Follicle

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Related to atretic follicle: corpus albicans, secondary follicle

follicle

[′fäl·ə·kəl]
(biology)
A deep, narrow sheath or a small cavity.
(botany)
A type of dehiscent fruit composed of one carpel opening along a single suture.

Follicle

 

a dry, one-celled, many-seeded, and monocarpel-lary fruit that opens along a ventral suture. The seeds are located along the suture on the edges of the carpel. Follicles are typical of the magnolias; of such members of Ranunculaceae as cowslip, garden columbine, aconite and larkspur; and of some genera of Rosaceae, such as Physocarpus.

The simplest follicles resemble a leaf folded in half lengthwise; the upper part corresponds to a stigma and the stem to a stalk. A large number of follicles may be positioned in a spiral on the axis of a blossom (as in the magnolia) to form a multiple fruit. Other types of fruits developed from follicles: nuts are follicles with a single seed, and beans are follicles with a different form of opening.


Follicle

 

a round, oval, or pear-shaped anatomical structure present in various organs in man and other vertebrates, having varied functions. In mammals egg cells develop within the ovarian follicle, which consists of a group of cells; one of these is the egg cell and the rest are epithelial cells surrounding the egg, first in one layer and then in several. As the follicle matures, spaces between the cells become filled with a clear liquid, and the single-layered primordial follicle is transformed into a mature multi-layered follicle, the Graafian follicle.

The follicle of the thyroid gland secretes thyroglobulin, a precursor of the thyroid hormones. Into the hair follicles, which enclose the hair roots and bulbs, empty excretory ducts of the sebaceous glands. Many lymphatic follicles are located in the mucous membranes of the digestive tract, the respiratory tract, and the urinary tract; for instance, follicles known as peyer’s patches are situated in the mucous membrane layer of the intestine.

References in periodicals archive ?
Scores of 1 +, 2 +, 3 + and 4 + were, respectively, considered for atretic follicles with 25, 50, 75 and 100 percent positivity for lipid staining.
In the animals undergoing BUAL, the cortex of ovaries was covered with small antral atretic follicles (<100-200 [micro]m).
Indeed, atretic follicles were observed in all classes of transitioning fish: early, mid, and late.
Thus, according to study results, it can be concluded that waves emitted from mobile phones may reduce the number of secondary and Grapian follicles by interfere in controlling routines and also increase the atretic follicles that can have adverse effect on fertility of female rats.
In addition, ovaries from BPA500 animals had fewer corpora lutea, fewer antral follicles, and more atretic follicles than did those from controls.
It seems that reductions in the number of primordial follicles, the number and diameter of secondary and antral follicles and the increase in the number of atretic follicles caused a significant decrease in ovarian weight in different stages of postnatal development.
In addition, histopathological changes in the ovary, including diabetes, polycystic ovary syndrome, ovarian enlargement [2,9] and atretic follicles have also been reported [2,21], although the exact mechanism is well known to have diabetes mellitus but construction has not increased free radical damage is the major mechanism [23] of antioxidants such as vitamins, flavonoids in the diet can have protective effects in diabetic patients [17].
Healthy primordial (type 2), primary (type 3 and 3 a), pre-antral (type 4, 5a and 5b), antral (type 6 and 7) and pre-ovulatory (type 8) ovarian follicles and their respective oocytes as well as atretic follicles in each category were quantified in those sections.
These consequences include 1) considerable follicular shrinkage (Witthames and Greer-Walker, 1987), 2) likely loss of atretic follicles and POFs (Klibansky and Juanes, 2007), and 3) incompatibility with histological methods (Hunter and Macewicz, 2003).
Oocytes were aspirated from the atretic follicles ranging in diameter from 2 to 5 mm using 18- gauge needle, into modified-PBS solution.