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TUTORIAL REPRODUCTIVE PHYSIOLOGY

Dr.Mohammed Sharique Ahmed QuadriAssistant Professor Physiology

Al Maarefa College

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Applied Aspects • Discrepancies occur between genetic and

anatomic sexes• Pseudo hermaphrodite: – Gonad of one sex and genitalia of other Male Pseudo Hermaphrodite:

• Genetic males whose target cells lack receptors for testosterone are feminized ( testicular feminizing syndrome)

• Defective testicular development • 5α reductsae deficiency ( enzyme, coverts testosteron to

DHT)

– Female phenotype & XY male genotype

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Applied Aspects

• Female Pseudo Hermaphrodite:– Congenital virilizing adrenal hyperplasia– Administration of androgen to mother

• Male phenotype and XX female genotype

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four possible defects produced by maternal nondisjunction of the sex chromosomes at the time of meiosis

(Turner’s syndrome)

(Klinefelter’s syndrome)

Abnormalities of testicular functionCryptorchidism – descent of testes is incomplete one or less commonly both side, testes remain in the abdomen

Male hypogonadism: Clinical picture depends on whether testicular deficiency develops before or after puberty. causes:– Testicular disease(Hypergonadotrophic Hypogonadism)– Disorder of hypothalamus or pituitary

(Hypergonadotrophic Hypogonadism)

Androgen secreting tumors : Leydig cell tumors (a rare condition) leads to precocious pseudopuberty in prepubertal boys

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A 15-year-old boy presents for his annual athletic physical. A thorough examination reveals unilateral cryptorchidism. The physician schedules a follow-up visit with the boy and his parents to discuss his recommendation for surgery to correct the defect because of his concerns of possible infertility in the future. Which of the following statements about spermatogenesis is correct?

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A) Mature spermatozoa are present at birth, but cannot be released until pubertyis reached.B)Spermatogenesis requires a temperature lower than internal body temperature.C)Spermatogenesis requires continuous release of gonadotropin- releasing hormone (GRH).D)Leydig cell secretion of testosterone requires follicle- stimulating hormone(FSH).E)Luteinizing hormone (LH) acts directly on Sertoli cells to promote cell division.

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The normal pattern of progesterone secretion during the menstrual cycle is exhibited by which of the following curves?

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• An 18-year-old emaciated female who has been on a strict diet regimen and training for a marathon presents with amenorrhea. Exogenous pulsatile

administration of gonadotropin-releasing hormone (GnRH) restores ovulation and menses. Ovulation is caused by a sudden increase in the secretion of which of the following hormones?

a. LHb. FSHc. GnRHd. Estrogene. Progesterone

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• In the following graph of changes in endometrial thickness during a normal 28-day menstrual cycle, the event designated A corresponds most closely to which of the following phases?

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a. The menstrual phaseb. The maturation of the corpus

luteumc. The early proliferative phased. The secretory phasee. Ovulation

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• A 26-year-old male with Klinefelter’s syndrome has seminiferous tubule dysgenesis. Which of the following is a function of Sertoli cells in the seminiferous tubules?

a. Secretion of FSH into the tubular lumenb. Secretion of testosterone into the

tubular lumenc. Maintenance of the blood-testis barrierd. Synthesis of estrogen after pubertye. Expression of surface LH receptors

Correlation Between

Hormonal Levels and

Cyclic Ovarian and Uterine

Changes

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Feedback control of FSH & LH during follicular phase

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Feedback control of FSH & LH during ovulation

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Feedback control of FSH & LH during luteal phase

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Precocious Puberty

• Early development of secondary sexual characteristics.– True precocious puberty• Early otherwise normal pattern of GnRH secretion • Disorders involving hypothalamus, infection or tumor

– Pseudo precocious puberty(no gametogenesis)• Congenital adrenal hyperplasia• Androgen secreting tumors(in males)• Estrogen secreting tumors( in females)