SGU SVM Histology Digestive Embryology

hpaul2's version from 2016-11-16 17:19

Primative gut

Question Answer
What structure is incorporated into the embryo to form the primitive gut (transverse folding)endoderm lined yolk sac
What happens to the primitive gut during longitudinal foldingthe foregut, midgut, and hindgut are created
What part of the gut remains connected to the yolk sacmidgut
What connects the midgut to the yolk sacvitelline duct
What are the 5 sections of the gutstomodeum, foregut, midgut, hindgut, proctodeum
What membrane is created where the endoderm of the rostral foregut meets the stomodeumbucco-pharyngeal membrane
What membrane is created where the endoderm of the caudal hindgut meets the ectoderm of the stomodeumproctodeum cloacalmembrane
What are the ‘imaginary borders’ of the gutcranial and caudal intestinal portals
What re the borders of the stomodeumthe oral opening to the buccopharyngeal membrane
What are the borders of the foregutbuccopharyngeal membrane to cranial intestinal portal
What are the borders of the midgutcranial intestinal portal to caudal intestinal portal
What are the borders of the hindgutcaudal intestinal portal to cloacal membrane
What are the borders of the proctodeumcloacal membrane to external opening


Adult structures

Question Answer
What structure does the stomodeum becomemouth
What structures does the foregut becomepharynx, esophagus, stomach, & cranial duodenum
What structures does the midgut becomecaudal duodenum, jejunum, ileum, cecum, & cranial colon
What structures does the hindgut becomecaudal colon & rectum
What structures does the proctodeum becomeanal canal & anus


Question Answer
Which side of the stomach grows fastestdorsal side
What structures become the lesser and greater curvatureventral mesogas & dorsal mesogastrium (respectively)
What does the cranio-caudal rotation causegreater curvature shifts left
What does the dorsal ventral rotation causecaudal stomach shifts right and cranial
Where does the spleen and gastro-splenic ligament arise fromsplancnic mesoderm of mesogastrium
What are the curvatures in the ruminant stomachdorsal and ventral curvature
What does the central axis of the ruminant stomach becomegastric groove
Compare the size of the rumen & reticulum to the abomasum at birth, 8 weeks, and 12 weeksbirth – R&R ½ size of abomasum; 8 weeks- R&R equal to abomasum; 12 weeks- R&R 2x the abomasums
What part of the ruminant stomach grows the slowestomasum

Midgut & colon

Question Answer
What are the three parts of the colon in the ruminantascending, transverse, & descending
What side does the descending duodenum develop onright side
What sides does the descending colon develop onleft side
What digestive structures develop cranially and caudallycranial- distal duodenum, jejunum, part of ileum; caudal- lower ileum, cecum, ascending & part of transverse colon
What are the three parts of the ruminant ascending colonproximal, spiral,& distal loops
What loop of the small intestine grows more rapidly than the otherscranial loop
What are the parts of the spiral loop of the ruminant ascending colon2 centripetal turns, central flexure, 2 centrifugal turns
What are the parts of the spiral loop of the ascending colon of sheep and goats3 centripetal turns & 3 centrifugal turns
What are the parts of the equine ascending colonventral & dorsal ascending colon
What are the parts of the ventral & dorsal equine ascending colonleft & right ventral, left & right dorsal
What are the parts of the ascending colon in the pigcentripetal & centrifugal coils


Question Answer
Where does the urorectal septum occurjunction of hindgut & allantois
What causes the formation of the urorectal septumthickening of endoderm & mesenchyme
What does the urorectal septum divide the cloaca intodorsal rectum & ventral urogenital sinus
What happens to the urorectal septum when it reaches the cloacal membranebecomes dorsal anal membrane & ventral urogenital membrane
What is the tissue between and on the surface of the dorsal anal membrane & ventral urogenital membrane calledbetween – perineal body; surface – perineum
What two structures enlarge to form the bladderproximal allantois & cranial urogenital sinus
What is the remaining allantois calledand what happens to iturachus, degenerates
What structures degenerate to become continuous with the proctodeumanalmembrane & urogenitalmembranes
What arteries supply the foregut, midgut, and hindgutforegut- celiacartery, midgut-cranial mesenteric, hindgut- caudal mesenteric


Question Answer
What is intestinal stenosislocal narrowing
What is intestinal atresiaclosure
In what life stage does intestinal stenosis and atresia occureyoung
What isatresia anifailure of anal membrane to break down
What species does atresia ani occur incalves, pigs
Whatiscounter-rotation of gutbody organs develop opposite to normal position
What is urorectal fistual (calves)abnormal development of urorectal septum; communication b/w rectum & urogenital sinus
What is Meckel’s divericulumpersistence of vitello-intestinal duct
In what species does Meckel’s divericulum occurhorse and pig
What isomphalocelefailure of retraction of midgut loop (hernia)
Patent urachus (urachal fistula)Urachus remains open – urine excreted at umbilicus


Question Answer
Where does the liver develop fromterminal part of foregut
What tissue layer does hepatic diverticulum grow fromendoderm
What does the diverticulum divide intopars hepatica & pars cystica
What does the pars hepatica develop intoliver cords & hepatic ducts
What does the pars cystic develop intogall bladder & cystic duct
What tissue do the epithelial liver cords develop fromendoderm
What tissue do the hepatic sinusoids develop fromvitelline veins
What cells doe the liver cords differentiate intohepatocytes
What cells are derived from the mesodermkupffer cells & connective tissue cells
What tissue is the CT capsule and ligaments of the liver derived fromsplanchnic mesoderm


Question Answer
Where does the pancreas form frombuds of the gut endoderm
What bud forms the left lobe of the pancreasdorsal pancreatic bud
What bud forms the right lobe of the pancreasventral pancreatic bud
What duct does the dorsal pancreatic duct formaccessory pancreatic duct
What duct does the ventral pancreatic duct formpancreatic duct
Where does the pancreatic duct open into the duodenum along with what structuremajor duodenal papilla; bile duct
Which species have a large accessory pancreatic ductdog, ox, pig
Which species have a small accessory pancreatic ducthorse, cat
Which species have no accessory pancreatic ductsheep, goat
Which species have a large pancreatic ducthorse, cat, sheep, goat
Which species have a small pancreatic ductdog
Which species have no pancreatic ductox, pig
What does the endodermal epi. of the pancreatic diverticulum becomesecretory pancreatic cacini & pancreaticislets