Reproduction 3

• GnRH pulse generator

  Dispersed GnRH neurons located in the hypothalamus (preoptic, anterior hypothalamic and ventromedial areas) that regulate LH and FSH production and release, gametogenesis, steroidogenesis, and secondary sexual characteristics
• In males where can the GnRH neurons be found in the hypothalamus

  Preoptic

  Anterior hypothalamic and ventromedial areas
• Function of GnRH pulse generator in males

  Regulates LH ans FSH production and release

  Which stimulate gametogenesis ,steroidogenesis ,secondary sexual characteristics
• Why Is GnRH IA released in a pulsatile manner 


  This us to avoid down regulation of GnRH receptors in tge anterior pituitary
• What is the other name for p450

  Cholesterol desolate enzyme
• LH function in steroidogenesis

  Increases activity of p450

  Increase synthesis and secretion of testosterone via cholesterol

  Spermatogenesis
• Which cells are closer to the blood testes barrier

  Primary spermatocytes
• Where is gonadotropin releasing hormone released from

  Hypothalamus

  Function: increase GnRH = initiation of spermatogenesis at puberty because it triggers release of LH and FSH
• Where is LH released from

  Anterior pituitary

  Function of LH stimulate Leydig cells to produce and release testosterone
• Where is FSH released from

  Anterior pituitary

  FSH in testes stimulate sertoli cells which help nourish sperm cells
• Where is testosterone released from

  Testes

  Function: responsible for secondary sexual charteristics during adolescence and it stimulates spermatogenesis
• What is male fertility controlled by

  Estrogen especially in rodents

  Estradiol is important for modulating libido ,erectile function and spermatogenesis and the efferent ductule epithelium ,regulates fluid reabsorption

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• What's the function of activin

  Promotes FSH release

  Stimulates sertoli cell proliferation

  activin A is critical for growth and differentiation during testicular and epididymal development in mammals
• What is the function of inhibin

  Suppresses FSH secretion

  Positively correlated with sertoli cell function, sperm number and spermqtogenic status
• Follistatin

  Suppresses FSH secretion (related to inhibin )

  Also positively correlated with sertoli cell function, sperm number, and spermatogenic status
• What a pheromones

  Chemical compounds that facilitate communication among animals through the olfactory system via the vomarnasl organ

  Usually pheromones are released in saliva and other body fluids
• Releaser pheromone


  Stimulates an immediate and reversible behavioral response

  Short lived

  Eg bore exude androstenone which elicits lordosis I sows during their estrus period
• Primer pheromones function

  Alters the physiology, so that it displays a modified response pattern to future stimuli

  Longer lasting

  Eg queen honey bees produce a multi-component pheromone from mandibular gland to inhibit the ovarian development of workers to keep them in a non reproductive stage