Follicle


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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 ?
Around15-20 slides (every fifth section) were prepared for estimation of follicle count from each ovary.
The size of each follicle was measured using a caliper, and each follicle was classified as dominant or subordinate depending on the diameter as previously recommended with minor modifications(Ireland, Murphee, and Coulson, 1980).
Many factors regulate hair follicle stem cell quiescence.
Acne involves sebaceous glands of follicles too, but they become blocked by sebum under the influence of testosterone in both sexes.
Before this, no one knew that increasing or decreasing the lactate would influence hair follicle stem cells.
The effect of testosterone propionate during fetal and neonatal life on ovaries and also in prepubertal and adult female rats have been studied and reported that it resulted in a significant increase in body weight; the total number of follicle was unchanged, but there was significant increase in activating transitory follicles and a decrease in small antral follicles.
In spite of some investigations regarding the effect of BMP15 on in vitro development of follicles (19, 20), according to our knowledge, there was poor information about the effects of BMP15 alone or in combination with FSH on the expression of genes related to the maturation of oocytes and follicular cells including follicle stimulating hormone receptor (FSHR), cytochrome P450 family 17 (CYP17), proliferating cell nuclear antigen (PCNA), and zona pellucida glycoprotein 3 (Zp3) genes.
Because no existing treatment not even surgical autografting can increase the number of hair follicles, any viable method of regenerating hair follicles has great potential to succeed where other methods fail.
Results: Significant number of cystic follicles was observed in ovaries of animals of group B as compared to group A.
Each eyelash follicle rotates through the same three stages of growth as other body hair follicles.
When the size of the follicle reached 18 mm, recombinant hCG (rhCG) (Ovitrelle; Merck-Serono, Geneva, Switzerland), 250 [micro]g was administered, and follicular puncture was performed after 34-36 hours.