Development of the Urinary System
The urogenital system arises during the fourth week of the event from urogenital ridges in the intermediate mesoderm on each side of the primitive aorta. The nephrogenic ridge is the part of the urogenital ridge that forms the urinary system.
Three sets of kidneys develop sequentially in the embryo. The pronephros is rudimentary and nonfunctional and regresses completely. The mesonephros is functional for only a short period of time and remains as the mesonephric (Wolffian) duct. The metanephros remains as the permanent adult kidney. It develops from the ureteric bud, an outgrowth of the mesonephric duct, and the metanephric mesoderm derived from the caudal part of the nephrogenic ridge.
Urine excreted into the amniotic cavity by the fetus forms a major component of the amniotic fluid. Urine formation begins towards the end of the first trimester and continues throughout fetal life. The kidneys develop in the pelvis and ascend during development to their adult anatomical. This normally happens by the ninth week. The adrenal medulla forms from neural crest cells that migrate into the fetal cortex and differentiate into chromaffin cells. Don't use plagiarised sources.Get your custom essay just from $11/page
Congenital Malformations of the urinary system
Congenital anomalies of the kidney and urinary tract anatomy (CAKUT) are common in children and represent approximately 30% of all prenatally diagnosed malformations. CAKUT is phenotypically variable and can affect the kidney(s) alone and/or the lower urinary tract. The spectrum includes more common anomalies such as vesicoureteral reflux and, rarely, more severe malformations such as bilateral renal agenesis. In young children, congenital anomalies are the leading cause of kidney failure and kidney transplantation or dialysis.
History of the male reproductive system
The male gonads are the testes; they are the source of spermatozoa and also of male sex hormones called androgens. The other genital organs are the epididymides, the ductus, or vasa, deferential; the seminal vesicles; the ejaculatory ducts; and the penis, as well as certain accessory structures, such as the prostate and the bulbourethral (Cowper) glands. The principal functions of these structures are to transport the spermatozoa from the testes to the exterior, to allow their maturation on the way, and to provide certain secretions that help form the semen.
Development of the male reproductive system
Male reproductive systems develop in close relation to the urinary tract. Until approximately seven weeks of gestation, the human embryo remains sexually bipotential. Subsequently, in males, testis-inducing factors cause differentiation from the default female phenotype. As the testis forms, testosterone and other androgens drive the formation of the external genitalia and internal male reproductive structures, while other testicular factors cause regression of female reproductive organ precursors. Androgens also play a role in the descent of the testicles from their origin in the upper abdomen. Germ cells enter an arrested phase of maturation in the first trimester.
Congenital malformations of the male reproductive system
Androgens have an extensive influence on the brain development in regions of the brain that are relevant for autism spectrum disorder (ASD), yet their etiological involvement remains unclear. Hypospadias (abnormal positioning of the urethral opening) and cryptorchidism (undescended testes) are two relatively common male birth defects that are strongly associated with prenatal androgen deficiencies.
The organs of the female reproductive system are the ovaries, oviducts, uterus, vagina, placenta, and mammary glands. They work together for the production of female gametes (oocytes), fertilization, support of the developing fetus, delivering it to the outside world, and nutrition of the newborn.
The ovaries are responsible for the production of an oocyte (oogenesis) and secretion of female sex hormones (estrogen and progesterone). When it releases a mature ovum, it travels down the oviduct to the uterus.
Development of the female reproductive system
“Development of the human female reproductive tract is reviewed from the ambisexual stage to advanced development of the uterine tube, uterine corpus, uterine cervix, and vagina at 22 weeks. Historically this topic has been under-represented in the literature, and for the most part, is based upon hematoxylin and eosin-stained sections.
Congenital malformations of the female reproductive system
An understanding of congenital anomalies as they are encountered in clinical practice is greatly enhanced by not only a knowledge of normal embryology and the mechanism of formation of normal infants but also an insight into the processes that result in the development of anomalies. An awareness of malformations and a systematic examination and appraisal of every neonate will greatly increase the number of such anomalies found.
The causes of congenital malformations or abnormalities present at birth may be either environmental or genetic (chromosomal abnormalities). It is not always easy to separate the two factors; both may be at work in the same embryo or fetus.
Conclusion
The organizations of both male and female reproductive systems are fairly similar. The germ cells of the reproductive organs originate from the pole cells that are among the first to differentiate during embryogenesis. Together with mesodermal tissue, they form the reproductive organs of the adult. A pair of gonads is connected by individual ducts to a common duct, constructed from both mesodermal and ectodermal origins. Both reproductive systems are coordinated by hormones and transcription factors, which are ultimately regulated by physiological and environmental factors. The chapter describes the main and accessory organs of male and female reproductive systems in insects, including the development of these organs and of eggs and sperm. It also discusses the physiological processes involved in vitellogenesis, ovulation, fertilization, oviposition, and spermatogenesis, and endocrine control of these processes in insects. Although short-lived insects have a relatively brief reproductive opportunity, they compensate with a diverse assemblage of reproductive strategies that allow prodigious numbers of offspring to be produced under a wide range of ecological circumstances
References
Hirsch, L.H(2020) Male Reproductive system Retrieved from
https://kidshealth.org/en/teens/male-repro.html
Nephrol, S.N(2010) Congenital anomalies of the kidney and urinary tract.Retrieved from
https://www.ncbi.nlm.nih.gov/pubmed/20807610
Rao, K.P, Burnett, L.A(2012) Development of the Male Reproductive System Retrieved from
https://link.springer.com/chapter/10.1007/978-1-4471-4405-2_2