Overview of Gastrointestinal Tract

Question 1

When does the primordial gut tube form?

Answer 1

4 week of human development

Question 2

Where is the primordial gut tube derived from?

Answer 2

From endoderm lining of the yolk sac

Question 3

What are the foregut structures?

Answer 3

Primordial pharynx and derivatives
Lower resp. system
Oesophagus and stomach
Duodenum
Liver and biliary apparatus

Question 4

What is the artery of the foregut?

Answer 4

Coeliac trunk

Question 5

What are the 3 constrictions of the oesophagus?

Answer 5

Cervical
Thoracic
Diaphragmatic

Question 6

What are the parts of the stomach?

Answer 6

Cardia
Fundus
Body
Pyloric

Question 7

What is the function of the pyloric sphincter?

Answer 7

Control discharge of stomach contents into the duodenum

Question 8

What structures lie upon the stomach (stomach bed)?

Answer 8

Diaphragm
Spleen
Left kidney
Adrenal gland
Splenic artery
Pancreas
Transverse mesocolon
Colon

Question 9

Describe the function of the biliary ducts

Answer 9

Carry bile from liver to gallbladder

Question 10

Where is bile produced and stored?

Answer 10

Produced in liver and stored in gallbladder

Question 11

What is the artery which supplies the gallbladder?

Answer 11

Cystic artery which lies in the triangle of calot

Question 12

Explain the triangle of Calot

Answer 12

Hepatic duct, cystic duct and visceral surface of the liver

Question 13

What is the pancreas function?

Answer 13

Accessory digestive gland
Exocrine and endocrine functions

Question 14

Where does pancreas lie?

Answer 14

Retroperitoneal
Lies along the transpyloric plane L1/L2

Question 15

What are the parts of the pancreas?

Answer 15

Head, Neck, Body and Tail

Question 16

What is the origin of the celiac trunk?

Answer 16

Abdominal aorta at T12

Question 17

What are the main branches of the celiac trunk?

Answer 17

Left gastric artery
Hepatic artery
Splenic artery

Question 18

What are the 3 arteries that the abdominal aorta?

Answer 18

Celiac trunk
Superior mesentery artery
Inferior mesentery artery

Question 19

What organs are in the midgut structures?

Answer 19

Small intestine including duodenum
Cecum
Ascending colon
Right half to 2/3 of transverse colon

Question 20

What is the duodenum?

Answer 20

Shortest and widest part of the small intestine
Its second part receives bile and pancreatic duct

Question 21

Explain a duodenal ulcer

Answer 21

Inflammatory erosions of duodenal wall - mainly 1st part

Question 22

What are some differences of the jejunum and the ileum?

Answer 22

Jejunum has long vesa recta instead of short
Ileum has more fat in mesentery
Ileum had more lymphoid nodules

Question 23

What is the artery which supplies midgut?

Answer 23

Superior mesentery artery

Question 24

What level of abdominal aorta is superior mesenteric artery branch from?

Answer 24

L1

Question 25

What are the main branches of the superior mesenteric artery?

Answer 25

Jejunal Ileal arteries

Question 26

What are the structures of the hindgut?

Answer 26

Left 1/3 of transverse colon Descending colon Sigmoid colon Rectum Upper part of anal canal Epithelium of urinary canal and most of uretha

Question 27

What is the artery suppling the hindgut?

Answer 27

Inferior mesenteric artery

Question 28

How can the large intestine be distinguished from the small intestine?

Answer 28

Omental appendices - small fatty projections Haustra or sacculations Teniae coli - thickened bands of smooth muscle

Question 29

Describe the appendix

Answer 29

Blind intestinal diverticulum with masses of lymphatic tissue Variable position - retrocecal most common

Question 30

What is Macburney's Point?

Answer 30

Site of max. tenderness in acute appendicitis

Question 31

What is the level of inferior mesenteric artery branches from abdominal aorta?

Answer 31

L3

Question 32

What are the branches of the inferior mesenteric artery?

Answer 32

Left colic Sigmoid arteries Superior rectal artery

Question 33

What is the terminal branch of the inferior mesenteric artery?

Answer 33

Superior rectal artery

Question 34

What is the innervation of the abdominal organs?

Answer 34

Autonomic Parasympathetic - vagus nerve and pelvic splanchnic nerve (S2-4) Sympathetic nerve - abdominal splanchnic nerves, prevertebral sympathetic ganglia and abdominal aortic plexus

Question 35

What is the function of the portal vein?

Answer 35

Transports venous blood from the spleen, pancreas, gallbladder and abdominal part of GIT

Question 36

What is the formation of the portal vein?

Answer 36

Union of splenic vein with superior mesenteric vein

Question 37

What is the location of the portal vein?

Answer 37

Behind the neck of the pancreas - L2

Question 38

What are 3 sites of porto-venal shunts?

Answer 38

Anorectal junction Gastroesophageal junction At umbilicus

Question 39

What are some consequences of venous enlargement during portal obstruction?

Answer 39

Haemorrhoids Oesophageal varices Caput medusae

Question 40

Describe the lymphatic drainage of the GIT

Answer 40

Thoracic duct receives most from wall and organs Lymph vessels run with corresponding arteries

Question 41

What are the 3 terminal groups of lumbar nodes?

Answer 41

Pre-aortic - drains organs supplied by anterior branches of aorta Lateral aortic Retro-aortic - posterior abdominal wall