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Development of the gonads. The development of the gonads is part of the prenatal development of the reproductive system and ultimately forms the testicles in males and the ovaries in females. The immature ova originate from cells from the dorsal endoderm of the yolk sac. Once they have reached the gonadal ridge they are called oogonia.
Gonadotropins are released under the control of gonadotropin-releasing hormone (GnRH) from the arcuate nucleus and preoptic area of the hypothalamus. The gonads — testes and ovaries — are the primary target organs for LH and FSH. The gonadotropins affect multiple cell types and elicit multiple responses from the target organs.
A gonad, sex gland, or reproductive gland[ 1 ] is a mixed gland and sex organ that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. [ 2 ] The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells.
Luteinizing hormone (LH, also known as luteinising hormone, [1] lutropin and sometimes lutrophin[2]) is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (GnRH) from the hypothalamus. [3] In females, an acute rise of LH known as an LH surge, triggers ...
A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting gametes, as well as facilitating fertilization and supporting the development and birth of offspring.
The evolution of sexual reproduction contains two related yet distinct themes: its origin and its maintenance. Bacteria and Archaea ( prokaryotes ) have processes that can transfer DNA from one cell to another ( conjugation , transformation , and transduction [ 4 ] ), but it is unclear if these processes are evolutionarily related to sexual ...
Sexual differentiation in humans is the process of development of sex differences in humans. It is defined as the development of phenotypic structures consequent to the action of hormones produced following gonadal determination. [1] Sexual differentiation includes development of different genitalia and the internal genital tracts and body hair ...
Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. [1] The sex hormones include the androgens, estrogens, and progestogens. Their effects are mediated by slow genomic mechanisms through nuclear receptors as well as by fast nongenomic ...