BIOL373 - UNIT 8 - REPRODUCTION EXAM ACTUAL QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS GRADED A++

BIOL373 - UNIT 8 - REPRODUCTION EXAM ACTUAL QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS GRADED A++ Summarize the Hypothalamic-Pituitary-Gonadal (HPG) Axis 1. Internal and environmental stimuli trigger hypothalamus 2. Hypothalamus releases GnRH (gonadotropin-releasing hormone) 3. Anterior pituitary releases LH and FSH (luteinizing hormone and follicle-stimulating hormone) 4. LH and FSH act on somatic cells What is the effect of stimulating somatic cells? Support gametogenesis directly or indirectly via steroids What are the 3 possible effects of steroids in the HPG axis? 1. support gametogenesis (gamete production) 2. negative feedback on anterior pituitary and hypothalamus 3. actions outside gonads What are the 4 major products of the steroidogenic pathway for men? 1. DHEA 2. Adione 3. Testosterone 4. DHT (via 5a-reductase) What. are the 3 major products of the steroidogenic pathway for women? What is unique about this? 1. Progesterone 2. Estrone 3. Estradiol to make estrone and estradiol, androgens must be made first! (adione and testosterone) Compare the main hormone products of gonadal steroids between testes and ovaries testes -- testosterone, converted to DHT within target cells ovaries -- estradiol and progesterone How do all gonadal steroids mediate feedback? What is the exception? negative feedback at hypothalamus and anterior pituitary except estradiol under specific conditions! sustained high levels of estradiol -- surge release of LH/FSH (positive feedback) What temperature does spermatogenesis require? 2-3 degrees less than body temperature What is testicular migration dependent on? androgens to form scrotal sac What is cryptorchidism? failure of testes to descend What is the male reproductive system pathway starting at the testes? 1. testes 2. epididymis 3. vas deferens 4. ureter from bladder connects 5. seminal vesicle 6. prostate gland 7. bulbourethral gland 8. urethra where in the testes are sperm produced? seminiferous tubules What are the 4 steps to form a spermatid? What occurs in each stage? 1. spermatogonia (mitotic) 2. primary spermatocyte (entered meiosis I) 3. secondary spermatocyte (entered meiosis II) 4. spermatid (completed meiosis but has not undergone cell remodelling) What are the 2 somatic cell types found in male testes? Where are they found within the testes? 1. Sertoli cells -- lumen 2. Leydig cells -- interstitium What is the function of sertoli cells? "nurse cells" -- coordinate spermatogenesis What is the function of Leydig cells? androgen release?