Part 12: Rectum Flashcards

1
Q

Describe the course of the rectum

A

Continuous with sigmoid colon, beings where mesocolon ends. Follows posterior concavity of sacrum with 3 lateral curves (upper to the R, middle to L then upper to R)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What produces the folds of Houston?

A

Circular muscle of wall projecting into lumen. May help seperate flatus from stool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How long is the rectum?

A

12cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the muscle wall of the rectum

A

2 layers - circular and longitudinal. The 3 taeniae of colon come together over rectum, no sacculations and no appendices epiploicae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is the anorectal junction?

A

3cm above cutaneous margin, 5cm from coccyx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What parts of the rectum are covered by peritoneum?

A

Anterior: Upper 2/3 covered by peritoneum, lower 1/3 is below reflected margin over bladder/seminal vesicles/vagina
Sides: Upper 1/3 covered with peritoneum
Posterior: Only covers upper 1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Waldeyer’s fascai relationship to the rectum?

A

Anchors lower part of the rectum to lower sacrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the blood supply of the rectum?

A
Superior rectal (continuation of IMA)
Middle and inferior rectal arteries and small portion from median sacral
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the course of superior rectal artery and margin of supply

A

S3 SRA divides into branches to supply thickness of muscles wall of upper and middle rectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where do middle rectal and inferior rectal arteries arise?

A

Middle rectal - internal iliac (supplies lower rectum)

Inferior rectal - internal pudendal artery (penetrates wall anal canal to supply lower rectum)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where is the pouch of douglas?

A

Rectouterine pouch in females
Rectovesical pouch in males (not called the pouch of douglas)
Dependent area therefore often source for collections of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the lymph drainage of the rectum?

A

Pass back along SRA, MRA and median sacral arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the nerve supply of the rectum?

A

Sympathetic branches from hypogastric plexus, accompany vessels
Parasympathetic S2,3 from pelvic splanchnic nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Briefly describe development of rectum

A

Rectum is developed from anorectal canal, with the anal membrane breaking down at the pectinate line. Above pectinate line is endoderm and below is ectoderm (hence the different blood supply between upper and lower part of canal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly