Presentation on theme: "1 Menstruation or Pregnancy Human Reproduction II."— Presentation transcript:
1 Menstruation or Pregnancy Human Reproduction II
S1-1-09 Describe the structure and function of the male and female reproductive systems. S1-1-10 Outline human development from conception through birth. Vocabulary & People OvulationMenstruationFertilization ZygoteEmbryoFetus
Ovulation: Release of ovum from a follicle in the ovary as a response to a hormonal signal (brain - LH). Follicle – cells surrounding the egg inside (becomes corpus luteum) Menstruation: Monthly cycle of changes that occur in the ovaries and uterus - including ovulation. Ovulation occurs around the 13-15 day of cycle The “egg(s)” is also know as an oocyte(s) or an ovum (ova)
Endometrium: the inside of the uterus – the part that prepares for the baby – also called endometrial lining Menstruation Ovulation
Menstrual Cycle consists for four steps: approximately 28 days before repeating STEP Key HormoneDAY Brain triggers development of a follicle Building up endometrium FSH Estrogen 1 - 13 Follicle releases ova (egg) – ovulation LH 13 - 15 Corpus Luteum forms Endometrium is maintained Progesterone 15 - 21 No fertilization – menstruation Endometrial lining and ova are expelled All hormones at low levels 21 - 28 Notice: two hormones made by the “shell ”– estrogen and progesterone – work to prepare the uterus for a fertilized egg
1421 142128 days 071421 Regression Pituitary gland Progesterone Estrogen 28 days FSH LH 07 07 Female Menstrual Cycle Brain Hormone Levels Ovarian Cycle Sex Hormone Levels Endometrial changes Notice: the shedding of the endometrium ends and begins the diagram - it’s a continuous CYCLE
Egg and sperm meet in the oviduct - Fertilization. Remember: the sex is determined by the male - X or Y sex chromosome in the sperm Nuclei join to produce a single diploid cell called a zygote Zygote implants into the endometrium and releases hormones to maintain the lining
1.Embryo Stage (the first 8 weeks) Zygote implants in endometrial lining and begins to grow (divide) by mitosis. Once implanted – called an embryo Cleavage: the process of mitotic divisions that change zygote into a multicellular embryo. Congrats! You are now officially pregnant
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.
Pregnancy can also be divided in 3 trimesters: 1 st trimester – conception to 3 rd month development of all body systems and organs fetus is particularly sensitive to alcohol/drugs sex can be determined 1 st trimester
2 nd trimester – 4 th to 6 th months period of rapid and continuous growth Only brain and lungs still developing embryo movements can be felt 2 nd trimester
3 rd trimester – 7 th to 9 th (birth) month fetus kicks, stretches and moves freely Eyes sense light, fingerprints have formed At end – fetus weighs 3300 grams, 35 cm long 3 rd trimester
And then, before you know it...
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 OvulationMenstruationFertilization ZygoteEmbryoFetus