriction?
left atrium
What sphincter lies between the oesophagus and pharynx?
cricopharyngeal sohincter
What is the significance of oesophgeal constrictions?
- more likely to cause blockage
- Hinder the passage of instruments
- Slow down the oassage of caustic substances - causing more damage
Indicate the:
- muscle type
- swallowing
- arterial supply
- venous drainage
- innervation
- lymphatic drainage
of the superior 1/3 of the oesophagus
- striated
- voluntary and rapid
- inferior thyroid artery
- brachiocephalic veins
- vagus (recurrent laryngeal)
- deep cervical
Indicate the:
- muscle type
- arterial supply
- venous drainage
- innervation
- lymphatic drainage
of the middle 1/3 of the oesophagus
- mix
- Aorta, brachiocephalic aa.
- Azygos
- Oesophgeal plexus (vagus + T1-4, greater splanchnic nerve)
- Trachaeobronchial
Indicate the:
- muscle type
- swallowing
- arterial supply
- venous drainage
- innervation
- lymphatic drainage
of the inferior 1/3 of the oesophagus
- smooth
- involuntary and slow
- left gastric artery, left inferior phrenic artery
- left gastric vein, oesophgeal vv.
- oesophgeal plexus (vagus + T1-4, greater splanchnic nerve)
- left gastric, coeliac
What is the shortest part of the oesophagus?
abdominal oesophagus (lower 1/3)
Where does the abdominal oesophagus travel?
- from the oesophageal haitus to the cardiac notch of the stomach
- passes through the right crus of diaphragm at T10
How is the abdominal oesophagus attached to the oesophgeal hiatus?
phreno-oesophgeal ligament
What is the arterial supply of the abdominal oesophagus?
left gastric artery, a branch of the coeliac trunk
What veins drain the abdominal oesophagus?
- left gastric, short gastric veins drain to portal vein
- oesopheal veins drain to azygos system
What is the nerve supply of the abdominal oesophagus?
- parasympathetic from vagus
- sympathetic from greater splanchnic (T5-T()
green = left gastric artery
red = oesophgeal veins
blue = left gastric vein
What is the lymphatic drainage of the abdominal oesophagus?
- left gastric lymph nodes
- celiac lymph nodes
What is the main reflux mechanism of the lower oesophgeal sphincter? (major and minor)
Major
- circular smooth muscle fibres
- right crus of diaphragm
Minor:
- Clasp fibres
- oblique entry of the oesophagus into the stomach
What is the Z-line?
gastro-oesophgeal junction is usually identified by a circumfenential ‘zigzag’ line between the pale pink oesophgeal squamous epithelium above and the red columnar epithelium below
What is Barrett’s Oesophagus?
pathological replcament of oesophgeal squamous epithelium by gastric columnar epithelium
What is the stomach?
a muscular sac
Where is the stomach located?
epigastric, left hypogastric (hypochondiral) and umbilical regions
What is Labbe’s triangle?
location where the sotmach is normally in contact with the abdominal wall
- left costal arch
- lower border of liver
- horizontal liver connecting the tips of right anf left 9th CC
What are the main functions of the stomach?
- Temporary storage of ingested food
- Mechanical breakdown of solid food
- Chemical digestion of proteins
- Mixes the food with gastric secretions to form chyme
- Regulation of the rate of passage of the chyme to the duodenum
- Secretion of
- acid to aid digestion and absorption of iron
- intrinsic factor for vitamin B12 absorption
- gut hormones
- Microbial defence
What are the 4 main parts of the stomach and the other defining features?
- Cardia: surrounds the opening of the esophagus into the stomach
- Fundus: area above the level of the cardiac orifice (usually filled with air)
- Body
- Pyloric part
- Pyloric [Gastric] antrum
- Pyloric canal
- Greater curvature
- Lesser curvature
- Anterior surface
- Posterior surface
What is the stomach related to anteriorly?
- Anterior abdominal wall
- Left costal margin
- Diaphragm
- Left pleura & lung (via diaphragm)
- Left lobe of the liver
What is the stomach related to posteriorly?
- Lesser sac
- Spleen
- Upper pole of left kidney
- Left suprarenal gland
- Pancreas
- Splenic artery
- Transverse colon
- Transverse mesocolon
What does the muscular wall of the stomach contain?
longitudnal, circular and oblqiue fibres (3 layers of muscle)
What forms the pyloric sphincter and what is its function?
- circular fibres in the pyloric region
- controls the outflow of gastric contents into the duodenum
Where does the coeliac trunk originate?
upper border of L1 vertebra
What are the 3 major branches of the coeliac trunk?
- left gastric artery
- common hepatic artery
- splenic artery
Describe the course of the left gastric artery and what it supplies
- direct branch of coeliac trunk
- runs along the lesser curvature
- supplies abdominal oesophagus, proximal lesser curvature and adjacent body of the stomach
Describe the course of the right gastric artery and what does it supply
- branch of the common hepatic artery
- runs along the lesser curvature
- Supplies the distal lesser curvature and body of the stomach
Describe the course of the left gastro-epiplogloic (gastro-omental) artery and what does it supply
- runs in the gastro-splenic (gastro-lienal) ligament
- left side of the greater and adjacent body of the stomach
Describe the course of the right gastro-epiplogloic (gastro-omental) artery and what does it supply
- branch of gastroduodenal branch of the common hepatic artery
- right side of greater curvature and adjacent body of the stomach
Describe the course of the short gastric arteries and what they supply
- branches of the splenic artery
- runs in the gastro-splenic (gastro-lienal) ligament
- the fundus of the stomach and abdominal oesophagus
blue = left gastric artery
green = right gastric artery
blue = left gastro-epiplogloic (gastro-omental) artery
green = right gastro-epiplogloic (gastro-omental) artery
red = short gastric arteries
How do the veins of the stomach run?
parallel to the arteries
Where do the left and right gastric veins drain into
portal vein
where do the Short gastric and left gastroepiploic veins drain into
splenic vein –> portal vein
Where does the right gastroepiploic vein drains into
the superior mesenteric vein –> portal vein
What is the sympathetic nerve supply of the stomach?
- greater splanchnic nerve(T5-9)
- coeliac plexus
- pain & vasomotor
What is the parasympathetic nerve supply of the stomach?
- vagal trunks (posterior = R; Anterior = L)
- Secretion
- Motility
- Afferents for emesis
Where does each zone of the stomach drain into lymphatics?
- Zone I (inferior gastric) –> subpyloric and omental nodes
- Zone II (splenic) –> pancreaticosplenic nodes
- Zone III (superior gastric) –>superior gastric nodes
- Zone IV (hepatic) –> suprapyloric nodes
Where does lymph from the stomach intially pass through
gastric and gastroepiploic arteries
eventually drained to coeliac nodes
What is a hiatus hernia?
Herniation of the stomach through the diaphragm into the mediastinum
Structures against which the posteroinferior surface of the stomach lies is called the bed of stomach. What lies within the bed of the stomach?
− Left crus of the diaphragm
− Spleen
− Left suprarenal gland
− Upper pole of the left kidney
− Body & tail of pancreas
− Transverse mesocolon
− Left colic (splenic) flexure
− Splenic artery
Who are hiatus hernias more common in
eldery and the obese
What are the 2 main types of hiatus hernia and what is their prevalence
− Sliding hernia (>90%)
− Para-oesophageal (rolling) hernia
What symptoms are associated with hiatus hernia?
asymptomatic
gastro-oesophgeal reflux
What can a para-oesophfeal hernia cause?
obstruction and/or ischaemia of the herniated stomach
What is the treatment of a symptomatic sliding hernia?
managing assoicated gastro-oesophgeal reflux, which may require anti-reflux surgery
Where is pain from the lower oesophagus referred to?
retrosternal area
Draw a diagram of each type of hiatus hernia
What is the longest part of the alimentery canal?
small intestine; extending from the pylorus to the ileocaecal valve
What mostly occurs in the small intestine
food digestion and absorption
What are the 3 parts of the small intestine?
duodenum, jejunum, ileum
What are the 4 parts of the duodenum?
- Superior (Ampulla or duodenal cap)
- Descending
- Horizontal
- Ascending
What is part 1 of the duodenum?
intraperitoneal (covered with peritoneum from all sides)
What are parts 2-4 of the duodenum?
retroperitoneal (behind the peritneum)
What ducts open into the duodenum?
common bile duct and pancreatic ducts
What are the functions of the duodenum?
digestion (especially fats)
absorption
Describe the course of the duodenum
- Transpyloric plane: Lower L1
- Descend, right of the midline from L2 to L3
- Horizontal at L3
- Ascend to L2
- Duodenojejunal flexure (ligament of Treitz)
What is the minor duodenal papilla?
opening of the accessory oancreatic duct
What is the major duodenal papilla?
common opening between the common bile and pancreatic ducts. Boundary between midgut and foregut
blue = minor duodenal papilla
red = major duodenal papilla
What is the blood supply of the duodenum up the the major duodenal papilla (ampulla od Vater)?
- derived from foregut
- supplied by branches of the common hepatic artery
- gastroduodenal artery
- supraduodenal artery
- superior pancteaticoduodenal artery (posterior and anterior)
What is the blood supply of the duodenum distal to the major duodenal papilla?
supplied by the midgut
- supplied by the inferior pancreaticoduodenal artery (anterior and posterior)
Where does the lymph of the duodenum drain to?
superior mesenteric or pancreoticoduodenal and pyloric nodes
Where do the veins of the duodenum drain to?
to hepatic portal vein, either directly or indirectly through the superior mesenteric and splenic veins
What artery is at risk of posterior ulcers in the duodenum?
- gastroduodenal artery in the first part of the duodenum
What is the SNS and PSNS supply of the duodenum?
- Sympathetic fibres via greater splanchnic nerves (T5-9)
- Parasympathetic fibers from vagus via the coeliac & superior mesenteric plexuses
What are the 3 main types of bariatric surgery?
- gastric bypass
- gastric sleeve or vertical gastrectomy
- adjustable gastric banding
