Severson: Gastrointestinal System Flashcards
The developing gut can be divided into the…
foregut
midgut
hindgut
What binds the cephalic end of the gut?
oropharyngeal membrane
What binds the caudal end of the gut?
cloacal membrane
The lining of the digestive system and its related gland develop from…
endoderm
The stomodeum and the proctodeum are lined by…
ectoderm
Skeletal muscle of the oropharynx and upper esophagus are derived from…
brachial arch mesoderm (4th and 6th arches)
Smooth muscle and CT of the GI tract develop from…
splanchnic mesoderm
The nervous component of the GI tract develops from…
Neural crest cells that migrate into the developing GI tract
What innervates the left colic flexure?
Vagus nerve (parasympathetic)
What innervates all but the left colic flexure?
pelvic splanchnic nerves (parasympathetic)
What is esophageal stenosis?
Narrowing d/t incomplete recanalization of the esophagus during development (epithelial cells persist)
What causes esophageal atresia?
Defective tracheoesophageal septum
What causes polyhydraminos?
esophageal atresia and stenosis (regurgitation and choking after birth when drinking milk)
What is tracheoesophageal fistula?
incomplete separation of the trachea from the esophagus (defective tracheoesophageal septum) that can lead to respiratory distress
What is a congenital hiatal hernia?
If the esophagus fails to lengthen the stomach can be drawn up into the thorax
What is the blood supply to the foregut? Midgut? Hindgut?
celiac artery (except pharynx and esophagus)
Superior mesenteric aretery
Hindgut Inferior mesenteric artery
How does the parasympathetic nerve supply differ between the three parts of the primitive gut?
foregut and midgut = vagus
hindgut= pelvic splanchnic
pharnyx, esophagus, stomach, upperduodenum, glands of pharyngeal pouches, thyroid, respiratory tract, liver, gallbladder and pancreas come from what part of the primitive gut?
foregut
Lower duodeum, jejunum, ileum, cecum, appendix, ascending and R1/2, and transverse colon come from waht part of the primitive gut?
midgut
The L 1/2 of the transverse colon, descending colon, sigmoid colon, rectum and superior anal canal come from what part of the primitive gut?
hindgut
What suspends the distal esophagus, stomach and proximal duodenum from the dorsal wall?
dorsal mesentery
The ventral mesentery is derived from…
the transverse septum
What connects the distal esophagus, stomach and proximal duodenum to the ventral wall?
Ventral mesentery
What encircles the liver and forms its visceral peritoneum?
ventral mesentery
What forms the lesser omentum?
Ventral mesentery between the stomach and first part of the duodenum
What forms the falciform ligament?
ventral mesentery between the liver and the ventral body wall
What passes in the free border of the falciform ligament?
umbilical vein
What important rotation occurs in the GI tract during development?
90 degree rotation of the stomach brings the GREATER CURVATURE to the left and the LESSER CURVATURE to the right
What becomes the ventral surface of the stomach and what nerve supplies it?
original left side
left vagus nerve
What becomes the dorsal surface of the stomach and what nerve is it supplied by?
Original right side
right vagus nerve
What forms the greater omentum?
Dorsal mesentery (grows rapidly and enlarges the omental bursa which is eventually obliterated)
What forms the gastrocolic ligament?
Dorsal mesogastrium and the transverse mesocolon fused together
Where is the gastrocolic ligament located?
between the stomach and the transverse colon