Flashcards in Anatomy 3 (lecture 5) Deck (48)
what are the functions of the large intestine?
Defence (commensal bacteria)
Absorption (H2O and electrolytes)
How is the caecum related to the peritoneum?
Intraperitoneal (quite mobile)
How is the ascending colon related to the peritoneum?
What does secondarily retroperitoneal mean?
It originally was originally intraperitoneal (embryology)
What is the transverse colon in relation to the peritoneum?
intraperitoneal - highly mobile (has own mesentery)
Descending colon in relation to the peritoneum?
What is the sigmoid colon in relation to the peritoneum?
Intraperiotneal - quite mobile as it has its own mesentery
Where are the 2 paracolic gutters?
Between the lateral edge of the ascending and descending colon and abdominal wall (called left and right paracolic gutters)
What are the paracolic gutters part of?
The greater sac of the peritoneal cavity
Where do the teniae coli run from and to?
From the caecum to the distal end of the sigmoid colon
What are the haustra?
Small pouches in the colon formed from the tonically contracted teniae coli
What causes darker blobs on a plain AXR?
What does faeces appear like in the rectum on a plain AXR?
"Mottled" - mixture of air and faeces
In what part of the abdomen do the caecum and appendix lie?
The right iliac fossa
What is the opening of the ileum into the caecum called?
The ileocaecal orifice
What is the opening of the appendix into the caecum called?
How is the appendix most often located in comparison to the caecum?
Position can vary causing a variation in the symptoms people present with e.g. men can present with testicular pain due to extending down to the pelvis and irritating structures
On what part of the caecum is the appendiceal orifice mostly always on?
What does this correspond to?
The posteromedial wall
McBurney's point (1/3 of the way between right Anterior Superior Iliac Spine and the umbilicus)
Usually the point of maximum tenderness in appendicitis
In what part of the abdomen does the sigmoid colon lie?
left iliac fossa
What is the mesentery of the sigmoid colon called
Sigmoid mesocolon (gives it a considerable degree of movement)
Abnormal twisting of a part of the GI tract
What is it called when the sigmoid colon twists around itself?
What does this result in?
What is the bowel at risk of if it is left untreated?
Where does the abdominal aorta lie in relation to the IVC?
Left of the IVC
What are the 3 midline branches of the abdominal aorta and what does each supply?
Celiac trunk (foregut organs)
Superior mesenteric artery (midgut organs)
Inferior mesenteric artery (hindgut organs)
What do the lateral branches of the abdominal aorta supply? (3)
Body wall (posterolateral)
Kidneys/ adrenal glands
Gonads (ovaries/ testicles)
What does the abdominal aorta bifurcate into?
What does this further bifurcate into?
Internal and external iliacs
See diagrams on superior mesenteric artery and inferior mesenteric artery
What is the predominant artery which anastomoses between the branches of the SMA and IMA?
Marginal artery of Drummond
What do arterial anastomoses between the SMA and IMA help to do?
Prevent intestinal ischaemia by providing a collateral route by which blood can travel