Question

Identify True/False statements. Correct each false statement to make it true. (a) Androgens are produced by Sertoli cells. (True/False) (b) Spermatozoa get nutrition from Sertoli cells. (True/False) (c) Leydig cells are found in ovary. (True/False) (d) Leydig cells synthesise androgens. (True/False) (e) Oogenesis takes place in corpus luteum. (True/False) (f) Menstrual cycle ceases during pregnancy. (True/False) (g) Presence or absence of hymen is not a reliable indicator of virginity or sexual experience. (True/False)

Short answer

(a) False, corrected to: Androgens are produced by Leydig cells. (b) True. (c) False, corrected to: Leydig cells are found in the testes. (d) True. (e) False, corrected to: Oogenesis takes place in the ovaries. (f) True. (g) True.

Step-by-step solution

- Evaluate statement (a)

Androgens are primarily produced by Leydig cells, not Sertoli cells. Sertoli cells support sperm cell development. Therefore, statement (a) is False. The correct statement should be: Androgens are produced by Leydig cells.

- Evaluate statement (b)

Spermatozoa indeed obtain nutrition and support from Sertoli cells. Therefore, statement (b) is True.

- Evaluate statement (c)

Leydig cells are not found in the ovary; they are found in the testes. Therefore, statement (c) is False. The correct statement should be: Leydig cells are found in the testes.

- Evaluate statement (d)

Leydig cells are responsible for the synthesis of androgens in males. Therefore, statement (d) is True.

- Evaluate statement (e)

Oogenesis takes place in the ovaries' follicles, not in the corpus luteum. The corpus luteum is involved in progesterone production after ovulation occurs. Therefore, statement (e) is False. The correct statement should be: Oogenesis takes place in the ovaries.

- Evaluate statement (f)

The menstrual cycle is indeed suspended during pregnancy. Therefore, statement (f) is True.

- Evaluate statement (g)

The state of the hymen is not a definitive indicator of virginity or sexual experience due to the variability in the hymen's physical attributes and how it can be affected by various non-sexual activities. Therefore, statement (g) is True.

Key concepts

Androgen Production

Androgen production is a fundamental aspect of human reproductive biology which primarily takes place in the Leydig cells within the testes. Androgens, such as testosterone, play a vital role in male development and reproductive function, influencing features like muscle mass, facial hair, and the deepening of the voice.

Biologically, the synthesis of androgens is stimulated by the luteinizing hormone (LH), which is secreted by the pituitary gland. Upon LH binding, Leydig cells begin the conversion of cholesterol into androgens. These hormones then perform various functions, including the promotion of sperm maturation in concert with Sertoli cells.

Sertoli and Leydig Cells

Sertoli and Leydig cells are specialized cells located within the testes that have distinct yet complementary roles in supporting male fertility.

Sertoli cells are often described as the 'nurse' cells of the testes. These cells provide structural support and nutrition to developing sperm cells, or spermatozoa, and also create a blood-testis barrier that protects the germ cells from potential toxins. They respond to the follicle-stimulating hormone (FSH) and aid in the regulation of sperm production through the secretion of inhibin, which inhibits FSH release.

In contrast, Leydig cells are found adjacent to the seminiferous tubules, where Sertoli cells are located. Leydig cells are primarily responsible for the production of androgens under the influence of LH. These cells play a crucial role in initiating and maintaining male secondary sexual characteristics and reproductive capability.

Oogenesis

Oogenesis is the process by which female gametes, or eggs, are produced in the ovaries. This process begins before birth when a finite number of primary oocytes are created and subsequently enter a suspended state called meiosis I. Oogenesis is characterized by a series of developmental stages, consisting of primary and secondary growth phases culminating in the formation of a mature ovum.

Each menstrual cycle triggers the growth of multiple oocytes, but typically only one reaches full maturity and is released during ovulation. The process from the development of the primary oocyte to a fertilizable egg is integral to female fertility and involves intricate hormonal controls. Unlike the continuous sperm production in males, oogenesis is cyclical and aligns with the menstrual cycle phases.

Menstrual Cycle

The menstrual cycle is a monthly series of physiological changes controlled by hormones, which prepare the female body for potential pregnancy. The cycle has several phases, including the follicular phase, ovulation, luteal phase, and menstruation.

The follicular phase is marked by the development of follicles in the ovaries, with one becoming dominant and maturing into an ovum. Ovulation is the release of this mature ovum into the fallopian tube. If fertilization does not occur, the luteal phase follows, where the corpus luteum forms from the remnants of the mature follicle and produces progesterone to maintain the uterine lining. The absence of pregnancy leads to the breakdown of the corpus luteum and a decrease in progesterone levels, resulting in menstruation, the shedding of the uterine lining.

Pregnancy interrupts this cycle as the hormonal environment shifts to support the developing embryo, effectively halting the menstrual cycle until after childbirth.