1.01 Embryonic/Fetal GI Flashcards
When does cranial/caudal and lateral folding take place and what do they form?
Week 4
cranial = foregut
lateral = midgut
caudal= hindgut
Dorsal and ventral mesentery remnants as related to the peritoneal cavity development correspond to what adult structures?
Primary (dorsal) and secondary (ventral) retroperitoneal organs
Embryonic diaphragm is made up of what?
Septum transversum (central tendon)
Pleuroperitoneal membranes
Dorsal mesentery of esophagus
Muscular ingrowth lateral walls
When do the primordial gut tube membranes rupture?
Week 4 - oropharnyngeal
Week 7 - cloacal
What kind of tissue are the gut structures, epithelium at gut tube, and glands derived from?
Endoderm
What kind of tissue are the stomodeum and anal pit that lead to epithelium at either end of the gut tube derived from?
Ectoderm
What is the blood supply to the foregut?
Celiac trunk
What are the derivatives of the foregut?
Primordial pharynx
Lower respiratory system
Esophagus
Stomach
Duodenum
Liver, biliary, and pancreas
When is the lumen for the esophagus recanalized?
Week 8 (End)
How does the stomach grow starting as a slight dilation of the foregut at Week 4?
Ventrodorsally (dorsal end faster) 90 clockwise
What sides of the stomach correspond to the ventral and dorsal stomach?
Ventral = left stomach
Dorsal = right stomach
What landmark marks the separation of blood supply and the foregut from the midgut?
Duodenal papilla
Where is the foregut in relation to the duodenal papilla?
Proximal
Where is the midgut relative to the duodenal papilla?
Distal
What is the midgut blood supply?
Superior mesenteric artery (SMA)
When is the duodenum recanalized?
Week 8 End of (like the esophagus)
Where does the duodenal loop go with the rotation of the stomach?
Retroperitoneal
What is the cranial and caudal breakdown of the hepatic diverticulum that develops between week 5-10?
Cranial = liver primordium
Caudal = gallbladder
When does hematopoiesis and bile formation become functional in development?
Week 6 & Week 12
What gives newborn meconium its dark green color?
Bile that first enters the duodenum in week 13
What tissue makes up the fibrous and hematopoietic tissue of the liver?
Mesoderm
What are the adult derivatives of the midgut?
Small intestine (distal duodenal papilla) = jejunum + ileum
Large intestine = cecum, appendix, ascending colon, proximal 2/3 transverse colon
What causes the physiological umbilical herniation at week 6?
Midgut growing ventrally to make the umbilical cord
What is the midgut rotation order? Total?
270 counter clockwise
90 - cranial - right
90 - caudal - right
90 - caudal - left
The additional rotation often large intestine to bring cecum to the RLQ pushes what two structures back to become secondary retroperitoneal?
Pancreas and duodenum
What are the adult derivatives of the hindgut?
Large intestine (distal 1/3 transverse colon, descending colon, sigmoid colon)
Urinary bladder epithelium
Urethra
What gives rise to the rectum, bladder, and primordial genitalia?
cloaca
What separates the cloaca into the urogenital sinus, rectum, and anal canal?
Urorectal septum
What connects to the cloaca ventrally?
Allantois
What part of anal canal is derived from the hindgut endoderm?
Superior 2/3
What part of the anal canal makes up the anal pit from ectoderm?
Inferior 1/3
What is the supply and innervation of the superior anal canal?
Superior rectal artery and autonomics
What is the supply and innervation of the inferiority anal canal?
Inferior rectal aa. And inferior rectal nerve
What separates the anal canal, where is it, and how can you tell?
Pectinate line
Inferior border of anal folds
Epithelium columnar —> stratified squamous
What does the primordial gut tube come from?
Endoderm from the umbilical vesicle
The bladder epithelium and urethra are derived from what?
Hindgut
The intraembryonic coelom folds into what embryonic body cavities?
Pericardial cavity
Two pericardialperitoneal canals
Peritoneal cavity
