Embryology: The Digestive System

Question 1

Fate Map: visceral layer of lateral plate mesoderm

Answer 1

visc layer mesoderm>

serous membranes+ dorsal mesentery + spleen

Question 2

spleen arises from

Answer 2

mesogastrium (dorsal mesentry of stomach)

lateral plate mesoderm, visceral layer

Question 3

dorsal mesentry arises from

Answer 3

visceral layer of lateral plate mesoderm

originally a suspensory ligament between the gut tube and dorsal body wall

Question 4

descending colon arises from

Answer 4

hindgut

Question 5

sigmoid colon arises from

Answer 5

hindgut

Question 6

rectum arises from

Answer 6

proximal portion: hindgut

distal portion: ectoderm

Question 7

fate map: midgut

Answer 7

midgut>
midgut loop>
herination into umbilical cord>
270 counterclockwise rotation>
small intestines + ascending colon + transverse colon

Question 8

small intestines arises from

Answer 8

*mostly midgut

proximal 1/3 of duodenum- foregut

Question 9

ascending colon arises from

Answer 9

midgut

Question 10

gall bladder arises from

Answer 10

foregut-
bile duct>
cystic diverticulum>
gall bladder

Question 11

cystic diverticulum is

Answer 11

def: a foregut intermediary between the bile duct and gall bladder

Question 12

liver arises from

Answer 12

foregut, hepatic diverticulum which grows in the dorsal mesentry

Question 13

bile duct arises from

Answer 13

foregut, hepatic diverticulum

Question 14

greater omentum arises from

Answer 14

growth of dorsal mesentery of stomach

Question 15

proximal duodenum arises from

Answer 15

foregut

Question 16

esophagus arises from

Answer 16

foregut

Question 17

stomach arises arises from

Answer 17

foregut

Question 18

pancreas arises from

Answer 18

foregut

Question 19

fate map: stomach

Answer 19

1. expansion of caudal foregut (greater sac)
2. longitudinal rotation:
   a. greater and lesser curvature
   b. spleen swings left
   c. liver swings right
3. ant/ post. rotation:
   a. fundus moves left and inferiorly
   b. pyloris moves right and superiorly

Question 20

spleen divides the dorsal mesentry of the stomach into ___ and ___ ligaments

Answer 20

splenorenal ligament

gastroplenic ligament

Question 21

lesser sac (omental bursa)

Answer 21

arises from: peritoneal space

def: the space posterior to the stomach after it completes its rotation

Question 22

greater sac

Answer 22

arises from: peritoneal space

def: space anterior to the stomach, grows into the greater omentum

Question 23

epiploic foramen

Answer 23

def: a communication between the greater and lesser sacs located near the hilum of the liver

Question 24

uncinate process of the pancreas arises from

Answer 24

ventral pancreatic bud

Question 25

tail of pancreas

Answer 25

dorsal pancreatic bud

Question 26

fate map: duodenum 1 2. 3.

Answer 26

1. foregut forms 2. long & coronal rotation of stomach: pull duodenum into a C-shape around the head of the pancreas 3. the duodenum is pressed against the dorsal body wall: it becomes secondarily retroperitoneal

Question 27

fate map: pancreas 1. 2. 3.

Answer 27

1. two buds form a. ventral pancreatic bud forms from bile duct b. dorsal pancreatic bud forms in foregut 2. rotation of duodenum: ventral bud rotates and meets with dorsal pancreatic bud 3. compression against dorsal body wall: secondarily retroperitoneal

Question 28

``` fate map: liver and gall bladder 1. 2. 3. 4. 5. ```

Answer 28

event: structure (s) 1. outgrowth of ventral foregut: liver bud 2. differentiation a. parenchyma- arise from liver bud b. connective tissue: aries from septum transversum 3. narrowing of foregut connection: bile duct formation 4. outgrowth of bile duct: cystic diverticulum> gall bladder 5. growth of liver: a. ventral mesentry is divided into hepatogastric ligament, hepatodudoneal ligament c. falciform ligament (connection to abdominal walll

Question 29

falciform ligament arises from

Answer 29

arises from: ventral mesentry due to: growth of the liver bud def: connects liver to abdominal wall

Question 30

hepatogastric ligament arises from

Answer 30

arises from: ventral mesentry due to: growth of the liver bud def: connects liver to stomach

Question 31

hepatodudoneal ligament

Answer 31

arises from: ventral mesentry due to: growth of the liver bud def: connects the liver to the duodenum

Question 32

``` fate map: midgut 1. 2. 3. 4. 5. 6. 7. 8. ```

Answer 32

1. elgonation: U-shaped midgut loop 2. herniation into umbilical chord 3. rotation (counterclockwise about SMA)- cranial limb towards right, caudal limb towards the left and develops cecal bud 4. retraction 5. rotation 2: 180 about SMA, cranial limb becomes located to the left, caudal limb to the right 6. ascent of colon: decum and appendix are displaced in the lower right quadrant 7. regression of vitelline duct 8. retroperitoneal formation of ascending/ descending colon

Question 33

vitelline duct

Answer 33

def. connects the midgut loop to the yolk sac during development

Question 34

caudal limb of midgut loop

Answer 34

most of large intestine

Question 35

crandial limb of midgut loop

Answer 35

most of small intestine

Question 36

subperitoneal structures

Answer 36

rectum

Question 37

intraperitoneal structures

Answer 37

``` stomach transverse colon sigmoid colon appendix cecum ```

Question 38

retroperitoneal, secondary structures

Answer 38

ascending colon | descending colon

Question 39

ventral mesentry

Answer 39

mesentry (lateral plate structure) that only forms in the abdominal foregut forms the lesser omentum & falciform ligament

Question 40

innervation: foregut

Answer 40

Sympathetic: Greater Splachnic Nerve celiac ganglion (T5-T9) Parasympathetic: Vagus Nerve (CN X)

Question 41

innervation: midgut

Answer 41

Sympathetic: lesser and least splachnic nerves superior mesenteric ganglion(T10-T12) Parasympathetic: Vagus Nerve (CN X)

Question 42

innervation: hindgut

Answer 42

Sympathetic: lumbar splachnic nerves (L1-L2) inferior mesenteric ganglion Parasympathetic: Pelvic Splanchnic nerves (S2-S4)

Question 43

vascular: foregut

Answer 43

celiac trunk

Question 44

vascular: midgut

Answer 44

superior mesenteric artery

Question 45

vascular: hindgut

Answer 45

inferior mesenteric artery