Anatomy: GIT overview

Question 1

What are the surface landmarks that mark the boundaries of the abdominal cavity?

Answer 1

Costal cartilage 9

Anterior Superior iliac spine

Tubercle of the iliac crest

Xiphisternum

Pubic symphysis

Question 2

What are the boundaries of the hypochondrium?

Answer 2

Superior and lateral part of the abdomen above the 9th costal cartilage and lateral to the midclavicular line.

Question 3

What are the boundaries of the epigastrium?

Answer 3

In the superior and middle part of the abdomen marked by the vertical line formed in the middle of both clavicles and above the horizontal line formed by the 9th costal cartilage.

Question 4

What are the boundaries of the lumbar abdomen?

Answer 4

Lateral to the vertical line formed by the middle clavicle and inferior to the 9th costal cartilage and superior to the ASIS.

Question 5

What are the boundaries of the umbilical abdomen?

Answer 5

Superior to the horizontal line formed by the ASIS and inferior to the horizontal line formed by the 9th costal cartilage.

Medial to vertical line formed by the middle of both clavicles.

Question 6

What are the boundaries of the iliac abdomen?

Answer 6

Below horzontal line formed by ASIS and above the pelvic brim

Question 7

What are the boundaries of the hypogastrium?

Answer 7

Above pubic symphysis and below horizontal line formed by ASIS

Question 8

What is the 9th costal cartilage also known as?

Answer 8

The transpyloric line

Question 9

What is the line that passes through the tubercles of the iliac crest?

Answer 9

Transtubercular line

Question 10

What is the line that goes through the middle of the clavicle called?

Answer 10

The midclavicular line

Question 11

Where does gut form from in the embryo?

Answer 11

Embryonic curvature traps part of the yolk sac inside the embryo to form the gut.

Question 12

How is the gut tube formed embryologically?

Answer 12

Embryonic curvature traps part of the yolk sac inside the embryo to form the gut tube.

Gut tube is made hollow (Lumen is formed) by canalisation of the gut.

Liver takes up space in abdominal cavity. Intestine lengthens into umbilicus which rotates and grows out forming an omphalocele (some kids can be born with this)

Gut twists around 90 degrees and then as fetus gets bigger the gut comes back into the abdominal cavity and then twists again another 90 - 270 degrees in total. At this stage the stomach is also rotating and the mesentery behind the stomach twists with it and forms the greater omentum.

Question 13

What could go wrong with canalisation of the gut tube?

Answer 13

Duplication (additional chambers formed within gut)

Stenosis (narrowing)

Question 14

What does mesentery do?

Answer 14

Keeps gut from dropping to the bottom of peritoneum and provides blood supply as well as nerve supply to the gut.

Question 15

What is the lesser omentum?

Answer 15

Mesentery between stomach and liver.

Question 16

What is the falciform ligament?

Answer 16

Ligament formed from the anterior abdominal wall to the liver that recedes after birth.

Question 17

What is an umbilical hernia?

Answer 17

Herniation of small pare of the gut through anterior abdominal wall.

Question 18

What artery supplies the embryonic primary intestinal loops?

Answer 18

The superior mesenteric artery (intestine loops around this artery)

Question 19

What is the epiploic foramen?

Answer 19

Space behind stomach formed by folds of mesentery.

Question 20

Where is the greater omentum located?

Answer 20

Anterior to the gut. It covers the intestines anteriorly

Question 21

What does the greater omentum do?

Answer 21

If there is a puncture of the abdominal cavity, it covers it up by adhering to the hole and prevent haemorrhage and bleeding.

Question 22

What are the layers of peritoneum?

Answer 22

Visceral layer

Parietal layer

Mesentery

Blood vessels.

Question 23

What is the function of peritneal layers?

Answer 23

Makes gut watertight

Suspends the gut

Contains nerves and blood vessels

Omentum contains infection

Question 24

What makes up the peritoneum?

Answer 24

Flattened endothelial cells on fibro-elastic connective tissue.

Question 25

How are the layers of the peritoneum different in terms of innervation?

Answer 25

Parietal peritoneum is sensitive to pressure, touch, pain, heat, cold, laceration, etc.

Visceral peritoneum is sensitive to stretching and is poorly localised and referred to dermatomes.

Question 26

What are the abdominal cavity parts?

Answer 26

Lesser sac is formed by the greater omentum which goes from the liver to the stomach anteriorly, continues and loops around inferiorly and moves posteriorly to connect to the transverse colon and then connects to posterior abdominal wall superiorly.

The space outside this sac is called the greater sac.

Question 27

What are the paracolic gutters?

Answer 27

Location near the colon where fluid accumulates.

Question 28

What are the important functions of the mesenteries of the abdomen?

Answer 28

They stop herniation caused by bidpedal posture (connection to posterior abdominal wall)

Supply blood/nerves to the gut

Sensitive to stretch

Contain infection

Useful in surgery (use its blood supply when arteries needed)

Question 29

What ligament connects the spleen to the kidneys?

Answer 29

The lienorenal ligament.

Question 30

What structures of the abdominal cavity are retroperitoneal?

Answer 30

The Duodenum

The pancreas

The ascending and descending colon

Kidneys

Rectum

Question 31

What structures of the abdominal cavity are intraperitoneal?

Answer 31

Stomach

Spleen

Small intestine

Transverse colon

The liver

Question 32

What is the blood supply of the gut from?

Answer 32

Celiac trunk supplies foregut

Superior mesenteric artery supplies midgut

Inferior mesenteric artery supplies the hindgut

Internal iliac artery supplies rectum (pudendal and rectal arteries)

Question 33

What develops from the foregut?

Answer 33

Stomach and first part of duodenum

Question 34

What develops from the midgut?

Answer 34

Everything after the stomach and first part of the duodenum until the middle of the transverse colon

Question 35

What develops from the hindgut?

Answer 35

The colon from the middle of the transverse colon until the rectum and anus

Question 36

What arteries supply the stomach?

Answer 36

Lesser curvature: Right and left gastric arteries (Left from celiac trunk and right from hepatic artery)

Greater curvature: Right and left gastroepiploic arteries (right from gastroduodenal, left from splenic, and also the short gastric arteries from the splenic artery)

Question 37

What structures form anastomoses for the stomach?

Answer 37

Celiac artery has 2 long anastomotic channels also along curvatures.

Question 38

What arteries form the anastomoses at the colon?

Answer 38

Superior and inferior mesenteric arteries.