http://upload.wikimedia.org/wikipedia/commons/7/75/Anorectum.gif

The terminal portion of the large intestine between the ileo-pelvic colon and the anus. [Dorian_AF, Elsevier's_encyclopaedic_dictionary_of_medicine, Part_B:_Anatomy_(1988)_Amsterdam_etc.:_Elsevier][VHOG]

uberon

terminal portion of large intestine, rectal sac, intestinum rectum

rectal

UBERON:0001052

In the lungfish, sharks and rays the rectum opens into the cloaca which also receives wastes (urine) from the kidneys and material from the reproductive organs. In bony fish the rectum reaches the outside environment through the anus, which is normally situated just in front the urinary and reproductive openings. However in some fish the digestive tract may be curled back on itself, and in the Electric Eel (Electrophorus electricus) the anus is situated in the fish's throat. -- http://www.earthlife.net/fish/digestion.html

• rectal lumen

• sigmoid colon
• anal canal

• rectosigmoid junction

• rectal artery

• rectal venous plexus

• serosa of rectum
• submucosa of rectum
• epithelium of rectum
• mucosa of rectum
• muscle layer of rectum
• rectum smooth muscle tissue
• rectal lumen