1 / 18

Reproductive System

Reproductive System. Chapter 16. Function. Production of offspring Male reproductive organ are testes Male gametes are called sperm Female reproductive organs are ovaries Female gametes are called ova. Male. Testes contain seminiferous tubules were spermatogenesis takes place

penda
Download Presentation

Reproductive System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Reproductive System Chapter 16

  2. Function • Production of offspring • Male reproductive organ are testes • Male gametes are called sperm • Female reproductive organs are ovaries • Female gametes are called ova

  3. Male • Testes contain seminiferous tubules were spermatogenesis takes place • Epididymis is a temporary storage site for sperm, sperm which are not used are resorbed • Ductus Deferens propel sperm toward seminal vessicles • Vasectomy • Urethra carries sperm to the outside

  4. Accessory glands • Seminal vesicles produce 60% of seminal fluid • Prostate activates sperm • Bulbourethral glands secrete thick mucous to clear urine from urethra prior to ejaculation • Semen is the transport medium for sperm • Provides nutrients and energy • Protects sperm from acidic environment of vagina • Antibacterial enzymes • Enzymes which enhance sperm motility

  5. Spermatogenesis • Seminiferous tubules contain two main cell types • Spermtgonia which divide to produce spermatocytes • Interstitial cells which provide protection and nourshment and secret testosterone • Spermatocytes undergo meiosis which produces gametes with 23 chromosomes (1/2 the genetic material) • This allows for the sperm and egg to combine for a total of 46 chromosomes

  6. Spermatogenesis • Spermatocytes undergo several divisions before becoming sperm • Sperm within seminiferous tubules are not functional • Sperm become functional as they proceed through the male reproductive tract

  7. Spermatogenesis • Testes produce sperm • Epididymis activate sperm motility • Seminal vesicles provide fructose, vitamin C, prostaglandins, further activating sperm • Prostate provides the final activation step of sperm

  8. Anatomy of Sperm • Head contains acrosome (enzymes which allow penetration of egg) and genomic DNA • Midpiece which forms the base of the tail and contains mitochondria to power sperm • Tail propels sperm through female reproductive tract

  9. Role of Hormones • Hypothalamus (GnRH) stimulates pituitary to release FSH and LH • FSH stimulates spermatogenesis • LH stimulates interstitial cells to secrete testosterone • Testosterone combined with FSH matures sperm (testes) but does not activate them • Testosterone also responsible for secondary sexual characteristics in males

  10. Female • Ova mature within ovaries becoming a secondary oocyte • Secondary oocyte enters uterine tubes via the fimbriae • Ovaries are not connected to fimbriae, they are in very close proximity • Fimbriae undulate (wave like motions) to guide the oocyte into the uterine tubes

  11. Female • Oocyte must be fertilized within uterine tubes or will not implant or will implant to low within the uterus to be viable • Uterine tubes guide oocyte to uterus • If fertilized oocyte will implant in uterine wall becoming fetus • Uterus leads to cervix • Cervix leads to vagina which is the exit for menstrual flow and birth canal for baby

  12. Oogenesis • Women are born with all the oocytes she will ever release • Arrested in meiosis I until fertilized by sperm • One primary follicle a month matures under presence of FSH • Primary follicle becomes secondary follicle • Once secondary follicle develops an antrum it is called a graafian follicle • Graafian follicle erupts (ovulation) in response to rising levels of LH, FSH, and estrogen produced by developing follicles • Estrogen is responsible for secondary sexual characteristics in females

  13. Uterine (Menstrual) Cycle • Menstrual Phase • Low levels of LH & FSH, estrogen & progesterone • Primary follicle maturing to secondary • Menstrual flow

  14. Uterine (Menstrual) Cycle • Proliferative Phase • Low levels of LH & FSH and progesterone • Rising levels of Estrogen • Secondary follicle maturing to graafian follicle • Uterine wall regenerating in preparation for implantation • Sudden spike in hormones: LH, FSH, estrogen

  15. Uterine (Menstrual) Cycle • Secretory Phase • Low levels of LH & FSH • Ovulation • Decreasing levels of estrogen • Increasing levels of progesterone • Uterine wall becomes enriched with blood vessels and glandular secretions in preparation for implantation • End of this phase is marked by decreasing estrogen and progesterone levels

More Related