Presentation on theme: "Menstruation or Pregnancy"— Presentation transcript:
1 Menstruation or Pregnancy Human Reproduction IIMenstruation or Pregnancy
2 S1-1-09 Describe the structure and function of the male and female reproductive systems. S Outline human development from conception through birth.Vocabulary & People Ovulation Menstruation FertilizationZygote Embryo Fetus
3 The “egg(s)” is also know as an oocyte(s) or an ovum (ova) Follicle – cells surrounding the egg inside(becomes corpus luteum)The “egg(s)” is also know as an oocyte(s) or an ovum (ova)Ovulation:Release of ovum from a follicle in the ovary as a response to a hormonal signal (brain - LH).Menstruation:Monthly cycle of changes that occur in the ovaries and uterus - including ovulation.Ovulation occurs around the day of cycle
4 OvulationEndometrium: the inside of the uterus – the part that prepares for the baby – also called endometrial liningMenstruation
5 All hormones at low levels Menstrual Cycle consists for four steps:approximately 28 days before repeatingSTEPKey HormoneDAYBrain triggers development of a follicleBuilding up endometriumFSHEstrogen1 - 13Follicle releases ova (egg) – ovulationLHCorpus Luteum formsEndometrium is maintainedProgesteroneNo fertilization – menstruationEndometrial lining and ova are expelledAll hormones at low levelsNotice: two hormones made by the “shell ”– estrogen and progesterone – work to prepare the uterus for a fertilized egg
6 Female Menstrual Cycle PituitaryglandBrain HormoneLevelsLHFSHFSH7142128 daysNotice: the shedding of the endometrium ends and begins the diagram - it’s a continuous CYCLEOvarianCycleRegressionSex HormoneLevelsEstrogenProgesterone7142128 daysEndometrialchanges7142128 days
8 Egg and sperm meet in the oviduct - Fertilization. Nuclei join to produce a single diploid cell called a zygoteZygote implants into the endometrium and releases hormones to maintain the liningRemember: the sex is determined by the male - X or Y sex chromosome in the sperm
9 MEIOSIS– MALES x x x x y y y y x y Female sperm Male sperm DIPLOID 2n 46 ChromosomesxyHAPLOID 1nFemale spermMale sperm
10 MEIOSIS– FEMALES x x x x x x x x x x Female egg DIPLOID 2n 46 ChromosomesxxHAPLOID 1nFemale egg
13 Once implanted – called an embryo Embryo Stage (the first 8 weeks)Zygote implants in endometrial lining and begins togrow (divide) by mitosis.Once implanted – called an embryoCongrats! You are now officially pregnantCleavage: the process of mitotic divisions that change zygote into a multicellular embryo.
14 Once bone forms - called a fetus (until born) 2. Fetus Stage (after 8 weeks till birth)Developing embryo forms bone cells around the ninth week of pregnancy.Once bone forms - called a fetus (until born)Placenta - exchanges waste and nutrients through umbilical cord.Amnion – protective sac filled with fluid.
15 Pregnancy can also be divided in 3 trimesters: 1st trimester – conception to 3rd monthdevelopment of all body systems and organsfetus is particularly sensitive to alcohol/drugssex can be determined1st trimester
16 2nd trimester – 4th to 6th months period of rapid and continuous growthOnly brain and lungs still developingembryo movements can be felt2nd trimester
17 3rd trimester – 7th to 9th (birth) month fetus kicks, stretches and moves freelyEyes sense light, fingerprints have formedAt end – fetus weighs 3300 grams, 35 cm long3rd trimester
19 CAN YOU ANSWER THESE QUESTIONS? S1-1-09: What parts make up the male and female sex systems and what is the function of each part?S1-1-10:How does a fertilized egg turn into a baby and what determines the gender?Vocabulary & People Ovulation Menstruation FertilizationZygote Embryo Fetus