The deep medullary portion of the testicular cords are stretched and converge towards the rete testis, which on the other side goes over into the efferent ductules (mesonephric tubules) that go out from the mesonephric duct (Wolff). From the 8th week the latter form compact convolutions, the ductus epididymidis.
What are cortical cords?
the cellular cords arising from the surface epithelium of the embryonic ovaries; the primordial germ cells in the cords differentiate into oogonia.
What is gonadal cortex and medulla?
The indifferent gonad now consists of an outer cortex and an inner medulla. In embryos with an XX sex chromosome complex, the cortex normally differentiates into an ovary and the medulla regresses. In embryos with an XY sex chromosome complex, the medulla differentiates into a testis and the cortex regresses.
Where are gonads derived from?
intermediate mesoderm
The gonads are derived from intermediate mesoderm. In humans, at 4 to 6 weeks of gestation, the urogenital ridges develop as paired outgrowths of coelomic epithelium (mesothelium). The gonads, adrenal cortex, kidney, and reproductive tract derive from the urogenital ridge (Figure 5-1).
What do primordial germ cells become?
These primordial germ cells migrate to the developing gonads, which will form the ovaries in females and the testes in males. After a period of mitotic proliferation, the primordial germ cells undergo meiosis and differentiate into mature gametes—either eggs or sperm.
What’s the difference between ovary and testes?
The ovaries are the female gonads. They are responsible for the production of the egg as well as the female steroid hormones, estrogen and progesterone. The testes are the male gonads. They are responsible for production of sperm and the male sex hormone.
What is indifferent stage?
An indifferent stage of genital development occurs where primordia of the organs of both sexes co‐exist. Two defined antagonistic pathways exist for sexual differentiation. The presence of the SRY gene on the Y chromosome promotes the development of male genital organs.
What are Epigenital tubules?
the epigenital tubules, establish contact with cords of the rete testis and finally form the efferent ductules of the testis Excretory tubules along the caudal pole of the testis, the paragenital tubules, do not join the cords of the rete testis 75.
How are gonads formed?
Gonads appear initially as a pair of longitudinal genital or gonadal ridges at the 4–5th week. Primitive gonads are formed by the proliferation of germ cells, which migrate from the yolk sac and undergo condensation of the underlying mesenchyme in the sixth week.
What are the two seminal tubules?
There are two types: convoluted and straight, convoluted toward the lateral side, and straight as the tubule comes medially to form ducts that will exit the testis. The seminiferous tubules are formed from the testis cords that develop from the primitive gonadal cords, formed from the gonadal ridge.
What is the main male gonad?
The gonads, the primary reproductive organs, are the testes in the male and the ovaries in the female. These organs are responsible for producing the sperm and ova, but they also secrete hormones and are considered to be endocrine glands.
What are medullary sex cords made of?
Medullary sex cords (orange) form testis cords. these later differentiate into solid seminiferous tubules that during puberty become hollow and actively produce spermatozoa. The surrounding connective tissue (pink) differentiates to form stromal cells.
What is the scientific name for the sex cord?
Anatomical terminology. In embryogenesis, the sex cords, (primitive sex cords or gonadal cords) are structures that develop from the gonadal ridges.
How are the primitive sex cords formed Quizlet?
These epithelial cells (from the gonadal ridges) will penetrate and invade the underlying mesenchyme to form the primitive sex cords. This occurs shortly before and during the arrival of the primordial germ cells (PGCs) to the paired gonadal ridges.
