Cloaca
: A common passageway for feces, urine and reproduction. At one point in the development of the human embryo, there is a cloaca. It is the far end of a structure called the hindgut. This structure then divides to form a rectum, a bladder, and genitalia. The presence of a cloaca is normal in many adult animals (birds, reptiles, amphibians, some fish, and even a few mammals). However, the persistence of a persistent cloaca in a person is a birth defect (a congenital malformation). Cloaca is the Latin word for drain or sewer.
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1. In early embryos, the endodermally lined chamber into which the hindgut and allantois empty. 2. In birds and monotremes, the common chamber into which open the hindgut, bladder, and genital ducts. [L. sewer]
- ectodermal c. the proctodeum of the embryo.
- endodermal c. terminal portion of the hindgut internal to the cloacal membrane of the embryo.
- persistent c. a condition in which the urorectal fold has failed to divide the c. of the embryo into rectal and urogenital portions. SYN: sinus urogenitalis, urogenital sinus (2).

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clo·aca klō-'ā-kə n, pl -acae -.kē, -.sē
1 a) the common chamber into which the intestinal, urinary, and generative canals discharge esp. in monotreme mammals, birds, reptiles, amphibians, and elasmobranch fishes
b) the terminal part of the embryonic hindgut of a mammal before it divides into rectum, bladder, and genital precursors
2) a passage in a bone leading to a cavity containing a sequestrum
clo·acal -'ā-kəl adj

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n.
the most posterior part of the embryonic hindgut. It becomes divided into the rectum and the urinogenital sinus, which receives the bladder together with the urinary and genital ducts.

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clo·a·ca (klo-aґkə) pl. cloaґcae [L. “drain”] 1. a common passage for fecal, urinary, and reproductive discharge in monotremes, birds, and lower vertebrates. See also cloacal aperture, under aperture. 2. in mammalian embryology, the terminal end of the hindgut before division into rectum, bladder, and genital primordia (see sinus urogenitalis). Failure to divide properly during development may result in persistent cloaca (q.v.). 3. in pathology, an opening in the involucrum of a necrosed bone. cloacal adj

Medical dictionary. 2011.

Look at other dictionaries:

  • cloacă — CLOÁCĂ, cloace, s.f. 1. Canal subteran în care se adună murdăriile dintr un oraş. 2. (Adesea fig.) Băltoacă murdară şi rău mirositoare; loc infect, plin de murdării. 3. Cavitate a corpului batracienilor, reptilelor şi păsărilor, în care se… …   Dicționar Român

  • Cloaca — Clo a ca, n.; pl. {Cloac[ae]}. [L.] 1. A sewer; as, the Cloaca Maxima of Rome. [1913 Webster] 2. A privy. [1913 Webster] 3. (Anat.) The common chamber into which the intestinal, urinary, and generative canals discharge in birds, reptiles,… …   The Collaborative International Dictionary of English

  • cloaca — porción terminal del intestino posterior antes de su división durante el desarrollo en recto, vejiga y estructuras genitourinarias primitivas. Puede ser persistente y ser evidente después del nacimiento [ICD 10: Q43 7] Diccionario ilustrado de… …   Diccionario médico

  • cloaca — s.f. [dal lat. cloaca, dalla stessa radice del gr. klýzō lavare, pulire ]. 1. (idraul.) [condotto sotterraneo che raccoglie e scarica le acque piovane e di rifiuto] ▶◀ chiavica, fogna. ‖ smaltitoio. 2. (fig., spreg.) [luogo lurido e maleodorante …   Enciclopedia Italiana

  • cloaca — 1650s, Modern Latin, euphemism for sewer, from L. cloaca sewer, drain, from cluere to cleanse, from PIE root *kleue to wash, clean (Cf. Gk. klyzein to dash over, wash off, rinse out, klysma liquid used in a washing; Lith. ЕЎluoju to sweep; O.E.… …   Etymology dictionary

  • cloaca — s. f. 1. Lugar onde se deitam as dejeções. = ESGOTO, LATRINA 2.  [Figurado] Lugar imundo. = SENTINA 3.  [Zoologia] Parte dos intestinos das aves e répteis.   ‣ Etimologia: latim cloaca, ae, esgoto, ventre …   Dicionário da Língua Portuguesa

  • cloaca — sustantivo femenino 1. Conducto por donde van las aguas sucias o residuales: Las ratas de las cloacas son asquerosas, pero ayudan a desatascarlas. Sinónimo: alcantarilla. 2. Lugar sucio y repugnante: Los sótanos de la casa eran una cloaca. 3.… …   Diccionario Salamanca de la Lengua Española

  • cloaca — (Del lat. cloāca). 1. f. Conducto por donde van las aguas sucias o las inmundicias de las poblaciones. 2. Lugar sucio, inmundo. 3. Zool. Porción final, ensanchada y dilatable, del intestino de las aves y otros animales, en la cual desembocan los… …   Diccionario de la lengua española

  • Cloaca — vgl. Kloake …   Das Wörterbuch medizinischer Fachausdrücke

  • cloaca — [klō ā′kə] n. pl. cloacae [klō′ā′sē΄, klō′ākē΄] or cloacas [L < cluere, to cleanse < IE base * k̑lū , to rinse, clean > Gr klyzein, to wash, Ger lauter, pure] 1. a sewer or cesspool 2. Zool. a) the cavity into which both the intestinal… …   English World dictionary

  • Cloaca — For other meanings, see Cloaca (disambiguation). An avian cloaca or vent; in this example, a red tailed hawk (Buteo jamaicensis) …   Wikipedia

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