Embryology: The Digestive System Flashcards
1. Describe the formation of the gut tube through longitudinal and lateral folding 2. describe the effect of rotations on the placement and peritoneal relationship of the abodominal organs, and spaces within the abodminal cavity in the adult 3. describe the vascular and nerve supply of adult derivatives of each region of the gut tube
Fate Map: visceral layer of lateral plate mesoderm
visc layer mesoderm>
serous membranes+ dorsal mesentery + spleen
spleen arises from
mesogastrium (dorsal mesentry of stomach)
lateral plate mesoderm, visceral layer
dorsal mesentry arises from
visceral layer of lateral plate mesoderm
originally a suspensory ligament between the gut tube and dorsal body wall
descending colon arises from
hindgut
sigmoid colon arises from
hindgut
rectum arises from
proximal portion: hindgut
distal portion: ectoderm
fate map: midgut
midgut> midgut loop> herination into umbilical cord> 270 counterclockwise rotation> small intestines + ascending colon + transverse colon
small intestines arises from
*mostly midgut
proximal 1/3 of duodenum- foregut
ascending colon arises from
midgut
gall bladder arises from
foregut-
bile duct>
cystic diverticulum>
gall bladder
cystic diverticulum is
def: a foregut intermediary between the bile duct and gall bladder
liver arises from
foregut, hepatic diverticulum which grows in the dorsal mesentry
bile duct arises from
foregut, hepatic diverticulum
greater omentum arises from
growth of dorsal mesentery of stomach
proximal duodenum arises from
foregut
esophagus arises from
foregut
stomach arises arises from
foregut
pancreas arises from
foregut
fate map: stomach
- expansion of caudal foregut (greater sac)
- longitudinal rotation:
a. greater and lesser curvature
b. spleen swings left
c. liver swings right - ant/ post. rotation:
a. fundus moves left and inferiorly
b. pyloris moves right and superiorly
spleen divides the dorsal mesentry of the stomach into ___ and ___ ligaments
splenorenal ligament
gastroplenic ligament
lesser sac (omental bursa)
arises from: peritoneal space
def: the space posterior to the stomach after it completes its rotation
greater sac
arises from: peritoneal space
def: space anterior to the stomach, grows into the greater omentum
epiploic foramen
def: a communication between the greater and lesser sacs located near the hilum of the liver
uncinate process of the pancreas arises from
ventral pancreatic bud
tail of pancreas
dorsal pancreatic bud
fate map: duodenum
1
2.
3.
- foregut forms
- long & coronal rotation of stomach: pull duodenum into a C-shape around the head of the pancreas
- the duodenum is pressed against the dorsal body wall: it becomes secondarily retroperitoneal
fate map: pancreas
1.
2.
3.
- two buds form
a. ventral pancreatic bud forms from bile duct
b. dorsal pancreatic bud forms in foregut - rotation of duodenum: ventral bud rotates and meets with dorsal pancreatic bud
- compression against dorsal body wall: secondarily retroperitoneal
fate map: liver and gall bladder 1. 2. 3. 4. 5.
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
falciform ligament arises from
arises from: ventral mesentry
due to: growth of the liver bud
def: connects liver to abdominal wall
hepatogastric ligament arises from
arises from: ventral mesentry
due to: growth of the liver bud
def: connects liver to stomach
hepatodudoneal ligament
arises from: ventral mesentry
due to: growth of the liver bud
def: connects the liver to the duodenum
fate map: midgut 1. 2. 3. 4. 5. 6. 7. 8.
- elgonation: U-shaped midgut loop
- herniation into umbilical chord
- rotation (counterclockwise about SMA)- cranial limb towards right, caudal limb towards the left and develops cecal bud
- retraction
- rotation 2: 180 about SMA, cranial limb becomes located to the left, caudal limb to the right
- ascent of colon: decum and appendix are displaced in the lower right quadrant
- regression of vitelline duct
- retroperitoneal formation of ascending/ descending colon
vitelline duct
def. connects the midgut loop to the yolk sac during development
caudal limb of midgut loop
most of large intestine
crandial limb of midgut loop
most of small intestine
subperitoneal structures
rectum
intraperitoneal structures
stomach transverse colon sigmoid colon appendix cecum
retroperitoneal, secondary structures
ascending colon
descending colon
ventral mesentry
mesentry (lateral plate structure) that only forms in the abdominal foregut
forms the lesser omentum &
falciform ligament
innervation: foregut
Sympathetic:
Greater Splachnic Nerve
celiac ganglion (T5-T9)
Parasympathetic: Vagus Nerve (CN X)
innervation: midgut
Sympathetic:
lesser and least splachnic nerves
superior mesenteric ganglion(T10-T12)
Parasympathetic: Vagus Nerve (CN X)
innervation: hindgut
Sympathetic:
lumbar splachnic nerves (L1-L2)
inferior mesenteric ganglion
Parasympathetic: Pelvic Splanchnic nerves (S2-S4)
vascular: foregut
celiac trunk
vascular: midgut
superior mesenteric artery
vascular: hindgut
inferior mesenteric artery