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Chapter 6

Human Sexuality ch.6.docx

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Western University
Psychology 2075

Human Sexuality Chapter 6 Conception Sperm meets egg: the incredible journey  The egg has no way of movement and is moved by the cilia that lines the fallopian tubes  A women’s cervix secretes mucus that flushes the passage ways to prepare for the arrival of the sperm  The sperm travel great distances to reach the vagina and are made up of the head, mid piece and tail  It is approximately 60 micrometers, and the DNA is found within the nucleus which is located in the head  The head also contains acrosome (a chemical reservoir) and RNA  The sperm is propelled forward by the flagella  this is powered by the mitochondria found within the tail  Approximately 200 million sperm are ejaculated each time a man ejaculates this may seem like a lot, but a lot of the sperm are either deformed, swim up the wrong fallopian tube, or flow out of the vagina due to gravity  Sperm are capable of swimming 1-3 centimeters per hour  Conception occurs in the last third of the fallopian tube  The sperm is attracted to the egg by a chemical secreted by the egg, they attach to the zona pellucida  The sperm surround the egg and secrete an enzyme called hyaluronidase o An enzyme secreted by the sperm that allow one sperm to penetrate the egg by dissolving the Zona Pellucida  Zygote: the developing organism from the time of the union of the sperm and the egg to about the second week of gestation  36 hours after conception the zygote undergoes rapid cell division, and about 5 to 7 days after conception the mass implants itself in the lining of the uterus  this is where it nourishes and grows  The cell mas is called an embryo from week two to week eight and from the on its is called a fetus Improving the chances of conception: making a baby  Conception is at its highest chance when the women is ovulating this tends to be 14 days after menstruation  A way to know if a women is ovulating is to take her basal temperature (right when she wakes up before she starts her day, when she has a spike in temperature you know that’s he will be ovulating), another way is by taking an ovulation test  It is best to have sex 4 time the week the women is ovulating, allowing the sperm to regenerate (allowing a build up off 200 million sperm)  It is best to have the women lying on her back so that the sperm does not flow out after ejaculation (best if she stays in this position for about half an hour to an hour)  Lubrication should not be used as it can block the entrance to the uterus Development of the Conceptus  In the past the relationship between the mother and the baby has been described as a harmonious co-existence  But diseases like gestational diabetes, which is just like diabetes except occurs during pregnancy and pre-eclampsia where the women has a high spike in blood pressure, protein in the urine and swollen feet hands in the third trimester  Pregnancy last about 9 months and is divided into three trimesters (trimester 1 month 1-3. Trimester 2 month 4-6 and the third 7-9) The Embryo and its Support system  During the first eight weeks of development, the major organ systems are developed with amazing speed  The mass of cells divided into the ectoderm and endoderm, later the mesoderm is developed between the two  The ectoderm will create the nervous system and the skin, the endoderm will differentiate into the digestive system from the pharynx to the stomach intestines, the rectum and the respiratory system  The muscles the skeleton, connective tissues, and reproductive and circulatory system derive from the mesoderm  The body of the baby develops head to feet, this is why the embryo has a very  Placenta: an organ formed on the wall of the uterus through which the fetus receives oxygen and nutrients and gets rid of waste products  The placenta is the place where the mothers blood and nutrients are exchanged with the baby  They are connected by the tendrils that penetrate the wall of the blood vessels in the uterus  It is important to remember that the mothers and the fetus’s circulatory systems are completely separate from one another  The fetus’s blood passes out of the body through the umbilical cord which is connected to the placenta  The blood of the fetus passes through the villa found in the placenta, and the mothers passes on the outside of these vessels, creating a membrane  The membrane is permeable to some molecules and nutrients like oxygen  It is also permeable to some drugs so the mother has to be careful of what she takes  Carbon dioxide and waste is passes out of the fetus and into the mother  Some disease can pass through the membrane syphilis  But the mother may have a terrible cold and the baby could be perfectly healthy  Another major function of the placenta is to produce estrogen and progesterone  physical symptoms of pregnancy may be caused by these elevated levels  The placenta also produces Human Chorionic Gonadotropin (hCG) o A hormone secreted by the placenta, it is the hormone detected in pregnancy tests  Umbilical Cord: the tube that connects the fetus and the placenta o Can be around 20 inches long and contains two main arteries and one vein  Two membranes surround the baby: the amnion and the Chorion  The amnion is the inner most layer and is filled with amniotic fluid o The watery fluid surrounding the fetus in the uterus, serves as protection for the baby Fetal Development  The fetus is mostly developed in the first trimester: it resembles a small human being and contains all the vital organs  Through the rest of the pregnancy it is mostly enlargement and differentiation of the different structures  Table 6.1 in the text book  During the seventh month of pregnancy the fetus turns to assume a head down position Pregnancy The stages of Pregnancy  The first trimester: o Women experience many different symptoms of pregnancy, some may experience nausea, tender breasts, tingling sensation in the nipples o A tell tale sign is a missed menstrual period  Not always the case, some women may randomly skip there period, or stress and disease can delay it o A women should know she is pregnant as soon as possible so that she can get the ore natal care that she needs, or if she does not want to carry the baby to term needs to know because it is much safer and simpler in the first trimester o Pregnancy tests are 99 percent affective (done in a laboratory) o Immunologic tests are done by the detection of hCG o Home pregnancy tests are not very reliable, they produce false negatives (10/18 women) and also have a 16 percent rate of false positives o Signs of pregnancy can be classifies into presumptive signs (breast tenderness, nausea), probable signs and positive signs (fetal heart beat active fetal movement and detection of fetal skeleton) o Women are often given a due date using Nagele’s rule (subtracting three months, adding seven days, and then adding a year o Some women experience frequent urination, breast swelling due to the mammary glands developing, nausea, or morning sickness (expel toxins), increased vaginal discharge and sleepiness o Women’s emotions vary when they are pregnant, some are happy, some become depressed o This can be from a number of reasons like if the partner is supportive, if the pregnancy was wanted, there economic status o Still Birth: delivery of a dead fetus, especially after the 28 week of gestation  The Second trimester o Experience the fetal movement o Physical problems include constipation and nosebleeds (caused by the increase in blood volume o Edema: excessive fluid retention and swelling o Colostrum: a watery substance that is secreted from the breasts at the end of pregnancy and during the first few days of delivery o Usually a period of calm and well-being o Women who have high partner support tend to report less anxiety and depression o Women who have previously had a child tend to be more distressed  This may reflect the demands associated with the care of other children  The third trimester o The uterus becomes large and hard, and some women are kept awake by the movement of the fetus o There is more pressure on the other organs of the body like the stomach, lungs and heart (increased blood volume)  Women feel low energy o The average baby weighs 7.9 pounds o The average amount of weight a woman should gain is between 15 – 40 pounds due to the baby, placenta, amniotic fluid etc. o Braxton-Hicks contractions: contractions of the uterus during pregnancy that are not part of actual labour o First pregnancy- around 2-4 weeks before labour the head drops into the pelvis this is called lightening, engagement, or dropping o Same with the second trimester, higher social support and love, the less anxiety a woman will experience. Women who have never had a baby before reported high dissatisfaction from the second semester to the third o Stressed women tend to have more complications during labour  The fathers experience in pregnancy o Couvade syndrome- men experience pregnancy symptoms like headaches indigestion and nausea o In a study blood samples were taken and men that should high symptoms had a high level of prolactin pre-pregnancy o In some cultures it is called couvade ritual were the men retires to bed while the women is in labour an experiences all the pains that the women does o Many men go through different types of classes to prepare for the baby, and talk to fathers o Fathers that have higher levels of prolactin in response to cues of a newborn have a higher father-infant bond  Diversity in the contexts of pregnancy o There are many different ways now a days a women will have a baby  Single mother  Common law  Artificial insemination Sex during pregnancy  It was believed that sex during pregnancy caused premature labour and or infection  Now it is believed that women can safely engage in sexual activity up until 4 weeks before pregnancy o There was a study done where orgasm reduced the risk of preterm labour  Many couples report a decline in the first trimester and even more in the third, but not a change in the second trimester o The decline in the third trimester could be due to the fact that the male is not attracted to the women in the later stages of pregnancy  The side to side position is probably the best while the women gets larger Nutrition during pregnancy  If there is inadequate nutrients the mother and the baby could be subject to a number of diseases o The mother could have hypertension, gestational diabetes and caesarian delivery o The baby could be subject to spina bifida, cleft palate, and hydrocephaly  It is important for the mother to get enough protein to build new tissues  Folic acid for growth (deficiency can cause anemia and fatigue)  Iron is needed because the fetus draws off iron for itself into the placenta  Mussel cramps, nerve pains, uterine ligament pains, sleeplessness and irritability- symptoms of calcium deficiency Substances that may result in birth defects  Substances taken during pregnancy o Teratogens: a substance that produces defects in a fetus o Health Canada has identified maternal drinking as one of the leading causes of preventable birth defects and developmental delays in children o Fetal alcohol spectrum disorder: all outcome associated with any amount of alcohol exposure during pregnancy o The deficiency is dependent on how much alcohol the mother drinks o The most serious is patterns of malformations is termed fetal alcohol syndrome: serious growth deficiency and malformations in the child of a mother who abuses alcohol during pregnancy  Causes small brain, small eye openings, joint, limb and heart malformations  Affects 1 percent of Canadians  Risk drinking is considered that the women has more than 7 drinks per week OR 5or more drinks on one occasion  Women that drink during pregnancy are 40% more likely to have a still birth than those who don’t o There is NO safe amount of alcohol to consume during pregnancy o 23% of women smoke during pregnancy- can cause a number of defects especially to do with the cardio vascular and respiratory system o **Table 6.2 summarizes effects  Dads and drugs o Marijuana has been linked to low sperm count and infertility o Drugs taken by the father may damage sperm o The father smoking during pregnancy has also been linked to cancer in the fetus  Viral illness during pregnancy o If the women gets rubella in the first trimester of pregnancy there is a 50% chance that the fetus will be born deaf, have cognitive defects, cataracts or congenital heart defect o By the 3 trimester the chance is only 10 percent o Herpes simplex can also pass over the placenta barrier – women also have a higher chance of spontaneously aborting o 28 percent of babies whose mothers have HIV will become infected (can be after or before birth, after due to breast milk)  Birth defects o There are genetic defects and chromosomal defects o Obesity in the mother is also shown to have effects on the fetus o About 4-5 percent of babies are born with a defect, and more than half of them we are unsure of why o ¼ of miscarried fetuses are malformed o Amniocentesis: a test to determine whether a fetus has birth defects; done by inserting a fine tube into the woman’s abdomen to obtain a sample of amniotic fluid  This allows the woman to know if the fetus has a defect and allows her to have the decision of abortion if she so chooses  Involves some risk, and should only be done if the women believes that she is a carrier, if she has already had a child with the defect or she is over 35  Should be done in between the 13 and 16 week of pregnancy o Chorionic villus sampling: a technique for prenatal diagnosis of birth defects; involves taking a sample of cells from the chorionic villus and analyzing them  Can be done in the first trimester (between 9 and 11 weeks)  It carries with a slight risk of fetal loss, but can be as low as 0.04% in experienced hands Birth The beginning of labour  There may be a bit of bloody mucus- this was the barrier so that no germs could pass into the vagina  The amniotic sac could burst (only happens in about 10 percent of women) and rush down the woman’s leg o Usually occurs within the next 24 hours after this  Braxton-hicks contraction may occur and be mistaken fro labour, but are very irregular  The mechanism that initiates labour is not known, but it is thought that the withdrawal of progesterone causes it (- which is know to inhibit uterine contractions) The stages of labour  First stage labour o Regular contractions o Changes that must occur:  Effacement: a thinning out of the cervix before labour  Dilation: an opening up of the cervix during labour (10 centimeters)  First stage labour: the beginning of labour, during which there are regular contractions of the uterus; the stage lasts until the cervix is dilated 8 centimeters  Contractions are spaced apart by 15-20 minutes- contractions last about 45 seconds to a minute  The late first stage- marked by the dilation between 5-8 centimeters and the contraction  The final dilation of the cervix is from 8-10 centimeters  This occurs during the transition phase: the most difficult part of labour at the end of the first stage during which the cervix dilates to 8-10 – this is where women report pain and exhaustion o ** The first stage can last anywhere from 2-24 hours- it averages at about 12-15 hours for the first pregnancy and about 8 for the second o A women is told to go to the hospital when the contractions are 4-5 minutes apart  Second-stage labour: Delivery o Second-stage labour: the stage during which the baby moves out through the vagina and is delivered o Last from a few minutes to a few hours o When the top of the babies head is visible, that is called crowning o Episiotomy: an incision made in the skin just behind the vagina, allowing the baby to be delivered more easily  Preformed when the baby starts crowning  Only 21% of women have this preformed now o Having this preformed will prevent impairment of sexual functioning later in life o When the baby is fully eased out of the canal, it is still connected to the mother by the umbilical cord (attached to the placenta that is still in the uterus) o When the baby takes its first breath of air, it body functioning changes dramatically  Blood flows to the lungs and a flap closes between the two atria- this takes a few minutes, and the baby turns from bluish tint to a pink  The umbilical cord is cut 3 inches from the body and eventually dries up and falls off o Silver nitrate is dropped on the eyes of the baby so it doesn’t get any infections  Third-stage labour o Third-stage labour: A stage where the after birth is expelled o Can take anywhere up to a few minutes to an hour Caesarean section (C-section)  Caesarean section: a method of delivering a baby surgically, by incision in the abdomen  There are many different reasons that a woman will have a C-section (pelvis too small, baby to big etc.)  Once women have a C-section, they don’t have to have all of there children in the same way  In 2004-2005 26% of births were by C section  Women are three times as likely to disease: thought to be the reasons are: o Older women giving birth o Fetal monitors are used increasingly; they give the physician early warning if the fetus is in distress, necessitating a caesarean to save the fetus o More women are requesting them with out knowing the medical differences  It was thought that a women should give a choice of how she wants to deliver the baby, because there are risks to both sides  It is now encouraged that women go through a natural birth UNLESS there is a medical reason determined by the physician ( this is due to the fact that there are health risks involved in a C-section that can effect the mother and the baby Childbirth options  Prepared childbirth o Programs try to eliminate fear associated with pregnancy, it is thought that fear causes tension, and that tension causes pain o Fernand Lamaze, created the Lamaze Method: a method of prepared
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