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Biology 30 Hormonal Control of Reproduction

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1 Biology 30 Hormonal Control of Reproduction
Conception, Pregnancy, Development, Birth

2 Did You Know? Whistling is rated the number one subconcious way to attract the opposite sex

3 Hormonal Control of Reproduction
Male Reproductive System Control Testosterone Primary Function Stimulate spermatogenesis Secondary Function Maturation of testes and penis Sex drive Facial hair Body hair Deeper voice Increased muscle strength Body oil secretion -- acne

4 Hormonal Control of the Testes
Hypothalamus releases Gonadotropin-Releasing Hormone (GnRH) Stimulates pituitary to release LH & FSH Pituitary releases Follicle-Stimulating Hormone (FSH) Stimulates spermatogenesis by seminiferous tubules Luteinizing hormone (LH) Stimulates testosterone production by interstitial cells Indirectly stimulates spermatogenesis because testosterone is required for sperm production.

5 Hormonal Control of the Testes
LH, FSH, and GnRH concentrations in the blood are controlled by negative feedback systems

6 Not enough testosterone in the blood. GnRH LH FSH Testes

7 Not enough testosterone in the blood. GnRH ICSH FSH Testes

8 Testosterone production
Not enough testosterone in the blood. GnRH ICSH Testosterone production Spermatogenesis FSH

9 Testosterone production
GnRH Testosterone ICSH FSH Inhibin Testosterone production Spermatogenesis

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11 Believe it or not… Simon (Sime-one), Tom Green, Nick Fitio, (Calgary Flames) John Kruk, (Phillies) Hitler and Napoleon were missing one testicle.

12 Hormonal Control of Female Reproduction
 Hypothalamus - produces releasing GnRH Anterior Pituitary – secrete gonadotropic hormones. FSH - follicle stimulating hormone. LH - luteinizing hormone. Ovaries - secrete the female sex hormones. Estrogen –thickening of uterine lining Progesterone – matures/maintains uterine lining

13 Hormonal Control of Reproduction
FSH is released from AP Start the ripening of ovum within follicle Estrogen is produced by follicle Development of endometrium for possible pregnancy Feedback to hypothalamus to inhibit FSH and release LH

14 Hormonal Control of Reproduction
LH surge on day 14 Stimulates ovulation Conversion of follicle into corpus luteum Progesterone production Continued development of endometrium Feedback to inhibit release of LH

15 Hormonal Control of Reproduction
If no fertilization Degeneration of corpus luteum Drop in hormone level

16 Menstruation The four phases

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19 Four Phases of Menstruation
1. Flow Phase (Menstrual Phase) Start of bleeding marks Day 1 of phase Shedding of the endometrium (uterine lining) Average = 4-5 days Sometimes up to 8 days Occurs due to low hormone levels

20 1

21 Four Phases of Menstruation
Follicular Phase Occurs during day 6-13 Period of repair and thickening of endometrium.

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23 Four Phases of Menstruation
Follicular Phase Occurs during day 6-13 Period of repair and thickening of endometrium. FSH from the pituitary promotes follicle development in the ovary.

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25 Four Phases of Menstruation
Follicular Phase Occurs during day 6-13 Period of repair and thickening of endometrium. WHY?? FSH from the pituitary promotes follicle development in the ovary. As follicle develops it produces estrogen, thickening of the uterine lining LH production increase FSH production decrease

26 FSH Decrease

27 Four Phases of Menstruation
Ovulation Phase LH causes ovulation to occur on day 14. Secondary oocyte is released from the follicle/ovary.

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29 Four Phases of Menstruation
Luteal Phase Final preparation of endometrium to receive the fertilized ovum LH stimulates development of the Corpus Luteum. causes progesterone levels to increase.

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31 Four Phases of Menstruation
Luteal Phase Final preparation of endometrium to receive the fertilized ovum LH stimulates development of the Corpus Luteum. causes progesterone levels to increase. Estrogen and progesterone inhibit GnRH, thereby decreasing LH and FSH levels. This low level of hormones initiates the flow phase.

32 GnRH

33 Builds Uterine Lining Maintains Uterine Lining Ovulation & Corpus Luteum Formation

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35 Menopause The end of a woman’s reproductive years
Between ages of 45 – 55 Ovaries no longer respond to FSH & LH from AP Ovaries do not produce estrogen or progesterone Marked by circulatory irregularities (hot flashes), dizziness, insomnia, sleepiness, depression Hormone replacement therapy may help.

36 Did You Know? Lions will have sex over 500 times with one mate. This is to ensure fertilization.

37 Fertilization Pregnancy Development Birth

38 Sperm

39 Sperm travels at .001 miles per hour.
Did You Know? Sperm travels at .001 miles per hour.

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41 3 Steps of Fertilization
Capacitating Acidic environment of the female reproductive tract causes small pores to open in the acrosome (“enzyme-loaded” head) of the sperm

42 Acrosome

43 3 Steps of Fertilization
Capacitating Acidic environment of the female reproductive tract causes small pores to open in the acrosome (“enzyme-loaded” head) of the sperm Acrosomal reaction Enzymes released from acrosome digest the outer membrane surrounding the egg cell

44 Steps of Fertilization
A single sperm cell fuses with the plasma membrane of ovum Head passes into the cytoplasm Electrochemical reaction in egg Makes membrane impermeable to other sperm

45 Fertilization must occur within a very short window of opportunity.
Egg is only fertile for hours Sperm are only fertile for 48 hours Sex (copulation) must occur no more than 48 hours before or 15 hours after ovulation

46 NO KIDDING Italian physicians promotes having regular sex with the same partner because it is good for digestion. He also states that having casual sex with many partners can cause indigestion.  

47 Pregnancy If pregnancy is established, menstruation does not occur.
Fertilized egg is called a zygote. Once cell division brings the total cell count to around 8, it is called a blastocyst. Takes 3-5 days for blastocyst to travel through oviduct to uterus. Blastocyst must implant into endometrium Occurs 2-4 days after reaching the uterus

48 Zygote

49 Cleavage

50 Blastocyst

51 Pregnancy During implantation, the blastocyst produces a hormone called HCG Human chorionic gonadotropin Prevents degeneration of corpus luteum Stimulates corpus luteum to increase progesterone secretion Maintains uterine lining Prevents contractions Pregnancy test detects HCG in the urine of women. “Turns the stick blue”

52 Pregnancy Tissue grows out from the embryo and mingles with endometrium to form placenta A disc-shaped organ Size of dinner plate Weighs less than 1 kg. Contains maternal & fetal blood vessels NO mixing of maternal and fetal blood!! Diffusion of gasses, nutrients, & wastes Continues production of HCG, estrogen, progesterone Maintains endometrium Corpus luteum not needed – dissolves

53 Embryo remains firmly attached to placenta by umbilical cord.
Pregnancy Progesterone & estrogen have a negative feedback effect on the hypothalamus No secretion of FSH No secretion of LH No new follicles mature Embryo remains firmly attached to placenta by umbilical cord.

54 Umbilical cord Contains: 2 fetal arteries One fetal vein
Pregnancy Umbilical cord Contains: 2 fetal arteries Fetus to placenta One fetal vein Placenta to fetus

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57 Also called parturition 38 – 42 weeks from conception
Childbirth Also called parturition 38 – 42 weeks from conception Average = 40 weeks Three stages of childbirth Labour Delivery Afterbirth

58 Childbirth Labour Delivery Involuntary
Rhythmic contractions of the uterus Causes cervix to open Diameter = 10 cm Delivery Involuntary uterine contractions Conscious abdominal contractions Mother forces baby out through cervix and vagina

59 Afterbirth Immediately after delivery
Childbirth Afterbirth Immediately after delivery Blood vessels in placenta contract Placenta separates from uterine wall Expelled by muscle contractions

60 Childbirth Why?? Nobody totally knows.
Baby plays some role in the timing. Progesterone decreases Allows uterus to contract Oxytocin from posterior pituitary Stimulates stronger uterine contractions Relaxin produced by placenta Causes ligaments of pelvis to loosen Larger passageway for baby

61 Scared of Childbirth?? Did You Know?
Human birth control pills work on gorillas. Erotodromomania is the abnormal impulse to travel to escape painful sexual situations.    Genophobia- Fear of sex.    Heterophobia- Fear of the opposite sex.  Erotophobia- Fear of sexual questions.   

62 But Did You Know That… The bonobo monkeys use sex (and/or sexual favors) to placate members of their social group instead of grooming. They are one of the few species of animals (humans being another) that have sex out of season and for fun.

63 Lactation During pregnancy, high levels of estrogen and progesterone prepare the breasts for milk production Each breast has about 20 milk glands Connect to the nipple by ducts Breast enlarges during pregnancy in preparation for lactation Expulsion of the placenta causes the mother's pituitary to secrete prolactin, Initiates lactation

64 Prolactin inhibits the release of LH
Lactation Prolactin inhibits the release of LH menstrual cycle is suppressed in nursing mothers The high estrogen and progesterone levels during pregnancy are thought to inhibit release of prolactin

65 The first fluid formed by the mammary glands is colostrum,
Lactation The first fluid formed by the mammary glands is colostrum, Thick contains lactose and milk proteins, lacks fat after a few days, milk is produced Oxytocin is released from hypothalamus when infant suckles Causes milk to be released from mammary glands

66 Biology 30 Yet to come… Embryonic Development
Birth Control Technologies STD Effect on Reproductive Systems

67 A blastocyst Fetal Development embeds in the uterine wall
Consists of cells of the future embryo Surrounded by a sphere of cells Embryonic membrane (extra-embryonic membrane) Support the developing embryo

68 Amnion Fetal Development Innermost embryonic membrane Next to baby
Fluid-filled sac that cushions the baby

69 Chorion Outermost membrane Part of the placenta Secretes HCG
Fetal Development Chorion Outermost membrane Part of the placenta Secretes HCG

70 Umbilical cord Fetal Development Connection between mother and baby
Belly-button to placenta Carries baby’s blood to and from placenta

71 Embryonic Development
Placenta (review) A disc-shaped organ Size of dinner plate Contains maternal & fetal blood vessels NO mixing of maternal and fetal blood!! Diffusion of gasses, nutrients, & wastes Continues production of HCG, estrogen, progesterone

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73 Embryonic Development
A blastocyst undergoes gastrulation Series of cell movements and shape changes Produces an embryo with 3 cellular layers Ectoderm Outer layer of cells Will become skin and nervous system Mesoderm Middle layer of cells Skeleton, muscles gonads, kidneys, circulatory system Endoderm Inner layer of cells Liver, pancreas, lungs, lining of digestive tract

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75 Human Gestation The 40 Week Journey

76 1st Trimester Human Gestation
From fertilization to end of 3rd month (0 – 13 weeks) Zygote begins cell division as it moves down oviduct Becomes blastocyst and implants in uterus

77 Human Gestation 1st Trimester Development of body organs
Heart starts beating by week 4 Week 7, testosterone begins to be secreted if a Y-chromosome is present This testosterone causes development of testes.

78 1st Trimester Human Gestation
By week-8 all major structures of the adult are present (in basic form) Embryo is now called a fetus Embryo is most sensitive during first trimester Due to rapid development Sensitive to radiation and drugs

79 Fertilization

80 6 weeks

81 7 weeks

82 8 Weeks

83 8 weeks

84 10 Weeks

85 11 Weeks

86 11 Weeks

87 14 Weeks

88 2nd Trimester Fetus grows rapidly To about 30 cm Quite active
Human Gestation 2nd Trimester Fetus grows rapidly To about 30 cm Quite active Hair begins to develop Cartilage of skeleton is replaced by bone

89 18 weeks

90 The Hand Picture May 2, 2000 USA Today

91 An Amazing Story -- Aug.19, 1999 Samuel Armas' tiny hand grips Dr. Joseph P. Bruner's finger just as Bruner finishes returning him to his mother's womb. Bruner, director of fetal diagnosis and treatment at Vanderbilt University Medical Center (Nashville), was performing a cutting-edge procedure on the 21-week-old fetus. The procedure on Samuel took about an hour.

92 An Amazing Story -- Aug.19, 1999 Bruner and Samuel's parents hope the surgery will alleviate the effects of spina bifida, a disabling birth defect in one or two of every 1,000 babies born. Because fetuses undergoing this procedure are so young -- Samuel could not survive outside his mother's womb -- this kind of surgery is gaining attention nationwide from the medical community and the media.

93 An Amazing Story -- Aug.19, 1999 During the procedure, surgeons remove the uterus from the mother, drain the amniotic fluid, perform surgery on the tiny fetus, replace everything and put the entire package back inside the mother. Dr. Bruner said regarding the picture, "The baby did not reach out," Bruner says. "The baby was anesthetized. The baby was not aware of what was going on."

94 An Amazing Story -- Aug.19, 1999 Bruner says he saw the hand "sort of pop up in the incision" on the womb, and he "reached over and picked it up." Samuel, now nearly 5 months old [may 2, 2000], & is “developing normally and hitting his monthly milestones. He smiles often and is nearly sitting up on his own.” It will take years to know how much difference the surgery made, but Alex Armas [father] says he's happy the photo has been seen by millions.

95 Samuel Armas 21 weeks

96 Human Gestation 3rd Trimester Rapid growth of fetus To about 53 cm
3-3.5 kg Fetal activity decreases Less room to move Fully mature Ready for birth

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114 Quick Review

115 Quick Review

116 Birth Control

117 Birth Control Sterilization
Most effective In males vas deferens is cut off and sealed Only effects sperm content of semen so minimal side effects In females tubal ligation or cutting of the oviducts Disadvantages of sterilization - hard to reverse

118 Quick Review

119 Birth Control "The pill" A combination of estrogen and progesterone given for 21 days of the 28 day cycle Effectively shuts down FSH and LH production so follicles do not develop. Many of the early problems have been sorted out but side effects possible

120 Birth Control – barrier methods
Diaphragms, cervical caps, vaginal sponges, condoms Condom fits over the penis and prevents semen from entering the female; Diaphragm which fits over the cervix and prevents semen from entering the uterus both of these methods are more reliable when used in conjunction with a spermicidal foam or jelly

121 Birth Control – barrier methods
IUD Inter-Utarian Device placed in the uterus by a physician, prevent implantation of the blastocyst in the endometrium. Best for women who have had one pregnancy, middle to older and are at low risk for STD’s

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123 "Natural family planning"
Birth Control "Natural family planning" Requires knowledge of the day of ovulation If known, can avoid the 4 days either side of ovulation to account for unusually long -lived sperm or eggs. Women need exceptionally regular cycles to be effective "Basal" body temperature measurements (T rises at ovulation), vaginal pH measurements (more alkaline), mucus thickness can help determine time ovulation.

124 Birth Control "Morning after pill“
Most are essentially a controlled overdose of normal birth control pills RU-486 now distributed by Planned Parenthood. Blocks progesterone receptors causing uterine lining to slough off taking embryo with it. Many people have ethical problems with these pills since they remove fertilized eggs. i.e. after "conception" has occurred. “abortion pill”

125 Reproductive Technologies
Ultrasound the use of high-frequency sound waves to visualize the fetus Amniocentesis a long needle is used to remove a sample of amniotic fluid from the amniotic sac surrounding the fetus, fetal cells in the fluid are cultured for 2 to 4 weeks and then analyzed for chromosomal defects and other genetic disorders

126 Amniocentesis

127 Reproductive Technologies
Chorionic Villi Sampling (CVS) a small sample of tissue is removed from the chorion, the fetal part of the placenta. Can be performed earlier in the pregnancy than amniocentesis results can be obtained within a few days greater risk of spontaneous abortion from CVS than from amniocentesis ethical considerations: essentially all detectable fetal disorders remain untreatable in the uterus, and many cannot be corrected even after birth

128 Reproductive Technologies
In Vitro Fertilization ova can be surgically removed from a woman whose oviducts are blocked These are fertilized in a petri dish in a laboratory The resulting embryos can than be inserted into the woman's uterus (or into a surrogate mother's uterus) Ethical considerations: post-menopausal woman can now have children; in surrogacy, who is the legal mother??? A-la Phoebe from “Friends”

129 Sexually Transmitted Diseases
Sexually transmitted diseases are transmitted from one person to another primarily by contact of the genital organs during sexual activity.

130 Crabs

131 Epididimitis Swelling Behind Testes

132 Genital Warts

133 Syphilis

134 Gonorrhea No Arrow Necessary

135 Sexually Transmitted Diseases
Syphilis caused by a spirochete bacterium. The first symptoms of syphilis may go undetected because they are very mild and disappear spontaneously. The initial symptom is a chancre; usually a painless open sore that usually appears on the penis or near the mouth, anus, or on the hands.

136 Syphilis may go on to more advanced stages, including a transient rash and, eventually, serious involvement of the heart and central nervous system. The full course of the disease can take years. Penicillin remains the most effective drug to treat people with syphilis.

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141 Initial Chancre on Hand

142 Sexually Transmitted Diseases
Gonorrhea discharge from the vagina or penis “Ooooze” and painful or difficult urination. The most common and serious complications occur in women and, these complications include PID, ectopic pregnancy, and infertility. Historically, penicillin has been used to treat gonorrhea, but in the last decade, four types of antibiotic resistance have emerged. New antibiotics or combinations of drugs must be used to treat these penicillin resistant strains.

143 Sexually Transmitted Diseases
Chlamydia many cases involve no symptoms and therefore infected persons may not seek medical treatment. This infection is now the most common of all bacterial STD's, with an estimated 4 to 8 million new cases occurring each year. In both men and women abnormal genital discharge burning with urination In women, untreated chlamydial infection may lead to pelvic inflammatory disease, one of the most common causes of ectopic pregnancy and infertility in women.

144 Chlamydia Many people with chlamydial infection, however, have few or no symptoms of infection. Once diagnosed with chlamydial infection, a person can be treated with antibiotics

145 Sexually Transmitted Diseases
Genital herpes Affects an estimated 60 million Americans. Approximately 500,000 new cases of this incurable viral infection develop annually. Caused by herpes simplex virus (HSV). painful blisters or open sores in the genital area. These may be preceded by a tingling or burning sensation in the legs, buttocks, or genital region. The herpes sores usually disappear within two to three weeks, but the virus remains in the body for life and the lesions may recur from time to time.

146 Sexually Transmitted Diseases
Genital herpes Severe or frequently recurrent genital herpes is treated with one of several antiviral drugs that are available by prescription. These drugs help control the symptoms but do not eliminate the herpes virus from the body. Suppressive antiviral therapy can be used to prevent occurrences and perhaps transmission. Women who acquire genital herpes during pregnancy can transmit the virus to their babies. Untreated HSV infection in newborns can result in mental retardation and death.

147 Sexually Transmitted Diseases
AIDS (acquired immunodeficiency syndrome) First reported in the United States in1981. It is caused by the human immunodeficiency virus (HIV), a virus that destroys the body's ability to fight off infection. An estimated 900,000 people in the United States are currently infected with HIV. People who have AIDS are very susceptible to many life-threatening diseases (called opportunistic infections) and to certain forms of cancer. Transmission of the virus primarily occurs during sexual activity and by sharing needles used to inject intravenous drugs.

148 Sexually Transmitted Diseases
Genital warts Caused by human papillomavirus, a virus related to the virus that causes common skin warts. Genital warts usually first appear as small, hard painless bumps in the vaginal area, on the penis, or around the anus. If untreated, they may grow and develop a fleshy, cauliflower-like appearance. Genital warts infect an estimated 1 million Americans each year. In addition to genital warts, certain high-risk types of HPV cause cervical cancer and other genital cancers. Genital warts are treated with a topical drug (applied to the skin), by freezing, or if they recur, with injections of a type of interferon. If the warts are very large, they can be removed by surgery.

149 Done Study for your exam


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