GI Tract Jennings W10 Flashcards
What does the retroperitoneal space contain?
Located behind the peritoneum - one surface covered by parietal peritoneum, the other, the abdominal wall.
Held in place
The space contains the kidneys, adrenal glands, pancreas, duodenum, nerve roots, lymph nodes, abdominal aorta, and inferior vena cava.
Parietal vs Visceral Peritoneum?
Parietal- lines the abdominal cavity (red)
Visceral- surrounds the organs (blue)
To lubricate the movement and expansion of the gut.
What is an intraperitoneal organ?
Organ covered by a layer of visceral peritoneum and suspended by mesenteries from the posterior abdominal wall, in the peritoneum cavity. Moveable
What is a mesentery?
A fold that attaches the intestine to the abdominal wall and holds it in place. stores fat and allows blood, nerves and lymph to supply the intestines.
What can the primitive gut be divided into and what are the corrosponding vessel branches?
Foregut: celiac trunk (abdominal oesophagus to mid duodenum- stomach, pancreas and spleen)
Midgut: superior mesenteric artery- rest of small intestine, ascending colon and ⅔ of transverse colon
Hindgut: inferior mesenteric artery- rest of colon, ends in anal canal.
Where does the inferior vena cava pierce the diaphragm?
T8 vertebrae
A) What forms the portal vein?
B) What does it bring to the liver?
A) splenic vein and superior mesenteric vein
B) Blood from the stomach, intestines, spleen, and pancreas.
Blood from the small intestine drains into what vein?
Superior mesenteric vein
Where does the upper GI tract start and end?
Pharynx, oesophagus with vagus nerve accompanying it (neck, trachea and thorax), oesophagus crossed by arch of aorta, oesophageal hiatus where diaphragm starts (T10/11), T12 joins stomach.
Therefore: C6 to T11/12
What a physiological sphincter, give an example?
Increased tone of muscle in the area
Lower oesophageal sphincter (gastro-oesophageal sphincter).
Located 3 cm to the junction of oesophagus where it meets the stomach.
It prevents acid and stomach contents travelling backward from the stomach
What does the lower oesophageal sphincter do?
Bundle of muscles that allows food from oesophagus into the stomach and prevents reflux of gastric contents and acids into the oesophagus.
It is NOT under voluntary control.
What reflex muscle tissue allows food to pass or be retained, and WHERE is it located?
The pyloric sphincter, located at the junction between the pylorus of the stomach and duodenum of small intestine
What is the role of chyme, and what allows it to pass through the stomach to where?
It increases the surface area of food by breaking it into smaller components, and stimulates digestive glands to secrete bile/enzymes.
The pyloric sphincter opening allows it to pass into the small intestine.
What are the two layers of peritoneum that pass between the stomach and duodenum?
Greater and lesser omentum
What nerve supply do the parietal and visceral layer have?
Parietal (intercostal nerve)- Well localised Somatic nerve supply, whereas visceral doesn’t (visceral afferent nerve)