SM_128b: GI Development & Organization

Question 1

Abdominal GI tract begins as a straight tube of _____ suspended by _____ and _____ that initially divide the abdominal cavity into left and right compartments

Answer 1

Abdominal GI tract begins as a straight tube of splanchnopleure suspended by dorsal and ventral mesenteries that initially divide the abdominal cavity into left and right compartments

Question 2

____ are layers of visceral peritoneum with fat, connective tissue, vessels, nerves, and lymphatics

Answer 2

Mesenteries are layers of visceral peritoneum with fat, connective tissue, vessels, nerves, and lymphatics

Question 3

GI is subdivided into ____, ____, and ____

Answer 3

GI is subdivided into abdominal foregut of large organs, midgut, and hindgut

Question 4

Abdominal foregut of large organs is supplied by the ____ branches

Answer 4

Abdominal foregut of large organs is supplied by the celiac trunk branches

Question 5

Midgut is supplied by the ____

Answer 5

Midgut is supplied by the superior mesenteric artery

Question 6

Hindgut is supplied by the ____

Answer 6

Hindgut is supplied by the inferior mesenteric artery

Question 7

_____ provides parasympathetic innervation to the foregut and midgut, while the _____ provides parasympathetic innervation to the hindgut

Answer 7

Vagus nerve provides parasympathetic innervation to the foregut and midgut, while the pelvic splanchnic nerves provides parasympathetic innervation to the hindgut

Question 8

____ forms in a bag of ____ of the foregut that continues to grow down over the intestines as the greater omentum

Answer 8

Lesser peritoneal sac forms in a bag of dorsal mesentery of the foregut that continues to grow down over the intestines as the greater omentum

Question 9

Rotation of the foregut / stomach 90 degrees to the right results in liver moving to the ____ and spleen moving to the ____

Answer 9

Rotation of the foregut / stomach 90 degrees to the right results in liver moving to the right and spleen moving to the left

Question 10

Midgut grows tremendously as it loops around the _____

Answer 10

Midgut grows tremendously as it loops around the superior mesenteric artery

Question 11

____ connects the transverse colon to the liver

Answer 11

Hepatocolic ligament connects the transverse colon to the liver

Question 12

____ connects the transverse colon to the diaphragm on the left

Answer 12

Phrenicocolic ligament connects the transverse colon to the diaphragm on the left

Question 13

____ connects the transverse colon to the stomach

Answer 13

Gastocolic ligament connects the transverse colon to the stomach

Question 14

____ of the liver is a fibrous cord that is a remnant of the umbilical vein

Answer 14

Round ligament of the liver (ligamentum teres) is a fibrous cord that is a remnant of the umbilical vein

Question 15

Organs in the body wall outside the greater peritoneal sac are in a ____ location

Answer 15

Organs in the body wall outside the greater peritoneal sac are in a retroperitoneal location

(aorta, IVC, kidneys, bladder, rectum, and vagina)

Question 16

Ascending and descending colon, pancreas, and duodenum initially have mesenteries but get pressed agains the body wall to become _____ as a result of the looping and tremendous growth of the midgut

Answer 16

Ascending and descending colon, pancreas, and duodenum initially have mesenteries but get pressed agains the body wall to become secondarily retroperitoneal as a result of the looping and tremendous growth of the midgut

Question 17

If you were inside the lesser peritoneal sac or its entryway through the epiploic foramen, you would be able to touch the _____, _____, _____, and _____ mesenteries

Answer 17

If you were inside the lesser peritoneal sac or its entryway through the epiploic foramen, you would be able to touch the splenorenal, hepatoduodenal, gastrosplenic, and hepatogastric mesenteries

(all are part of / continuous with the dorsal mesogastrium that makes up the walls of the lesser sac)

(phrenicocolic ligament is an adhesion of the left colic flexure to the diaphragm, which is outside and unrelated to the dorsal mesogastrium / lesser sac)

Question 18

____ is secondarily retroperitoneal

Answer 18

Duodenum is secondarily retroperitoneal

Question 19

____ is the junction of abdominal foregut and midgut

Answer 19

Middle of the duodenum is the junction of abdominal foregut and midgut

Question 20

If Meckel’s diverticulum, a remnant of the yolk sac stalk, becomes inflamed and needs to be removed, you would look for it at ____ after surgical entry into the abdominal cavity

Answer 20

If Meckel’s diverticulum, a remnant of the yolk sac stalk, becomes inflamed and needs to be removed, you would look for it at terminal ileum after surgical entry into the abdominal cavity

Question 21

Epiploic foramen is under the ____

Answer 21

Epiploic foramen is under the hepatoduodenal ligament

Question 22

Ligamentum teres is a remnant of the ____

Answer 22

Ligamentum teres is a remnant of the liver bud

Question 23

GI tract is divided into the ____, ____, and ____

Answer 23

GI tract is divided into the abdominal foregut, midgut, and hindgut

Question 24

___ is a mesentary of the stomach

Answer 24

Omentum is a mesentary of the stomach

Question 25

\_\_\_\_ envelops the embyro and umbilical cord, while the yolk sac and allantois are compressed into the \_\_\_\_

Answer 25

Amnion envelops the embyro and umbilical cord, while the yolk sac and allantois are compressed into the umbilical cord

Question 26

Mesentary is \_\_\_

Answer 26

Mesentary is 2 layers of visceral peritoneum supporting the gut tube and providing a route for vessels and nerves

Question 27

\_\_\_\_ artery feeds to the abdominal foregut

Answer 27

Celiac artery feeds to the abdominal foregut

Question 28

\_\_\_\_ artery feeds the midgut

Answer 28

Superior mesenteric artery artery feeds the midgut

Question 29

\_\_\_\_ artery feeds the hindgut

Answer 29

Inferior mesenteric artery feeds the hindgut

Question 30

\_\_\_\_ arises forom the breakdown of the ventral mesentery of the midgut and hindgut

Answer 30

Peritoneal cavity arises forom the breakdown of the ventral mesentery of the midgut and hindgut

Question 31

\_\_\_\_ is a yolk sac remnant off the distal ileum

Answer 31

Meckel's diverticulum is a yolk sac remnant off the distal ileum (can be sinus, fistula, cyst, or fibrous cord)

Question 32

Abdominal foregut is supplied by the \_\_\_\_, innervated by the \_\_\_\_, and ____ ventral mesentary

Answer 32

Abdominal foregut is supplied by celiac trunk, innervated by vagus nerve, and has ventral mesentary

Question 33

Midgut is supplied by the \_\_\_\_, innervated by the \_\_\_\_, and ____ ventral mesentary

Answer 33

Midgut is supplied by the superior mesenteric artery, innervated by the vagus nerve, and does NOT have ventral mesentary

Question 34

Hindgut is supplied by the \_\_\_\_, innervated by the \_\_\_\_, and ____ ventral mesentary

Answer 34

Hindgut is supplied by the inferior mesenteric artery, innervated by the pelvic splanchnic nerves, and does NOT have ventral mesentary

Question 35

Describr factors that complicate the abdominal plan

Answer 35

Factors that complicate the abdominal plain * Formation of the lesser peritoneal sac within the dorsal mesogastrium (greater omentum) * Growth of the greater omentum * Growth of the midgut * Looping of the midgut around the superior mesenteric artery * Rotation of the foregut / stomach 90 degrees to the right

Question 36

\_\_\_\_ bags out to the left as the stomach rotates and bounds the lesser sac

Answer 36

Dorsal mesogastrium bags out to the left as the stomach rotates and bounds the lesser sac

Question 37

\_\_\_\_\_ is the space behind the stomach, while the ____ bounded by parietal peritoneum

Answer 37

Lesser sac is the space behind the stomach, while the greater sac is the peritoneal cavity bounded by parietal peritoneum

Question 38

Lesser sac and greater sac communicate via the \_\_\_\_

Answer 38

Lesser sac and greater sac communicate via the epiploic foramen of Winslow

Question 39

At 2 months, the ____ falls to the right and the entrance to the lesser sac is now under \_\_\_\_

Answer 39

At 2 months, the liver / lesser omentum falls to the right and the entrance to the lesser sac is now under the free edge of the lesser omentum

Question 40

Natural ____ are called ligaments

Answer 40

Natural mesenteries are called ligaments * Coronary ligament, falciform, hepatogastric, hepatoduodenal, gastosplenic (gastrolienal), and splenorenal (lienorenal)

Question 41

\_\_\_\_ of mesenteries involve the transverse colon

Answer 41

Adhersion of mesenteries involve the transverse colon * Gastrocolic, phrenicocolic (suspensory ligament of the spleen), hepatocolic

Question 42

\_\_\_\_ are round ligaments of the liver and uterus and the ovarian ligament

Answer 42

Fibrous cords are round ligaments of the liver and uterus and the ovarian ligament

Question 43

Spleen separates the ____ and ____ ligaments

Answer 43

Spleen separates the gastrosplenal and splenorenal ligaments

Question 44

Lesser omentum is the ____ and ____ ligaments

Answer 44

Lesser omentum is the hepatoduodenal and hepatogastric ligaments

Question 45

Describe subdivision of the dorsal and ventral mesenteries

Answer 45

Subdivisions of the dorsal and ventral mesenteries

Question 46

\_\_\_\_ is second half of duodenum, jejunum, ileum, ascending colon, and most of transverse colon

Answer 46

Midgut is second half of duodenum, jejunum, ileum, ascending colon, and most of transverse colon

Question 47

\_\_\_ descends to complete the midgut loop by week 20

Answer 47

Large intestine descends to complete the midgut loop by week 20

Question 48

\_\_\_\_ is a congenital umbilical hernia of the midgut

Answer 48

Omphalocele is a congenital umbilical hernia of the midgut

Question 49

\_\_\_\_ is a midgut hernia due to ventral wall defect

Answer 49

Gastroschisis is a midgut hernia due to ventral wall defect (alongisde the umbilical cord, organs are bathed in amniotic fluid)

Question 50

Peritonealized organs develop in \_\_\_\_

Answer 50

Peritonealized organs develop in mesenteries * Stomach, intestines, liver, spleen, gall bladder, and uterus

Question 51

Primarily retroperitoneal organs are \_\_\_\_

Answer 51

Primarily retroperitoneal organs are superficial to parietal peritoneum * Kidneys, aorta, IVC, rectum, bladder, and vagina

Question 52

Secondary retroperitoneal organs are \_\_\_\_

Answer 52

Secondary retroperitoneal organs are pushed against the body wall so they appear retroperitoneal after growth of the midgut * Ascending colon * Descending colon * Pancreas * Duodenum

Question 53

\_\_\_\_, \_\_\_\_, \_\_\_\_, and ____ are secondarily retroperitoneal organs

Answer 53

Ascending colon, descending colon, pancreas, and duodenum are secondarily retroperitoneal organs

Question 54

Greater omentum is lifted to show the \_\_\_\_

Answer 54

Greater omentum is lifted to show the midgut (ascending and transverse colon and small intestine) (teniae coli and haustra in large intestine)

Question 55

Small intestine is pulled to the left to show the \_\_\_\_

Answer 55

Small intestine is pulled to the left to show the midgut loops

Question 56

Midgut is pulled to the right to show the \_\_\_\_

Answer 56

Midgut is pulled to the right to show the hindgut