What does caeca mean?
Caeca is the plural form of caecum, referring to blind-ended pouches found where the small intestine meets the large intestine in many animals. In humans there is typically a single caecum, but in other species — rabbits, horses, koalas, many birds and fish — caeca may be paired or numerous and can be strikingly long, serving as fermentation chambers that break down tough plant fibre with the help of gut microbes. Beyond the intestine, zoologists apply the term to any blind sac branching off a hollow organ, such as the hepatic caeca that aid digestion in insects and crustaceans. The word derives from Latin caecus, meaning blind, reflecting the structure's closed end. It belongs firmly to formal anatomical and veterinary vocabulary; general readers meet it mainly in biology textbooks or nature documentaries about herbivorous animals.
nounThe plural of 'caecum' — the blind-ended pouches forming the first part of the large intestine, at the junction with the small intestine. The term is also used more broadly in zoology for any blind-ending sac or tube branching off a hollow organ.
- The paired or multiple blind-ending intestinal pouches of an animal, especially where the small intestine meets the large intestine.
- In zoology and anatomy generally: any blind sac or diverticulum branching from a hollow organ, such as the hepatic caeca of arthropods.
"In rabbits, the caeca are greatly enlarged to aid the digestion of cellulose."
"Dissection revealed two elongated caeca extending from the junction of the small and large intestine."
"The insect's digestive tract bore numerous hepatic caeca surrounding the foregut."
'Caeca' itself is already a plural noun; its singular form is 'caecum' (or 'cecum' in American spelling). A rarely used feminine plural variant 'caecae' exists but is not standard.
"The specimen's caeca were unusually elongated."
Rabbits and koalas owe their ability to survive on fibrous plants largely to enormously long caeca that ferment cellulose their own enzymes cannot touch.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of caeca
Caeca comes directly from Latin, the plural of caecum, which itself derives from caecus meaning 'blind' or 'hidden' — so called because the pouch ends blindly rather than continuing onward like most of the digestive tract. The Latin root also gives English words such as 'caecal' (the adjective form) and, through Greek-influenced medical usage, terms like 'coeliac'. American spelling variants 'ceca' and 'cecum' reflect simplified orthography adopted in US medical literature.
Related word forms
How caeca is actually used
Strictly anatomical or zoological register; almost never encountered outside scientific, medical, or veterinary contexts. Spelling follows British conventions ('caeca', 'caecum'); American texts typically use 'ceca' and 'cecum'.
Easily confused with caeca
The coccyx is the tailbone at the base of the spine, whereas caeca are pouch-like structures of the digestive tract.