Ascending and transverse colon (Dave's notes)

Question 1

Describe the length and boundaries of the ascending colon

Answer 1

15cm long from the ileocaecal junction to the hepatic flexure

Question 2

What are the relations of the ascending colon?

Answer 2

• The ascending colon lies on the iliac fascia and the anterior layer of the lumbar fascia.
• The right paracolic gutter lies laterally.
• An embryonic mesentary is retained in 10% of adults.

Question 3

Describe the teniae coli of the ascending colon

Answer 3

The teniae coli of the ascending colon lie anterior, posteriomedial and posteriolateral. The wall is sacculated between them.

Question 4

Describe the appendices epoploicae of the ascending colon

Answer 4

The appendices epiploicae project from the serous coat. Blood vessels to these perforate the muscle wall and may form a tract from mucous membran perforation = diverticulae

Question 5

What is the blood supply of the ascending colon?

Answer 5

Ileocolic and right colic from SMA

Question 6

Describe the length and boundaries of the transverse colon

Answer 6

• 45cm in length from hepatic to splenic flexure.
• hangs down to a variable extent in contact with the anterior abdominal wall.
• Completely invested in peritoneum

Question 7

What are the relations of the transverse mesocolon

Answer 7

The transverse mesocolon hangs from the right kidney, D2, pancreas, and the inferior pole of the left kidney

Question 8

Describe the teniae coli of the transverse colon

Answer 8

The teniae of the transverse colon rotate such that the antior tenia of the ascending colon becomes the posterior tenia of the transverse colon.

Question 9

How do the appendices epiploicae of the transverse colon differ to those of the ascending colon?

Answer 9

They are larger and more numerous

Question 10

What is the blood supply of the transverse colon? What is the significance of this?

Answer 10

The blood supply of the transverse colon is - for the proximal 2/3, from the ???right middle colic from the SMA, and for the distal 1/3rd, from the left colic, from the IMA. This leaves an avascular window.