160 Sentences With "theca" | Random Sentence Generator

"The scaffold would be useful in these cases once we have iPS-derived female oocytes and the hormone producing somatic cells (granulosa and theca) and we are able to develop a complete in vitro iPS-derived follicle," Woodruff told TechCrunch.

The theca folliculi comprise a layer of the ovarian follicles. They appear as the follicles become secondary follicles. The theca are divided into two layers, the theca interna and the theca externa. Theca cells are a group of endocrine cells in the ovary made up of connective tissue surrounding the follicle.

Theca interna cells express receptors for luteinizing hormone (LH) to produce androstenedione, which via a few steps, gives the granulosa the precursor for estrogen manufacturing. After rupture of the mature ovarian follicle, the theca interna cells differentiate into the theca lutein cells of the corpus luteum. Theca lutein cells secrete androgens and progesterone. Theca lutein cells are also known as small luteal cells.

Over a period of months, the granulosa cells and thecal cells secrete antral fluid (a mixture of hormones, enzymes, and anticoagulants) to nourish the maturing ovum. In tertiary follicles, the single-layered theca differentiates into a theca interna and theca externa. The theca interna contains glandular cells and many small blood vessels, while the theca externa is composed of dense connective tissue and larger blood vessels.

Theca cells (along with granulosa cells) form the corpus luteum during oocyte maturation. Theca cells are only correlated with developing ovarian follicles. They are the leading cause of endocrine- based infertility, as either hyperactivity or hypoactivity of the theca cells can lead to fertility problems.

The stele is divided into three parts, the tetramerous proxistele closest to the theca tapering through the mesistele to the dimerous dististele furtherest from the theca.

The stele is divided into three parts, the tetramerous proxistele closest to the theca tapering through the mesistele to the dimerous dististele furthest from the theca.

Stroma-like theca cells are recruited by oocyte-secreted signals. They surround the follicle's outermost layer, the basal lamina, and undergo cytodifferentiation to become the theca externa and theca interna. An intricate network of capillary vessels forms between these two thecal layers and begins to circulate blood to and from the follicle. The late-term secondary follicle is marked histologically and structurally by a fully grown oocyte surrounded by a zona pellucida, approximately nine layers of granulosa cells, a basal lamina, a theca interna, a capillary net, and a theca externa.

The theca externa is the outer layer of the theca folliculi. It is derived from connective tissue, the cells resembling fibroblasts, and contains abundant collagen. During ovulation, the surge in luteinizing hormone increases cAMP which increases progesterone and PGF2α production. The PGF2α induces the contraction of the smooth muscle cells of the theca externa, increasing intrafollicular pressure.

Hyperactivity of theca cells causes hyperandrogenism, and hypoactivity leads to a lack of estrogen. Granulosa cell tumors, while rare (less than 5% of ovarian cancers), involve both the granulosa cells and the theca cells.

Dinoflagellate theca can sink rapidly to the seafloor in marine snow.

The body of Cothurnocystis consists of a chalice (or theca) and a stem (tail or foot). The theca is fattened, boot-shaped and asymmetrical. The edges of the flat sides of the theca seem to consist of 14 elements, 11 defining the outline of the theca, and 3 are processes, one forming a "toe"-spike, a second a heel-spike and a third a lip-spike. The so-called "obverse"-side ("toe" pointing left), is covered with one thin integument, at the "reverse"-side the integument is interrupted by a "strut" formed by a branch of an element near the attachment of the stem, and a branch of an element at the top of the theca.

A frustule is usually composed of two identically shaped but slightly differently sized thecae. The theca which is a bit smaller has an edge which fits slightly inside the corresponding edge of the larger theca. This overlapping region is reinforced with silica girdle bands, and constitutes a natural "expansion joint." The larger theca is usually thought of as "upper," and is thus termed the epitheca.

The granulosa cells, in turn, are enclosed in a thin layer of extracellular matrix – the follicular basement membrane or basal lamina (fibro-vascular coat in picture). Outside the basal lamina, the layers theca interna and theca externa are found.

The labrum has a tube shape and the basal theca is slightly enlarged.

Batrachedra theca is a moth in the family Batrachedridae. It is found in Mexico.

In biology, the theca of follicle can also refer to the site of androgen production in females. The theca of the spinal cord is called the thecal sac, and intrathecal injections are made there or in the subarachnoid space of the skull. In human embryogenesis, the theca cells form a corpus luteum after a Graafian follicle has expelled its secondary oocyte arrested in second meiosis. Thecal shape is also important in graptolite and pterobranch taxonomy.

The smaller theca is usually thought of as "lower," and is thus called the hypotheca. As the diatom divides, each daughter retains one theca of the original frustule and produces one new theca. This means that one daughter cell is the same size as the parent (epitheca and new hypotheca) while in the other daughter the old hypotheca becomes the epitheca which together with a new and slightly smaller hypotheca comprises a smaller cell.

The "theca" is a Latin term, meaning covering or sheath. Together they essentially mean "lipped sheath".

Sutilizona theca is a species of sea snail, a marine gastropod mollusk in the family Sutilizonidae.

Byronia is a genus of theca-bearing cnidarians with a close affinity to the coronatid scyphozoans.

Strawberry anther with parallel thecae A theca (plural thecae) refers to a sheath or a covering.

Each type of cell behaves differently in response to FSH. Theca interna cells express receptors for luteinizing hormone (LH). LH induces the production of androgens by the theca cells, most notably androstendione, which are aromatized by granulosa cells to produce estrogens, primarily estradiol. Consequently, estrogen levels begin to rise.

The transverse surface groove is called the cingulum which runs laterally around the whole organism, whereas the other groove, sulcus, starts from ventral midpoint of the cingulum vertically down to the posterior end of the organism typically. The cingulum is a useful morphological feature in discerning species. For instance, the angle of descent of the cingulum varies among species. The theca is also separated by the cingulum into epitheca for theca above the cingulum and hypotheca for theca below the cingulum.

FSH induces the granulosa cells to make aromatase that converts the androgens made by the theca interna into estradiol.

Like most echinoderms, blastoids were protected by a set of interlocking plates of calcium carbonate, which formed the main body, or theca. In life, the theca of a typical blastoid was attached to a stalk or column made up of stacked disc-shaped plates. The other end of the column was attached to the ocean floor by a holdfast, very much like stalked crinoids. The stalk was usually relatively short, and in some species, was absent, with the holdfast being attached directly to the base of the theca.

In microbiology and planktology, a theca is a subcellular structural component out of which the frustules of diatoms and dinoflagellates are constructed.

Theca cells are then stimulated to produce testosterone, which is sent in a paracrine fashion to neighboring granulosa cells for conversion to estradiol.

In the lab, the cell types interacted with one another and functioned for all intents and purposes like a real ovary, even successfully maturing a human egg from its earliest stages in the follicle to a fully developed form. To build the ovary, honeycombs of theca cells were formed, one of two key types in the ovary, donated by reproductive-age patients at Women & Infants Hospital of Rhode Island. Together with human egg cells, donated granulosa cells were inserted into the honeycomb shape the theca cells formed. In days, the theca cells enveloped the granulosa and eggs, mimicking a real ovary.

The species Graciacystis could reach a theca length of . The theca of cinctans contained three major openings. The mouth was located on the right side of the anterior end, in the cinctus, and was associated with marginal grooves. All species had a left marginal groove, but the right marginal groove was sometimes absent and always shorter than the left one.

The genus name, Amylotheca, derives from the Latin, amylum (starch), and theca (case), and refers to the starch cells in the locules of the ovary.

The theca of cinctans was surrounded on its margins by a frame of large stereom plates called a cinctus, and the dorsal and ventral surfaces were covered in a tessellated arrangement of small plates. The stele was essentially an extension of the cinctus, rather than a discrete appendage, and would have been fairly stiff side-to-side but possibly more flexible up and down. The stele was not a holdfast, but may have served to stabilize the animal. In most cinctans, the overall shape of the theca was only mildly asymmetrical, but in the unusual genus Lignanicystis the theca was highly asymmetrical, convergent on the stylophorans in some respects.

Desmoschisis is asexual reproduction in dinoflagellates which the parent cell divides to produce two daughter cells, each daughter retaining half the parent theca, at least temporarily. During desmoschisis, the theca undergoes fission along a predetermined suture between thecal plates. The fission suture is oblique, usually from the top left to the bottom right (as in oblique binary fission).FENSOME R.A., TAYLOR F.J.R., NORRIS G., SARJEANT W.A.S., WHARTON D.I. & WILLIAMS G.L. 1993.

SF-1 levels is strongly expressed at the onset of follicular development in theca and granulosa cells which precedes expression of the aromatase enzyme responsible for estrogen biosynthesis.

In cells without gonadotropic stimulus, PFOS inhibit theca cells but not granulosa, while PFOA inhibit granulosa cells but not theca. These differences are explained by the different types of PPARs in cell type. The study used concentrations below the range found in human blood circulation, suggesting that this may occur in human population. These results indicated PFOS and PFOA act as endocrine disruptors on ovarian cells which could affect subsequent sexual steroids.

These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single competent oocyte in humans. They also consist of granulosa cells and theca of follicle.

There are five types of thecae ornamentation in this genus. Type A is a smooth theca or a theca with shallow depressions, a single row of pores lines the anterior and posterior cingular lists and the margins of the large epithecal and hypothecal plates. Type B has a more pitted thecal surface but has fewer pores; Type C is characterized by shallow hexagonal reticulation in the theca and a pore in the middle of each areola. Type D exhibits large, spherical areolation in the thecal surface with pores in the center of every 3-5 areolae; type E is characteristic of laterally flattened Dinophysis and consists of a circular areolation thecal surface and a central pore in nearly all areolae.

The church holds a relic, in the form of a bone fragment, of pope saint Cornelius. The relic holder is a silver- white neo-gothic metal monstrance of 33,5 centimetre height, with a round theca of about 4 centimetre diameter, which contains the bone fragment. The backside of the theca holds a red wax seal, around which the words Elenchi Dioecesi Brugenni 22.052 are written in pencil. It is not certain when the relic was acquired.

Results show the disruptor effect of PFOS and PFOA depends on cell type. PFOS and PFOA inhibit the secretion of steroid hormones in both theca cells and granulosa cells with gonadotropic stimulus.

The cytoplasm may contain additional organelles and macromolecules such as lipid droplets, vacuoles, and lysosomes. Additionally, the starch produced by Tetraselmis is the same as those produced from land plants. The theca of most species closely encloses the cell body, but can become separated due to irregularities in cell shape. Theca are usually smooth, but some species have developed distinct creases that cross perpendicularly near the cell apex, giving the cell the appearance of being divided into four longitudinal sections.

Androstenedione is converted to either testosterone or estrone. Conversion of androstenedione to testosterone requires the enzyme 17β-hydroxysteroid dehydrogenase. Androstenedione is released into the blood by theca cells. Conversion of androstenedione to estrone requires the enzyme aromatase.

Diagram of the hormones released by the hypothalamic-pituitary-ovarian axis during the early and late follicular phase of the human ovarian cycle. Broken lines represent absence of action and size of the arrows indicates relative concentrations of the hormone. The tonic FSH and LH pulses sufficiently stimulate the theca cells of the follicle to produce androgen substrates for granulosa cell aromatase and induces cytochrome P450 enzymes that can produce progesterone later in the luteal phase. Androgen substrates from the theca cells are used by the enlarging granulosa cells to produce more estradiol.

This alga has remarkable characteristics, including four flagella, a theca (polysaccharide envelope) and a vacuole (stigma or "eyespot") that contains photo-receptor molecules. T. convolutae lives in the free living state in the water column but is mainly benthics. Thus, in hospite, the alga does not have the same phenotype as in the free living state: it no longer has its flagella, its theca and stigma. These phenotypical differences did not allow Geddes, Delage and Haberlandt to deduce that the green cells in the tissues could have been micro-algae.

Species range in length from 40-170 µm. They are therefore classed as microplankton. Ornithocercus heteroporus - prominent lists on display Ornithocercus is a thecate dinoflagellate. This means they are armored with overlapping cellulose plates collectively called a theca.

These ganglia contain neurons whose postganglionic axons innervate the stomach, liver, gallbladder, spleen, kidney, small intestine, and the ascending and transverse colon. They directly innervate the ovarian theca and secondary interstitial cells and exert an indirect action on the luteal cells.

Some authors have interpreted what appear to be petals as petaloid staminodes. The stamens are 10 to 15 in number. The anthers are basifixed, as in all of Hamamelidaceae. Each theca has one sporangium, whereas for most angiosperms, there are two.

The tubarium has a variable number of branches or stipes and different arrangements of the theca, these features are important in the identification of graptolite fossils. In some colonies, there are two sizes of theca, the autotheca and the bitheca, and it has been suggested that this difference is due to sexual dimorphism. Graptolite zooid inside tubarium A mature zooid has three important regions, the preoral disc or cephalic shield, the collar and the trunk. In the collar, the mouth and anus (U-shaped digestive system) and arms are found; Graptholitina has a single pair of arms with several paired tentacles.

The theca are divisible into left and right sides longitudinally by a sagittal suture; there is also a latitudinal girdle. Structurally complex, the genus is characterized by possession of extensive girdle and sulcal lists (wing-like extensions of the cell wall). Their theca have numerous pores which open flush to the surface of the plate on the outside but have a raised rim on the inside, their number being positively correlated with cell size. The hypotheca of most species are covered in areolae (shallow depressions) which are deepened by secondary thickening which takes place in mature cells.

Theca cells are stimulated by luteinizing hormone (LH), with signaling originating in the hypothalamus of the brain. Gonadotropin releasing hormone (GnRH) is released by projections of the hypothalamus into the anterior pituitary gland. Gonadotrophs are stimulated to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are released into the bloodstream to act upon the ovaries. Within the ovaries, transmembrane G-protein coupled receptors (GPCRs) bind to LH in the bloodstream, and the signal is transduced to the interior of theca cells through the action of the second messenger cAMP and third messenger protein kinase A (PKA).

ET-2 is believed to act on the follicle by binding to and stimulating EDNRA, which is expressed constitutively on the external layer of theca cells (another type of steroid-producing stromal cell). This causes smooth muscle cells surrounding the ovary to contract. This smooth muscle layer encapsulates the ovary but is absent at the site where the oocyte is expelled, creating a region of low surface tension which weakens the follicle wall and promotes the release of an egg. ET-2 also binds to and activates EDNRB, which is constitutively expressed by granulosa cells and theca interna.

In each case, the wall is rigid and essentially inorganic. It is the non-living component of cell. Some golden algae, ciliates and choanoflagellates produces a shell-like protective outer covering called lorica. Some dinoflagellates have a theca of cellulose plates, and coccolithophorids have coccoliths.

It measures 12–16 µm in length and 7–11 µm wide, is a peridinin-containing photosynthetic dinoflagellate with a thin theca. Its large nucleus is spherical and present posteriorly, whereas its single chloroplast is parietal, lobed, and extends into the epi- and hyposome.

Side view of a female on Papaver rhoeas. Thecophora pusilla can reach a length of . This species appears to be highly variable. Thorax and abdomen of this very small conopid is mainly greyish-black, with a broad and relatively high theca in the females.

The anterior pituitary complex and hypophyseal portal system, where FSH and LH are released. Theca cells are responsible for synthesizing androgens, providing signal transduction between granulosa cells and oocytes during development by the establishment of a vascular system, providing nutrients, and providing structure and support to the follicle as it matures. Conversion of testosterone to estradiol through the action of aromatase. Theca cells are responsible for the production of androstenedione, and indirectly the production of 17β estradiol, also called E2, by supplying the neighboring granulosa cells with androstenedione that with the help of the enzyme aromatase can be used as a substrate for this type of estradiol.

Pelagomonas calceolata is uniflagellate, about 1.5 × 3 μm in size. Microtubular roots, striated roots and a second basal body are absent. A thin organic theca surrounds most of the cell. There is a single chloroplast with a girdle lamella and a single, dense mitochondrion with tubular cristae.

Akashiwo sanguinea is a species of marine dinoflagellates well known for forming blooms that result in red tides. The organism is unarmored (naked). Therefore, it lacks a thick cellulose wall, the theca, common in other genera of dinoflagellates. Reproduction of the phytoplankton species is primarily asexual.

Pistils are depressed globose or depressed trapezoidal in shape, 1-locular and with many ovules. Stamens consist of short filaments with thecae at the tip, dehiscing by a pore. Pollens squeezed out from the theca pore like a droplet. Fruits are berries with round to ellipsoidal shapes.

Androstenedione is a substrate for estrogen production in granulosa cells which produce aromatase. Thus, theca cells and granulosa cells work together to form estrogens. Androstanedione is a 5α-reduced metabolite of 4-androstenedione which serves as an intermediate in the biosynthesis of the androgen and neurosteroid androsterone.

Eleuteroschisis is asexual reproduction in dinoflagellates in which the parent organism completely sheds its theca (i.e. undergoes ecdysis) either before or immediately following cell division. Neither daughter cell inherits part of the parent theca.FENSOME R.A., TAYLOR F.J.R., NORRIS G., SARJEANT W.A.S., WHARTON D.I. & WILLIAMS G.L. 1993.

In 2018, an in vitro toxicology study analyzed the disruptor effect of PFOS and PFOA on porcine ovarian cell steroidogenesis. Specifically, the study focused on secretion in porcine theca and granulosa cells, controlling gonadotropic stimulation. PFOS and PFOA chemicals were used from Sigma-Aldrich Co. (St. Louis, MO, USA).

The labium, when present, is a flattened plate derived from the somite of the first walking leg. While large in many Eupnoi and Dyspnoi, it is small in most Laniatores and absent in Cyphophthalmi. The term stomotheca is derived from Ancient Greek stoma "mouth" and theca "case, box".

While sometimes leaflike (laminar), more commonly they consist of a long thread-like column, the filament, surmounted by a pollen bearing anther. The anther usually consists of two fused thecae. A theca is two microspoorangia. The gynoecium (women's house) is the collective term for the female organs (carpels).

Five ovaries were obtained and dissected to collect theca and granulosa cells. The experimental design included: evaluation of PFOS & PFOA on basal steroid secretion, stimulation of LH on theca cells and FSH on granulosa cells, effect of PFOS & PFOA on steroidogenesis in the stimulated cells, quantification of steroid hormones by chemiluminescence, protein content determination, statistical analysis. The treatment groups had 9 data points each, from which the mean and standard deviation were calculated. The control group had 15 data points. A multi-factor analysis of variance (ANOVA) and Tukey’s test were used for the concentrations of P4, A4 and E2. The two groups were compared using a Student’s “t”, with statistical significance set at p < 0.05.

Cell culture of granulosa cells can be performed in vitro. Plating density (number of cells per volume of culture medium) plays a critical role for the differentiation. A lower plating density makes granulosa cells exhibit estrogen production, while a higher plating density makes them appear as progesterone producing theca lutein cells.

This indicates that karyogamy has occurred. The theca then begins to develop and the cell becomes motile. As the planozygote matures, it shrinks and becomes immobile, eventually developing into a cyst. The cyst further develops to contain a single nucleus that makes up much of the volume of the cell.

Due to their long stratigraphic range, many fossil species (namely their cysts) have been described. By contrast, descriptions of extant species are primarily based on the motile stages (namely on the thecae, which are less diverseLewis, J., 1991. Cyst-theca relationships in Scrippsiella (Dinophyceae) and related orthoperidinoid genera. Bot. Mar. 34, 91–106.

Hence, both granulosa and theca cells are essential for the production of estrogen in the ovaries. Estrogen levels vary through the menstrual cycle, with levels highest near the end of the follicular phase just before ovulation. Note that in males, estrogen is also produced by the Sertoli cells when FSH binds to their FSH receptors.

They have rarely been associated with chronic kidney disease (secondary to reduced hCG clearance) and hyperthyroidism (given the structural homology with TSH). These cysts resolve after pregnancy. Rarely, when the theca-lutein cysts are stimulated by gonadotropins, massive ascites can result. In most cases, however, abdominal symptoms are minimal and restricted to peritoneal irritation from cyst hemorrhage.

This species has a straight body which is 70-200 µm long and 30-50 µm wide, with the epitheca gradually tapering into an anterior horn. C. furca has long spines, and is an "armoured" species with a theca of thick cellulose plates. The cells are nearly flat, with the ventral side concave and the dorsal side being convex.

Mantis ootheca An ootheca (pl. oothecae ) is a type of egg mass made by any member of a variety of species including mollusks (such as Turbinella laevigata), mantises, and cockroaches. The word is a Latinized combination of oo-, meaning "egg", from the Greek word ōon (cf. Latin ovum), and theca, meaning a "cover" or "container", from the Greek theke.

Cinctans were asymmetrical animals, though some species were nearly bilaterally symmetrical. Like all echinoderms, cinctans have a skeleton made of plates of stereom. The body of cinctans was divided into two sections, the main body, called the theca, and a posterior appendage called a stele. The overall shape of cinctans has been compared to a tennis racquet.

Cincta is an extinct class of echinoderms that lived only in the Middle Cambrian epoch. Homostelea is a junior synonym. The classification of cinctans is controversial, but they are probably part of the echinoderm stem group. Cinctans were sessile, asymmetrical animals with a skeleton made of stereom plates and a racquet-shaped body composed of a theca and stele.

The mouth was at the summit of the theca. Radiating like flower petals from the center were five food grooves, or ambulacra. Each ambulacrum had many long thin fine structures called brachioles, which were used to trap food particles and bring them to the mouth. Brachioles were delicate structures, and in fossils are not usually preserved in place.

The steroidogenic acute regulatory protein, commonly referred to as StAR (STARD1), is a transport protein that regulates cholesterol transfer within the mitochondria, which is the rate-limiting step in the production of steroid hormones. It is primarily present in steroid-producing cells, including theca cells and luteal cells in the ovary, Leydig cells in the testis and cell types in the adrenal cortex.

This adult ovarian phenotype suggests that in the absence of ERα, estrogen is no longer able to perform negative feedback on the hypothalamus, resulting in chronically elevated LH levels and constant ovarian stimulation. These results identify a pivotal role for ERα in the hypothalamus, in addition to its role in the estrogen-driven maturation through theca and interstitial cells of the ovary.

The apical pore in one Durinskia species is a slit-like pore that is located at the apex of the epitheca. The epitheca is either similar in size or slightly longer than the hypotheca. There are no ornaments on the smooth and thin theca in this genus. The cingulum slightly descends downward toward the medial of the organism by around half its width.

SF-1 expression is localized to adult steroidogenic tissues correlating with known expression profiles of steroid hydroxylases. Using in situ hybridization with SF-1 cRNA specific probe detected gene transcripts in adrenocortical cells, Leydig cells, and ovarian theca and granulosa cells. SF-1 specific antibody studies confirmed expression profile of SF-1 in rats and humans corresponding to sites of transcript detection.

Polycystic ovaries can be viewed by the ultrasound, and it will show multiple, small cysts in the ovaries. Some symptoms that people may experience with PCOS are irregular periods, acne, infertility, and excessive hair growth. PCOS is associated with excess levels of male hormones (androgens) or hyperandrogenism. Studies have shown that hyperandrogenism could be caused by a reaction between ovarian theca cells and reactive oxygen species.

The release of gonadotropins, LH and FSH, act on the gonads for the development and maintenance of proper adult reproductive physiology. LH acts on Leydig cells in the male testes and theca cells in the female. FSH acts on Sertoli cells in the male and follicular cells in the female. Combined this causes the secretion of gonadal sex steroids and the initiation of folliculogenesis and spermatogenesis.

Dinophysis acuminata is an oval-shaped protist. It measures 30-35 μm in length and 38-58 μm in diameter. The body is reddish- brown in colour and is covered with an armour-like covering called theca, which is made up of cellulose. The anterior end has a crown-like platform, which is the smaller epitheca; while the posterior is simply rounded constituting a larger hypotheca.

During staminate athesis, the staminate flower thecae point upward and emit odour. Shortly after that, the limb splits away from the lower spathe, coincidentally pollen droplet extrudes from the tips of the theca horns. Once the fertilization is successful, the interstice staminodes become photosynthetic, thicken, and harden until the fruits are fully developed. The enlarged berries push the staminodes up and staminodes shed away.

There are usually five stamens. The filaments are fused to the corolla, while the anthers are generally connate (syngenesious anthers), thus forming a sort of tube around the style (theca). They commonly have basal and/or apical appendages. Pollen is released inside the tube and is collected around the growing style, and then, as the style elongates, is pushed out of the tube (nüdelspritze).

Primordial follicles containing the primary oocyte, arrested at prophase of meiosis I, develop into primary follicle containing cuboidal granulosa cells. A secondary follicle is formed with a few granulosa cell layers, as well as a theca layer. Finally before ovulation, a tertiary follicle is formed containing a follicular-fluid filled antrum. Of these small antral follicles, 1 will become dominant and ovulate (in monoovulatory species).

Like most echinoderms, Pentacrinites was composed of numerous calcite plates which were arranged into different body parts. Pentacrinites had 3 kinds of body parts: arms, cup (calyx or theca) and stem. The stem consisted of a stack of numerous 5-sided beads (or columnal plates) with a canal at their centre. The stem had flexible appendages (or cirri) that were used to attach an individual.

Furthermore, granular and theca cells in the follicles will express relaxin in increasing levels depending on their size. During early pregnancy, the preimplantation conceptus will express relaxin, which will promote angiogenesis in the endometrium by up-regulating VEGF. This will allow the endometrium to prepare for implantation. In horses alone, the embryo in the uterus will express relaxin mRNA at least 8 days after ovulation.

The inner petals are slightly shorter. Its flowers have cylindrical receptacles that are 3-4 millimeters long. Its flowers have numerous oblong stamens that are 2-2.5 millimeters long. The tissue that connects the theca is hairy an terminates in a tuft of hairs at the top of the anthers. Its flowers have 4-5 oblong, carpels that are 5-7 millimeters long and covered in hairs.

These secondary sources of estrogens are especially important in postmenopausal women. The pathway of estrogen biosynthesis in extragonadal tissues is different. These tissues are not able to synthesize C19 steroids, and therefore depend on C19 supplies from other tissues and the level of aromatase. In females, synthesis of estrogens starts in theca interna cells in the ovary, by the synthesis of androstenedione from cholesterol.

Follicular atresia is the breakdown of the ovarian follicles, which consist of an oocyte surrounded by granulosa cells and internal and external theca cells. It occurs continually throughout a woman's life, as she is born with millions of follicles but will only ovulate around 400 times in her lifetime.[Faddy, M. J. "Follicle dynamics during ovarian ageing." Molecular and Cellular Endocrinology 163.1 (2000): 43-48.

The Apusozoa are an Obazoa phylum comprising several genera of flagellate eukaryotes. They are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. They are grouped together based on the presence of an organic shell or theca under the dorsal surface of the cell. The name derives from the Ancient Greek words for footless () and animal ().

It has a critical role in granulosa cell and theca cell growth, as well as in differentiation and maturation of the oocyte. GDF9 has been connected to differences in ovulation rate and in premature cessation of ovary function, therefore has a significant role in fertility. The cell surface receptor through which GDF9 generates a signal is the bone morphogenetic protein type II receptor (BMPR2).

The highest level of the cholesterol side-chain cleavage system is found in the adrenal cortex and the corpus luteum. The system is also expressed at high levels in steroidogenic theca cells in the ovary, and Leydig cells in the testis. During pregnancy, the placenta also expresses significant levels of this enzyme system. P450scc is also present at much lower levels in several other tissue types, including the brain.

Blastoids are small marine echinoderms that originated in Ordovician period and became extinct at the end of the Permian. They were never as diverse as their cousins, the crinoids. They were very similar in anatomy to crinoids, having a stem attached to the seafloor while a head held their internal organs. Their head is what makes them easy to distinguish from crinoids, with a five pointed “star” on their theca.

The plates form within alveolae and therefore the wall is found within the cell membrane. Lists are rigid outgrowths from edges of specific thecal plates supported by ribs. The ribs vary in number and development between species (the number of ribs is species specific) and are necessary for expansive list growth. The theca consists of 17 or 18 plates which are divided into epithecal, hypothecal, girdle, and ventral area.

Sandra Ann Carson, M.D., is the principal innovator of the first artificial human ovary. This innovation was reported in the Journal of Assisted Reproduction and Genetics, and recognized by Time magazine as one of the top 10 medical breakthroughs in 2010. In this work, Carson, et al. introduced theca cells donated by reproductive-age patients into "3-D Petri dishes" designed to resemble the sponge-like cells of a human ovary.

Khaya anthotheca, with the common name East African mahogany, is a large tree species in the Meliaceae family, native to tropical Africa. The name anthotheca was taken from the Greek word anthos, meaning flower, while theca refers to a capsule. It is known by a number of other common names, including Nyasaland, red or white mahogany. Oos-Afrikaanse mahonie is the Afrikaans name and acajou is its name in French.

A series of five spiracle plates surrounded the star-shaped mouth, which included the anus, mouth and entrances to a set of five complex, folded respiratory organs known as hydrospires. These spiracles prevented mixing of the various fluids. Waste elimination was through the anispiracle, an opening formed by the fusing of anus and adjacent spiracles. Pentremites godoni, a blastoid from the Lower Carboniferous of Illinois; basal view of theca.

Dinophysis acuta is a marine unicellular protist, and is the largest among Dinophysis. It is an armoured species with a distinct body covering called theca or test. The body is laterally compressed with a small, cap-like epitheca and a much larger hypotheca. It has the double collars (known as cingulum) around the top of the cell, and a further wing (known as the sulcus) running vertically down the cell.

In females, FSH insensitivity results in diminished development of ovarian follicles and granulosa cells and low to normal estrogen levels, elevated to very elevated gonadotropin levels, and low inhibin B levels, whereas males present with diminished Sertoli cell proliferation and moderately elevated FSH levels, normal to slightly elevated LH levels, normal testosterone levels, and reduced inhibin B levels. Due in part to elevated LH levels, which stimulate androgen production by theca cells in the ovaries, and due in part to FSH insensitivity, resulting in a lack of aromatase in nearby granulosa cells that normally convert androgens into estrogens, it could be expected that females with FSH insensitivity might present with symptoms of hyperandrogenism at puberty. However, this has not been found to be the case. This may be in part because FSH, via stimulation of granulosa cells and the resultant secretion of yet-unidentified paracrine factors (but possibly including inhibin B), has been shown to significantly enhance the LH-mediated stimulation of androgen production by theca cells.

In addition, theca cells predominantly secrete the relatively weak androgen androstenedione, whereas granulosa cells, signaled to do so by FSH under normal circumstances, convert androstenedione into its more potent relative testosterone (which is subsequently converted into estradiol). Hence, in females, FSH insensitivity may not only result in deficiencies in estrogen production by granulosa cells, but in diminished androgen synthesis by both theca and granulosa cells as well, which could potentially explain why hyperandrogenism does not occur. FSH insensitivity presents itself in females as two clusters of symptoms: 1) hypergonadotropic hypogonadism or hypoestrogenism, resulting in a delayed, reduced, or fully absent puberty and associated sexual infantilism (if left untreated), reduced uterine volume, and osteoporosis; and 2) ovarian dysgenesis or failure, resulting in primary or secondary amenorrhea, infertility, and normal sized to slightly enlarged ovaries. Males on the other hand are significantly less affected, presenting merely with partial or complete infertility, reduced testicular volume, and oligozoospermia (reduced spermatogenesis).

Accordingly, the Prorocentrales may be called desmoflagellates, and in some classifications were treated as a separate class Desmophyceae. All members have chloroplasts and a theca, which is composed of two large plates joined by a sagittal suture. This structure is shared with the Dinophysiales, and they are probably sister groups. This does not show up on rRNA trees, which also show two separate groups of Prorocentrum, but they leave their relationships mostly unresolved.

In dinoflagellate species with desmokont flagellation (e.g., Prorocentrum), the two flagella are differentiated as in dinokonts, but they are not associated with grooves. Dinoflagellates have a complex cell covering called an amphiesma or cortex, composed of a series of membranes, flattened vesicles called alveolae (= amphiesmal vesicles) and related structures. In In armoured dinoflagellates, these support overlapping cellulose plates to create a sort of armor called the theca or lorica, as opposed to athecate dinoflagellates.

A depiction of the ovarian cycle in animals In human adult females, the primordial follicle is composed of a single oocyte surrounded by a layer of closely associated granulosa cells. In early stages of the ovarian cycle, the developing follicle acquires a layer of connective tissue and associated blood vessels. This covering is called the theca. As development of the secondary follicle progresses, granulosa cells proliferate to form the multilayered membrana granulosum.

In the ovary, the LHCG receptor is necessary for follicular maturation and ovulation, as well as luteal function. Its expression requires appropriate hormonal stimulation by FSH and estradiol. The LHCGR is present on granulosa cells, theca cells, luteal cells, and interstitial cells The LCGR is restimulated by increasing levels of chorionic gonadotropins in case a pregnancy is developing. In turn, luteal function is prolonged and the endocrine milieu is supportive of the nascent pregnancy.

The body plan for this class was simple: a main body (theca), composed of many small plates, with a peripheral rim for attachment, and (in some species) a pedunculate zone for extension and retraction. Circling and sometimes attached to the body was a peripheral rim of plates. The main feature consisted of five arms, or ambulacra, in the body wall radiating outwards from the central mouth. The ambulacra grew either curved or straight.

When curved, they may all turn in the same direction or else one or two on the right side will curve opposite the others. The ambulacra are built of underlying floor plates that form the food groove and protective cover plates that roof the food groove. The anus was under the mouth region and was made of small triangular plates to form a cone-shaped area. The bottom surface of the theca is unplated.

During the first few hours after expulsion of the ovum from the follicle, the remaining granulosa and theca interna cells change rapidly into lutein cells. They enlarge in diameter two or more times and become filled with lipid inclusions that give them a yellowish appearance. This process is called luteinization, and the total mass of cells together is called the corpus luteum. A well-developed vascular supply also grows into the corpus luteum.

Friedrich Vieweg dem aeltern, Berlin, Germany. When a pollinator probes a male stage flower for nectar, (pushing the posterior anther theca) the lever causes the stamens to move and the pollen to be deposited on the pollinator. When the pollinator withdraws from the flower, the lever returns the stamens to their original position. In older, female stage flowers, the stigma is bent down in a general location that corresponds to where the pollen was deposited on the pollinator's body.

Theca lutein cyst is a type of bilateral functional ovarian cyst filled with clear, straw-colored fluid. To be classified a functional cyst, the mass must reach a diameter of at least three centimeters. These cysts result from exaggerated physiological stimulation (hyperreactio luteinalis) and are usually associated with markedly elevated levels of beta-human chorionic gonadotropin (beta-hCG). They are thus associated with gestational trophoblastic disease (molar pregnancy), diabetes mellitus, alloimmunisation to Rh-D, and multiple gestations.

9-21 It is highly expressed in the oocyte and has a pivotal influence on the surrounding somatic cells, particularly granulosa, cumulus and theca cells. Paracrine interactions between the developing oocyte and its surrounding follicular cells is essential for the correct progression of both the follicle and the oocyte.Castro, F., Cruz, M. and Leal, C. (2015). Role of Growth Differentiation Factor 9 and Bone Morphogenetic Protein 15 in Ovarian Function and Their Importance in Mammalian Female Fertility — A Review.

Rhabdopleura compacta colony with creeping and erect tubes. Each graptolite colony originates from an initial individual, called the sicular zooid, from which the subsequent zooids will develop; they are all interconnected by stolons. These zooids are housed within an organic tubular structure called a theca, rhabsodome, coenoecium or tubarium, which is secreted by the glands on the cephalic shield. The composition of the tubarium is not clearly known, but different authors suggest it is made out of collagen or chitin.

Dinoflagellate cysts described in the literature have been linked to a particular motile stage through morphological similarities and/or co-occurrence in the same population/culture or through the technique of establishing the so-called cyst-theca relation by incubation of the cysts. Geologists use a cyst-based taxonomy, whilst biologists use a motile-stage based taxonomy. Therefore cysts can have different names than the corresponding motile stages. Living cysts can be easily isolated from the sediment using sodium polytungstate, a heavy liquid.

Vegetative cells of diatoms are diploid (2N) and so meiosis can take place, producing male and female gametes which then fuse to form the zygote. The zygote sheds its silica theca and grows into a large sphere covered by an organic membrane, the auxospore. A new diatom cell of maximum size, the initial cell, forms within the auxospore thus beginning a new generation. Resting spores may also be formed as a response to unfavourable environmental conditions with germination occurring when conditions improve.

In mature specimens, the fossula has almost disappeared and the top axial area is smooth and wide with septa that project slightly starting outside this area, and continuing almost to the basal peduncle, which is small. The oldest specimens are flat, have "short deformed septa" and no fossula, but do have a theca between the basal septa. Some specimens consist of two corralites joined together. All of these physical characteristics are similar to those of some other fossil coral species, like Hadrophyllum orbignyi.

The Middle Devonian blastoid Hyperoblastus from the Milwaukee Formation; Wisconsin; lateral view of theca. Like crinoids, blastoids were high-level stalked suspension feeders (feeding mainly on planktonic organisms) that inhabited clear-to-silty, moderately agitated ocean waters from shelf to basin. The food gathering system of blastoids consisted of several types of ambulacra. Food entered the brachiolar ambulacra, was transferred to the side ambulacra through the brachiolar pit, then transferred to the main (median) ambulacra, and finally entered the mouth.

Paracrinoids are characterized by a mouth with two to five feeding arms arranged asymmetrically, or somewhat bisymmetrically. They have a U-shaped gut, and their anus is located next to the mouth. They have irregularly shaped bodies (theca), and a stem, superficially similar to crinoids, and may have used the stem to attach themselves to a substrate, although some reconstructions show them partially buried in sediment.Fossil Invertebrates, 1987, Boardman, Richard S., Cheetham, Alan H., and Rowell, Albert J., editors, pp. 580-1.

The remainder of the male reproductive system is derived from embryonic mesoderm, except for the germ cells, or spermatogonia, which descend from the primordial pole cells very early during embryogenesis. The aedeagus can be quite pronounced or de minimis. The base of the aedeagus may be the partially sclerotized phallotheca, also called the phallosoma or theca. In some species the phallotheca contains a space, called the endosoma (internal holding pouch), into which the tip end of the aedeagus may be withdrawn (retracted).

Approximately from the attachment of the stem to the "toe"-spike, is a structure reminiscent of a windpipe, that has been interpreted as a series of slits in the integument. The attachment of the stem seems to consist of four sets of left and right elements, becoming narrower further from the theca. Further down single and uniform elements of the stem seem comparable to the anatomy of sealily stems. The "instep" of the boot seems to hold both the mouth and the anus.

Thus, many tissues producing steroids, including the adrenal glands, testes, and ovaries, produce progestogens. In some tissues, the enzymes required for the final product are not all located in a single cell. For example, in ovarian follicles, cholesterol is converted to androstenedione, an androgen, in the theca cells, which is then further converted into estrogen in the granulosa cells. Fetal adrenal glands also produce pregnenolone in some species, which is converted into progesterone and estrogens by the placenta (see below).

Ovulation is a process where ovarian follicles rupture, releasing eggs that can be fertilized. Follicle dominance results due to competition between follicles, as only some will be selected for further development, which are known as the dominant follicle(s). During development some follicles are further ahead in development. The more developed follicles will have more blood vessels in theca of follicle, which means they will have more hormones such as FSH available to cross over the basement membrane into the follicle.

The thecal sac or dural sac is the membranous sheath (theca) or tube of dura mater that surrounds the spinal cord and the cauda equina. The thecal sac contains the cerebrospinal fluid which provides nutrients and buoyancy to the spinal cord. From the skull the tube adheres to bone at the foramen magnum and extends down to the second sacral vertebra where it tapers to cover over the filum terminale. Along most of the spinal canal it is separated from the inner surface by the epidural space.

The insignia of the praetorian prefect of Illyricum, as depicted in the Notitia Dignitatum: the ivory inkwell and pen case (theca), the codicil of appointment to the office on a blue cloth-covered table, and the state carriage.Kelly (2004), p. 41 Originally, the praetorian prefects were drawn from the equestrian class. Constantine's reforms entailed the reservation of this office for members of the senatorial class, and its prestige and authority were raised to the highest level, so that contemporary writers refer to it as the "supreme office".

The typical cell size of Dinophysis ranges from 30 to 120 µm, they are medium-sized cells. It is possible for the cell size of Dinophysis to vary from large, vegetative cells to small, gamete-like cells. Dinophysis have hypothecae that consist of two large plates, which take up most of the space of the theca, as well as some small platelets. The genus is characterized by having 18 plates: four epithecal plates, two small apical plates, four sulcal plates, four cingular plates, and four hypothecal plates.

The adrenals become markedly enlarged (hyperplastic) by the accumulated lipid. Lipid accumulation is thought to damage the cells further (“second hit hypothesis”). Because P450scc and StAR are also essential for sex steroid synthesis in the testis and ovary, the production of testosterone by Leydig cells in the testis and androgens (which leads to estrogen production by granulosa cells) and progesterone by ovarian theca cells and luteal cells, respectively, can also be impaired. Similar to the adrenal gland, cholesterol accumulation damages the Leydig cells of the testes.

Fragilariopsis kerguelensis is a unicellular, phototrophic, microalga with a range in size of 10 - 80 μm. It is encased in a heavily silicified cell wall, called the frustule, and is identified by its unique theca, raphe and striations, which distinguish it from other diatoms. They are native to pelagic environments of the Southern Ocean within a temperature range of -1° to 18° C. F. kerguelensis is known to form community chains that consist of 20-100 cells and can be up to 300 μm long.

Some species also have a twisted cell posterior that is mirrored in the thecal wall produced. The only perforation of the theca is where the flagella emerge, which is termed the apical depression. The pore is a long slit with thecal extensions that border it, extending upwards to protect the flagella base. In cells that have lost their flagella the thecal extensions grow to cover the slit, but they do not fuse; non-motile cells of Tetraselmis have flagellar stubs that remain within the thecal compartment.

For example, a lower plating density makes granulosa cells exhibit estrogen production, while a higher plating density makes them appear as progesterone-producing theca lutein cells. Cells can be grown either in suspension or adherent cultures. Some cells naturally live in suspension, without being attached to a surface, such as cells that exist in the bloodstream. There are also cell lines that have been modified to be able to survive in suspension cultures so they can be grown to a higher density than adherent conditions would allow.

Durinskia is a genus of dinoflagellate that can be found in freshwater and marine environments. This genus was created to accommodate its type species, Durinskia baltica, after major classification discrepancies were found. While Durinskia species appear to be typical dinoflagellates that are armored with cellulose plates called theca, the presence of a pennate diatom-derived tertiary endosymbiont is their most defining characteristic. This genus is significant to the study of endosymbiotic events and organelle integration since structures and organelle genomes in the tertiary plastids are not reduced.

In baronii, the anthers are very narrowly triangular at 5 to 6 times as long as wide, measuring 6 mm (0.236-inch) to 6.5 mm (0.256-inch) in length by 1.0 mm (0.039-inch) to 1.3 mm (0.051-inch) wide. They are pubescent inside at the base of the connective, the sterile part of the anther as opposed to the theca, which is the part of the anther that carries pollen, and are just below where the anther occurs with the pistil head, part of the female reproductive organ in a flower.

As the amplitude of LH pulses increases, the theca cells of the ovaries begin to produce testosterone and smaller amounts of progesterone. Much of the testosterone moves into nearby cells called granulosa cells. Smaller increases of FSH induce an increase in the aromatase activity of these granulosa cells, which converts most of the testosterone to estradiol for secretion into the circulation. The remaining testosterone, together with adrenal androgens is responsible for the typical androgenic changes of female puberty: pubic hair, other androgenic hair as outlined above, body odor, acne.

Chlorodendrales scales are unique from other Prasinophyceae lineages because the scales fuse to form a theca, which acts as an exterior protective casing for the cell. All Prasinophyceae lineages produce these external scales within the Golgi apparatus, and secrete the scales via the endomembrane system. Vesicles budding from the trans-Golgi face carry the scales to the cell surface, and upon fusion release the scales to the external cell face. In Chlorodendrales lineages, these scales fuse after secretion to produce the thecal wall, in which individual scales bind by cross-linking to one another.

As this genus containing species is part of the subphylum Alveolata and phylum Dinoflagellata, it has the defining characteristics of these groups. As in all alveolates, species in Durinskia have flattened vesicles known as alveoli under the plasma membrane. One of Durinskia’s shared characteristics with some dinoflagellates is the cellulose plates contained in alveoli forming the outer armor, theca. The other shared characteristics between Durinskia and dinoflagellates include the presence of condensed chromosomes in the large nucleus called the dinokaryon, and the two surface grooves that each bears one flagellum.

The sulcus is narrow and may widen as it extends to the posterior end of the organism as in D. agilis. The plates that form the theca immediately above and directly below the cingulum are called the precingular plates and postcingular plates respectively. In the genus Durinskia, organisms have 6 precingular plates and 5 postcingular plates; the cingulum and sulcus is composed 5 unequal plates and 6 plates respectively. Although the shape of the plates varies among species, all species have cingular plates that do not align with the postcingular plates.

The general stylophoran body plan consists of a flattened theca and a single jointed appendage which extends from it. Stylophoran tests are composed of stereom calcite plates, which has traditionally been the basis for assigning them to Echinodermata. However, they also lack the radial symmetry characteristic of most other echinoderms, with the earlier members of the group being flattened and asymmetrical, and the later ones closer to bilateral symmetry. In Mitrocystites and perhaps in other forms the appendage does not end in an attachment organ, and may have served the organism for movement.

The granulosa cells in the corpus luteum develop extensive intracellular smooth endoplasmic reticula that form large amounts of the female sex hormones progesterone and estrogen (more progesterone than estrogen during the luteal phase). The theca cells form mainly the androgens androstenedione and testosterone rather than female sex hormones. However, most of these hormones are also converted by the enzyme aromatase in the granulosa cells into estrogens, the female hormones. The corpus luteum normally grows to about 1.5 centimeters in diameter, reaching this stage of development 7 to 8 days after ovulation.

The Homalozoa lacked the typical pentamer body form of other echinoderms, but all were sessile animals. Instead all Homalozoans were markedly asymmetric, and were extremely variable in forms The body (theca) was covered with calcite plates with a number of openings. Their form is in some cases so unusual that it is unclear which openings are to be considered as mouth and anus. Many of them were stalked, similar to sea lilies (crinoids), but often their bodies were bent over, so that the mouth and anus projected forwards rather than upwards.

D. contigua was initially called Zosterophyllum contiguum by Li and Cai, based on parts of two spikes (strobili) of sporangia. When further specimens were found, a review by Li and Edwards agreed that the plant was a zosterophyll, but decided that the sunken sporangia and the absence of sporangial stalks were sufficient to require a new genus, Demersatheca. The name is derived from demersus, Latin for sunken, and theca, Latin for container, referring to the organization of the sporangia. Hao and Xue in 2013 considered the genus as incertae sedis within the tracheophytes (vascular plants).

The inhibition of rotation provided by their thecae would lead to increased water flow over parts of the cell which could enhance their feeding-current system. One study found that the area in contact with the highest volume of external medium due to water flow is also a region where there are markedly less barriers to nutrient transfer (two less membranes - including theca). By comparing extant morphologies in dinoflagellate species, it has been suggested that ancestral species were benthic and had streamlined cells. As lifestyles became more planktonic, the large cingular and sulcal lists evolved alongside.

Data extracted from the Prasinophyceae are defined by their cellular scales which are composed of carbohydrates, and Chlorodendrales are unique within this group due to these scales forming a fused thecal wall. Cells of Chlorodendrales are completely covered in scales, which fuse around the cell body producing the theca, but remain individually separated on the flagella, of which there are typically four per cell. Species within Chlorodendrales live in both marine and fresh water habitats, occupying both benthic and planktonic food webs. Additionally, they are photoautotrophs, meaning they produce their own food through the conversion of sunlight into chemical energy.

During gestation, the cells of the primordial gonad that lie along the urogenital ridge are in a bipotential state, meaning they possess the ability to become either male cells (Sertoli and Leydig cells) or female cells (follicle cells and theca cells). TDF initiates testis differentiation by activating male-specific transcription factors that allow these bipotential cells to differentiate and proliferate. TDF accomplishes this by upregulating SOX9, a transcription factor with a DNA-binding site very similar to TDF's. SOX9 leads to the upregulation of fibroblast growth factor 9 (Fgf9), which in turn leads to further upregulation of SOX9.

The insignia of the praetorian prefect of Illyricum, as depicted in the Notitia Dignitatum: the ivory inkwell and pen case (theca), the codicil of appointment to the office on a blue cloth-covered table, and the state carriage. In addition to his military functions, the praetorian prefect came to acquire jurisdiction over criminal affairs, which he exercised not as the delegate but as the representative of the emperor. By the time of Diocletian he had become a kind of grand-vizier as the emperor's vice-regent and 'prime minister.' Constantine removed active military command in 312.

The taxon was erected by Danish marine biologist Paul Lassenius Kramp in 1938 to accommodate certain families of hydrozoans with biphasic life histories. It includes genera with medusae with ecto-endodermal statocysts and with gonads alongside their radial canals, and also genera which have polyps that are not covered by a theca. Molecular analysis performed by Collins in 2006 has since shown that the Limnomedusae are not monophylic. The family Armorhydridae, which contains a single genus and a single species, Armorhydra janowiczi, is found living in coarse sediment, has hollow tentacles and has no radial canals.

LH supports theca cells in the ovaries that provide androgens and hormonal precursors for estradiol production. At the time of menstruation, FSH initiates follicular growth, specifically affecting granulosa cells. With the rise in estrogens, LH receptors are also expressed on the maturing follicle, which causes it to produce more estradiol. Eventually, when the follicle has fully matured, a spike in 17α-hydroxyprogesterone production by the follicle inhibits the production of estrogens, leading to a decrease in estrogen-mediated negative feedback of GnRH in the hypothalamus, which then stimulates the release of LH from the anterior pituitary.

In pure morphological terms, a dinocyst can be described as the body formed by the cyst wall, as well as the space it encloses and all the spaces within it. Cysts may develop their wall immediately within the theca, and such cysts are called proximate. Alternatively, the cyst may comprise a more or less spherical central body with processes or crests, and such cysts are termed chorate or proximochorate. Cysts may have a single-layered wall (autophragm), a two-layered wall (comprising an outer periphragm and an inner endophragm) or a three-layered wall (ectophragm, periphragm and endophragm if the outer wall is structurally supported, or otherwise periphragm, mesophragm and endophragm).

In the tertiary follicle, the basic structure of the mature follicle has formed and no novel cells are detectable. Granulosa and theca cells continue to undergo mitotis concomitant with an increase in antrum volume. Tertiary follicles can attain a tremendous size that is hampered only by the availability of FSH, which it is now dependent on. Under action of an oocyte-secreted morphogenic gradient, the granulosa cells of the tertiary follicle undergo differentiation into four distinct subtypes: corona radiata, surrounding the zona pellucida; membrana, interior to the basal lamina; periantral, adjacent to the antrum and cumulus oophorous, which connects the membrana and corona radiata granulosa cells together.

Primordial follicles are activated to grow into antral follicles. Communication between the oocytes and the surrounding somatic cells, such as the granulosa cells and the theca cells, is involved in the control of primordial follicle activation. There are various activator signalling pathways that are involved in the control of ovarian follicle activation, including: Neurotropin, nerve growth factor (NGF) and its tyrosine receptor kinase (NTRK1), neurotrophin 4 (NT4), brain-derived neurotrophic factor (BDNF) and their receptor NTRK2. Additional ligands have a role in facilitating primordial follicle activation such as transforming growth factor-beta (TGF-B), growth differentiation factor 9 (GDF9) and bone morphogenic protein 15 (BMP15).

Engolpia were of various forms, oval, round, four-cornered and of various materials ranging from gold to glass. In 1571 two gold encolpia, square in form, were found in tombs of the ancient Vatican cemetery, engraved on one side with the monogram of Christ between the Alpha and Omega, and on the other with a dove. Another, now lost, was found in the tomb of Maria, wife of the Emperor Honorius, bearing the names of the imperial couple with the legend VIVATIS and the monogram. The famous treasure of Monza contains the theca persica, enclosing a text from the Gospel of St. John, sent by Pope St. Gregory the Great (590-604) to Queen Theodolinda for her son Adaloald.

Unlike synthetic polymers, there has been a success with a wider range of natural polymers: collagen, plasma clots, fibrin, alginate and decellularized ovarian tissue. The microenvironment of the structure should mimic that of the natural ovary, so the artificial ovary should support the follicles structurally, but also cellularly. Ovarian stromal cells are integrated into the microenvironment as they play an important role in early development of the follicles. They release various factors which positively regulate the transition of primordial follicles to primary follicles, but also release other cells which will differentiate into theca cells; those that play a supportive role for growing follicles and produce sex steroids such as androstenedione and testosterone.

This culminated in a 2001 revision of the genus Coprinus, which was split into four genera; C. micaeus was transferred to Coprinellus. Due partly to their ready availability and the ease with which they may be grown in the laboratory, C. micaceus and other coprinoid mushrooms were common subjects in cytological studies of the 19th and 20th centuries. The German botanist Johann Heinrich Friedrich Link reported his observations of the structure of the hymenium (the fertile spore- bearing surface) in 1809, but misinterpreted what he had seen. Link thought that microscopic structures known today as basidia were thecae, comparable in form to the asci of the Ascomycetes, and that each theca contained four series of spores.

The preference of pathway is based upon whether the dinoflagellate host cell is thecate or athecate. To be thecate in dinoflagellates means to have an outer layer of cellulose plates that serves as an extra layer of protection, to be athecate means to not have this covering. If the dinoflagellate is thecate, then the pathway of infection will be nuclear; the process will follow with the de- attachment of dinoflagellate theca. If the host cell is athecate, then cytoplasmic infection will proceed which is indicated by the presence of vacuole-like structures in the cytoplasm, and because the nucleus is not infected first the dinoflagellate cell is resilient for longer than the thecate cell.

Androstenedione is a substance of weak androgenic activity which serves predominantly as a precursor for more potent androgens such as testosterone as well as estrogen. This compound crosses the basal membrane into the surrounding granulosa cells, where it is converted either immediately into estrone, or into testosterone and then estradiol in an additional step. The conversion of androstenedione to testosterone is catalyzed by 17β-hydroxysteroid dehydrogenase (17β-HSD), whereas the conversion of androstenedione and testosterone into estrone and estradiol, respectively is catalyzed by aromatase, enzymes which are both expressed in granulosa cells. In contrast, granulosa cells lack 17α-hydroxylase and 17,20-lyase, whereas theca cells express these enzymes and 17β-HSD but lack aromatase.

Common to the genus Karenia, this species shares morphological characters such as a smooth theca and a linear apical groove on its apex. At the same time, this species can be distinguished from its cogenerates on the basis of morphological characteristics within its vegetative cells, including the location and shape of its nucleus; the excavation of its hypotheca; the characteristics of its apical and sulcal groove extensions on the epitheca; the shape of its cells, as well as their size and symmetry; the degree of dorsoventral compression; and the presence of an apical carina. Species that present said dorsoventral compression are shown to swim in a distinctive fluttering motion.Rhodes, Lesley, and Susie Wood.

The choir stalls, Baroque, is the work of Matthew de Prado and the three largest altar pieces, along with the Relief Chapel of the same temple, are the work of Fernando de Casas Novoa, creating here one of the most exquisite Baroque nationally and internationally. Currently, this building has enabled part as a museum of religious art, which is accessed through the door of the church of St. Martin, and is distinguished as one of the best in the community. You can visit also the temple itself, the statio (sacristy), the sacristy, the former printing, the pharmacy, the chapel of the relics (theca) or the Renaissance choir of the Cathedral of Santiago de Compostela, and various collections of gold, ivory or liturgical vestments.

Sappinia tend to form distinct clusters in culture, possibly due to congregation where the bacterial count is highest. The sister genus Thecamoeba does not produce a true theca (shell), but are so named because they contain a very thick, dense glycocalyx, which can be up to 0.5 mm thick. Unlike Thecamoeba, Sappina species have highly varied glycocalyces depending on the strain and life cycle stage, and none are as thick or well defined as in Thecamoeba. Another difference between Thecamoeba and Sappinia is the surface of the dorsal region; Thecamoeba species tend to have well defined longitudinal ridges on the dorsal surface, whereas Sappinia species have a smooth dorsal surface, with some small wrinkles along the edges of the cell.

The most recent resting place of Cuthbert's remains, in Durham Cathedral Cuthbert died on 20 March 687 in his hermit's cell on Inner Farne Island, two miles from Bamburgh, Northumberland, and was taken back to the main monastery at Lindisfarne to be buried. Eleven years later the coffin was re-opened, and according to his biographies (including prose and verse ones by Bede from about 720) his remains were found to be "incorrupt" or undecayed. This was a traditional attribute of sainthood and helped greatly in his subsequent cult. He was reburied in a new coffin, apparently over the original one, which is described in his biographies, and matches the surviving coffin closely; this is called a levis theca ("light chest" in Latin) in Bede's biography.

This triptych (animal + micro-algae + bacterial consortium) is a good example of the Holobiont paradigm that explains that an organism (animal or plant) is a complex and dynamic association involving microbial populations necessary for development, growth and to some extent, for the life of the organism. S. roscoffensis does not have a digestive system at any time during its development. However, on its ventral side there is an orifice considered as "a mouth" which allows it to ingest (without digesting) the micro-algae Tetraselmis convolutae. The latter gives access to a digestive syncytium through which the future micro-algae in hospite is first vacuolated (it loses its flagella and its theca) then transits to be finally located under the epidermis of the animal without being internalized in the cells but in contact and between the cells of the worm.

The genetic component appears to be inherited in an autosomal dominant fashion with high genetic penetrance but variable expressivity in females; this means that each child has a 50% chance of inheriting the predisposing genetic variant(s) from a parent, and, if a daughter receives the variant(s), the daughter will have the disease to some extent. The genetic variant(s) can be inherited from either the father or the mother, and can be passed along to both sons (who may be asymptomatic carriers or may have symptoms such as early baldness and/or excessive hair) and daughters, who will show signs of PCOS. The phenotype appears to manifest itself at least partially via heightened androgen levels secreted by ovarian follicle theca cells from women with the allele. The exact gene affected has not yet been identified.

The gonadotropins affect multiple cell types and elicit multiple responses from the target organs. As a simplified generalization, LH stimulates the Leydig cells of the testes and the theca cells of the ovaries to produce testosterone (and indirectly estradiol), whereas FSH stimulates the spermatogenic tissue of the testes and the granulosa cells of ovarian follicles, as well as stimulating production of estrogen by the ovaries. Although gonadotropins are secreted in a pulsatile manner (as a result of pulsatile GnRH release), unlike the case of GnRH and GnRH agonists, constant/non-pulsatile activation of the gonadotropin receptors by the gonadotropins does not produce functional inhibition. This can be seen during the first 7–10 weeks of pregnancy, where constantly high and progressively-increasing levels of hCG circulate and mediate production of estrogen and progesterone by the corpus luteum until the placenta takes over the production of these hormones.

He was a keen wooden boat designer and builder having spent many years handcrafting full-scale, seaworthy wooden boats. He also conducted marine research off the coast of Queensland in his spare time, for the protection and understanding of the endangered manta-ray. He was a member and fellow of the Royal College of Obstetricians and Gynaecologists since 1976 and 1971, respectively, and a foundation fellow (since 1979) of the Australian College of Obstetricians and Gynaecologists since 1979. Also, a FRCOG (England) 1986, and FACOG (AM) 1988. Kerin’s Ph.D. thesis was titled “On the endocrine function of the human GraaFian follicle”, submitted in December 1977 to the Department of Obstetrics and Gynaecology at the Queen Elizabeth Hospital, The University of Adelaide, in fulfilment of the requirements for the degree of Doctor of Medicine in which his aim was to obtain an “understanding of the changing cyclical relationship which exists between the theca and granulosa cells of the isolated human Graafian follicle, in vitro, with respect to its ability to produce the three basic classes of sex steroids, namely the androgens, oestrogens and progestins” and to “critically examine factors controlling human ovarian follicle behaviour, in the hope of achieving a better understanding of female ovarian function”.