Block 7 Dr Yin Repro Embryo

Zona pellucida
During the primary follicle stage, an amorphous substance appears, separating the oocyte from the follicular cells.
Contains specific proteins (ZP1, ZP2, ZP3) secreted by the oocyte and form an extracellular coat of glycoproteins.
ZP-3 is most important; acts as receptors for sperm binding and for inducing the acrosomal reaction.

The underdeveloped ductus epididymis and ductus deferens in a 15-year-old boy suggest a defect in the development of the male reproductive system. The mesonephric ducts, also known as Wolffian ducts, give rise to these structures. During embryonic development, the mesonephric ducts differentiate into the epididymis, ductus deferens, and seminal vesicles in males. The other options listed in the question, such as primitive sex cords, paramesonephric ducts, epigenital tubules, and paragenital tubules, are not involved in the development of these structures.

Theses are granulosa cells

Theca interna, theca externa, and granulosa cells
Stromal cells around the multilaminar primary follicle (theca folliculi) forms an inner theca interna (richly vascularized cellular layer), and an outer theca externa (fibrous c.t.)

Theca interna cells: steroid-producing cells, possess LH receptors on their cell membrane; produce androstenedione (male sex hormone), which enters the granulosa cells where it is converted by the enzyme aromatase into the estrogen estradiol.

Granulosa cells and theca interna are separated by a thickened basal lamina.

The seminal colliculus is the correct answer because it is the male counterpart of the hymen in females. The sinus tubercle in females gives rise to the hymen, which is a thin membrane that partially covers the opening of the vagina. In males, the derivative of the sinus tubercle is the seminal colliculus, which is a small elevation on the posterior wall of the prostatic urethra. It contains the openings of the ejaculatory ducts and the prostatic utricle, which is the remnant of the female Müllerian ducts in males.

also should know blue and black arrows

In the luteal phase of the menstrual cycle, the endometrium undergoes changes that are mainly influenced by progesterone. Progesterone is produced by the corpus luteum and causes the endometrium to become thicker and more vascularized, preparing it for potential implantation of a fertilized egg. Ischemia and necrosis of the stratum functionale, thickening of the stratum basale, presence of straight tubular glands, and necrosis and sloughing off of the endocervix are not characteristic changes of the endometrium in the luteal phase.

Chorion frondosum is a component of the placenta. The placenta is an organ that develops during pregnancy and is responsible for providing oxygen and nutrients to the developing fetus. The chorion frondosum is the part of the chorion that contains the chorionic villi, which are finger-like projections that help in the exchange of nutrients and waste between the mother and the fetus. The other options listed are also components of the placenta, but the chorion frondosum specifically refers to the part of the chorion that is involved in nutrient exchange.

If the excretory tubules from the nephrogenic cord regress completely after the second month of development, the ductuli efferentes will not form properly. The ductuli efferentes are small ducts that connect the rete testis to the ductus epididymis. They play a crucial role in transporting sperm from the testes to the epididymis for maturation and storage. Without properly formed ductuli efferentes, the transport of sperm would be disrupted, leading to reproductive issues in males.

Polyhydramnios refers to an excess of amniotic fluid during pregnancy. It can be caused by various factors, such as gastrointestinal (GI) atresia. GI atresia refers to a condition where there is a blockage or absence of a portion of the gastrointestinal tract, leading to impaired digestion and absorption. This can result in increased production and accumulation of amniotic fluid. Therefore, GI atresia can be a potential cause of polyhydramnios.

theca interna

interstitial gland, from remaining granulosa cells of atretic follicle.

atretic follicle which produces estrogen until menopause.

The allantois is a structure in the primitive umbilical cord that gives rise to the median umbilical ligament. During development, the allantois connects the developing embryo to the developing placenta. As the embryo grows, the allantois becomes incorporated into the umbilical cord and eventually forms the median umbilical ligament in the adult. This ligament is a remnant of the allantois and serves no significant function in humans.

Atresia of the caudal ends of the paramesonephric ducts refers to the abnormal closure or blockage of the lower part of the ducts, which are responsible for the development of female reproductive organs. This would most likely result in an atretic cervix, which means the cervix is closed or narrowed, preventing the normal passage of menstrual blood or sperm. The other options, such as uterus didelphys, double vagina, uterus bicornis, and short and atretic vagina, do not specifically match the given information about the atresia of the paramesonephric ducts.