Fallopian tube isthmic mucus and ovum transport

Transcytosis is the process in which molecules are internalized by endocytosis, transported across the cell, and released through exocytosis from the opposite end of the cell. Molecules such as insulin, immunoglobulins, and certain nutrients are transferred through the recycling endosomes by recycling and transcytosis.
IgG molecules from a mother undergo transcytosis starting around 13 weeks of gestation. The amount of IgG transferred and entering the fetal blood circulation increases with...

The journey of sperm from its origin to the point of ejaculation begins within the seminiferous tubules of the testis. Here, Sertoli cells produce fluid that propels non-motile sperm through a series of conduits, starting with the straight tubules leading to the rete testis. This interconnected network of tubules acts as the initial pathway for sperm, guiding them into the efferent ductules and then into the epididymis for maturation.
The maturation phase occurs in the epididymis, where sperm...

The ovaries are roughly the size of almonds and measure approximately 2 to 3 centimeters in length. These paired structures are situated within the pelvic region and are anchored by the mesovarium—a peritoneal extension that also connects them to the wider structure of the broad ligament. The support system extends to the suspensory ligament, housing blood and lymphatic vessels. In addition, the ovarian ligament tethers the ovaries to the uterus.
On the ovarian surface, a layer of cuboidal...

The menstrual cycle includes a critical component known as the ovarian cycle, which undergoes two main phases each month—the follicular phase and the luteal phase. The follicular phase is variable and averaging around 14 days. Ovulation, triggered by a surge in luteinizing hormone (LH), marks the transition between the two phases. The second phase, the luteal phase, is relatively consistent, lasting approximately 14 days, and is marked by the activity of the corpus luteum. While a cycle length...

The ovarian cycle is meticulously regulated by the hypothalamic-pituitary-gonadal axis. This cycle orchestrates the release of a mature oocyte, essential for reproduction.
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle.  At puberty, GnRH secretion increases in both frequency and...

The uterine or fallopian tubes function as the conduit through which oocytes travel from the ovaries to the uterus. Each fallopian tube measures approximately 10 to 13 cm long and is anatomically divided into the infundibulum, ampulla, isthmus, and interstitial part (or intramural segment). The infundibulum is characterized by its funnel shape and features extensions called fimbriae which reach towards the peritoneal cavity. These fimbriae play a critical role during ovulation as they extend...