1.01 Embryonic/Fetal GI

Question 1

When does cranial/caudal and lateral folding take place and what do they form?

Answer 1

Week 4
cranial = foregut
lateral = midgut
caudal= hindgut

Question 2

Dorsal and ventral mesentery remnants as related to the peritoneal cavity development correspond to what adult structures?

Answer 2

Primary (dorsal) and secondary (ventral) retroperitoneal organs

Question 3

Embryonic diaphragm is made up of what?

Answer 3

Septum transversum (central tendon)
Pleuroperitoneal membranes
Dorsal mesentery of esophagus
Muscular ingrowth lateral walls

Question 4

When do the primordial gut tube membranes rupture?

Answer 4

Week 4 - oropharnyngeal
Week 7 - cloacal

Question 5

What kind of tissue are the gut structures, epithelium at gut tube, and glands derived from?

Answer 5

Endoderm

Question 6

What kind of tissue are the stomodeum and anal pit that lead to epithelium at either end of the gut tube derived from?

Answer 6

Ectoderm

Question 7

What is the blood supply to the foregut?

Answer 7

Celiac trunk

Question 8

What are the derivatives of the foregut?

Answer 8

Primordial pharynx
Lower respiratory system
Esophagus
Stomach
Duodenum
Liver, biliary, and pancreas

Question 9

When is the lumen for the esophagus recanalized?

Answer 9

Week 8 (End)

Question 10

How does the stomach grow starting as a slight dilation of the foregut at Week 4?

Answer 10

Ventrodorsally (dorsal end faster) 90 clockwise

Question 11

What sides of the stomach correspond to the ventral and dorsal stomach?

Answer 11

Ventral = left stomach
Dorsal = right stomach

Question 12

What landmark marks the separation of blood supply and the foregut from the midgut?

Answer 12

Duodenal papilla

Question 13

Where is the foregut in relation to the duodenal papilla?

Answer 13

Proximal

Question 14

Where is the midgut relative to the duodenal papilla?

Answer 14

Distal

Question 15

What is the midgut blood supply?

Answer 15

Superior mesenteric artery (SMA)

Question 16

When is the duodenum recanalized?

Answer 16

Week 8 End of (like the esophagus)

Question 17

Where does the duodenal loop go with the rotation of the stomach?

Answer 17

Retroperitoneal

Question 18

What is the cranial and caudal breakdown of the hepatic diverticulum that develops between week 5-10?

Answer 18

Cranial = liver primordium
Caudal = gallbladder

Question 19

When does hematopoiesis and bile formation become functional in development?

Answer 19

Week 6 & Week 12

Question 20

What gives newborn meconium its dark green color?

Answer 20

Bile that first enters the duodenum in week 13

Question 21

What tissue makes up the fibrous and hematopoietic tissue of the liver?

Answer 21

Mesoderm

Question 22

What are the adult derivatives of the midgut?

Answer 22

Small intestine (distal duodenal papilla) = jejunum + ileum
Large intestine = cecum, appendix, ascending colon, proximal 2/3 transverse colon

Question 23

What causes the physiological umbilical herniation at week 6?

Answer 23

Midgut growing ventrally to make the umbilical cord

Question 24

What is the midgut rotation order? Total?

Answer 24

270 counter clockwise
90 - cranial - right
90 - caudal - right
90 - caudal - left

Question 25

The additional rotation often large intestine to bring cecum to the RLQ pushes what two structures back to become secondary retroperitoneal?

Answer 25

Pancreas and duodenum

Question 26

What are the adult derivatives of the hindgut?

Answer 26

Large intestine (distal 1/3 transverse colon, descending colon, sigmoid colon) Urinary bladder epithelium Urethra

Question 27

What gives rise to the rectum, bladder, and primordial genitalia?

Answer 27

cloaca

Question 28

What separates the cloaca into the urogenital sinus, rectum, and anal canal?

Answer 28

Urorectal septum

Question 29

What connects to the cloaca ventrally?

Answer 29

Allantois

Question 30

What part of anal canal is derived from the hindgut endoderm?

Answer 30

Superior 2/3

Question 31

What part of the anal canal makes up the anal pit from ectoderm?

Answer 31

Inferior 1/3

Question 32

What is the supply and innervation of the superior anal canal?

Answer 32

Superior rectal artery and autonomics

Question 33

What is the supply and innervation of the inferiority anal canal?

Answer 33

Inferior rectal aa. And inferior rectal nerve

Question 34

What separates the anal canal, where is it, and how can you tell?

Answer 34

Pectinate line Inferior border of anal folds Epithelium columnar —> stratified squamous

Question 35

What does the primordial gut tube come from?

Answer 35

Endoderm from the umbilical vesicle

Question 36

The bladder epithelium and urethra are derived from what?

Answer 36

Hindgut

Question 37

The intraembryonic coelom folds into what embryonic body cavities?

Answer 37

Pericardial cavity Two pericardialperitoneal canals Peritoneal cavity