Abdomen organs

• Oesophagus


  Muscular tube from the pharynx to the stomach designed for propulsion of food (peristalsis)

  
• Oesophagus


  • Average diameter is 2cm
  • About 25-30cm in an adult male
  • Slightly less in females and less than half of that in a new-born
• Parts of the oesophagus

  • Cervical part
  • Thoracic part
  • Abdominal part

  
• Cervical part of oesophagus

  • 1/5 of total length
  • Starts at lower border of cricoid cartilage
  • Descends anterior to C6 and C7 and extends into thoracic inlet

  
• Thoracic part of oesophagus

  • Extends from T1 to T10
  • Longest part
  • Extends to oesophageal hiatus within in the right crus of the diaphragm

  
• Abdominal part of oesophagus

  • Shortest
  • About 1/6 of total length
  • Ends at cardial orifice of stomach

  
• Sites of constriction of the oesophagus

  • Cervical constriction (upper oesophageal sphincter)
  • Thoracic (bronchoaortic) constriction
  • Diaphragmatic constriction

  
• Cervical constriction


  • 15cm from incisor teeth
  • Narrowest point
  • Partly due to the inferior constrictor muscle
• Thoracic (bronchoaortic) constriction


  • At 22.5cm from incisors due to aortic arch seen anteroposteriorly
  • At 27.5cm from incisors due to crossing of left main bronchus seen laterally
• Diaphragmatic constriction


  • At 37-40cm from incisors
  • Due to passing of the oesophagus through the oesophageal hiatus
• Awareness of these constrictions is important when passing instruments through the oesophagus into the stomach and viewing radiographs of patients who are experiencing difficulty swallowing
• Course of the oesophagus


  1. Median at its commencement opposite C6

  2. Deviates slightly to left until C7

  3. Returns to median plane at T5

  4. Inclines to left & forward at T7

  5. Enters abdomen & sharply deviates to left at T10

  6. Joins stomach at T1
• Neurovasculature and lymphatics of the oesophagus

  • Arterial supply
  • Venous drainage
  • Lymphatics
  • Innervation

  
• Stomach


  Most dilated part of the GIT between the oesophagus and small intestine
• Location of the stomach

  • Epigastric, umbilical and left hypochondriac regions
  • Dependent on contents and surrounding viscera
  • Can distend down to hypogastric region

  
• Shape of the stomach

  • J-shaped
  • Modified by changes in content and surrounding viscera
  • In obese- high and transverse
  • In asthenic- long and narrow
• Capacity of the stomach

  • 30ml at birth
  • 1L at puberty
  • 1.5L in adults
  • Twice normal capacity in full distension
• Parts of the stomach

  • Cardia
  • Fundus
  • Body
  • Pyloric

  
• Cardia


  • Surrounds the cardial orifice (superior inlet of stomach)
  • In supine position, the orifice lies posterior to 6th left costal cartilage, 2-4 cm from median plane, at the level of T11

  
• Fundus


  • Dilated superior part related to the left dome of the diaphragm
  • Limited inferiorly by the horizontal plane of the cardial orifice
  • Cardial notch- between oesophagus and fundus
  • In supine position, the fundus lies posterior to the left 6th rib, in the plane of the midclavicular line
• Pyloric


  • Funnel shaped outflow region
  • Pyloric antrum- wider part leading to pyloric canal
  • Pyloric canal- narrower part
  • Pylorus- distal sphincter region of the pyloric part
  • In supine position, the pyloric part lies in the transpyloric plane, about 1.25cm from the midline
• Transpyloric plane


  Midway between jugular notch superiorly and pubic crest inferiorly, transects the 8th costal cartilage and L1 vertebra
• Curvatures of the stomach

  • Lesser curvature
  • Greater curvature
• Lesser curvature


  • Forms the shorter concave right border of the stomach
  • Angular notch (incisure) marks the junction of the body and the pyloric part, lies just to the left of the midline
• Greater curvature


  • Forms the longer convex border of the stomach (4-5 times longer)
  • Passes inferiorly to the left from the junction of the 5th intercostal space and the MCL, curves to the right passing deep to the 9th/10th left costal cartilage, continues medially to reach pyloric antrum
  • Covered by peritoneum and gives attachment to gastrosplenic ligament and greater omentum

  
• Gastric folds (rugae) diminish with distension
• Oesophageal opening and physiological sphincter at level of T11
• Pyloric opening and anatomical sphincter at level of L1, identified by pre-pyloric vein of Mayo which runs vertically across its anterior surface

  
• Arterial supply to stomach

  • Right gastric
  • Left gastric
  • Gastroduodenal
  • Right gastro-omental
  • Left gastro-omental
  • Short gastric

  
• Right and left gastric anastomose along lesser curvature, right and left gastro-omental anastomose along greater curvature
• Venous drainage of stomach

  • Short gastric
  • Splenic vein
  • Left gastro-omental
  • Right gastro-omental
  • Superior mesenteric vein
  • Left gastric
  • Hepatic portal vein
  • Right gastric

  
• Lymphatic drainage of stomach

  • Along right and left gastric vessels to gastric nodes and then to aortic nodes
  • Along gastro-omental vessels to pyloric (subpyloric) nodes
  • Along short gastric and splenic vessels to suprapancreaticoduodenal nodes and then to aortic nodes

  
• Innervation of stomach


  • Parasympathetic: Anterior and posterior vagal trunks
  • Sympathetic: Coeliac plexus from greater splanchnic nerve

  
• Parasympathetic innervation


  • Secretomotor to glands, motor to muscles
• Sympathetic innervation


  • Vasomotor to blood vessels, pain fibres from muscles, motor to pylorus for sphincteric constriction
• Duodenum


  Shortest, widest and most fixed part of small intestine
• Location of duodenum


  • Retroperitoneal except for proximal half of the superior part
  • Extent: pylorus on the right to duodenojejunal flexure on the left, flexure at the level of L2, 2-3cm from the left of the midline
• Shape of duodenum


  • C-shaped with convexity to the right side and concavity enclosing the head of the pancreas

  
• Location of duodenum


  • Epigastric and umbilical regions
• Parts of the duodenum

  • Superior
  • Descending
  • Inferior
  • Ascending