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Learn about the male and female reproductive systems, including hormone production, secondary sex characteristics, and the structures involved in reproduction. Understand the process of fertilization, development, and embryonic layers. Explore the journey from fertilization to fetal development.
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Human Reproduction Part II Human Reproductive Systems Our species lives on……. http://www.youtube.com/watch?v=hAgOk3-loUY&feature=related
Male Sexual Development • Testosterone is the male reproductive hormone • Secreted in small amounts untilpuberty • Puberty begins when: • Hypothalamus Pituitary increased FSH and LH GONADS (TESTES) • GONADS TESTOSTERONE • Testosterone produces male 2ndary sex characteristics(such as body hair, muscle development, deep voice)
Male Reproductive Parts • Testes: • Male reproductive gland • Sperm and testosterone produced • Scrotum: • Protective sac around testes • Keeps testes cool (this keepsthe sperm at an optimumtemperature for development • Epididymus: • Stores sperm while they mature • Vas Deferens: • Tube that carries sperm from epididymis to urethra
Male Reproductive Parts • Prostate gland-- the largest of several glands which add lubricating and other fluids to the sperm • Urethra: • tube through the penis carrying sperm to the outside of the body • Other glands work together to produce seminal fluid. • Combination of sperm and seminal fluid = semen
6. penis -- adaptation forinternal fertilization of the female • Semen travels from testes →vas deferens→ urethra→ penis → outside of the body through ejaculation (uncontrolled muscle contractions) 2010 Reproduction -SMB
Female Reproductive System Side view
Female Sexual Development • Estrogen and progesterone are the female reproductive hormones • Puberty begins when: • Hypothalamus Pituitary increased FSH AND LH GONADS (OVARIES) • GONADS Estrogen and progesterone • Estrogen produces female 2ndary sex characteristics (broadening of pelvis, breast development, and are involved in the menstrual cycle and pregnancy).
Female Reproductive Parts • Ovaries: • Female Reproductive Gland (females have two of these) • Eggs (ova) produced here • Also contain follicles: • Place where eggs mature • Fallopian tubes (Oviduct): • Tubes that carry an egg from ovary to uterus • Place of fertilization • Egg Travel: From the ovaries → fallopian tubes/oviducts → uterus
Uterus: • Mostly muscle • implantation and developmentof the embryo and fetus before birth occurs here • Vagina(or birth canal) • entry point for sperm from the male and exit tube for the baby when it is born 2010 Reproduction -SMB
HUMAN REPRODUCTIVE SYSTEMS Diagrams…. 2010 Reproduction -SMB
Types ofFertilization External: gametes fuse outside the body of the female • Occurs in animals that breed in the water (most invertebrates- Fish/amphibian) • The two parents release their eggs into the water, and the sperm fertilizes the eggs. • Internal – gametes fuse inside the body of a female • Fertilization occurs inside the female body where it is moist • Occurs mostly in animals that reproduce on land and some aquatic animals like sharks, reptiles, and mammals
COMPARISON 2010 Reproduction -SMB
FERTILIZATION • DAY 0 • When sperm penetrates egg • Sperm releases special enzymes to do this • Forms a ZYGOTE • Recombination occurs: • Combining of genetic info from both parents (n=23) (n=23) (2n=46) Sperm + egg = zygote • Occurs in the oviduct
Multiple births: • fraternal twins- 2 eggs • identical twins- one egg that splits in two, always the same http://www.brainpop.com/health/geneticsgrowthanddevelopment/twins/ - Conjoined twins (aka Siamese twins) are identical twins whose bodies are joined in utero. Abby & Brittany Hensel Abby & Brittany turn 16 http://www.bing.com/videos/search?q=abby+and+brittany+hensel&mid=78A3B27DF1EF569A364278A3B27DF1EF569A3642&view=detail&FORM=VIRE2&adlt=strict
Occurs in the oviduct Zygote begins a series of mitoticdivisions (cleavage) to undergo differentiation Division process is rapid - no increase in size, just the number of cells: 1 cell→ 2 cells→ 4→ 8→ 16→32→64→ 128 …etc Implantationof zygote in uterus occurs around day 7 Early Development- The First Week 2010 Reproduction -SMB
EMBRYONIC DEVELOPMENT 2010 Reproduction -SMB
Embryonic Layers and Functions GASTRULATION • Cells in zygote form into 3 distinct layers • The cells within each layer DIFFERENTIATE to form specialized cells (muscle, liver, heart, etc) then tissue and organs. • This is caused by gene activation which can be influenced by the environment.
These developing cells are now called an embryonic stems cells and can be used as for medical research and application • http://www.brainpop.com/science/cellularlifeandgenetics/stemcells/ • http://www.pbs.org/wgbh/nova/body/stem-cells-breakthrough.html 2010 Reproduction -SMB
HUMAN FETAL DEVELOPMENT Placenta – Develops at 3 weeks Placenta is a fetal organ Connects mother and fetus Food, gases and wastes DIFFUSE across blood vessels 2010 Reproduction -SMB
2. Umbilical cord- rope-like structure that connects the fetus to the placenta 3. Amnion- membrane surrounding the fetus 4. Amniotic fluid – fills the amnion, protects the fetus, and absorbs shock
Most critical time of development is the 1st trimester when organs are developing Harmful environmental risk factors include drugs, alcohol tobacco medicines poor diet, toxic substances infections This can halt development or cause major developmental issues Not taking care can result in miscarriage or can severely damage embryo/fetus First and Second Trimester Dangers!!!! 2010 Reproduction -SMB
Later Development • 8 weeks = FETUS • Umbilical cord forms at 3 months • Body systems become more specialized • Fetus becomes bigger Birth (36 weeks)
Human fetal development 4 weeks 7 weeks 2010 Reproduction -SMB
Human fetal development 10 weeks 2010 Reproduction -SMB
Human fetal development 12 weeks 2010 Reproduction -SMB 20 weeks
Human fetal development The fetus just spends much of the 2nd & 3rd trimesters just growing …and doing various flip-turns & kicks inside amniotic fluid Week 20 2010 Reproduction -SMB
Human fetal development 24 weeks (6 months; 2nd trimester) fetus is covered with fine, downy hair called lanugo. Its skin is protected by a waxy material called vernix 2010 Reproduction -SMB
Getting crowded in there!! 32 weeks (8 months) The fetus sleeps 90-95% of the day & sometimes experiences REM sleep, an indication of dreaming 2010 Reproduction -SMB
Human fetal development 30 weeks (7.5 months) umbilical cord 2010 Reproduction -SMB
The end of the journey! And you think 9 months of Biology is hard! 2010 Reproduction -SMB
The Menstrual and Ovarian Cycles The Truth behind PMS!!
Menstrual Cycle Begins at puberty and ends at menopause Takes about 28 days Regulated by four hormones: estrogen, progesterone, FSH and LH Menopause The menstrual cycle stops permanently usually between the ages of 45 and 50 although it may occur sooner. The permanent cessation of the cycle is called Menopause.
Vocabulary- THE HORMONES A. Secreted by the Pituitary gland: • FSH (Follicle Stimulating Hormone) • Stimulates follicle to cause egg to mature • LH (Luteinizing Hormone) • Causes release of mature ovum (ovulation) • Prepares uterus for implantation of fertilized egg B. Secreted by Ovaries: • Estrogen • Causes uterine lining to thicken • Progesterone: • Works with estrogen to finish uterine lining thickening
The Cycles A.Ovarian Cycle: • Occurs over 28 days in the ovaries • Process during which an ovum matures in a follicle and is released during ovulation • After ovulation, a corpus luteum (yellow body) is left behind B. Menstrual (Uterine) Cycle: • Occurs over 28 days • Process during which uterine lining is preparing for fertilized ovum • If fertilization occurs, this cycle stops until after birth • If not fertilized, lining sheds (menstruation!) and cycle begins again
Menstrual Cycle Flow Chart • Menstruation (3-5 days) • Uterine lining sheds andFSH increases • This causes drop in estrogen and progesterone • Occurs if egg is not fertilized
Menstrual Cycle Flow Chart • Follicle Stage: (10-14 days) • Low estrogen = FSH to be released (negative feedback) • This stimulates growth of follicle • Follicle (egg) matures causing estrogen levels to go up • Uterine lining begins to thicken again • Menstruation (3-5 days) • Uterine lining sheds andFSH increases • This causes drop in estrogen and progesterone • Occurs if egg is not fertilized
Menstrual Cycle Flow Chart • Follicle Stage: (10-14 days) • Low estrogen = FSH to be released (negative feedback) • This stimulates growth of follicle • Follicle (egg) matures causing estrogen levels to go up • Uterine lining begins to thicken again • Menstruation (3-5 days) • Uterine lining sheds andFSH increases • This causes drop in estrogen and progesterone • Occurs if egg is not fertilized • Ovulation (1 day) • Major SPIKE of LH • This causes follicle to break and release egg into oviduct
Menstrual Cycle Flow Chart • Follicle Stage: (10-14 days) • Low estrogen = FSH to be released (negative feedback) • This stimulates growth of follicle • Follicle (egg) matures causing estrogen levels to go up • Uterine lining begins to thicken again • Menstruation (3-5 days) • Uterine lining sheds andFSH increases • This causes drop in estrogen and progesterone • Occurs if egg is not fertilized • Ovulation (1 day) • Major SPIKE of LH • This causes follicle to break and release egg into oviduct • Corpus Luteum Phase (10-14 days) • LH and FSH levels crash • Corpus luteum forms from broken follicle • Corpus luteum secretes estrogen and progesterone • This thickens uterine lining to prepare for egg
What is going on all at once? Negative Feedback: • When one hormone is increased it shutsoff another hormone • Ex. Glucagon is high, Insulin is Low Ovary response Uterus response
REPRODUCTIVE TECHNOLOGY • In vitro Fertilization Process • http://www.youtube.com/watch?v=GeigYib39Rs • http://www.sumanasinc.com/webcontent/animations/content/invitrofertilization.html 2010 Reproduction -SMB
Directions: READ your review book pageS 71-72. Fill out the blank columns for each of the 4 technologies listed. 2010 Reproduction -SMB