Lower GI Tract Flashcards
At which vertebral level does the oesophagus pierce the diaphragm?
T10
What is a body cavity?
A space/area surrounded by a body wall
What forms a body wall?
Skeleton
Muscle
Which bones form the abdominal cavity?
Ribs
Spine
Pelvis
Which muscles form the abdominal cavity?
Diaphragm
Back
Anterolateral wall
What type of membrane is the peritoneum?
Continous serous membrane
Which two layers define the peritoneal cavity?
Visceral serous pericardium
Parietal serous pericardium
What is located in the peritoneal cavity (under normal circumstances)?
Small amount of peritoneal fluid secret by the peritoneum
What is peritonitis?
Inflammation of peritoneum caused by surgery/trauma
Peritonitis leads to guarding. What is guarding?
Stiffening of the abdominal wall
What are the intraperitoneal abdominal organs?
Liver and gall bladder
Stomach
Spleen
Parts of the SI and LI
What are the retroperitoneal abdominal organs?
Kidneys
Adrenal gland
Pancreas
Parts of the SI and LI
What shape is the stomach?
J-shape
Where is the stomach located?
(mainly) left upper quadrant
What is the function of the stomach?
Defence against infection by production of stomach acid - digestion - production of chyme
and absorption
What is the function of the pyloric sphincter?
If contracted it constricts food entering the duodenum
What is the function of the small intestine?
Responsible for transit, digestion and absorption
What attaches the small intestine to the body wall?
Mesentery
Where is the small intestine located?
In all 4 quadrants
What are the three parts of the small intestine?
Duodenum
Jejunum
Ileum
What is mesentery?
Double layer of peritoneum that connects the intraperitoneal organs to the body wall and allows passage of neurovasculature
What is the function of the LI?
Transit, reabsorption of water and electrolytes, and stool ofrmation
What are the components of the LI?
Caecum Ascending colon (retroperitoneal) Transverse colon (intraperitoneal) Descending colon (retroperitoneal) Sigoimd colon (intraperitoneaL)
Rectum and anus are the terminal end of the LI. What is their function?
Stool formation
Waste excretion
The muscular wall of the rectal and anal canal is _____ muscle
Smooth
The sphincter forming the anus is ____ muscle
Skeletal
By which mechanisms does the GI tract move contents distally?
Peristalsis
What is peristalsis?
Waves of simultaneous shortening of the length or a segment of the tube contracting the outer longitudinal layer of smooth muscle
+
Narrowing of the luminal diameter of that segment by contracting inner circular layer of smooth muscle
Which sphincters control flow through the GI tract?
Cricopharyngeal
Pyloric
External anal
Where is the circopharyngeal sphincter?
Between the laryngopharynx and oesophagus (prevent regurgitation)
Where is the pyloric sphincter?
Between stomach and duodenum
Control release of chyme from stomach
Where is the external anal sphincter?
Between the anus and external environment to control the release of stool from the anal canal
What is part of the foregut?
Oesophagus - mid duodenum
Liver and gall bladder
Spleen
1/2 pancreas
What is part of the midgut?
Mid duodenum - proximal 2/3 of transverse colon + 1/2 pancreas
What is part of the hindgut?
Distal 1/3 of transverse colon - proximal 1/2 of anal canal
The aorta passes through the duodenum and descends in the ________
retroperitoneum
The IVC ascend in the __________ and passes through the diaphragm
retroperitoneum
What is the arterial supply to the foregut?
Coeliac trunk
What is the arterial supply to the midgut?
Superior mesenteric artery
What is the arterial supply to the hindgut?
inferior mesenteric artery
What is the venous drainage from the foregut?
Splenic vein
What is the venous drainage from the midgut?
SMV
What is the venous drainage from the hindgut?
IMV
The splenic vein, SMV and IMV combine to form the?
Hepatic portal vein
Venous drainage from the GI tract goes to which organ first?
Liver
What is the function of the portal venous system?
Drains from absorptive parts of the GIT and associated organs to the liver via the hepatic portal vein
Foregut structures drain their lymph via lymph nodes located along the _________ artery towards the _______ nodes
splenic
coeliac
Midgut structure drain their lymph via nodes located along the ____________ artery towards the ___________ nodes
SMA
Superior mesenteric
Hindgut structures drain they lymph via nodes located along the ________ artery towards the ________ nodes
inferior mesenteric
inferior mesenteric
What can result in obstruction/blockage of the GIT?
External compression or internal obstructuion
What is the body’s response to obstruction/blockage of the GIT?
Increase peristalsis proximal to the site of obstruction to attempt to remove it
What type of pain does a patient with a GIT obstruction/Blockage tend to experience?
Colicky pain
