Rectum at a glance
- What it is
- The rectum is the final straight portion of the large intestine before the anal canal.
- Location
- It lies in the pelvis in front of the sacrum and coccyx. It begins at about S3 and ends at the anorectal junction, where puborectalis loops around it. In males it lies behind the bladder, seminal vesicles and prostate.
- Function
- It stores feces until defecation.
- Body system
- Digestive · single, midline structure
- FMA ID
- FMA14544 (Foundational Model of Anatomy)
Key facts
- About 12 to 15 cm long.
- It has three lateral curves with transverse rectal folds (valves of Houston).
- The taeniae coli spread out into a continuous longitudinal muscle layer.
- Supplied by the superior rectal artery (from the inferior mesenteric) and the middle and inferior rectal arteries (from the internal iliac and internal pudendal).
Clinical relevance
The rectum is a common site of colorectal cancer. Low tumours may be felt on digital rectal examination.
Structures next to the rectum
The nearest named structures in the 3D model, measured from the centre of each part:
- Seminal vesicle · reproductive
- Coccygeus · muscular
- Pubococcygeus · muscular
- Internal iliac vein · cardiovascular
- Sacrum · skeletal
- Puborectalis · muscular
- Obturator vein · cardiovascular
- Calcaneal branches of posterior tibial artery · cardiovascular
- Urinary bladder · urinary
- Prostate · reproductive
References
- Foundational Model of Anatomy: Rectum (FMA14544). EMBL-EBI Ontology Lookup Service.
- OpenStax. Anatomy and Physiology 2e, §23.1 Overview of the Digestive System. Rice University, 2022.
- Mitsuhashi N. et al. (2009). BodyParts3D: 3D structure database for anatomical concepts. Nucleic Acids Research 37, D782–D785. Data © The Database Center for Life Science, CC BY 4.0.
Explore the whole body in the interactive 3D human anatomy model, or browse the A–Z list of human structures.