1 Male reproductive tract Reproduction a Urethra and seminal release share an external opening through the penis b Primary male sex organs gonads are the testes because they produce sperm c gametes Testes hang below the body in order to produce viable sperm at 37 degrees celsius 2 Sperm production a Spermatogenesis production of sperm spermatozoa in the seminiferous tubules sperm factories Hallmark of sexual maturity i ii Make gametes spermatozoa b Testis contains seminiferous tubules that are responsible for making c Epididymis where immature not yet motile sperm travel 20 days finish development ability to swim and can be stored for several months d Vas deferens also called the ejaculatory duct empties the epididymis into the copulatory organ the penis e 3 steps of spermatogenesis i Mitosis of spermatogonia stem cells Continued division of spermatogonia 1 2 After puberty 2 main type of cells a Type A cells b Type B cells i Mitosis to make more spermatogonia ii Stay close to basal lamina Become primary spermatocyte i i ii Meiosis 1 Primary spermatocytes undergo meiosis 1 a Form secondary spermatocytes Haploid 2 Secondary spermatocytes undergo meiosis 2 a Form spermatids iii Spermiogenesis 1 Occurs in epididymis 2 Spermatids mature a Spermatozoa Head genetic functions i ii Midpiece metabolic functions iii Tail locomotor functions f Cells involved in sperm production i Sertoli cells 1 Surrounded dividing spermatogonia spermatocytes 2 Support developing sperm a Called sustentocytes i Functions 3 Sustenance cells a Tight junctions between sertoli cells Form a blood testis barrier i b Regulate spermatogenesis Signals Secrete testicular fluid Eat bad sperm cells excess cytoplasm i ii iii iv Make androgen binding protein ii Leydig cells 1 In connective tissue surrounding the seminiferous tubules a Secrete hormones androgens 3 Semen a Mixture of sperm testicular fluid and accessory gland secretions Seminal vesicles Prostate gland Bulbourethral glands b Alkaline substance i ii iii i ii Neutralize urine and acidic vagina Components 1 Prostaglandins 2 Fructose a Catabolism makes ATP 4 Hormonal regulation of male reproduction a Production of gametes and sex hormones regulated by Hypothalamic pituitary gonadal axis HPG axis i 1 Involves the hormones a GnRH gonadotropin releasing hormone b FSH follicle stimulating hormone i Stimulates spermatogenesis indirectly 1 Causes sertoli cells to release a Androgen binding protein ABP i ii Binds testosterone Testosterone concentration high near spermatogenic cells Promotes spermatogenesis iii c LH luteinizing hormone i Binds to Leydig cells d e Testosterone Inhibin 1 Gets them to secrete testosterone 2 Testosterone triggers spermatogenesis b Hypothalamus releases gonadotropin releasing hormone GnRH c GnRH stimulates gonadotropic cells in AP i Causes release of FSH 1 2 LH d Testosterone entering the blood Sex organ maturation Secondary sex characteristics i ii 1 Body hair 2 Deeper voice 3 Broader shoulders iii Steroid Increased muscle mass 4 5 Libido 1 Binding protein in plasma 2 Intracellular receptor a Dimerize b Go into nucleus c Bind to DNA d Regulate gene expression 5 Female reproductive system a Urinary bladder and urethra ventral to the female uterus vagina b Urinary and reproductive systems have two separate openings c Primary female sex organs are the ovaries because they produce house egg gametes i ii iii Vagina Cervix 1 Uterus Connects vagina to uterus 1 Receives ova mature gametes 2 Uterus composed of 3 layers a Endometrium Innermost layer lines uterine cavity i ii Where embryo implants b Myometrium Smooth muscle Contracts to expel baby c Perimetrium Outermost Serous layer i ii i ii iv Oviduct uterine tube Fertilization 1 2 Not directly connected to ovary 3 Infundibulum a Fimbriae i Catch ovum during ovulation v Ovaries 1 Cortex where ova formed 2 Hilum blood vessels nerves 3 Follicles a Contains 1 egg cell oocyte b Surrounding cell layer vi Oogenesis 1 Oogonia a Diploid stem cells b Undergo mitotic divisions during fetal development 2 Oogonia transform into primary oocytes diploid a Surrounded by single layer of follicle cells b This is primordial follicle vii Before puberty viii At puberty 1 1 Primary oocyte arrested at prophase 1 Primary oocytes finish meiosis 1 a Produce 2 haploid cells i ii Smaller cell first polar body Cannot be fertilized 1 Larger cell become secondary oocyte 1 Stopped at metaphase 2 of meiosis ix x Secondary oocyte released during ovulation 1 Stopped at metaphase 2 If sperm penetrates oocyte 1 Secondary oocyte finishes meiosis 2 Forms 2nd polar body a b Produces large ovum 6 Comparing oogenesis vs spermatogenesis a Spermatogenesis All haploid i 4 functional gametes Sperm b Oogenesis 4 haploid cells Only 1 functional gamete ovum 3 polar bodies 1 Unequal cytoplasmic divisions 2 Fertilized egg has most nutrients 7 Regulation of the female reproductive system a Hypothalamus GnRH b AP LH and FSH ii iii i ii iii i ii iii Estrogens and progesterone FSH causes granulosa cells to release estrogens LH stimulates theca cells to produce androgens triggering ovulation and corpus luteum formation