Reproduction Quiz Flashcards
Testes
produce sperm (spermatogenesis inside structures called seminiferous tubules) and testosterone
Epididymis
Maturation (motility) and storage of sperm cells
Vas deferens/ Sperm duct
Carries mature sperm cells to seminal vesicle and prostate gland (arousal)
Seminal vesicle
adds nutrient-filled fluids (fructose – for energy) and mucous (protection) to mature sperm cells (seminal vesicle secretions = 70% of fluid volume of semen)
Prostate Gland
adds alkaline fluids (helps neutralize acidic environment of vagina so sperm can survive - prostate gland secretions = 30% of fluid volume of semen)
Semen travels out of the body through the….
urethra inside the penis
Ovaries
produce oocytes (they mature in the ovary during oogenesis prior to ovulation) and produces estrogen and progesterone
Fimbriae
tissue adjacent to ovary that sweeps an “egg” into the fallopian tube
Oviducts/ Fallopian tubes
tube that transports oocyte to uterus (where fertilization occurs as well)
Uterus
location where fertilized egg will implant and develop
Endometrium
Blood rich, mucous membrane lining the uterus to provide nutrients to implanting embryo
Vagina
passageway for penis to deliver sperm to
uterus (note that a muscular opening called the cervix protects the uterus); passageway for birth from uterus
Seminiferous Tubule
-Spermatogenesis (creation of male gametes) occurs in the testes in structures called seminiferous tubules
-Each tubule is surrounded by a membrane (basement membrane) which is lined with cells called germline epithelium cells (diploid)
-Germline epithelium cells divide by MITOSIS to make spermatogonia (which grow into primary spermatocytes (diploid cells) that divide by MEIOSIS to make spermatozoa)
-Sertoli cells in the tubules nourish developing spermatozoa
-Leydig cells (produce testosterone) and blood capillaries are found OUTSIDE/ surrounding the tubules
Spermatogenesis Steps
1.Germline cells (in seminiferous tubules) divide by mitosis to produce spermatogonia (2n)
* - some return to basement membrane and some continue growth into primary spermatocytes (2n)
2.FSH (follicle-stimulating hormone) stimulates meiosis I in primary spermatocytes (producing haploid (n = 23) secondary spermatocytes)
3. LH (luteinizing hormone) stimulates Leydig cells in the testes to produce testosterone
4. Testosterone stimulates meiosis II in secondary spermatocytes (producing 4, haploid (n= 23) spermatids) and stimulates Sertoli cells
5. Spermatids differentiate into sperm with nourishment from -Sertoli cells (tails, midsections – mitochondria) and move into the interior portion of the seminiferous tubules (the lumen) to be transported to the epididymis (for storage and maturation – mobility/ swimming)
Oogenesis (Pre-PHASE 1)
- Germline cells in the ovaries divide by mitosis to produce oogonia (fetus)
- Oogonia undergo growth to become primary oocytes (fetus)
- Primary oocytes begin meiosis I, but are arrested at Prophase I until puberty
* - Note: Primary oocytes are each surrounded by a layer of supporting cells called follicle cells. Primary oocytes + follicle cells = “primary follicles”
Oogenesis PHASE 1: FOLLICULAR PHASE (Days 5-~14)
- FSH (follicle-stimulating hormone) stimulates ONE primary oocyte (“follicle”) to mature and complete meiosis I (producing two haploid (n = 23) cells – one secondary oocyte and one polar body)
* - Note: the division of the cytoplasm in meiosis in oocytes is UNEQUAL, resulting in one LARGE (largest cell in the human body by volume) secondary oocyte, and one small cell called a polar body (basically just a reservoir for the extra set of chromosomes – will later degenerate) - The secondary oocyte (“follicle”) secretes estrogen (to inhibit FSH - negative feedback - so only one follicle matures at a time, and to stimulate the lining of the uterus (endometrium) to “repair”/ grow and develop new tissues rich in blood vessels – to nourish an embryo if fertilization occurs)
- Secondary oocytes begin meiosis II, but arrest at Prophase II/ Metaphase II. (Note: meiosis II will ONLY be completed IF the oocyte is fertilized by a sperm cell (this will produce another polar body and an ovum)