cloaca (redirected from avian cloaca)

cloaca /clo·a·ca/ (klo-a´kah) pl. cloa´cae   [L.]

1. a common passage for fecal, urinary, and reproductive discharge in most lower vertebrates.

2. the terminal end of the hindgut before division into rectum, bladder, and genital primordia in mammalian embryos.

3. an opening in the involucrum of a necrosed bone.cloa´cal

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clo·a·ca (kl-k)

n.

1. In early embryos, the entodermally lined chamber into which the hindgut and allantois empty.

2. The common cavity into which the intestinal, genital, and urinary tracts open in vertebrates such as fish, reptiles, birds, and some mammals.

3. An opening in a diseased bone containing a fragment of dead bone.

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clo·acal (-kl) adj.

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cloaca

[klō·ā′kə] pl. cloacae

Etymology: L, sewer

1 (in embryology) the end of the hindgut before the developmental division into the rectum, the bladder, and the primitive genital structures.

2 (in pathology) an opening into the sheath of tissue around a necrotic bone.

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cloaca [klo-a´kah] (pl. cloa´cae) (L.)

1. a common passage for fecal, urinary, and reproductive discharge in most lower vertebrates.

2. in mammalian embryos, the terminal end of the hindgut before division into rectum, bladder, and the primordia of the reproductive organs.

3. an opening in the covering or sheath of a necrosed bone. adj., adj cloa´cal.

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cloaca

pl. cloacae [L.]

1. a common passage for fecal, urinary and reproductive discharge in most lower vertebrates.

2. the terminal end of the hindgut before division into rectum, bladder and genital primordia in mammalian embryos.

3. an opening in the involucrum of a necrosed bone.

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avian cloaca

in birds the cloaca is divided into three poorly defined compartments: a coprodeum or a continuation of the rectum, a urodeum into which the urogenital ducts open (in the female the left genital duct is the oviduct) and the proctodeum which carries the cloacal bursa and the proctodeal glands.

common cloaca

the urorectal septum fails to develop; defecation and urination share a common cavity. Seen in Manx cat.