Short Notes: Anatomy of the Rectum & Anal Canal

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ANATOMY
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, RECTUM AND ANAL CANAL
Rectum

 Continuation of sigmoid colon at the level of S3
 from the rectosigmoid junction to the anorectal
junction
 12cm long
 In front of lower 3 pieces of sacrum and coccyx
 No taenia coli, sacculations, appendices
epiploicae
 Lower part is dilated to form the rectal ampulla
 Direction of the rectum
 Downwards & backwards → Downwards →
 Downwards & forwards
 Shows lateral and antero-posterior curvatures
 3 lateral curvatures which are convex to,
 Right
 Left Due to mucosal folds
 Right
 2 Antero-posterior curvatures
a) Sacral flexure - due to concavity of
sacrum and coccyx.
b) Perineal flexure - due to backward bend
at the anorectal junction.

Relations

 Peritoneal relations
 upper 1/3rd front and side
 middle 1/3rd only the front
 lower 1/3rd below the level of peritoneum

 visceral relations
 Posterior - [female, male similar]
 Waldeyer’s fascia
 Sacrum, coccyx
 Median sacral, superior rectal vessels
 Sympathetic trunk

 Anterior - [Male]
 Denonvilliers’ fascia
 Upper 2/3 - recto vesical pouch
 Lower 1/3 - base of bladder
Ductus deferens
Seminal vesicles


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