Sem 1 - K - Foregut 1 - Stomach and duodenum - Morphology, anatomical relations, surface anatomy, blood vessels and lymph

Question 1

Where does the digestive tract start and end?

Answer 1

The digestive tract runs from mouth (oral cavity) to anus

Question 2

Where does the foregut start and end?

Answer 2

Theforegut runs from distal oedophagus to the mid-duodenum - therefore contains the proximal part of the duodenum

Question 3

What are the organs of the foregut?

Answer 3

Distal oesophagus Liver Gallbladder Stomach Spleen Pronximal duodenum 1/2 of pancreas

Question 4

Where does the blood supply to the foregut arise? Where does the blood in the foregut drain to? Where does the lymph drainage of the foregut go to?

Answer 4

The blood supply to the foregut comes from the coeliac axis (aka coeliac trunk aka coeliac artery) which is a branch of the abdominal aorta at T12 vertebral level The blood in the foregut drains to the hepatic portal vein The lymph from the foregut drains back to the pre-aortic nodes a T12 aka the coeliac nodes

Question 5

Organs can be intra, retro and infraperitoneal State which organs of the abdomen are each

Answer 5

• * Intraperitoneal organ - almost completely covered by peritoneum - stomach, gallbladder, liver, spleen, small intestine, 1st part of duodenum, caecum (some appendix), transverse and sigmoid colon
• * Retroperitoneal (extraperitoneal) - kidneys and suprarenal glands, 2nd/3rd/4th parts of duodenum and pancreas, ascending/descending colon, 2/3rds of rectum
• * Infraperitoneal (subperitoneal) - lower 1/3rd of rectum and many pelvic organs

Question 6

The stomach is a muscular bag Is the organ intra,retro or infra peritoneal? What extends from its lesser and greater curvature?

Answer 6

The stomach is a intraperitoneal organ From its lesser curvature extends the lesser omentum From its greater curvature extends the 4 fold periotneal layer thick greater omentum

Question 7

Lets talk about the morphology of the stomach What are the layers of the stomach from outside to inside? What are the regions of the stomach?

Answer 7

Serosa, muscularis externa - longitudinal, circular then oblique layer Submucosa Mucosa The cardiac region Fundus Body Pylorus

Question 8

From the external view, the stomach is a smooth muscular bag When opened up, the inner surface is highly folded. What is this known as? What is usually the superior and inferior borders of the stomach? (remember it changes position as it fills)

Answer 8

The internal surface of the is a highly folded surface and is known as rugae - it greatly increases the surface area of the stomach The superior border of the stomach is the 5th to 6th rib The inferior borer of the stomach is the transpyloric plane

Question 9

What are the three regions of the pylorus? Which region demarcates the level of the transpyloric plane?

Answer 9

Pyloric antrum Pyloric canal Pyloric sphinter at L1 level - transpyloric plane

Question 10

What level is the transpyloric plane? Also what are the sphincters off the stomach known as? (give 3 names for the proximal sphincter)

Answer 10

The transpyloric plane lies at the 8th rib - L1 vertebral level Sphincters * Lower oesophageal sphincter aka gastroesophageal sphincter aka cardiac sphincter * Pyloric sphincter

Question 11

What are the anatomical relations of the stomach? Superior Anterior and Posterior

Answer 11

Superior - oesophagus and left dome of diaphragm Anterior - diaphragm, greater omentum, left lobe of liver and gallbladder Posteirorly - Splenic artery, spleen, pancreas, left adrenal gland, left kidney, lesser sac, transverse colon and mesocolon

Question 12

What is the arterial supply to the lesser curvature of the stomach? state where the branches arise What is the branches to the fundus of the stomach?

Answer 12

The right gastric artery - branch of the common hepatic artery branch of the coeliac trunk The left gastric artery - direct branch of the coeliac trunk Supplying fundus Short gastric arteries - these are from the splenic artery (branch of coeliac trunk) and supply the fundus of the stomach

Question 13

What is the arterial supply to the greater curvature of the stomach? State where the branches arise

Answer 13

Gastro-omental artery = gastroepiploic artery Right gastroomental artery - this is a branch of the gastroduodenal artery (branch of the common hepatic artery which is from the coeliac trunk) Left gastroomental artery - branch from the splenic artery

Question 14

State again in summary the arterial supply to the stomach

Answer 14

Lesser curvature

• Left gastric artery - coeliac trunk branch
• Right gastric artery - common hepatic branch

Greater curvature

• Left gastrepipoloic artery - splenic artery branch
• Right gastrepiploic artery - gastroduodenal branch

Fundus -

• Short gastric arteries - splenic artery branch

Question 15

Right and left gastric arteries anasomtose for the lesser curvature of the stomach Right and left gastroomental arteries anasotmase for the greater curvature of the stomach What is the venous drainage of the stomach?

Answer 15

Left and right gastric veins drain directly into the hepatic portal vein Short gastric veins and left gastro-omental vein drain into the splenic vein Right gastro-omental drains into the superior mesenteric vein which joins with the splenic vein to become the hepatic portal vein

Question 16

The stomach has various groups of nodes for lymphatic drainage * Cardiac ring of nodes around base of oesophagus * Gastro-omental nodes * Pancreaticoduodenal nodes * Pancreaticosplenic nodes * Gasric * Pyloric Where do all these lymph nodes collectively drain to and where does that structure drain?

Answer 16

These groups of lymph nodes all drain to the pre-aortic lymph nodes at T12 - the coeliac axis nodes which drains into the cisterna chyli - this then drains into the thoracic duct

Question 17

What is the nerve supply to the stomach?

Answer 17

• The stomach has an autonomic nerve supply from the ANS
• Parasympathetis from anterior & posterior vagal trunks - posterior trunk goes to coeliac plexus
• Sympathetic from the greater splanchnic nerve carried to the coeliac plexus - sympathetics ride along arteries to organs

Question 18

The greater splanchnic nerve supplies sympathetics to the stomach

• What are its nerve roots and how does it pass through the diaphragm?
• The same question for both lesser and least splanchnic nerves

Answer 18

• Greater splanchnic nerve - T5-T9 ganglia
• Lesser splanchnic nerve - T10 and T11 ganglia
• Both pass through openings in crura at T12
• Least splanchnic nerve - T12 ganglia
• Passes through diaphragm with the sympathetic chain behind the medial arcuate ligament

Question 19

The pylorus of the stomach attaches to the duodenum which has 4 regions Approximately how long is the duodenum? What are the four regions of the duodenum and which are intra/retroperitoneal?

Answer 19

Duodenum - approximately 25 centimetres long 1st part of the duodenum - the only intraperitoneal part - the duodenal cap The other three parts are retroperitoneal 2nd part - descending part- entrance of bile and pancreatic ducts 3rd part - transverse part 4th part - ascending part - to jejunum

Question 20

Have the duodenal cap (1st part), descending, transverse and ascending duodenum The duodenum has a mucous membrane What are the thick inner folds of the dudodenum known as?

Answer 20

Plicae circulares

Question 21

What is the ampulla of vater also known as? What is it formed by? Where is it located?

Answer 21

The Ampulla of Vater is also known as the Hepatopancreatic ampulla It is formed by the union of the common bile duct (R+L hepatic ducts + cystic duct) and the pancreatic duct It is located at the major duodenal papilla in the 2nd part of the duodenum

Question 22

The ampulla of vater empties into the major duodenal papilla which has a sphincter of smooth muscle around it What is this sphincter known as? (both names) and what is its function?

Answer 22

This is the Sphincter of Oddi (hepato-pancreatic sphincter) Controls the flow of pancreatic and bile fluids into the duodenum - if it is closed, the fluids will travel back into the gallbladder along the common bile then cystic duct where the bile will be stored and concentrated

Question 23

If the dudodenum begins at the pyloric sphinter, what is this vertebral level and what is the plane running transversely known as? What is the junction at the end of the duodenum known as and where is it in relation to the midline?

Answer 23

Duodenum begins at the L1 vertebral level - transverse pyloric plane It ends at the duodenal-jejunal junction which is 3cm left of the midline

Question 24

What are the anatomical relations of all 4 parts of the duodenum?

Answer 24

1st part - duodenal cap - liver, gallbladder, bile duct, portal vein, IVC 2nd part - transverse colon, right kidney and ureter, pancreas 3rd part - superior mesenteric vessels, right ureter, right psoas major, IVC, aorta, pancreas 4th part - root of mesentery, jejunum, aorta, left psoas major

Question 25

The duodenum has a blood supply from both the foregut and midgut main arteries What is the blood supply to the duondeum?

Answer 25

Proximal half - Superior pancreaticoduodenal artery - branch of the gastroduodenal branch of the common hepatic artery from the coeliac trunk Distal half - Inferior pancreaticoduodenal artery - branch of the superior mesenteric artery

Question 26

What is the venous drainage of the duodenum?

Answer 26

Proximal half - superior pancreaticoduodenal vein direct to the hepatic portal vein Distal half - inferior pancreaticoduodenal to the superior mesenteric vein

Question 27

What is the nerve supply to the duodenum? Where is pain felt from the duodenum?

Answer 27

Sympathetics - greater and lesser splanchnic nerves Parasympathetics - vagal nerves from coelic and superior mesenteric plexus

Question 28

General rule = lymph drainage follows arterial supply Duodenum dual arterial supply so dual lymph drainage What is therefore the lymphatic drainage of the duodenum?

Answer 28

Proximal part - pancreaticoduodenal nodes to gastroduodenal and pyloric nodes to the pre-aortic coeliac nodes at T12

Distal part - pancreaticoduodenal nodes to the pre-aortic superior mesenteric nodes at L1