oesophagus, stomach and duodenum Flashcards
what type of epithelium is found in the oesophagus
stratified squamous epithelium with submucosal mucous glands and smooth muscle
where does the oesophagus pass through the diaphragm
right crus of the diaphragm at t10 (7th costal cartilage), just left of the midline
what is the arterial, venous and lymphatic supply of the abdominal oesophagus
left gastric artery
left gastric vein to portal vein
nodes along the left gastric artery and coeliac nodes
what is the innervation of the abdominal oesophagus
anterior vagal trunk derived from the left vagus and a posterior vagus from the right vagus
via the oesophageal plexus
describe the portocaval anastomosis
submucosal veins in the oesophagus form an anastomosis between the middle and lower thirds
the middle thirds drains to the azygous vein -> SVC and the lower thirds drains to the portal vein
portal hypertension may lead to blood escaping into the azygous vein
what are the components of the physiological sphincter
- contraction of right crus
- tonic contraction in the circular layers of smooth muscle in the lower oesophagus
- oblique entry of the oesophagus into the stomach
under vagal control
what is the Z line
transition from squamous epithelium to columnar epithelium
where is the cardiac orifice
40-43 cm from the incisors
what are the 4 parts of the stomach
cardia
fundus
body
pylorus ( antrum and canal)
what makes up the pyloric sphincter
thickened circular muscle in the pyloric region that controls the outflow of stomach contents
what is magenstrasse
mucosal rugae that help directs fluids from fundus to pylorus
what does the stomach do
receives and stores food and fluid
adds more fluid, acid and enzymes to create chyme and carry out digestion
what is the arterial supply of the stomach
derived from the coeliac trunk
left gastric artery arises from the coeliac trunk
the right gastric artery arises from the hepatic artery which is a branch of the coeliac trunk
which artery supplies the lower thirds of the oesophagus and upper right part of the stomach
left gastric artery. it arises from the coeliac trunk and goes to the oesophagus and then down along the lesser curvature
which artery supplies the lower right part of the stomach
right gastric artery
arises from the hepatic artery at the pylorus and runs left along the lesser curvature
what do the short gastric arteries arise from
the splenic artery at the hilum of the spleen and pass forward into the gastrosplenic ligament to supply the fundus
what are the branches of the splenic artery
short gastric arteries, left gastro-omental artery (left gastro-epiploic artery)
greater pancreatic artery dorsal pancreatic artery,
what artery supplies the lower part of the greater curvature
right gastro epiploic artery
from the gastro duodenal branch of the hepatic artery
what artery supplies the upper part of the greater curvature
left gastro epiploic artery
where is the gastro duodenal artery
posterior to the first part of the duodenum
where do the stomach veins drain to
portal circulation
the left and right gastric veins drain directly to the portal vein
where do the short gastric veins and the left gastro epiploic veins drain to
splenic vein
what does the right gastro epiploic vein drain into
the superior mesenteric vein which goes to the portal vein
where does lymph from the stomach drain to
coeliac nodes located around the coeliac trunk
what is the innervation of the stomach
sympathetic fibres T5-9 via the greater splanchnic nerves via the coeliac plexus
parasympathetic fibres from the right and left vagus nerves
what is a vagotomy
vagal trunks are cut to reduce gastric acidity and prevent ulcers. however also affects motility. Now nerves are cut more selectively to maintain sphincteric function
what forms the stomach bed
posterior wall of the lesser sac and retroperitoneal structures between it and the post abdominal wall:
part of the diaphragm (left crus), the spleen, the left suprarenal gland and upper pole of the left kidney Inferiorly: body and tail of pancreas, transverse mesocolon, left colic flexure and the splenic artery
how long is the small intestine
6-7 metres long
how long is the duodenum
20-25 cm long, adjacent to the head of the pancreas. mainly retoperitoneal
what is the function of the duodenum
continued digestion, esp. fats absorption
where does the duodenum receive bile and pancreatic ducts
major and minor duodenal papilla
where is the first part of the duodenum (superior part)
begins
at the pylorus and runs upward, backward and to the right, starting on the transpyloric plane at the level of the 1st lumbar vertebra
where is the second part of the duodenum (or descending part)
runs vertically downward in front of the hilum of the right kidney on the right side of the 2nd and 3rd lumbar vertebrae
where is the 3rd part of the duodenum ( horizontal part)
runs horizontally to the left on the subcostal plane, passing in front of the vertebral column at L3 and following the lower margin of the head of the pancreas
where is the 4th part of the duodenum (ascending part)
runs upward and to the left to the duodenojejunal flexure at L2
usually at the same level as the duodenal cap
where is the major duodenal papilla aka ampulla of Vater
halfway down the medial border of the duodenum
what are the anterior relations of the superior part of the duodenum
The quadrate lobe of the liver and the gallbladder
what are the posterior relations of the superior part of the duodenum
The lesser sac (first inch only), the gastroduodenal artery, the bile duct and portal vein, and the inferior vena cava
what are the superior relations of the superior part of the duodenum
The entrance into the lesser sac (the epiploic foramen)
what are the inferior relations of the superior part of the duodenum
The head of the pancreas
where is the anterior aspect of the superior part of the duodenum
in the peritoneal cavity, therefore ulcers could open into the cavity causing peritonitis and gas under the diaphragm, but the posterior part is retroperitoneal
what are the anterior relations of the descending part of the duodenum
The gallbladder (gall stone ileus) and the right lobe of the liver (at its start), the transverse colon, and the coils of the small intestine
what are the posterior relations of the descending part of the duodenum
The hilum of the right kidney and the right ureter
what are the lateral relations of the descending part of the duodenum
The ascending colon, the right colic flexure, and the right lobe of the liver
what are the medial relations of the descending part of the duodenum
The head of the pancreas, the bile duct, and the main pancreatic duct
what are the anterior relations of the horizontal part of the duodenum
The root of the mesentery of the small intestine, the superior mesenteric vessels contained within it, and coils of jejunum
what are the posterior relations of the horizontal part of the duodenum
The right ureter, the right psoas muscle, the inferior vena cava, and the aorta
what are the superior relations of the horizontal part of the duodenum
The head of the pancreas
what are the inferior relations of the horizontal part of the duodenum
Coils of jejunum
what are the posterior relations of the ascending part of the duodenum
The left margin of the aorta and the medial border of the left psoas muscle
what are the anterior relations of the ascending part of the duodenum
The beginning of the root of the mesentery and coils of jejunum
where is the paraduodenal recess
where the duodenal junction gains a mesentery
hernias are possible but rare
what is the arterial supply of the upper half of the duodenum
supraduodenal and gastroduodenal branches of the hepatic artery
what is the arterial supply of the lower half of the duodenum
superior mesenteric artery (midgut) that gives the Inferior pancreaticoduodenal artery, which quickly divides into anterior and posterior branches
what do the superior and inferior pancreaticoduodenal arteries form
anterior and posterior anastomotic arches
which artery is at risk with posterior ulcers of the 1st part of the duodenum
gastroduodenal artery
what is the venous drainage of the duodenum
The superior pancreaticoduodenal vein drains into the portal vein; the inferior vein joins the superior mesenteric vein
what is the lymph drainage of the duodenum
Coeliac and SM nodes
what is the nerve supply of the duodenum
sympathetic greater (T5 to T9) and lesser splanchnic (T10 and 11) nerves and parasympathetic (vagus) nerves via the coeliac and superior mesenteric plexuses
where does the oesophagus start
c6 as a continuation of the pharynx
what is the supply of the upper oesophagus
Arterial supply from inferior thyroid arteries
Venous drainage to brachiocephalic veins
Nerve supply from branches of the vagus nerves (recurrent laryngeal nerves)
Lymphatics drain to deep cervical nodes
what is the supply of the middle oesophagus
Arterial supply direct from thoracic aorta and bronchial arteries
Venous drainage to azygos system (systemic)
Nerve supply from the oesophageal plexus (vagus and sympathetic)
Lymphatics drain to tracheobronchial nodes
what is the supply of the middle oesophagus
Arterial supply from left gastric artery
Venous drainage to left gastric veins and therefore to portal vein
Nerve supply from branches of the oesophageal plexus (vagus and sympathetic)
Lymphatics drain to left gastric and coeliac nodes
what are the 4 oesophageal constrictions
Upper oesophageal sphincter 17cm
Arch of aorta
Left main bronchus at 28cm
Diaphragm at 43cm
what are the 3 layers of stomach muscle from outside to in
longitudinal
circular
oblique
list the 6 sphincters of the digestive tract
UES LES Pyloric sphincter ileocaecal valve IAS EAS
What are the four layers of the GI tract
mucosa
submucosa
muscularis
serosa
what are the 3 layers of the mucosa
epithelia
lamina propria
muscularis mucosa
what is gallstone ileus
small bowel obstruction caused by a gallstone in the small intestine
what nerve goes to the pyloric sphincter
nerve of Laterget
at what vertebral level is the umbilicus
L3 and L4 vertebrae
what is the angular incisure
a notch at the inferior end of the lesser curvature
marks the change between the body and the pylorus
what arteries supply the fundus
short gastric
what artery supplies the upper part of the greater curvature
left gastroomental which is a branch of the splenic artery
what artery travels through the gastrosplenic ligament
left gastroomental
what artery supplies the inferior part of the greater curvature
right gastroomental which arises from the gastroduodenal branch of the hepatic artery
what is the right gastric artery a branch of
the hepatic artery
what are the short gastric arteries a branch of
the splenic artery
where does the stomach refer pain to
lower chest and epigastrium
what are the branches of the gastroduodenal artery
the right gastroepiploic artery
the superior pancreaticoduodenal artery which gives a posterior and superior branch
what are the branches of the SMA
inferior pancreaticoduodenal arteries intestinal arteries ileocolic right colic middle colic
what is the greater splanchnic nerve
travels from the thorax to the abdomen and supplies the foregut
T5-9
modulates the enteric nervous system and contributes to the coeliac plexus
what is the lesser splanchnic nerve
modulates the enteric NS of the midgut
what is the blood supply of the greater omentum
gastroepiploic arteries
