anal pit

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1. a hollow fovea or indentation.
2. a pockmark.
3. to indent, or to become and remain for a few minutes indented, by pressure.
anal pit proctodeum.
auditory pit a distinct depression in each auditory placode, marking the beginning of the embryonic development of the internal ear.
lens pit a pitlike depression in the fetal head where the lens develops.
nasal pit (olfactory pit) a depression appearing in the olfactory placodes in the early stages of development of the nose.
pit of stomach the epigastric fossa or epigastric region.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

a·nal pit

an ectodermally lined depression under the caudal eminence to the terminal part of the embryonic hindgut; at its bottom there is an epithelial plug. When this epithelial plug ruptures, the anal orifice is established.
Synonym(s): proctodeum (2)
Farlex Partner Medical Dictionary © Farlex 2012

a·nal pit

(ā'năl pit)
1. An ectodermally lined depression under the taillike caudal eminence adjacent to the terminal part of the embryonic hindgut; at its bottom, proctodeal ectoderm and cloacal endoderm form the cloacal plate. When this epithelial plate ruptures, the anal and urogenital external orifices are established.
Synonym(s): proctodeum.
2. Terminal portion of the insect alimentary canal.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


1. A tiny hollow or pocket. Synonym: depression; fossa
2. To be or become marked with a shallow depression; to cause a depression on pressure in edema.
3. A small depression in the enamel surface of a tooth often connected with one or more developmental grooves. It contributes to pit and fissure caries. Synonym: occlusal pit

anal pit


auditory pit

A pit that develops in the auditory placode.

costal pit

The inferior facet on the body of a thoracic vertebra. It articulates with the head of a rib.
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gastric pit

Any of many foveolae in the gastric mucosa into which the gastric glands open. See: illustration

lens pit

The depression on the skin of the embryonic head where the lens of the eye will develop.

nasal pit

In the embryo, one of two horseshoe-shaped depressions on the ventrolateral surface of the head bounded by lateral and median nasal processes. It gives rise to nostrils and a portion of the nasal fossa.
Synonym: olfactory pit

occlusal pit

Pit (3).

olfactory pit

Nasal pit.

optic pit

A small indentation of the optic nerve head. It may sometimes release fluid below the retina, which can cause central retinal detachment.

primitive pit

A minute depression at the anterior end of the primitive groove or streak and immediately posterior to the primitive knot.

pit of the stomach

1. Colloquial term for the depression at the end of the xiphoid process.
2. Colloquial term for the center of the abdominal region above the navel.
Medical Dictionary, © 2009 Farlex and Partners