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Chapter 16 Reproduction and the Early Years of Life.

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Presentation on theme: "Chapter 16 Reproduction and the Early Years of Life."— Presentation transcript:

1 Chapter 16 Reproduction and the Early Years of Life

2 Chapter 16 Vocabulary Fertilization – the union of a sperm and an egg Sperm – male gametes or reproduction cell; contains one-half of the instructions needed for the development of a new human being Egg – Female reproductive cell, also called an ovum; contains one-half of the instructions needed for the development of a new human being Testes – two small glands that secrete testosterone and produce sperm Penis – tube-shaped organ that extends from the trunk of the body just above the testes Ovaries – female reproductive structures that produce eggs and female sex hormones Ovulation – the release of an egg from an ovary

3 Chapter 16 Vocabulary Vagina – female reproductive structure that receives the sperm Cervix – the base of the uterus, which bulges down into the vagina; has a small opening through which sperm can enter the uterus Uterus – the hollow muscular organ that provides a place for the baby to grow before birth; also called the womb Pap test – a medical procedure in which cells from the cervix are removed and tested for cancer Embryo – a fertilized egg after it has attached itself to the wall of the uterus Fetus – a developing individual from the ninth week of pregnancy until birth

4 Chapter 16 Vocabulary Semen – a thick fluid containing sperm and other secretions from the male reproductive system Testosterone – the male sex hormone Sterility – the inability to reproduce

5 16.1 The Endocrine System The endocrine glands are ductless or tubeless organs or groups of cells that secrete hormones directly into the bloodstream Hormones are chemicals substances that help regulate many of your body’s functions The adrenal glands help the body deal with stress and respond to emergencies Maintaining Your Endocrine Health – Eat balanced meals to ensure that you get nutrients you need, and use stress-management techniques – Sleep is also important to the endocrine health – Engage in regular physical activity to keep your body strong – Also have regular medical checkups Stress, infection, and changes in the balance of fluid and minerals in the blood can cause hormone levels to fluctuate

6 16.1 The Endocrine System

7 16.2: The Male Reproduction System Life is the result of the union of a sperm cell from a male and an egg cell or ovum from a female The union of the sperm and egg is called fertilization Each sperm and egg contain one half of the instructions needed for the development of a new, unique human being The process of producing a new individual is called reproduction or having children One job of the male reproduction system is to produce sperm and transport them into the body of the female Figure 16.5 The Parts of the Male Reproduction System – Scrotum is the loose sac under the penis. Inside are two testes which produce sperm – The Vas deferens connects the testes and the penis and the sperm travels through this tube – Along the way are glands that produce fluids that nourish and protect the sperm

8 16.2 The Testes Testes also called testicles are two egg-shaped structures that hang inside the scrotum Two functions for the testes: – Make sperm – testes hang away from the body so that the temperature inside them is slightly cooler than the rest of the body If temp. is too high the sperm will not fertilize an egg: defective Testes produce about 50,000 sperm every minute – Produce the male sex hormone testosterone Testosterone is necessary for sperm production and the development of male sex characteristics At puberty the amount of testosterone increases which causes boys bodies to change

9 16.2: The Vas Deferens and the Urethra Sperm must be able to leave the body for reproduction to occur After sperm is made in the testes, they travel to a structure called the epididymis, located at the top of each testis In the epididymis sperm become fully mature After about two to 10 days, the sperm leave the epididymis and travel through a tube called the vas deferens. Males have two of these tubes The vas deferens tubes lead to the urethra, which is the tube that runs through the center of the penis The sperm and urine leaves the body through the urethra Along the way sperm pass by glands that add fluids to the sperm. These nourish and protect the sperm, and enable the sperm to move on their own. The addition of these fluids to the sperm creates the fluid called semen

10 16.2: The Penis Through the penis the sperm reaches the inside of the female’s body During sexual excitement the arteries leading to the penis open wider, allowing more blood to flow into the penis. At the same time some of the veins in the penis close or narrow so that less blood flows out The accumulated blood causes the penis to become larger, longer, and firmer and to point upward instead of hanging downward This state is an erection which makes it possible for the penis to be inserted into the female’s vagina Ejaculation is the process by which semen leaves the body – During ejaculation, muscles around the urethra and the base of the penis contract. The contraction moves the sperm out of the body – Ejaculation is also called an orgasm – Ejaculation can occur during sleep called nocturnal emission or a “wet dream”

11 16.2: Pathways to Fertilization During sexual intercourse the sperm are deposited inside the female’s vagina, a few inches from the egg From a sperm’s point of view, this is a long and difficult journey – Each sperm has a tail that propels it forward – Sperm are streamline and much smaller than most cells in the body. Their streamline shape and small size make it easier for them to swim quickly The semen in one ejaculation contains 40 million to 400 million sperm So many are released because the majority of the sperm will never make it to the egg – Sperm will become trapped in mucus or die on the way Millions are also released because the presence of many sperm is necessary to help one sperm fuse with an egg

12 16.2: Pathways to Fertilization cont… The egg is protected by a layer of many smaller cells Sperm contain enzymes that break down this layer of cells Only after many sperm have released their enzymes can one sperm make it to the inside of the egg After one sperm has made it inside, a protective shield forms, which prevents other sperm from fusing with the egg

13 16.2: Disorders of the Male Reproduction System Something can go wrong with the male reproduction system even if he takes good care of himself Testicular Torsion – means “twisted testis” – Really means spermatic cord, which suspends each testis in the scrotum and contains many blood vessels – Can become twisted during strenuous exercise or even during sleep – Very rare, but its an emergency situation. Testicular torsion can destroy the testes. Pain in the groin Undescended Testes – One or both testes remain inside the body rather than hanging loose in the scrotum – If testes don’t descend into the scrotum by 2 yrs old medical treatment is necessary – Undescended testes are more likely to cause cancer – Infertility may result

14 16.2: Disorders of the Male Reproduction System Inguinal Hernia – Sometimes part of an intestine protrudes into the scrotum through a weakness in the abdominal wall – It’s painful and require surgery to correct Infertility – Being unable to reproduce – Males infertility means he has too few sperm or his sperm are unable to fertilize an egg – Caused by exposure to harmful drugs or X rays, the development of testicular mumps as an adult, or a genetic defect – Medical treatments are available for many kinds of male infertility Enlarged Prostate Gland – Prostate gland obstructs the outlet of the urinary bladder. Very dangerous and uncomfortable Prostate Cancer – Requires surgical treatment – Most common cancer in American males – 2 nd most common cause of deaths due to cancer in American males

15 16.2: Disorders of the Male Reproduction System Testicular Cancer – Cancer of the testes – Most common form of cancer in males between 15 and 35 – If detected and treated early, there is an excellent chance of recovery – Monthly examination of testes for early detection is suggested Care of the Male Reproductive System – A few simple steps to take care of the male reproductive organs – Wash the penis and scrotum daily, and check for sores or bumps – Don’t wear extremely tight clothing. Can cause pain – Do the testicular self-examination once a month to detect lumps or other abnormalities to detect early signs of cancer

16 16.3 The Female Reproduction system The job of the female reproduction system is to produce an egg and to provide a place where the egg and the sperm can join After the union of egg and sperm the fertilized egg begins its development into a new individual The female reproduction system provides the new individual with shelter and nourishment for the nine months before birth After birth a woman’s breasts are able to provide nourishment in the form of milk Breast are part of the female reproductive system

17 16.3: The Vagina, Cervix, and Ovaries The vagina is a muscular tube that receives the sperm The upper end of the vagina is the cervix, which has a small opening through which sperm can enter the uterus During birth the baby pass through the cervix and vagina, so the vagina is sometimes called the birth canal The ovaries are located in the lower part of the abdomen. One on each side of the uterus. Two Functions of the ovaries: – Produce the eggs – usually only one mature egg at a time – Product sex hormones – these hormones called estrogen and progesterone cause girly features and the monthly release of an egg and menstrual cycle Ovulation is the release of an egg from an ovary After ovulation the egg can be fertilized by a sperm

18 16.3: The Fallopian Tubes and the Uterus Once an egg is mature fluid sweeps it from the ovary into the fallopian tube which takes it to the uterus Fertilization occurs in the fallopian tube If the sperm meets the egg in the upper third of the fallopian tube, it can be fertilized If the egg is not fertilized within 12 to 24 hours after its release from the ovary it begins to break down The eggs continues to travel toward the uterus fertilized or not It reaches the uterus four or five days after leaving the ovary Unfertilized it will dissolve in the uterus, fertilized it will implant in the wall of the uterus, where it will grow into an embryo The uterus is a muscular organ about the size of a fist sometimes called the womb – Main job is to provide a place for the baby to grow

19 16.3: The menstrual Cycle The uterus undergoes cyclical changes monthly, which prepare it to receive and nourish a fertilized egg. These changes are called the menstrual cycle During the menstrual cycle, the inner lining of the uterus thickens, and many tiny blood vessels grow into the thickened lining These changes are caused by sex hormones One of two things can happen from these changes – If the egg has been fertilized, hormones are released that tells the uterus to maintain its thickened lining. She is pregnant – The egg was not fertilized the thickened uterine lining breaks down and the female menstruates Except during pregnancy a woman release an egg every month from puberty until about the age of 50

20 16.3: The menstrual Cycle If the egg is not fertilized the blood vessels of the lining close up and then break The cells of the lining comes loose from the inside of the uterus Blood from the broken vessels help to wash these cells out of the uterus The mixture of blood and cells is call menstrual fluid The time during which the menstrual fluid flows out the body is called the menstrual period. Usually last from three to seven days After the menstrual period is completed, the uterus begins to prepare a new thicken lining that will be ready for the next egg The average menstrual cycle last 28 days. The time from the first day of a menstrual period until the first day of the next period This cycle can vary for some women and that is an irregular cycle Age of the first menstrual period varies between 12 and 14 and some 10 All of these individual differences are perfectly normal

21 16.3: Disorders of the Female Reproduction System Menstrual cramps are very common – Felt in the lower abdominal area caused by the contracting of the uterus – Warm bath and exercise can relieve cramps, medication OTC’s, if nothing helps see the doctor PMS (Premenstrual Syndrome) are problems experienced before the menstrual period – Swelling and tenderness of the breasts, irritability, bloated feeling, constipation, headaches, and fatigue, depression, crying, anxiety, and anger – Usually occur one to two days before the period but may happen sooner – Reduce intake of salt and sugar, avoid caffeine and nicotine, regular exercise and relaxation exercises can help

22 16.3: Disorders of the Female Reproduction System Vaginitis (Bacterial Vaginosis) is something that most women will have at some point in their lives – Itching or soreness of the vulva, unpleasant odor, increase in discharge from the vagina, and sometimes a burning sensation – Douching for vaginitis is not recommended – Important to know most fluids from the vagina are perfectly normal. If fluid is whitish and nonirritating it is probably normal Toxic Shock Syndrome a rare but dangerous bacterial infection that affects the immune system and the liver – Associated with the use of highly absorbent tampons – Tampons should be changed frequently at least every 4 to 6 hours – High fever, nausea, diarrhea, dizziness, and a sunburn-like rash on the palms of hands or bottom of feet – Can cause death, go to the emergency room Ovarian Cysts is a growth on the ovary – A woman may have pain or no symptoms

23 16.3: Disorders of the Female Reproduction System Cancers can occur in any part of the woman’s reproductive system – Doctors recommend that all sexually active females, regardless of age have a yearly pelvic examination to detect cancers early – Pap test are used during the exam, in which cells from the cervix are removed and tested for cancer – Women should check their breast for lumps and other abnormalities each month Infertility means unable to have children – Most common cause is failure to ovulate – to release an egg – Underweight women because of eating disorders or excessive exercise do not ovulate – Scar tissue in the fallopian tubes. May be the result of surgery or infection – Sexually transmitted diseases

24 16.3: Care of the Female Reproduction System Take the following simple stems to keep everything working smoothly – Wash the external reproductive organs daily with a mild, nonirritating soap. Feel for any unusual bumps or sores – Don’t use “feminine hygiene” sprays – Don’t use douches unless they are medicated douches recommended for you by your doctor – During menstruation, change sanitary pads or tampons often, at least 4-6 hours. Don’t use deodorant tampons, or tampons with greater absorbency than you need – Visit a health care provider once a year to make sure that your reproductive system is healthy – Perform a monthly breast self-examination to find lumps or other abnormalities

25 16.3: How to do a Breast Self- Examination

26 Chapter 17.1 Pregnancy, Birth, and Childhood Development – Before fertilization the sperm and egg are two separate cells which each contain ½ of the information needed for the development of a new person – After fertilization there is only one cell that contains all the information needed for the development of a new person – After ejaculation, it takes the sperms between 15 mins and an hour to reach the fallopian tube and fertilize the egg – The fertilized eggs travels toward the uterus – 30 hours after fertilization the egg divides into two cells – The two cells then divide into four cells and the four into eight and so on – About four days after fertilization, the fertilized egg finally reaches the uterus – The eggs rests on the soft, thick lining of the uterus, it begins to burrow into the lining. It’s now an embryo – By the 10 th day the embryo contains thousands of cells and is completely buried in the uterine wall. This is implantation

27 17.1: From Mother to Baby The embryo implants itself into the wall of the uterus and use all the nutrients that were stored in the egg before fertilization The placenta is the structure that allows the embryo to get what it needs from the mother The placenta is a disc-shaped organ that is attached to the inner wall of the uterus It is connected to the embryo by a structure called the umbilical cord Oxygen, antibodies, and nutrients from the mother’s blood diffuse through the walls of the embryo’s blood vessels in the placenta These things then travel through the blood vessels in the umbilical cord to the baby

28 17.1: Changes During Pregnancy Once implanted the embryo grows rapidly A heart and brain begin to form. Eyes appear and the face takes shape Small buds on the sides of the body become arms and legs Internal organs like the lungs, stomach, and liver are developing The embryo floats in a warm, fluid-filled pouch called the amniotic sac Eight weeks after fertilization the embryo is only 30 mm long (a little over an inch), but all the major organs are formed and growing From the ninth week until birth, it is called a fetus Pregnancy test look for HCG (human chorionic gonadotropin) After three weeks a female will have enough HCG in her blood and urine for a positive test

29 17.1: Development Inside the Uterus

30 17.1 Childbirth 1 st a month or two before birth, the fetus drops to a lower position 2 nd in the 1 st stage of delivery (dilation), strong uterine contractions cause the cervix to dilate 3 rd the cervix has completely dilated by the end of this stage 4 th During the second stage (expulsion), the head emerges fully and the shoulders rotate 5 th By the third stage (placental), the baby has been born. The uterus expels the placenta and the umbilical cord The final stage is when contractions are strong enough to push the baby out is labor (between 5 and 20 hours)

31 17.1: Complications of Pregnancy and Birth

32 Questions

33 Active Learning Create informational brochures that describes to younger female and male students what happens to their bodies as they mature. Target your brochures to adolescents between the ages of 8 and 13. Include illustrations and use information that is well organized and easy to understand. – Females include information about menstruation - what it is, what happens to the body, why it happens, and how to manage the changes. – Males include information on how to maintain reproductive health and how to do a testicular self-exam (TSE)


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