Anatomy of the Lower GI system

Question 1

At what level does the oesophagus pierce the diaphragm?

Answer 1

T10

Question 2

Describe the abdominal and pelvic cavity?

Answer 2

The abdominal cavity and pelvic cavity are continuous with each other, only separated by peritoneum (roof of pelvic cavity).

Question 3

What is peritonitis?

Answer 3

Inflammation of the peritoneum caused by infection from surgery or trauma - leads to guarding

Question 4

Describe the peritoneum?

Answer 4

Continuous membrane which secretes lubricating peritoneal fluid into the peritoneal cavity

Lines the abdominal cavity and invests viscera

Question 5

Describe the visceral and partial peritoneum?

Answer 5

Visceral - invests an orga

Parietal - touches the enteral body wall

Question 6

What is retroperitoneal?

Answer 6

Lays posterior to the peritoneum - behind

Question 7

What are the retroperitoneal organs?

Answer 7

Kidneys 
Adrenal gland
Pancreas
Parts of small intestine
Parts of large intestine

Question 8

What are the pelvic organs of the GI tract?

Answer 8

Rectum
Anal canal
Anus

Question 9

Where is the stomach mostly located?

Answer 9

in the left lower quadrant

Question 10

What is the small intestine attached to the body wall by?

Answer 10

A mesentery

Question 11

What are the parts of the small intestine?

Answer 11

Duodenum
Jejunum
Ileum

Question 12

What is the mesentery?

Answer 12

A double layer of peritoneum

Connects intraperionteal organs to the body wall

Question 13

What parts of the large intestine are retroperitoneal?

Answer 13

Ascending and descending colon are retroperionteal

Question 14

What is peristalsis?

Answer 14

waves of SIMULTANEOUS shortening of the length of a segment of the tube PLUS narrowing of the luminal diameter in that segment

Question 15

describe what the outer longitutal layer and the inner circular layer of the walls of the intestine do?

Answer 15

Outer longitudinal - smooth muscle - shortens the tube

Inner circular - smooth muscles - constricts (narrows) the diameter

Question 16

What is the mucosa like in the oral cavity, oesophagus and anus?

Answer 16

Protective - areas of greatest mechanical friction

Question 17

What is the mucosa like in the stomach?

Answer 17

Secretory - minimally absorptive

Question 18

What is the mucosa like in the small intestine and large intestine?

Answer 18

Absorptive

Question 19

Name the sphincter at the junction between laryngopharynx & oesophagus to help prevent regurgitation?

Answer 19

Cricopharyngeal sphincter

Question 20

Name the sphincter at the junction between stomach & duodenum to control the release of chyme from the stomach?

Answer 20

Pyloric sphincter

Question 21

Name the sphincter at at the junction between anus & external environment to control the release of stool from the anal canal?

Answer 21

External anal sphincter

Question 22

What are anatomical sphincters?

Answer 22

are discrete areas where muscle completely encircles the lumen of the tract

Can be composed of smooth or skeletal muscle

Question 23

Describe the track of the IVC in the abdomen?

Answer 23

It ascend in the retroperitoneum then passes through the diaphragm into the right atrium

Question 24

Describe the track of the aorta in the abdomen?

Answer 24

The Aorta leaves the left ventricle passes through the diaphragm the descends in the retroperitoneum

Question 25

What are the 3 midline branches of the abdominal aorta from superior to inferior?

Answer 25

Coeliac trunk Superior mesenteric artery Inferior mesenteric artey

Question 26

What do the 3 midline branches supply?

Answer 26

Coeliac trunk - foregut organs Super mesenteric artery - midgut organs Inferior mesenteric artery - hindgut organs

Question 27

Describe the venous drainage to the abode organs, what drains each section?

Answer 27

Foregut - splenic vein Midgut - Superior mesenteric vein Hindgut - inferior mesenteric vein (drains hindgut via splenic vein)

Question 28

What do all the veins join up to form and take to the liver?

Answer 28

The hepatic portal vein

Question 29

What is the hepatic portal vein formed by?

Answer 29

The splenic vein and the superior mesenteric artery

Question 30

Describe the portal venous system?

Answer 30

Drains from absorptive parts of GI tract and associated organs to the liver via hepatic portal vein This blood de-oxygenated and nutrient-rich

Question 31

Describe the systemic venous system?

Answer 31

Drains de-oxygenated blood from the rest of the body to the right atrium of the heart. Include blood from the liver via hepatic veins

Question 32

Describe where foregut structures drain their lymph via?

Answer 32

Via nodes located along the splenic artery towards the coeliac nodes (located around the origin of the coeliac trunk)

Question 33

Describe where midgut structures drain their lymph via?

Answer 33

Via nodes located along the superior mesenteric artery towards the superior mesenteric nodes (located around the origin of the superior mesenteric artery)

Question 34

Describe where hindgut organs drain their lymph via?

Answer 34

Via nodes located along the inferior mesenteric artery towards the inferior mesenteric nodes (located around the origin of the interior mesenteric artery)

Question 35

What is the body response to obstruction of the GI tract?

Answer 35

increased peristalsis proximal to the site of the obstruction in an attempt to remove it

Question 36

Why might a patient experience colicky pain?

Answer 36

Because peristalsis occurs in waves so the pain will come and go as the body tried to get over the obstruction