Embryology Flashcards
derivatives for foregut
esophagus stomach liver gallbladder proximal duodenum
artery of foregut
celiac trunk
derivatives of midgut
dustal duodenum jejenum ileum cecum\appendix ascending colon proximal transverse colon
artery of mid gut
Superior mesentric
Derivatives of hindgut
distal transverse colon descending colon sigmoid colon rectum proximal anus
arery of hindgut
Inferior mesentric
Spleen develops from
mesoderm
Lung bud appears at
4th week
esophagus reaches its final length in
7th week
Epthelium and glands of esophagus develop from
Endoderm
Recanalization of esophagus occurs by
8th week
Striated muscle of esophagus is derived from
Mesenchyme of pharyngeal arches
Smooth muscle of esophagus is dervied from
Splanchnic mesenchyme
Esophageal atersia occurs from
Deviation of the tracheoesophageal spetum posteriorly or from failure of recanalization
results in polyhyrdoamnios
Esophageal stenosis occurs in the
distal 3rd due incomplete recanalization or failkure of blood vessels to develop
Congintal hiatal hernia is due to
short esophagus, leadsa to stomach herniating into thorax
Slight dilation of stomach occurs in
middle 4th week
Which border of stomach develops faster
Doral border -greater curvature
Rotation of stomach
90 degrees clockwise longt axis
Omental bursa if formed by
Dorsal mesogastrium
Hypertrophic pyloric stenosis
Marked muscular thickening of the pylorus (mostly circular muscle)
leads to projectile vomiting
Duodenum develops in
4th week
Lumen of duodenum is obliteraed in
5th and 6th weeks
Duodenal stenosis involves
horizontal (3rd)
ascending (4th) parts
bile containing vomit happens
Duodenal atrersia occurs at
hepatopancreatic ampulla
AR inheritience
Double bubble
Duodenal atresia
Liver and bilary organs develope in
4th week
Mass of splanchnic mesoderm between developing heart and midgut
Spetum transversum
Cranial part of hepatic diverticulum forms
Liver
Hpeatic cords and epithelial linig of bilary apparatus develops from
endoderm
Hempatopoeituc tissue and kuppferr cells derived from
septum trasversum
Liver enlarges during
5th-10th week
Hematopoesis in liver begins in
6th week
Liver forms 10% weight of fetus in
9th week
Bile formation begins in
12th week
Caudal part of hepatic diverticulat forms
gallbladder
stalk od diverticulum forms
cystic duct
Bile duct is formed from
Stalk connecting hepatic and cystic ducts to the duodenum
Ventral mesentry forms
lesser omentum
falciform ligament
visceral peritoneum of liver
Most common form of extrahepatic bilary atersia is
Obliteration of bile ducts at or superior to prota hepatis
Jaundice occurs with clay coloured stools
Dorsal pancreatic bud forms
Part of head
neck
body
Ventral pancreatic duct forms
Uncinate process
inferior part of head
Main pancreatic duct is formed by
fusion of DISTAL doral duct and ventral duct
assecory pancreatic duct is formed by
proximal part of dorsal duct
Parenchyma of pancreas develops from
endoderm of pancreatic buds which form network of tubules
Pancreatic acini develop from
cell clusters around the dns of primordial pancreatic ducts
Pancreatic islets develop from
groups of cells that seperate tubules
Insulin secretion begins in
10th weeks
Glucagon is released at
15th weeks
connective tissue and speta of pancreas develop from
splanchnic mesenchyme
Annular pancreas
due to growth of bifid ventral pancreatic bud
Spleen is derived from
Mass of mesenchymal cells between layers od dorsal mesogastrium
Spleen begins to develop in
5th week
spleen acquires its shape in
fetal period
Notches in the superior border of spleen are remnants of
Grooves seperating fetal lobules
Capsule, CT amd parencyma of spleen are derived from
mesenchymal cells of splenic primordium
Hematopeosis in spleen occurs in
8th week-birth
Accesory spleens occur where
Hilum iof spleen
tail of pancreas
gastrosplenic ligament
Physiological umblical herniation occuers in
6th week
Lopp communicates with the yolk stalk until
10th week
Roation od mid gut in umblical cord
90 degrees counter clockwise around axis of superior mesentric
Intestines return to abdomen in
10th week
Large intestine rotation while returning
180 degrees counterclockwise
Cecal bud appears in
6th week
Omphalocele
non return of midcut in the abdomen
causes pulmonary and thoracic hypoplasia
Omphalocele is covered by
epithelium of umblical cord
Umblical hernia
greater omentum and part of small intestine herniate through an imperfectly closed umblicus
normal until 3-2 years
Umblical hernia is covered by
Subcutaneous tissue and skin
Gastroschisis
Extrusion of viscera without involving the umblical cord due to split in ant abdomimal wall into the amniotic cavity
Nonrotation of midgut
Cecum lies below pylorus and causes duodenal obstruction
Midgut volvulis
Twisting of the the midgut due to improperly positioned intestines may cause obstruction of superior mesentric artery leading to infarction and gagrene of intestine
present with bile vomit
Reversaed rotation
Midgut rotates clockwise
duodenum lies anterior to superior mesentric instead of transverse colon
small intestine lies on the left
Subhepatic cecum and appendix
Cecum adheres tominferior surface of liver when it returns to the abdomen
causes problems while appendicitis
Mobile Cecum
May herniate into the right inguinal canal
Is due to incomplete fixation of ascending colon
may cause volvulus
Internal hernia
Small intestine passed into the mesentry of midgut during return of the intestines
no symptoms
Stenosis/atresia of small intestine
Most often in ileum and duodenum
incomplete recanalization or infarction
most often occurs during 10th week
Ileal Diverticulum (Meckels)
Most common anomaly may cause symptoms mimicking appendicitis
Cloaca
Endoerm lined chamber in contact with surface ectoderm at cloacal membrane
endoderm of cloaca
ectoderm of proctoderm or anal pit
Dorsal Part of cloaca forms
Rectum and anal canal (7th week)
Vnetral part of cloaca forms
Urogenital sinus
Megacolon (Hirshsprung idsease)
Aganglionosis in the distal bowek
failure of neural crest cells to migrate into wall of colon during 5th-7th weeks
Imperforate anus
Incomplete seperation of of cloaca
Anal membrane perforates in
8th week
most common anorectal anomaly
Anorectal agenensis
causes [assage of muconium in urine
