GI anatomy Flashcards
Dimensions of the oral cavity
• Roof - hard and soft palaes •Posterior : ‘Oropharyngeal isthmus’ opens into the oropharynx • Border between mouth and pahrynx is marked with palatoglossal arch • Closure of oropharyngeal isthmus via palatoglossus(muscle of soft palate)
Thyroglossal duct
• Terminal sulcus - apex of the V is the foramen cecum • Thyroglossal duct connects the foramen cecum to the thyroid gland, if persists causes thyroglossal duct cysts.
The tongue
All have taste buds on their surface except filliform. 1. Fungiform papillae - Round and large - along margins of tongue 2. Filiform papillae - small, mucosal projections 3.Foliate papillae - Liner folds of mucosa, sides of tongue 4. Vallate papillae - Blunt ended, cylindrical -largest -anterior to the terminal sulcus
Salivary glands
- Parotid glands - outside of oral cavity - external surface of masseter and buccinator muscle 2. Submandibular - below mylohyoid - outside oral cavity -secreates serous fluid and mucus 3. Sublingual (smalles) is lateral to submandibular duct - 5% saliva of oral cavity
Parotitis
- infllammation of the parotid gland • Caused by mumps • May cause blockage of salivary duct calculi
development of GI tract
Foregut - coeliac trunk of abdominal aorta Midgut - superior mesenteric Hindgut - inferior mesenteric
The oesophagus
- Cervical - continous with oropharynx 2. Thoracic - T1-T10 3. Abdominal (oesophageal hiatus to cardia of stomach)
Three constrictions of oesophagus
- Cervical (C5/C6) due to cricoid cartilage 2. Thoracic - due to aortic arch 3. Abdominal at the oesophageal hiatus
oesophageal atresia
• Absence of contiguity with oesophagus due to imapproprate divison of the foregut into trachea and oesophagus • Congential obstruction of oesphagus into a blind-ended pouch • Tracheoesophageal fistula - an abnormal connection between the esophagus and trachea
Oesophageal stenosis/stricture
Narrowing or tightening of the oesophagus, making swallowing difficult assoc with • GOR (gastrooesophageal reflux disease) - stomach acid affects oesophagus • Hiatus hernia - when part of the stomach squeezes into the chest through an opening in the diaphragm
The deriviatives of the foregut
• Stomach •Duodenum • Liver • Gallbladder •Pancreas •Spleen
Pyloric stenosis
• Pylorus is the muscular valve between the stomach and small intestine •idiopathic thicking of the pyloric musculature results in progressive gastric outlet obstruction • Hypertrophic pylorus can be palpated as olive size mass in the right upper quadrant • Barium meal shows elongated pylorus with narrown lumen • Ultrasound is the main modality of choice to measure changes in wall thickness
The biliary tree
•empty into descending duodenum • Left and right hepatic duct until to form common hepatic duct • Common hepatic duct + cystic duct = common bile duct • Common bile duct joins with pancreatic duct to enter the descending duodenum at the major duodenal papilla
Biliary atresia
• one or more bile ducts are abnormally narrow, or absent - obliteration of common duct - atresia of hepatic duct • obstruction to bile flow •Build up of bile leads to cirrhosis / jaundice/hepatomegaly/splenomegaly
Annular pancreas
• second part of the duodenum is surrounded by a ring of pancreatic tissue continous with the head of the pancreas • Embryological failure of the ventral bud to rotate with the duodenum •portion of the pancreas can constrict the duodenum and impair the flow of food to the rest of the intestines