Anatomy 3 Flashcards
Describe the oesophagus
Muscular tube - 25cm long and extends from the pharynx to the stomach. The abdominal part of oesophagus is only 1.25cm long.
What are the three constrictions of the oesophagus?
Cervical, thoracic and diaphragmatic
What is the vertebral level of the oesophageal opening (hiatus) in the diaphragm?
T10
What other structures other than the oesophagus that goes through the oesophageal hiatus in the diaphragm?
- L gastric vein
- L gastric aa.
- Vagus nerve
What is the blood supply to the abdominal part of the oesophagus?
Artery: Branches of L gastric artery
Vein: L gastric vein and azygous vein
What is the lymphatic drainage of the abdominal part of the oesophagus?
L gastric nodes and coeliac nodes
What is the clinical importance of the abdominal part of the oesophagus?
Important site for portosystemic anastomoses. in portal hypertension, the anastomoses open and forms venous dilatations called oesophageal varies. Their rupture causes severe and dangerous haematemesis (vomiting of blood)
Describe the stomach
It is a muscular bag forming the widest and most distensible part of the digestive tube. It has two orifices and openings, two curvatures and two surfaces.
What are the two orifices of the stomach??
Cardinal (from oesophagus) and pyloric (into duodenum)
What are the two curvatures of the stomach?
Lesser and greater curvature
What are the two surfaces of the stomach?
Anterior and posterior
What are the different parts to the stomach?
- Cardinal orifices
- Fundus
- Body
- Pyloric antrum
- Pyloric canal
- Duodenum
What is the pyloric sphincter?
Band of smooth muscle between stomach and duodenum (pylorus) which controls discharge of chyme into small bowel
Formed from the muscular external.
What is the clinical importance of the pyloric sphincter?
- Some are borne with congenital pyloric stenosis -> thickening of smooth muscle in the pylorus
- Carcinoma of stomach
- Gastric ulcers and vagotomy
Where is the lesser omentum?
Extends from lesser curvature of the stomach to the liver
Where is the greater omentum?
Greater curvature of the stomach to the transverse colon
Describe the interior of stomach
Contains gastric folds (rugae) which are formed from gastric mucosa and submucosa, and is the most apparent in the pyloric and greater curvature
What is the stomach bed?
The stomach lies on several structures in the abdominal cavity which forms the bed
- L dome of diaphragm
- L kidney
- Spleen
- Splenic artery
- Pancreas
- Colon
- Transverse mesocolon
Name the four primary lymph nodes which drain the stomach
- Gastric (superior) group
- Supra-pyloric group
- Pancreaticollenal group
- Inferior gastric sub-pyloric group
All eventually drain into the coeliac lymph nodes
What is the clinical importance of the 4 primary stomach lymph node groups?
Gastric carcinoma (Cancer) is common and occurs along the greater curvature.
What nerve is key in controlling gastric motility?
Vagus nerve
What is the effect of the stomach which vagal stimulation?
- Pylorus -> increased contraction
* Gastric secretion -> increased
What is the clinical importance of the vagus nerve innervation on the stomach?
The arrangement of vagal branches to the stomach allows for highly selective vagotomy to be used to treat over-active gastric acid secretion.
This denervates the funds and body, decreasing secretion, while the supply to the antrum remains so preserving essential gastric motility.
Describe the structure of the small intestine
- Extends from the pylorus of the stomach to the ileocecal junction
- Duodenum, jejunum and ileum
- Foregut/midgut boundary occurs in the 2nd part of the duodenum at the major duodenal papilla (also where duodenum receives the opening for pile and pancreatic duct)
What is the peritonisation of the different parts of the small bowel?
- Duodenum -> retroperitoneal
- Jejunum -> intraperitoneal
- Ileum -> intraperitoneal
Which part of the small intestine is the shortest, widest and most fixed part?
Duodenum