GI embryology And Histology Flashcards
what does the foregut enclose and what is it supplied by and innnervation
Oesophagus liver, stomach, part of duodenum and spleen, supplied by coeliac trunk
Greater splanchnic
midgut encompasses and vasculature and innervation
1/2 of dueodenum , jejunum and ileum to 2/3 of transverse colon , by Sma lesser splanchnic
hindgut and vasculature and innervation
1/3 of transerve colon to anal canal
Supplied by ima
Least splanchnic
where is visceral pain felt in the foregut
epigastric region
mesentries of theforegut
dorsal and ventral
What happens in elongation
the vitaline duct grows and growth of mesentary
loops - primary intestinal loop
where is the caudal limb
distal part of ileum
Histology of lips and tongue
Outer lips highly keratinised
Inner less
Ventral tongue non keratanising squamous epithelium
Dorsal tongue is keratinised
Histology of Oesophagus
Stratified squamous non keratanising
Histology of stomach
Simple Columnar
Histology of Small and large intestine, rectum and Anus
Small simple columnar with crypts and villi
Colon is simple columnar and rectum
Anal canal stratified squamous
Duodenum histology
Few pilcae circulares
Few goblet cells
Long crypts
Histology of jejunum
Close packed pilcae circulares
Many goblet cells
Short crypts
Colon histology
All looks the same
No villi
Muscularis externa , into three longitudinal bands
How would stomach cells stain
Parietal cells are cuboidal with a dark standing nucleus
Chief cells would stain purple with blue nucleus
What are tastebuds
Peripheral chemoreceptors in the epithelium of upper / dorsal surface of the tongue , soft palate as well as pharynx
Function of a tastebud
Transduction of a chemical stimuli into a nervous signal
How many types of taste buds
4
Nerves involved in innervating the taste buds
Facial
Glossopharangyeal
Vagus
Facial nerve and taste buds
Innervates anterior 2/3 on tongue
Glossopharangyeal and taste buds
Posterior 1/3 on tongue
Vagus nerve and tastebuds
Epiglottis region and pharanygeal
From what germ layer does the gt system form
Endoderm
Midgut development
Rapid elongation makes the 1 intestinal loop
Rotates and herniates due to lack of space in abdom cavity
It then retracts as there is more space ( 3 months. )
Development of stomach and Oesophagus and innervation
Cn10
Endoderm
Expansion of primitive gut tube makes the Oesophagus
Stomach rotates 90*
Growth of posterior stomach gives rise to greater curvature
What does the dorsal mesentery of the stomach become
Greater omentum
Embryology of pancreas
Originated as two buds Dorsal - neck body , tail part of head Ventral - uncinate process part of head Buds undergo rotation , Exocrine and endocrine cells are a foregut derivative
Histology of exocrine pancreas
Serous acinar , simple epithelium
Lobulated connective tissues that stains dark
Beta cells stain blue by aldehyde fuchsin
Ducts of pancreas epithelia
Simple columnar epithelia
Histology of sinusoids
Lined with endothelial cells and flanked by plates of hepatocytes
Portal triad histology
Wrapped in connective tissue
Bile duct is cuboidal epithelium
Histology in endocrine pancreas
Pancreatic islet of langerhans