1 / 19

Reproduction

Reproduction. Reproduction . Reproduction is the process by which organisms produce offspring. Male Reproductive System. Sperm = reproductive cells of males

hsavage
Télécharger la présentation

Reproduction

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. Reproduction

  2. Reproduction • Reproduction is the process by which organisms produce offspring

  3. Male Reproductive System • Sperm = reproductive cells of males • Functions of the male reproductive system are to produce sex hormones, to produce & store sperm, and to deliver sperm to the female reproductive system • Keeping healthy: • Cleanliness • Sexual abstinence • Protection from trauma • Self-exams

  4. Female Reproductive System • -Eggs, or ova, are the reproductive cells in women • The functions of the female reproductive system are to produce sex hormones, to produce eggs, and to provide a nourishing environment in which a fertilized egg can develop into a baby • Keeping healthy: • Cleanliness • Sexual abstinence • Prompt treatment for infections • Self-exams

  5. Egg Traveling Through Female Reproductive System

  6. Pregnancy • 1) Fertilization • Only a few hundred of the hundreds of million of sperm that enter the vagina usually make it to the egg • Only one sperm can fertilize the egg • Within seconds after fertilization occurs, the surface of the egg changes so that no more sperm can enter the egg • In the 1st week after fertilization, the fertilized egg undergoes many cell divisions & travels to the uterus

  7. Pregnancy • 2) Zygote • The united sperm & egg is called a zygote • Within 36 hours, while the zygote is still traveling through the fallopian tube, it begins to divide

  8. Pregnancy • 3) Cell Division • From the two-cell stage until about 9 weeks after fertilization, the growing structure is called an embryo

  9. Pregnancy • 4) Blastocyst • About 5 days after fertilization, the embryo reaches the uterus, where it floats free for a few days • This ‘clump’ of cells is called a blastocyst

  10. Pregnancy • 5) Implantation • Once the blastocyst forms, it begins to attach itself to the wall of the uterus

  11. Development in the Uterus • Amniotic sac • Fluid-filled bag of thin tissue that develops around the embryo • Placenta • The attachment holding the embryo to the wall of the uterus; oxygen and nutrients move from mother’s blood into the placenta • Umbilical cord • Develops between the embryo & placenta; embryo’s lifeline; blood vessels inside carry oxygen & nutrients to growing embryo

  12. Development in the Uterus • During the first 2 months, major body systems and organs begin to form • By the end of 8 weeks, the embryo is about an inch long & has recognizable features like arms, legs, ears & eyes • From the 3rd month until birth, the unborn child is called a fetus

  13. Healthy Pregnancy • Getting proper nutrition & exercise and avoiding drugs & environmental hazards are especially important before & throughout pregnancy • Pregnant women only need to eat about 300 extra calories a day • Folic acid is a very important vitamin • It helps develop the neural tube, which will turn into the spinal cord

  14. Healthy Pregnancy • A pregnant woman should talk to her doctor before using any prescription or over-the-counter drugs, including pain medications, creams & lotions and vitamins • Environmental hazards: • Xrays • Lead • Mercury • Cat litter

  15. Child Birth • 1) Labor • The work performed by the mother’s body to push the fetus out • For a 1st child, labor can last 2-24 hours or longer • Contractions of the muscles of the uterus cause the cervix to dilate, or expand • Near the end of this stage, the amniotic sac breaks

  16. Child Birth • 2) Delivery of baby • This stage can take from 30 minutes to more than 2 hours • Contractions continue & the baby is pushed out • Once the baby is out, the doctor clamps & cuts the umbilical cord • Baby is looked over, and it’s vital signs are listened to

  17. Child Birth • Delivery of after birth • Even though the baby is born, the birth process is not complete • Contractions push out the placenta during this third stage • This lasts only about 15-30 minutes

  18. Complications at Birth • Stillbirth: Occurs when a fetus dies and is expelled from the body after the 20th week of pregnancy • Cesarean section: C-section; surgical method of birth; incision in lower abdomen to uterus • Premature birth: delivery of a live baby before the 37th week of pregnancy; the earlier the birth, the more problems the baby tends to have; organs may not be fully developed

  19. Multiple Births • Identical twins • Twins that develop from a single fertilized egg; are the same sex & have the same inherited traits since they are from the same zygote • Fraternal twins • Sometimes two eggs are released from the ovary & are fertilized by two sperm; are no more alike than siblings; may or may not be the same sex • Triplets or more • Are less common than twins

More Related