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The Reproductive System

Reproductive System Slide 1 Introduction Now let’s begin the final section of Unit 3, the reproductive system. Before we begin we need to define the term gamete, as we will see this over and over again. Gametes are eggs and sperm. They are unique cells because they only have half the numbers of chromosomes than the other cells of the body. We will discuss this further when we explore cell division in unit 4. Slide 2 Male versus female reproductive system Let’s start our exploration of the reproductive system by looking at the differences between the male and the female reproductive systems. The first difference is that after puberty males produce sperm throughout their lives, while females produce eggs between puberty and menopause. Men are constantly producing their gametes and therefore are constantly producing hormones. Females on the other hand have a reproductive cycle in which different hormones are produced at different times. Another difference is that men have a shared reproductive and urinary tract; in females these two systems are separate. Slide 3 Male Reproductive Anatomy The male reproductive system consists of the male gonads, which are called the testes, accessory reproductive organs, which include ducts, glands, and external genitalia that aid sperm production/delivery. The next several slides will discuss the main structures of the male reproductive system in detail. Slide 4 Testes The testes are the primary reproductive organ of the male. The testes have dual functionality. The first function is hormone secretion. The testes secrete testosterone, which is the male sex hormone responsible for: 1. development and maintenance of secondary sexual characteristics 2. stimulating protein synthesis 3. promoting growth of skeletal muscles The second function of the testes is spermatogenesis, the formation and maturation of sperm cells. Within the testes are a structure called seminiferous tubules, and this is where sperm cells are produced. In cross section the seminiferous tubules appear roughly circular. Within the seminiferous tubules are interstitial cells, and these are the cells that secrete testosterone. Slide 5 Epididymis The epididymis is a highly coiled, 18 inch long tube that is positioned outside of the testes. Once sperm are produced, they move to epididymis by peristaltic movement, where they mature and are stored until needed. Stored sperm remain fertile for approximately 4060 days. Older sperm disintegrate and are reabsorbed by epididymis. Slide 6 Vas Deferens The vas deferens is a muscular tube that passes upward alongside the testicles and transports the semen from the epididymis during ejaculation. This is the structure that is cut during a vasectomy.
 
 
 
 
 
 
 
Reproductive System Slide 7 Accessory Glands Three accessory glands secrete fluids that mix with the sperm. The combination of sperm and this fluid is called semen. 1. seminal vesicles (paired) The seminal vesicles are a pair of glands dorsal to bladder, each ~5 cm long. They secrete a viscous yellowish liquid rich in fructose, prostaglandins and other nutrients that comprises ~60% of the semen. Fructose serves as energy source for sperm. 2. prostate gland (single) The prostate gland is below the urinary bladder, is ~3 cm in diameter, and surrounds the ejaculatory duct at the junction with the urethra. The prostate secretes a thin, milky liquid that protects sperm from the acidity of male urethra and female vagina 3. bulbourethral glands (paired) The bulbourethral glands are small (~1cm) peashaped glands below the prostate. During sexual arousal they produce a clear, slippery fluid that lubricates the head of the penis in preparation for intercourse. This fluid also protects sperm by helping to neutralize the acidity of residual urine in urethra. During arousal some of this fluid may appear at tip of penis and may contain sufficient sperm to fertilize the egg even without actual ejaculation. Slide 8 Scrotum The testes develop inside the body cavity and descend into the scrotum shortly before birth. Sperm develop best at temperatures below the average human body temperature. The scrotum changes size to maintain the ideal temperature for sperm production and storage. When cold, the scrotum shrinks to retain heat; and when warm, the scrotum distends to release heat. These changes occur automatically and are under the control of the central nervous system. An elevated temperature of the scrotum, and the testes inside, can cause sperm development to stop temporarily. A fever can kill hundreds of thousands of sperm cells. Slide 9 YouTube Video Male Reproductive Anatomy https://www.youtube.com/watch?v=nr5W9trSv8I Slide 10 Female Reproductive Anatomy The function of the reproductive system is to produce offspring. It is the only major system that doesn’t work continuously. In females it is activated at puberty and ceases to function at menopause. The female reproductive system consists of the female gonads, which are called the ovaries, accessory reproductive organs, which include ducts, glands, and external genitalia that aid in egg production and development of a fetus. The next several slides will discuss the main structures of the female reproductive system in detail. Slide 11 Ovaries The ovaries perform two major functions: 1. oogenesis, which is the formation of eggs; and 2. hormone secretions, mainly estrogen and progesterone Within follicles in the ovaries are partially developed egg cells. A newborn baby girl already contains ~2 million eggs that have partially developed.
 
 
 
 
 
 
 
Reproductive System Slide 12 Fallopian Tubes The fallopian tubes are open at one end to receive the egg at ovulation. The opening is enlarged and partially surrounds the ovary with a feathery projections called fimbriae. The fallopian tubes are ciliated along their length and have muscular wall to move an egg down to uterus. The fallopian tubes are the site of fertilization. Slide 13 Uterus The uterus is a thick pearshaped, muscular organ. It consists of three sections (fundus, body, and cervix). The fundus is the upper portion, the body is the mid portion, and the cervix is the lower portion that extends into the vagina. The uterus receives the egg from fallopian tube and if fertilized, holds the embryo and fetus during development. Slide 14 Endometrium The endometrium is the lining of the uterus. This lining thickens each month in preparation for pregnancy. If an egg is not fertilized, then the lining sloughs off. The endometrium, itself, has two layers. The functional layer is the part that builds up and sheds each cycle. The basal layer is not shed and from it the functional layer develops. Slide 15 Vagina The vagina leads to outside of the body. It is a muscular tube with thin walls, but is easily distended. The vagina has great capacity for expansion during birth to accommodate fetal passage. Mucosa secretions from the vagina produce lubricating fluid during sexual arousal. Slide 16 YouTube Video Female Reproductive Anatomy https://www.youtube.com/watch?v=toKp0SGyv5w Slide 17 Check Your Understanding Now that we have learned about the male and female reproductive systems, let’s check your knowledge of the subject. The following slides will have a series of questions on the topic. Be sure to click “Submit” after answering each question. Slides 18 through 32 Male and Female Reproductive Systems Interactive Quiz A nongraded assessment of your knowledge of the male and female reproductive systems. Slide 33 Physiology of erection The penis of the male contains three large compartments of spongy, erectile tissue. During normal activities, the arteries that flow into the penis are constricted. This prevents blood from flowing into the erectile tissue and the penis remains flaccid. During sexual arousal, chemicals are produced which the relax smooth muscles within incoming arteries. Blood flows into the erectile tissues and the expansion of the spongy tissue clamps off veins. When the veins are clamped off, blood cannot leave the tissue, resulting in an erection. Erectile dysfunction is defined as the persistent inability to attain or maintain penile erection sufficient for sexual intercourse. Erectile dysfunction mediations, such as Viagra, Cialis, and Levitra work by relaxing the muscles in the spongy tissue of the penis, which increases blood flow and triggering an erection.
 
 
 
 
 
 
 
Reproductive System Slide 34 Sperm structure Sperm develop within the highly coiled seminiferous tubules of the testes. When the sperm are fully mature they are extremely small, being little more than a bag of genetic material with a tail. The head of the sperm cell contains the nucleus and an acrosome. The acrosome contains digestive enzymes that help the sperm penetrate the coatings surrounding the egg. The tail consists of a flagellum which allows the sperm to swim through the female reproductive tract to the egg. Sperm also contain a fair number of mitochondria to provide it the ATP energy needed for swimming and fertilization. Slide 35 Seminal fluid Most of you already know that sperm is released in a fluid. Sperm swim and to do so they must be in a fluid medium. The fluid is produced by the seminal vesicles and the prostate gland. The fluid also contains a variety of other compounds that will help the sperm accomplish the job of fertilizing an egg. The bulbourethal gland produces an alkaline fluid that protects the sperm from urine and acidic environment of the female vaginal tract. Remember that urine is slightly acidic and sperm and urine share the tract in the male. The female vaginal tract is also acidic as a natural defense mechanism. The bulbourethral gland also produces a lubricant that lubricates the passage for the sperm. The seminal vesicles produce prostaglandins. Prostaglandins cause smooth muscle, like the muscle found in the uterus to contract. Contractions of the uterus help to propel the sperm higher into the female reproductive tract. Fructose is also produced by the seminal vesicles, which the sperm use as a source of fuel. Finally, the prostate gland produces antibiotic enzymes that help to keep the fluid safe from bacterial infection. Slide 36 Hormones Do you remember our discussion of hormones from unit 2? Hormones are chemical messengers that the body produces in one place, but have their action at another site in the body. Most hormones are proteins; however the sex hormones are an exception because they are lipids. The sex hormones most people are familiar with are the female hormone estrogen and the male hormone testosterone. These are the hormones responsible for the secondary sex characteristics of females and males, such as breast in women and facial hair in men. Slide 37 Male hormonal control Let’s look at the hormonal control of the male reproductive system. In both male sand females the hypothalamus, a part of the brain, produces a hormone called gonadotropin releasing hormone, or GnRH. GnRH causes the pituitary gland to release two hormones, follicle stimulating hormone, abbreviated FSH, and luteinizing hormone, abbreviated LH. In males the FSH is responsible for the production of sperm and another hormone called inhibin. LH causes the production of testosterone. There is a negative feedback mechanism here. When levels of sperm get too high, the hormone inhibin stops the production of GnRH, FSH, and LH. High levels of testosterone will also inhibit the production of GnRH, FSH, and LH. Slide 38 YouTube Video Male Hormonal Control https://www.youtube.com/watch?v=YWIHDsaIjBs
 
 
 
 
 
 
 
Reproductive System Slide 39 Female reproductive system The female reproductive cycle is more complicated than that of the male. Let’s start by looking at what happens inside the system and then look at the hormonal control of the system. Slide 40 Ovaries Eggs are found inside the ovaries in an arrested state of development. A female is born with all the eggs she will ever have inside of her ovaries. To begin the cycle an egg divides inside a structure called the follicle. The follicle secretes the hormone progesterone. Progesterone tells the uterus to build up a lining for the preparation of a fertilized egg. The lining of the uterus is called the endometrial lining. At ovulation, the follicle burst open and the eggs leaves the ovary and travel down the fallopian tube. The fallopian tube is also known as the oviduct. Slide 41 Corpus luteum What is left of the follicle transforms into another structure called the corpus luteum. The corpus luteum continues to secrete progesterone. If the egg is not fertilized, the corpus luteum will disintegrate in about 10 days. The disintegration of the corpus luteum means that the level of progesterone drops, and the endometrial lining is no longer maintained. The lining of the uterus is what is shed during menstruation. Slide 42 Fertilization If the egg is fertilized, the corpus luteum will not disintegrate and will continue to secrete progesterone to maintain the endometrial lining. Progesterone is known as the hormone of pregnancy. The egg is fertilized in the fallopian tube, but after fertilization will implant itself in the thick endometrial lining. Implantation takes place about 7 to 10 days after fertilization. After the embryo has implanted in the endometrial lining, it begins to send tissue out to the lining that will develop into the placenta. The placenta secretes a hormone called human chorionic gonadotropin, abbreviated HCG. HCG is the hormone detected by a pregnancy test. Slide 43 Female hormonal control What causes all of these events to occur? The answer is hormones. The hormone FSH (the same follicle stimulating hormone we saw in the male reproductive system) causes the follicle to develop within the ovary. FSH is also responsible for the production of estrogen in the female. The hormone LH (again this is the same luteinizing hormone we saw in the male reproductive system) causes ovulation and leads to the development of the corpus luteum and the hormone progesterone. Slide 44 Menstrual cycle The female hormones are cyclic. This means that the hormones increase or decrease based on the events taking place in the reproductive tract. Let’s look at what happens during that cycle. The levels of FSH and LH peak around the time of ovulation. FSH levels are high during the time the follicle is developing. LH levels are the lowest at the time of menstruation. Progesterone levels are high right after ovulation, because this is when the corpus luteum is intact and secreting progesterone. After the corpus lutem disintegrates, progesterone levels decrease sharply. Slide 45 Ovarian and Uterine Cycles Animation
 
 
 
 
 
 
 
Reproductive System Slide 46 Check Your Understanding Now that we have learned about the hormones involved in the reproductive system, let’s check your knowledge of the subject. The following slides will have a series of questions on the topic. Be sure to click “Submit” after answering each question. Slides 47 through 56 Hormones Involved in Reproduction Interactive Quiz A nongraded assessment of your knowledge of the hormones involved in reproduction. Slide 57 Contraception Birth control, or contraception, is any method which prevents the sperm and the egg (oocyte) from making contact, or prevents an embryo from implanting in the endometrium. There are many forms of contraception, each with varying degrees of reliability. Slide 58 Efficacy How effective is effective? Efficacy of birth control methods has always been a major concern. If you’re going to use it, it should work, right? Most nonsurgical methods of birth control are between 7590% effective in preventing pregnancy. Surgical sterilization is one method of birth control which provides nearly 100% prevention of conception. We’ll overview several methods of each in the next several slides. Slide59 Categories of Birth Control There are several categories of birth control. These include sterilization, barrier methods, inhibition of the release of gametes, and the prevention of embryo implantation. We will discuss the various forms of birth control that are within each of these categories in further detail throughout the remainder of this lecture. Slide 60 Sterilization Sterilization is considered a permanent form of birth control. During a sterilization procedure, the ducts that carry the gametes are closed or blocked. Sterilization in a male is called a vasectomy, while in a female it is called a tubal ligation. The details of each of these procedures will be detailed on the following slides. Slide 61 Vasectomy A vasectomy blocks each vas deferens and keeps sperm out of the seminal fluid. The sperm are absorbed by the body instead of being ejaculated. Without sperm, the ejaculate cannot cause pregnancy. A vasectomy is the most effective birth control for men. It is nearly 100 percent effective. However, a vasectomy is not immediately effective. Sperm remains beyond the blocked tubes. Another form of birth control must be used until the sperm are used up. It usually takes about three months. A simple test semen analysis shows when there are no more sperm in your ejaculate. Slide 62 Tubal Ligation During a sterilization procedure, a health care provider closes or blocks a woman’s fallopian tubes. Closing the tubes can be done in several ways. One way is by tying and cutting the tubes this is called tubal ligation. The fallopian tubes also can be sealed using an instrument with an electrical current. They also can be closed with clips, clamps, or rings. Sometimes, a small piece of the tube is removed.
 
 
 
 
 
 
 
Reproductive System Sometimes, tiny inserts are put in the tubes. Tissue grows around them and blocks the tubes. The brand names for these types of sterilization are Adiana and Essure. Slide 63 Barrier Methods The next category of birth control we will discuss are barrier methods. Barrier methods of birth control provide physical barriers that prevent the sperm from coming in contact with the egg, therefore fertilization and pregnancy cannot occur. Slide 64 Diaphragm The diaphragm is a shallow, domeshaped cup with a flexible rim. It is made of silicone and inserted it into the vagina prior to sexual intercourse. When it is in place, it covers the cervix. Diaphragms prevent pregnancy by keeping sperm from joining with an egg. In order to be as effective as possible, the diaphragm must be used with spermicidal cream, gel, or jelly. Diaphragms work in two ways: The diaphragm blocks the opening to the uterus. The spermicide kills most of the sperm. Slide 65 Male Condoms Male condoms are worn on the penis during intercourse. They are made of thin latex or plastic that has been molded into the shape of a penis. Condoms prevent pregnancy and reduce the risk of sexually transmitted diseases. Condoms prevent pregnancy by collecting semen when a man ejaculates. This keeps sperm from entering the vagina. Pregnancy cannot happen if sperm cannot join with an egg. In addition, by covering the penis and keeping semen out of the vagina, anus, or mouth, condoms also reduce the risk of sexually transmitted infections. Slide 66 Females Condoms The female condom is a plastic pouch that is used during intercourse to prevent pregnancy and reduce the risk of sexually transmitted diseases. It has flexible rings at each end. Just before vaginal intercourse, it is inserted deep into the vagina. The ring at the closed end holds the pouch in the vagina. The ring at the open end stays outside the vaginal opening during intercourse. Female condoms work to prevent pregnancy by covering the inside of the vagina. They collect semen when a man ejaculates. This keeps sperm from entering the vagina. Pregnancy cannot happen if sperm cannot join with an egg. Slide 67 Sponge The sponge is made of plastic foam and contains spermicide. It is soft, round, and about two inches in diameter. It has a nylon loop attached to the bottom for removal. It is inserted deep into the vagina before intercourse. The sponge prevents pregnancy by keeping sperm from joining with an egg. It works in two ways: The sponge covers the cervix and blocks sperm from entering the uterus. The sponge also continuously releases a spermicide that kills most sperm.
 
 
 
 
 
 
 
Reproductive System Slide 68 Cervical Cap The cervical cap is a silicone cup shaped like a sailor’s hat. It is inserted it into the vagina and over the cervix. The cervical cap prevents pregnancy by keeping sperm from joining with an egg. In order to be as effective as possible, the cervical cap must be used with spermicide cream or jelly. The cap works in two ways: The cervical cap blocks the opening to the uterus. The spermicide kills most of the sperm. Slide 69 Inhibition of the release of gametes In order for pregnancy to occur gametes must be released from both the male and the female and unite in the female reproductive tract. Another category of birth control prevents the release of gametes. Slide 70 Birth Control Pills It’s pretty common for people to be confused about how birth control pills work. Here’s what it boils down to: birth control pills are made of hormones. Recall from our discussion of the endocrine system that hormones are chemical messengers that are made in one part of the body and have their effect in another part of the body. Some birth control pills contain two hormones estrogen and progestin. These are called combination pills. Some are progestinonly pills. Most women on the pill take combination pills. The hormones in the pill work by keeping a woman’s ovaries from releasing eggs, or ovulating. Pregnancy cannot happen if there is no egg to join with sperm. The hormones in the pill also prevent pregnancy by thickening a woman’s cervical mucus. The mucus blocks sperm and keeps it from joining with an egg. The hormones also thin the lining of the uterus. In theory, this could prevent pregnancy by keeping a fertilized egg from attaching to the uterus. Slide 71 The Patch The birth control patch is a thin, beige, plastic patch that sticks to the skin. It is used to prevent pregnancy. A new patch is placed on the skin once a week for three weeks in a row, followed by a patchfree week. Like the birth control pill, the birth control patch releases hormones. The hormones in the patch are the same hormones as in the birth control pill estrogen and progestin. The hormones work by keeping a woman’s ovaries from releasing eggs ovulation. Pregnancy cannot happen if there is no egg to join with sperm. The hormones in the patch also prevent pregnancy by thickening a woman’s cervical mucus. The mucus blocks sperm and keeps it from joining with an egg. The hormones also thin the lining of the uterus. In theory, this could prevent pregnancy by keeping a fertilized egg from attaching to the uterus. Slide 72 Injections The birth control shot is an injection of a hormone that prevents pregnancy. Each shot prevents pregnancy for three months. The shot is also known by the brand name DepoProvera. The birth control shot releases a hormone progestin into the body. The progestin in the shot works by keeping a woman’s ovaries from releasing eggs ovulation. Pregnancy cannot
 
 
 
 
 
 
 
Reproductive System happen if there is no egg to join with sperm. The progestin in the shot also prevents pregnancy by thickening a woman’s cervical mucus. The mucus blocks sperm and keeps it from joining with an egg. The hormone also thins the lining of the uterus. In theory, this could prevent pregnancy by keeping a fertilized egg from attaching to the uterus. Slide 73 Vaginal Ring The vaginal ring is a small, flexible ring a woman inserts into her vagina once a month to prevent pregnancy. It is left in place for three weeks and taken out for the remaining week each month. The vaginal ring is commonly called NuvaRing, its brand name. Like other methods of birth control, NuvaRing releases hormones. The hormones in NuvaRing are the same hormones as in the birth control pill estrogen and progestin. The hormones work by keeping a woman’s ovaries from releasing eggs ovulation. Pregnancy cannot happen if there is no egg to join with sperm. The hormones in NuvaRing also prevent pregnancy by thickening a woman’s cervical mucus. The mucus blocks sperm and keeps it from joining with an egg. The hormones also thin the lining of the uterus. In theory, this could prevent pregnancy by keeping a fertilized egg from attaching to the uterus. Slide 74 Implanon Implanon is a thin, flexible plastic implant about the size of a cardboard matchstick. It is inserted under the skin of the upper arm. It protects against pregnancy for up to three years. Like several other methods of birth control, such as the birth control shot, Implanon releases a hormone progestin. The progestin in Implanon works by keeping a woman’s ovaries from releasing eggs ovulation. Pregnancy cannot happen if there is no egg to join with sperm. The hormone in the implant also prevents pregnancy by thickening a woman’s cervical mucus. The mucus blocks sperm and keeps it from joining with an egg. The hormone also thins the lining of the uterus. In theory, this could prevent pregnancy by keeping a fertilized egg from attaching to the uterus. Slide 75 Prevention of Embryo Implantation The final category of birth control we will cover is the prevention of embryo implantation. Birth control methods in this category affect the uterus, so that is an egg is fertilizaed, it can not easily implant into the uterus. Slide 76 IUD The letters IUD stand for “intrauterine device.” IUDs are small, “Tshaped” devices made of flexible plastic. A health care provider inserts an IUD into a woman’s uterus to prevent pregnancy. There are several brands of IUD available in the United States including ParaGard, Mirena, Skyla, Kyleena, and Liletta. These IUDs are divided into 2 types: copper IUDs (ParaGard) and hormonal IUDs (Mirena, Kyleena, Liletta, and Skyla). The ParaGard IUD doesn’t have hormones. It’s wrapped in a tiny bit of copper, and it protects you from pregnancy for up to 12 years. The Mirena, Kyleena, Liletta, and Skyla IUDs use the hormone progestin to prevent pregnancy. Progestin is very similar to the hormone progesterone that our bodies make naturally. Mirena, Kyleena, and Liletta work for up to 5 years, while Skyla works for up to 3 years.
 
 
 
 
 
 
 
Reproductive System IUDs affect the way sperm move, preventing them from joining with an egg. If sperm cannot join with an egg, pregnancy cannot happen. IUDs also alter the lining of the uterus. This may keep a fertilized egg from attaching to the lining of the uterus. The progestin in the Mirena, Kyleena, Liletta, and Skyla IUDs also helps prevent pregnancy. Progestin works by keeping a woman’s ovaries from ovulating. Slide 77 Other Methods There are other methods of birth control that do fit into the categories discussed earlier in this lecture. These methods include: fertility awareness based methods, lactational amenorrhea method, and withdrawal method. Each of this will be discussed in detail. Slide 78 Emergency Contraception Emergency contraception is a safe and effective way to prevent pregnancy after unprotected intercourse or birth control failure. It is most effective when used within 72 hours after unprotected intercourse. Emergency contraception works by: Preventing ovulation Inhibiting the movement of sperm Altering the endometrium of the uterine lining Emergency contraception can be used if: The condom broke or slipped off and ejaculation occurred within the vagina. You forgot to take your regular birth control method (birth control pills, contraceptive vaginal ring, or contraceptive patch). Your diaphragm or cap slipped out of place and ejaculation occurred within the vagina. You miscalculated your “safe” days. He didn’t pull out in time. You weren’t using any birth control. You were forced to have unprotected vaginal sex. Emergency contraception is also known as the morningafter pill, emergency birth control, backup birth control, and by the brand names Plan B OneStep, ella, and Next Choice. Many people call emergency contraception the “morningafter pill.” But that name is a little confusing. You can use emergency contraception up to 72 hour after unprotected intercourse not just the “morning after.” Slide 79 Immunocontraception Immunocontraception is a way of making the body attack gametes through an immune response. Although not used much in humans, immunocontraception has been used in some animals. For example, the habitat of the koala in Australia has been severely depleted. Kolas are in danger of overpopulation. Some female koalas are injected in the arm with the coating of a pig egg. The pig egg and koala egg are similar and because the coating in not where is should be, the female koala develops an immune response to this coating. When her reproductive system produces an egg, her body’s immune system attacks and destroys the egg. She cannot become pregnant.
 
 
 
 
 
 
 
Reproductive System Slide 80 Birth Control Research There are many forms of birth control that are in the research or clinical trial phase. Some these include a reversible vasectomy in which an injection of a polymer gel called Vasalgel is injected into the vas deferens. The Vasalgel can later by dissolved and it is believed that fertility returns within a few months. Another research branch of birth control is preventing sperm activation. This is based on the idea the calcium is needed by the sperm to release enzymes necessary to penetrate the egg membrane. A drug that blocks these calcium channels would prevent sperm from fertilizing an egg. Research is also being conducted on preventing sperm binding to the egg prior to fertilization. A drug that blocks the receptors that allow this binding would prevent fertilization. Finally, the immune system is being testing as a means to prevent fertilization. HCG is the hormone produced that signals the corpus luteum to continue to release progesterone. An antiHGC vaccine would induces formation of antiHCG antibodies by a woman blocking this hormone and preventing pregnancy. The effects are reversible and normal fertility is restored. This vaccine has no effect on the menstrual cycle. The antiHCG vaccine is currently undergoing clinical trials in several countries, no adverse effects have been noted, but the vaccine is not yet available on the market. Slide 81 Efficacy The table on this slide shows how effective each type of birth control is. There are two types of data listed: 1) the number of pregnancy when the birth control method is used correctly; and 2) the number of pregnancies that typically occur when using a specific type of birth control As you can tell, human error, plays a large role in the effectiveness of some, but not all methods of birth control. Surgical methods are the most effective, while rhythm or Fertility awareness based methods have the highest typical failure rate. If you would like more information about birth control methods, including the risks, benefits, and costs of each of the methods discussed in this lecture, please vist www.plannedparenthood.org Slide 82 Check Your Understanding Now that we have learned about contraception, let’s check your knowledge of the subject. The following slides will have a series of questions on the topic. Be sure to click “Submit” after answering each question. Slides 83 through 88 Birth Control and Emergency Contraception Interactive Quiz A nongraded assessment of your knowledge of contraception. Slide 89 Summary This slide is a summary of all of the “Check Your Understanding” questions from this lecture. Be sure to review the questions you answered incorrectly. Slide 90 Infertility Although some people may be trying to avoid pregnancy, others may be trying to get pregnant. Some couples have problems getting pregnant, and this is called infertility. Female infertility is often caused by hormone imbalances or disease. Male infertility is often caused by low sperm count or poor sperm motility.
 
 
 
 
 
 
 
Reproductive System Slide 91 Increasing fertility There are various ways to help couples suffering from infertility. In in vitro fertilization, also known as IVF, the sperm and egg are joined outside of the body and the embryo is placed in the uterus. In gamete intrafallopian transfer, also known as GIFT, sperm and egg are placed in the fallopian tube for fertilization to occur. In artificial insemination, sperm from a donor is placed in the vagina. Other fertility treatments also exist. Slide 92 Sexually Transmitted Diseases Sexually transmitted diseases (STDs) are caused by infections that are passed from one person to another during sexual contact. These infections often do not cause any symptoms. Medically, infections are only called diseases when they cause symptoms. That is why STDs are also called “sexually transmitted infections.” But it’s very common for people to use the terms “sexually transmitted diseases” or “STDs,” even when there are no signs of disease. There are many kinds of sexually transmitted diseases and infections. And they are very common more than half of all of sexually active people will get one at some time in our lives. Because many STDs do not have symptoms, if left untreated, STDs can lead to infertility. In order to avoid sexually transmitted diseases, safer sex practices should be used. Using condoms makes vaginal, oral, and anal intercourse safer sex.
 
 
 
 
 
 
 
Reproductive System Slide 93 Categories of STDs There are three categories of STDs. They are bacterial, viral, and parasitic. Examples of bacterial STDs include Chlamydia, gonorrhea, and syphilis. Some examples of viral STDs are Herpes, HIV, Genital Warts, and Hepatitis. Pubic lice or crabs are an example of a parasitic STD. [In the following slides, we will discuss specific each of these STDs in detail.] delete from audio Slide 94 Review This brings us to the end of unit 3. In this unit we have explored homeostasis and the circulatory, immune, and reproductive systems of humans.

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