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Examples follow, but neither the list nor the discussions are exhaustive. In arteries and veins, the inner wall is the tunica intima, the outer wall is the tunica adventitia, and they are separated by the tunica media. More generally, the tunica adventitia or simply the "adventitia" is the outermost connective tissue covering round any internal ...
The zona pellucida is a translucent matrix of cross-linked glycoprotein filaments that surrounds the mammalian oocyte and is 6.5–20 μm thick depending on the species. Its formation, which depends on a conserved zona pellucida-like (ZP) module that mediates the polymerization of egg coat components, [2] is critical to successful fertilization. [3]
The embryological origin of granulosa cells remains controversial. In the 1970s, evidence emerged that the first cells to make contact with the oogonia were of mesonephric origin. It was suggested that mesonephric cells already closely associated with the oogonia proliferated throughout development to form the granulosa cell layer. [2] [3] [4]
Many of the features found in ovaries are common to all vertebrates, including the presence of follicular cells and tunica albuginea There may be hundreds or even millions of fertile eggs present in the ovary of a fish at any given time. Fresh eggs may be developing from the germinal epithelium throughout life.
The tunica albuginea is composed of short connective tissue fibers. It is located immediately inside the surface epithelium (previously known as germinal epithelium) which is continuous with the peritoneum. It is non-vascularised. [1] It is thinner than the tunica albuginea of the testis, and its thickness varies across the ovary. [1]
Tunica albuginea may refer to: Tunica albuginae (clitoris), the fibrous-elastic sheath of connective tissue that surrounds the shaft and glans of the clitoris; Tunica albuginea oculi, the tough fibrous layer that covers most of the eyeball; Tunica albuginea (ovaries), the connective tissue covering of the ovaries
In animals, the process involves a sperm fusing with an ovum, which eventually leads to the development of an embryo. Depending on the animal species, the process can occur within the body of the female in internal fertilization, or outside in the case of external fertilization. The fertilized egg cell is known as the zygote. [2] [5]
These organs are responsible for the production of the egg cells (ova) and the secretion of hormones. The process by which the egg cell (ovum) is released is called ovulation. The speed of ovulation is periodic and impacts the length of a menstrual cycle. After ovulation, the egg cell travels through the fallopian tube toward the uterus.