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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

What do the superior and inferior mesenteric nodes drain into

Intestinal lymph trunks and subsequently the cisterna chyli where it ultimately empties into the thoracic duct