The Abdomen: Gut Embryology Flashcards
Parietal peritoneum origin
Somatic mesoderm
Visceral peritoneum origin
Splanchnic mesoderm
What structure does the intra-embryonic mesoderm give rise to?
Peritoneal cavity
The dorsal mesentery suspends which areas of the gut?
Foregut, midgut, and hindgut
Innervation to midgut
Sympathertic motor: Least splanchnic nerve (superior mesenteric ganglion)
Parasymp motor: Vagus
Sensory: Enteric nervous system
Which area of the gut is suspended by ventral mesentery?
Foregut
Match the ligaments to the associated mesentery and gut area:
Foregut
Mesocolon (transverse, ascending, descending)
Lienorenal
Midgut
Falciform ligament
Lesser omentum
Hepatogastric
Hepatoduodenal
Hindgut
Mesoduodenum
Greater omentum
Gastrosplenic
Ligamentum teres
Dorsal mesentery:
Foregut: greater omentum; gatsrosplenic, lienorenal,mesodueodenum
Midgut/Hindgut: Mesocolon (transverse, ascending, descending)
Ventral mesentery:
Foregut: lesser omentum (hepatogastric, hepatoduodenal), Ligamentum teres, falciform ligament
List the location of the following ligaments in the gut and or what they connect:
Greater omentum
Gastrosplenic ligament
Mesocolon
Lienorenal ligament
Falciform Ligament
Lesser omentum
Ligamentum teres
Greater omentum, gastrosplenic, lienoral ligaments all belong to the foregut.
Greater omentum: Curtain over the entire abdomen
Gastrosplenic: stomach and spleen
Lienorenal (“spleeno”-renal): kidney and spleen
The mesoduodenum belongs to both the mid and hindguts. It connects the duodenum to posterior abdomnal wall
Falciform ligament, Lesser omentum, and ligamentum teres are all foregut ligaments.
Falciform ligament: connects liver to the anterior abdominal wall
Lesser omentum: connects liver to stomach (hepatogastric), and liver to duodenum (hepatoduodenal)
Ligamentum teres: connects the liver to the umbilicus
Innervation to the foregut
Sympathetic motor: Greater splanchnic (celiac ganglion)
Parasympathetic motor: Vagus
Sensory: Enteric nervous system
Innervation to hindgut
Symp motor: least splanchnic nerve (inferior mesenteric ganglion)
Parasymp motor: S2,S3,S4 (pelvic splanchnic)
Sensory: Enteric Nervous System
Foregut Organ/Origin/Associated Ligament (s)
Stomach/___\_/___\_ (3x)
___\_/___\_/Hepatogatsric + 2 others
Duodenum/___\_/____\_
____\_/dorsal and ventral buds/___\_
Gall bladder/___\_/___\_
Stomach/Dilation of the gut tube (longitudinal and anteroposterio rotations)/hepatogastric (lesser omentum); greater omentum; gastrosplenic
Liver/Hepatic diverticulum/hepatogatsric, hepatoduodenal, falciform
Duodenum/distal extension of stomach/hepatoduodenal
Pancreas/Dorsal and ventral pancreatic buds/none
Gall bladder/outgrowth of the bile duct/none
3 steps of midgut development
- Elongation
- Rotation
- Retraction
Describe the elongation step of midgut development. At what stage in fetal development does this occur (in terms of weeks?)
a. Formation of primary intestinal loop
b. Umbilical herniation (when guts herniate into the umbilicus)
Week 5
What structures arise from the cephalic and caudal portions of the primary intestinal loop?
Cephalic: upper part of ileum; duodenum and jejunum (basically the small intestines)
Caudal: lower part of ileum; appendix, cecum; ascending colon; 2/3 of transverse colon
Around what important blood vessel does the primary intestinal loop rotate during midgut development?
What issue may arise from occlusion of this blood vessel?
What structures arise during the rotation step?
What tendinous structures can you follow from the colon to lead you to the appendix?
The SMA: Superior Mesenteric Artery
Intestinal atresia (e.g. Apple peel atresia) resulting in severe underdevelopment of intestines
Cecum and Appendix
Taenia coli
