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PHYS4
Reproduction I
| Question | Answer |
|---|---|
| What are the primary reproductive organs? And what do they generally produce? | Testes and ovaries; produce hormones and gametes |
| What are accessory reproductive organs? | ducts and glands |
| What is the central organ responsible for the production of sex hormones? | Hypothalamus |
| What hormone secreted by the hypothalamus does this? And where does it act? | GnRH that acts on anterior pituitary |
| What does it do at the ant. pituitary? | Makes it release gonadotropoins like FSH and LH |
| What are steroid sex hormones released in response to FSH and LH for females? Males? | Estrogen and progrestrone for females and adrogens for males |
| GAMETE PRODUCTION | GAMETE PRODUCTION |
| What are gametes? Give examples of them AND their location? | reproductive cells; like the ova (ovaries) and spermatozoa (testes) |
| What are teh stages of gametogensis? | Mitosis then meiosis |
| When does mitosis become predominat? | Fetal development |
| What are teh steps of haploid cell formation? | Start with diploid cell-->mitosis-->1st dvision- of meiosis-->2nd division of meiosis-->haploid cell |
| What happens in the first division/ | Crossing over |
| So, what two core things happen in meisosi? | Crhomosomes replicate (92 total) and crossing over occurs |
| In crossing over, exchange of genes between what takes place? | Homologous chromosomes |
| Corssing over serves to? | combine mom and dad's DNA to 2^23 possibilities |
| In SECOND meiotic division, what key things must be noted? | 1. no replication of DNA, sister chromatids divide |
| TESTES | TESTES |
| What are the testes responsible to produce? | adronogens (testrostrone), and sperm |
| When does sperm production in males start? stop? | starts in puberty and doesn't stop |
| Where is spterm produced? What is involved in sperm production? | Made in seminiferous tubules with the help of sertolli cells. |
| What activates sertolli cells? | FSH |
| What is the role of leydic cells? | secrete testrostrone w/ help of LH |
| What comprises teh structure of sperm (describe each) | Head (has DNA), Acrosome (penetrate egg), midpiece (mitochondria for movement) and flaggellum |
| Sperm gets into the sertolli cells to differentiate, how does it get out? Describe teh strucutre of the sertolli cells: | Tight junctions prevent stuff from coming in, but does let Primary spermatocytes out |
| What factors influence sperm development? | Abs, drugs, temp |
| Does environment play a role more in females or males? What is important in the other one? | Males > females; in utero in females is important |
| What is responsible to store sperm? | Epididymis and Vas Deferens |
| What secretes important stuff to make semen? | Bulbourethral glands |
| What secretes the bulk of semen? | Seminal vesicles and prostate gland |
| What is the transport path of sperm? | 1. Seminiferous tubules, 2. epididymis, 3. Vas deferens 4. Ejaculatory ducts 5. Urethra |
| What two signals initiate erections? | CNS input and somatosensory input to penis |
| What are the steps invovled in an erection? | Inihibit sympathetic-->increase parasympathetic reflex-->release NO-->Vasodilate-->compress veins (blood can't leave, so erection lasts for some time) |
| What are teh two phases of ejaculation? | Emission and expulsion |
| Emission steps involved? | Sympathetic input-->contraction of stuff that has to do with sperm travel path--> secretion into urethra |
| Expulsion involves? | Smooth muscle contracts in Urethra and skeletal muscle of penis expel semen |
| So what is the key different b/w erection and ejaculatioN? | Erection is the inhibition of sympathetic activitiy but ejaculation is stimulation of sympathetic activity |
| What strongly influences sperm development? | Testrostrone |
| What does FSH do to sertoli cells? | Makes them produce adrogen bidning protein |
| What does ABP do? | stimulates spermatogensis |
| What is the role of LH? | Binds to Leydig cells to stimulate secretion of testostrone and estrogen |
| What does testrone do? (3 things) | Acts on sertoli cells by diffiusing to help differentiate sperm; 2. get into blood to make hair, bone (estrogen)...3. negative feedback on hypothalmase to decrease GnRH and LH (less testrostone made) |
| What is the impact of anabolic steroids on sperm, testrone and muscle mass? | Decrease sperm and testrostrone, but increase muscle mass |
| What is teh action of inhibin AND what is it produced by? | Made by sertolli cells, inhibits release of GnRH and FSH |
| When are inhibin levels high? | When sperm count is high |