GI Anatomy 2 Flashcards
Which nerves run anteroinferiorly on the transversus abdominis muscle?
T9 to L1
Where does the transversalis fascia lie?
Superficial to the parietal peritoneum
What is the nerve supply to the parietal peritoneum and how do these nerves course?
Anterior rami of spinal nerves T7 - L1 (somatic afferents)
The run in between the transversus abdominus and internal oblique then at lateral edge of the rectus sheath, enter the rectus sheath and pass posterior to the rectus abdominis (near to the midline, they give off an anterior cutaneous branch)
What characteristic does suspension by a mesentery confer to an organ?
1) Mobility
2) Prevent tangling
3) Conduit for vessels and nerves
Which organs of the abdominal cavity lie retro peritoneally?
1) 2nd and 3rd parts of the duodenum
2) Supra renal glands
3) Kidneys
4) Pancreas
5) Ascending, descending colon
6) Rectum
7) Aorta and IVC
8) Ureters
What is an adhesion?
Fibrous bands of scar tissue that form between internal organs, joining them together abnormally
How many layers of peritoneum in a mesentery?
2
How many layers of peritoneum in the greater omentum?
4
How many layers of peritoneum in the transverse mesocolon?
6
What is the mesocolic shelf and what does it separate the abdominal cavity into?
Mesocolic shelf = transverse mesocolon
Separates the abdominal cavity into a supra colic space and an infracolic space
What is the space in between the liver and the diaphragm called?
The subphrenic space
What is the sub hepatic channel and what is its inferior limit?
Space under the liver, the inferior limit is the transverse mesocolon
Which organs are located in the supracolic compartment?
1) Liver and gall bladder
2) Stomach
3) Duodenum
4) Spleen
What is the hepatorenal pouch of Rutherford Morison and what is it continuous with?
Space posterior to the liver limited by the posterior abdominal wall and the right kidney
Continuous with the right paracolic gutter
Why is the hepatorenal pouch of Rutherford Morison of surgical significance?
Lowest and deepest space within the abdominal cavity when youre lying supine that free fluid and pus gathers in
What is the name of the opening that leads into the lesser sac?
Epiploic foramen (of Winslow)
What structures form the 4 boundaries of the epiploic foramen of winslow?
Anterior = free edge of lesser omentum (gastroduodenal ligament) containing the portal triad Posterior = IVC Inferior = First part of duodenum Superior = caudate lobe of the liver
What ligament runs between the spleen and the left kidney?
Lienorenal ligament
What is the phrenico colic ligament?
fold of peritoneum between the diaphragm and the splenic flexure
What are the paracolic gutters?
depressions formed between the lateral margins of the ascending and descending colon and the posterolateral body wall
Why are the paracolic gutters clinically important?
Gutters through which material can pass from one part of the abdominal cavity to another
Major vessels and lymphatics tend to be on the medial or posterior side of the colon
Paracolic gutters are a good access point for surgeons without cutting vasculature
What is the name for the line of attachment of the mesentery to the posterior abdominal wall?
The root of the mesentery
Where does the mesentery run from and to?
From the duodenojejunal flexure to the right sacroiliac joint
Which side of the infracolic compartment communicates with the pelvis?
The left infra colic compartment
Which blood vessels run in the mesoappendix?
Appendicular artery (branch of posterior ileocolic artery from the superior mesenteric artery) Appendicular vein (empties into the ileocolic vein)
Where does the appendix receive its innervation from, where do visceral afferent fibres from the appendix enter the spinal cord?
Fibres from the superior mesenteric plexus
Visceral afferent enter the spinal chord at T10
Over which artery is the sigmoid mesocolon attached to the posterior abdominal wall?
The division of the left common iliac artery
Where does the rectovesical pouch lie?
inbetween the bladder and the rectum
Where does the recto uterine pouch (of douglas) lie?
Inbetween the rectum and the uterus
Where does the uterovesical pouch lie?
inbetween the uterus and the rectum
What is the difference in innervation of the visceral and the parietal peritoneum?
1) Visceral peritoneum = visceral afferent and efferent
2) Parietal peritoneum = somatic branches of associated spinal nerves (T7-L1)
What are the parts of the stomach?
1) Cardia (gastroesophageal junction)/ cardiac orifice
2) Fundus (superior to cardia)
3) Body
4) Pyloric antrum
5) Pyloric canal (pylorus)
What is meant by an anatomical sphincter and a functional sphincter?
Anatomical sphincters have localised and circular muscle thickening
Functional sphincters do not have this and achieve their action through muscle contraction
Are the pylorus and cardiac orifice anatomical or physiological sphincters?
Cardiac orifice = physiological sphincter
Pylorus = anatomical sphincter
At what level is the transpyloric plane?
Passes through the lower border of L1
Where does the pylorus lie?
To the right of the midline in the transpyloric plane (through lower border of L1)
Which nerves may sink into the muscular wall of the stomach anteriorly and posteriorly?
Anteriorly = left vagus Posteriorly = right vagus
How did the left and right vagus nerves come to lie anteriorly and posteriorly (respectively) on the stomach?
Rotation of the stomach 90 degrees on the craniocaudal axis during development
What is the difference between a hiatal hernia and a congenital hernia?
Hiatal hernia is aquired, stomach pushed through oesophageal hiatus, reducible hernia
Congenital hernia is due to insufficient elongation of the oesophagus during development, some of the stomach will lie supradiaphragmatically, hernia is irreducible