Flashcards in Colon Deck (43):
1
Parts of the colon
Ascending
Transverse
Descending
Sigmoid
2
Length of the colon
150cm
3
Course of the ascending colon
Ascends from the caecum to the right lobe of the liver and turns 90 degrees to move horizontally at the right colic flexure
4
Where is the right colic flexure
Deep to ribs 9-10 and inferior part of the liver
5
What kind of peritoneal structures are the ascending and descending colon
Secondary retroperitoneal
6
What percentage of people have a short mesentery of the ascending colon
25%
7
Where is the right paracolic gutter
Between the lateral aspect of the ascending colon and the posterolateral abdominal wall
8
What's the longest part of the colon
Transverse colon
9
What's the most mobile part of the colon
Transverse colon
10
Where does the transverse colon run from and to
Right colic flexure to the left colic flexure
11
Differences between the left (splenic) and right (hepatic) colic flexures
Left colic flexure is more superior, more acute and less mobile than the right colic flexure
12
What does the phrenicocolic ligament attach
Diaphragm to the left colic flexure
13
Where is the left colic flexure
Anterior to the left kidney
14
Vertebral level of the transverse colon
L3 (level of the umbilicus) but in tall thin people it may extend into the pelvis
15
Where does the sigmoid colon run from and to
From the left iliac fossa to the S3 vertebra
16
Shape of the sigmoid colon
S-shaped
17
What signals the rectosigmoid junction
Termination of the teniae coli
18
Length of the sigmoid colon
Variable but roughly 40cm
19
Describe the sigmoid mesocolon and the consequence of this
Very long therefore the sigmoid colon is very mobile which can lead to volvulus of the sigmoid colon
20
What kind of peritoneal structure is the transverse colon
Intraperitoneal
21
Where is the transverse mesocolon
Fused with the posterior wall of the lesser sac and loops down inferior to the level of the iliac crests
22
Where is the root of transverse mesocolon
What is it continuous with
Inferior border of the pancreas
Continuous with the posterior parietal peritoneum
23
What percentage of people have a short mesentery of the descending colon
33%
24
Where does the descending colon run from and to
From the left colic flexure to the left iliac fossa
25
What does the descending colon cross
Lateral border of the left kidney
26
Where is the left paracolic gutter
Between the lateral aspect of the descending colon and the posterolateral abdominal wall
27
Describe the root of the sigmoid mesocolon
Inverted V-shaped attachment
28
Arterial supply of the ascending colon and right colic flexure
Abdominal aorta -> SMA -> ileocolic artery
Abdominal aorta -> SMA -> right colic artery
29
What do the ileocolic and right colic arteries anastomose with and what does this form
They anastomose with the right branch of the middle colic artery to form a series of arcades that forms the marginal artery (continuous arterial channel round the large intestine)
30
Venous drainage of the ascending colon and right colic flexure
Ileocolic and right colic veins which drain into the SMV and subsequently the hepatic portal vein
31
Link the embryological origin of the transverse colon to its blood supply
Derived from midgut and hindgut so is supplied by the superior and inferior mesenteric vessels
32
Arterial supply of the transverse colon
Abdominal aorta -> SMA -> middle colic artery
Abdominal aorta -> SMA -> right colic artery
Abdominal aorta -> IMA -> left colic artery
33
Venous drainage of the transverse colon
Middle colic vein which drains into the SMV and subsequently the hepatic portal vein
34
Arterial supply of the descending colon
Abdominal aorta -> IMA -> left colic artery
35
Arterial supply of the sigmoid colon
Abdominal aorta -> IMA -> sigmoid arteries
36
Venous drainage of the descending colon
Left colic vein which drains into the IMV
37
Venous drainage of the sigmoid colon
Sigmoid veins which drain into the IMV
38
Where do vasa recta arise from
The marginal artery (of Drummond)
39
Innervation of ascending colon and proximal 2/3 transverse colon
Superior mesenteric plexus
40
Innervation of distal 1/3 transverse colon, descending colon and sigmoid colon
Inferior mesenteric plexus
Sympathetic - lumbar splanchnic nerves
Parasympathetic - pelvic splanchnic nerves
41
What does lymph from the ascending and transverse colon drain into
Superior mesenteric nodes
42
What does lymph from the descending and sigmoid colon drain into
Inferior mesenteric nodes
43