The hair grows from the bottom of the follicle by a multiplication of the cells covering the papilla upon which its root is moulded.
What is the structure and origin of the ovarian folliclein the rabbit, and (f) of the ovarian stroma?
The ripening follicle moves to the surface of the ovary and bursts, the ovum falls into the body cavity.
This ripening of an egg and rupture of a follicle corresponds with the monthly flow.
The ulcer is either on the apex of the dome of an isolated follicle or is within the area of a Peyer's patch.
Multiplication of the cells within the follicle (follicular suppuration) causes over-stretching and the wall bursts, forming the first stage of the follicular ulcer.
They result from the breaking down of the exposed wall of the closed follicle from over-distension.
Externally to the zona radiata there may generally be observed a somewhat granular structure, against which the follicle cells abut, and I cannot agree with Waldeyer (loc cit.
At a later period the lower part of the stalk at its junction with the follicle becomes continuously narrowed, and at the same time a rupture takes place in the cells which form it.
The membrane would seem indeed to be formed in some instances even before the ovum has a definite investment offollicle cells.
Apart from these more obvious points, an examination of the follicle cells from the surface, and not in section, demonstrates that the general resemblance in shape of follicle cells to the stroma cells is quite delusory.
The cells of the follicle are much more columnar towards the inner side than towards the outer.
Before the egg is quite ripe both kinds of follicle cells undergo retrogressive changes (Pl.
Round the completed follicle a very delicate membrana propria folliculi appears to be present.
I have ovaries both of the dog and cat of an equivalent stage, and in both of these the cells of the nests or egg tubes may be divided into two categories, destined respectively to become ova and follicle cells.
Semper considers the larger cells of such a follicle to be probably primitive ova destined to become permanent ova.
The follicle, however, draws in with it into the stroma a number of additional epithelial cells in the form of a stalk connecting the follicle with the superficial epithelium.
The figure shews the commencing differentiation of the cells of the germinal epithelium into true ova and follicle cells.
In the course of the development of the ova they are broken up by stroma ingrowths, and each follicle with its enclosed ovum is eventually isolated by a layer of stroma.
The formation and development of the Graafian follicle begins at puberty and continues until the menopause or "change of life" of the woman.
The follicleis dilated at the bottom to correspond to the root bulb, and the ducts of one or more sebaceous glands open into it.
They are formed by a dilatation of the hair follicle and sebaceous duct within the skin, and contain a gray or yellowish sebaceous mass.
Impoverished state of blood, the result of kidney diseases or of local friction or contusions, with the entrance of pus cocci through the damaged skin or through a hair follicle or a sebaceous gland.
At the bottom of each follicle is a conical, vascular papilla, similar in every respect to those on the surface of the dermis; this papilla fits into a corresponding depression in the root of the hair.
The body hair has its origin in a layer of the epidermis, deeply imbedded in the corium as though it were in a little sac or follicle (Fig.
The rest of the torn follicle makes itself over into a peculiar yellowish body, the true corpus luteum, should pregnancy occur.
The follicle bursts, the ovum is discharged and wanders, the uterus waits and wonders.
Until again, another follicle swells, another ovum matures, and the premenstrual state of sex high tide cycles back.
In Aphrophora the follicles of each testis are free, forming a dense cluster, each follicle being connected with the vas deferens by a short duct.
Figure 2 is from the follicle of a young egg; here we find 28 chromosomes, but no small one.
A #boil# results when the infection is located in a hair follicle or sebaceous gland.
After an interval of from six to ten days a soft white slough is discharged; this is known as the "core," and consists of the necrosed hair follicle or sebaceous gland.
The orifice of the partly blocked sebaceous follicle is sometimes visible, and the contents of the cyst can be squeezed through the opening.
A pericarp, opening longitudinally on one side and having the seeds loose in it; a follicle; a double follicleor pair of follicles.
In fact, a follicleof the ovary bursts, and, to be precise, that one which protrudes most beyond the surface of the ovary.
This bursting of the follicle has not actually been observed.
We know well that in the case of the lower animals when rutting, as in the case of the human female during menstruation, an ovum is liberated from the follicle in the ovary, and ordinarily passes away in the menstrual discharge.
Eimer, Beneke, Van Bamecke, and Hensen, call attention to the phenomenon which is observed in the case of bats, who for a whole month before the detachment of the ovum from the follicle have their uteri full of semen.
But the greatest disease that is to bee feared, is the Cataphalusie, that is to saie, good fellowes this yeere for want of money shall oft times be contented to part companie.
The hairs are cuticular products growing from an enlarged papilla lodged in the depth of a follicle or sac, hollowed out in the skin and extending to its deepest layers.
When an abscess occurs about a hair follicle it is called a boil or furuncle; when several hair follicles are involved, resulting in the formation of more than one exit for the inflammatory products, it is called a carbuncle.
The hair follicle is lined by cells of epidermis, which at the bottom are reflected on the papilla and become the root of the hair.
Each tooth comes out traversing and widening the narrow aperture through which the “tail” of the follicle passes.
He therein describes with great accuracy the dental follicle from its first appearing to the moment of birth, following it throughout its evolution.
Clopton Havers held that the dental follicle no longer furnishes any nourishment to the enamel from the moment that this has reached its perfect formation.
Although the author does not express himself very explicitly, he seems to consider the follicle of the tooth substantially identical with its ligament.
The more recent and softer the tooth, the more its follicle has a mucous appearance and differs from the nature of membranes.
In my patient, however, in addition to her nasal trouble, I found an enlarged follicle about the size of a pea back of the posterior pillar of the pharynx, at the junction of posterior pillar and pharynx.
This follicle was removed by a simple process, when, as if by magic, the G sharp responded and has since remained unimpaired.
The immediate exciting cause is the entrance into the follicleof a microbe, the staphylococcus pyogenes aureus.
On the general surface the fungus has its seat in the epidermis, especially in the corneous layer; upon the scalp and bearded region the epidermis, hair-shaft, root and follicle are invaded.
The disease is primarily a perifolliculitis, the follicle and its sheath subsequently becoming involved in the inflammatory process.
The oval and somewhat enlarged part of the hair within the follicle is called the root, or bulb, and the uniform cylinder beyond the follicle is called the shaft.
Numbers of ova die without reaching maturity, the follicular cells degenerate, and the follicle becomes filled with the cells of the theca interna, which have a resemblance to those of the true corpus luteum.
Substances diffusing from the ovum would be present in the follicle cells during this process, and probably act as a stimulus.
The materials for this, at any rate, passed through the follicle cells, and it is probable that these cells were not entirely passive, but actively secretory in the process.
In the wall of the follicle two layers are distinguished, the theca externa, which is more fibrous, and the theca interna, which is more cellular.
The feather, on the other hand, is a tubular structure arising from a papilla at the base of a deep follicleextending inwards from the surface of the skin.
The same substances diffusing from the ovum during its development in the uterus would continue to stimulate the follicle cells, and thus explain not merely their persistence, but their secretory activity.
Another outgrowth from the follicle forms a sebaceous gland.
Originally in the reptilian ancestor, or in the Monotreme, the ovum in the follicle secreted yellow-coloured yolk.
Bühler on the other hand, confirmed my own negative result with regard to oviparous Teleosteans, and also found no hypertrophy of the follicle in Cyclostomes which are also oviparous.
These cells, which are well marked off from the surrounding flattened peritoneal elements, increase in number by division, and form small masses surrounded by a follicle of peritoneal cells, and attached by a stalk to the peritoneum.
Its development at this point appears to be due to the fact that the follicle is here incomplete; so that the cuticular membrane deposited by it is also incomplete.
By the rupture of the stalk the whole folliclebecomes eventually detached, and the further development of the ovum takes place in the body cavity.
The most remarkable modification of the follicle is that which is found in Mammalia.
In Sipunculus the ova in the body cavity are surrounded by a follicle which is thrown off before they become ripe.
The follicle cells are not as a rule directly absorbed into the body of the ovum, though in some instances, as in Sepia (vide p.
At first the follicle is similar to that of other Vertebrata, and is formed of flat cells derived from the germinal cells adjoining the ovum.
At this time or slightly before, the follicle cells together with the germinal mass, which throughout exhibits no signs of atrophy, become thrown off, and the ovum is left invested in its vitelline membrane.
In many cases some of the germinal cells form a follicle, while other germinal cells form a mass within the follicle destined eventually to be used as pabulum.
The ovum now becomes more or less separate from the mass of germinal cells, rapidly grows in size, and soon forms the most considerable constituent of the follicle (fig.
In Phascolosoma there is nofollicle (Semper, Spengel).
There is always a chorion formed as a cuticular deposit of the follicle cells, which is frequently sculptured, finely perforated, etc.
It is believed by Packard to be moulted after the formation of the limbs, and to be equivalent to the amnion of Insects, while by Dohrn it is regarded as a product of the follicle cells.
The follicle cells soon become larger and give rise to an envelope round the egg of the nature of a chorion.
The spores would appear to enter through the unbroken cutaneous surface, and to germinate mostly in and around the hair-follicle and sometimes in the shaft of the hair.
Graafian follicle with two ova, about to divide into two follicles, from a rabbit six weeks after birth.
The hair follicle and the sebaceous gland, which have undergone necrosis, are found in this core.