QuestionSBA
QuestionChoice
This is not the correct answer. During puberty, oestrogen is responsible for external genital development in females. During the follicular phase of the menstrual cycle, oestrogen is secreted by the granulosa cells surrounding the follicles in the ovary which exerts a negative feedback on the pituitary gland to decrease secretion of Follicular Stimulating Hormone (FSH) and Luteinising Hormone (LH). This allows only one follicle to mature, and subsequently, when the oestrogen levels are high enough, it triggers positive feedback to the hypothalamic-pituitary-gonadal axis which results in a surge of LH that stimulates the dominant follicle to release an ovum. As such, oestrogen is not involved in the regression of the paramesonephric duct.
10027365
e
Oestrogen
QuestionChoice
This is not the correct answer. At puberty, Luteinizing Hormone (LH) secreted by the anterior pituitary gland stimulates the Leydig cells to produce androgens (testosterone). This results in the spermatogenic tubules canalising and the process of spermatogenesis initiating when the cells become more organized. In females, the lack of testosterone due to the absence of Leydig cells results in the regression of the mesonephric duct, while the absence of anti-mullerian hormone stimulates the development of paramesonephric ducts which subsequently give rise to the internal female genitalia. As such, testosterone is not involved in the regression of the paramesonephric duct.
10027364
d
Testosterone
QuestionChoice
This is the correct answer. During the fifth to sixth week of development, primordial germ cells migrate into the intermediate mesoderm of the genital ridge, surrounded and supported by somatic cells. The intermediate mesoderm forms two ductal systems, namely the mesonephric duct and the paramesonephric (Mullerian) duct. If the genital ridge expresses SRY (Sex determining region of Y chromosome), the somatic cells differentiate as Sertoli cells which secrete Anti-Mullerian Hormone (AMH), causing the paramesonephric (Mullerian) duct to degenerate. This prevents the female reproductive tract from developing. In females, the absence of AMH stimulates the development of the paramesonephric ducts, which give rise to the internal female genitalia.
10027361
a
Anti-Mullerian Hormone (AMH)
QuestionChoice
This is not the correct answer. Follicular Stimulating Hormone (FSH) and Luteinising Hormone (LH) are glycoproteins secreted by the gonadotropic basophils in the anterior pituitary gland that correlate with the menstrual cycle in females. FSH acts on Sertoli cells resulting in spermatogenesis in males and follicular development (oestrogen production) in females. As such, it does not contribute to the regression of the paramesonephric duct.
10027362
b
Follicular Stimulating Hormone (FSH)
QuestionChoice
This is not the correct answer. Luteinizing hormone (LH) and Follicular Stimulating Hormone (FSH) are glycoproteins secreted by the gonadotropic basophils in the anterior pituitary gland that correlate with the menstrual cycle in females. LH acts on Leydig cells resulting in testosterone production in males and corpus luteum production (progesterone production) in females. As such, it does not contribute to the regression of the paramesonephric duct.
10027363
c
Luteinising Hormone (LH)
Concept
Chapter
2693
3871
Development of the male reproductive system
Topic
171
Embryology
17870
During embryogenesis, what hormone is secreted by males which results in the regression of the paramesonephric duct?
a