HUMAN BIOLOGY TERM 2.docx

[CHAPTER 11:] -Humans reproduce sexually, a process of the joining of a male and female sex cell to produce a single cell called a zygote, which develops to produce a new individual. 11.1: [1) male reproductive system ] -Male gonads (primary sex organ that produces gametes) consist of two testes...

[CHAPTER 11:] -Humans reproduce sexually, a process of the joining of a male and female sex cell to produce a single cell called a zygote, which develops to produce a new individual. 11.1: [1) male reproductive system ] -Male gonads (primary sex organ that produces gametes) consist of two testes or testicals where spermatozoa (sperm) is produced. These ts are held by skin called scrotum, physically looks like one pouch of skin but is internally divided in two sacs containing each t. -For the production of sperm it requires a temp of 2 degrees lower than body temp, which is why ts lie in scrotum outside body. The walls of the scrotum have smooth muscle fibres which can contract too pull ts closer too body if temp is colder and loosen too let them hang if temperature is warmer. Each t is oval in shape, internally they compartments filled with fine tubes called seminiferous tubules. These tubles join too form short tubles that connect too ducts, which leave testes and enter the epididymis. Between these tubles there are clusters of interstitial cells (spermatagonia) that secrete male hormones Testes- produce sperm and manufacture the male sex hormone, testosterone. Epididymis-Sperm storage and maturation. Vas deferens- transports sperm from the epididymis to the seminal vesicles. Seminal vesicle, prostate gland & Cowper's gland- secrete fluids that form part of the semen. Seminal vesicle- small pouch like organ behind bladder. secretes fluid which is rich in sugars and main part of semen. Prostate gland- where the two vas deferens join the urethra secretes alkaline fluid which helps activate sperm. Cowpers gland- 2 small yellow glands which secretes a lubricant part of semen, makes up a tiny bit. Urethra- carries semen and urine through the penis to the outside. Penis- the external male organ which introduces semen into the female vagina and through which urine passes during urination. [Female reproductive organs:] -in the ovaries, each germ cell is enclosed in a follicle, as a follicle matures it moves towards the surface of ovary and ruptures, egg is expelled into a funnel like opening called fallopian tubes, uterine ducts or oviducts, they carry egg away from ovaries too the uterus, the uterine tube begins with finger like projections called fimbriae, which help guide egg too uterine tube, lining of tube contains cilia which moves egg towards uterus, smooth muscle contractions also aid in the movement. -the uterus is a organ behind bladder infront of rectum, held by pelvic capacity by broad ligaments, wall of uterus is made of soft mucous membrane called endometrium. 1\. Ovaries- produce ova (eggs) and manufacture the female sex hormones, estrogen and progesterone. 2\. Fallopian tube- transports ova to the uterus. Generally the site of fertilisation. 3\. Uterus- houses and nourishes the fetus during pregnancy. 4\. Vagina- the female organ of sexual intercourse, where the sperm are deposited. It also serves as the birth canal. \- Vagina is a muscular structure that can enlarge too receive penis and give birth. \- Hymen is a thin fold of tissue that is usually stretched or torn by intercourse or other things. \- labia majora, labia minora, clitoris. 11.2: -Gamete development from meiosis to mature gametes is called gametogenesis. There are two types : formation of spermatozoa in testis is called spermatogenesis and formation of ova in ovary is called oogenesis Spermatogenesis occurs in the seminiferous tubles, these tubules are lined with immature cells called spermaogonium. The daughter spermatagonium cell is copied then stays near the membrane too produce more spermatozoa. Copied daughter spermatagonium is then pushed away from membrane. This is all a process of mitosis. Then meiosis 1 happens, creating primary spermatocytes. Then secondary spermatocytes with meisosis 2 making two haploid spermatocytes. This creates haploid spermatids, which then undergo maturation and create spermatozoa. Sperm contains head (has the 23 haploid chromosomes, with genetic info in the nucleus, fluid filled vesicle at tip called acrosome, fluid has enzymes which is important when sperm reaches egg too break down layer of cells around egg for fertilization), neck, middle (contains mitochondria too provide energy for sperm, tail (has contractile motions too propel sperm formard)  A diagram of a diagram of a cell Description automatically generated with medium confidence  **[CHAPTER 12]** -A sperm and a ova is brought together by fertilization, creating a zygote which develops into a embryo. \- sexual intercourse allows fertilization too happen naturally and normally. A erect penis which fills with blood rushing too places in the erectile tissue will become large and firm entering the vagina which it will then deposit its semen containing sperm allowing it too swim and fertilise with the egg after ovulation. -when sexual stimulation happens inside vagina the rhythmic contrations of the epididymis, seminal vesicle, prostate gland, vase deferens occurcausing the contents of the ducts and gland too escape body, this is ejaculation. Journey after ejaculation: when male ejaculates in the entrance of uterus this is called insemnimation. Millions of sperm will enter but some will die in the acidic environment, but some will survive because its swimming in a protective fluid. Next sperm must pass through the cervix that is usually tightly closed but while woman ovulates the cervix becomes open. The sperm swim through the cervix which has a thin milky watery consistency for easier passage. Then the sperm will continue too swim towards the uterus, millions die in the mucus and get trapped in the folds of the cervix, but may continue on their journey soon. Inside the uterus, muscular uterine contractions assist in moving the sperm towards egg. However, many more are destroyed when the womans immune system cells mistake them as forigners and kill them, trapping the sperm as they pass by. Then half the sperm move towards empty fallopian tube and other half move towards unfertilised egg fallopian tube. In the fallopian tube, tiny cilia push the egg towards the uterus, sperm must surge against this motion, some sperms will get tangled in the cilia and die. Chemicals in the reproductive tract cause the head of sperm too change and cause it too become more hyperactive giving it energy too swim harder. The few sperms left swim towards the egg which is covered in cells called corona radiata. Sperm mst push through too reach the outer layer of the egg called zona pellucida. When sperm reaches this layer they attach sperm receptors on the surface which trigger their acrosomes too release digestive enzymes, enabling sperm too mburrow into the layer. Inside the zona pellucida is a narrow fluid filled space just outside the egg cell the first sperm too make contact will fertilise the egg, their outer membranes of sperm and egg fuse and pull sperm inside, this fusion causes changes too the membrane which makes impossible for sperm too attach. Egg releases chemicals which push sperm out and the zona layer hardens and traps sperm. Inside egg after fertilization: Inside egg, the sperms the tightly packed genetic info comes apart and then reforms too 23 chromosomes, female genetic material awakens and also finishes dividing results in female nucleus also with 23 chromosomes. Microtubules pull each pronucleus together, joining them creates 46 chromosomes, a unique genetic code arises. This is a single cell called a zygote. The cilia and fallopian tube gently sweep the fertilized egg towards the uterine lining too grow into a human. 12.2: Blastocyst formation- The zygote divides by mitosis to form a ball of cells known as the **morula**. The morula travels down the Fallopian tube and into the uterus. The cells of the morula continue to divide and about five days after fertilisation have formed a hollow ball of cells known as the **blastocyst. The blastocyst consists of about 100 cells. The outer cell layer will form the placenta, and a cluster of cells on the interior - the inner cell mass - forms the embryo** **Implantation-** the blastocyst remains free in the uterus cavity but is then attached firmly too the soft endometrium which is called implantation, this allows the ball of cells too receive correct nourishment from the glands and blood vessels of uterine lining. Hormone production- high levels of oestrogen and progesterone in blood stops endometrium too break down which stops menstruation. In the early stages it's the corpus lumen which create these hormones but soon after the placenta does this, after second month the cells are called a feotus. Cell differentiation- the inside mass of a blastocyte is stem cells. These under right environment can become specialized cells. Primary germ layers- During the second week of development three layers of cells form from which the various organs of the body will be derived. The three layers are the **ectoderm**, **mesoderm** and **endoderm** -- these form the embryonic disc. Embryonic membranes: Development of placenta- organ that appears from featul and maternal tissues supplies nutrition and removes wastes from fetus, a endocrine organ producing a number of hormones too maintain pregnancy  12.3pregnancy From embryo too faetus: Week 4 - Brain and nervous system are developing at a rapid pace. - Optic vesicles, which later form the eyes, begin to develop this week on the sides of the head, - as do the passageways that will make up the inner ear. - Heart will begin to beat around this time, and it may even be detected on ultrasound examination. - The beginnings of the digestive and respiratory systems are forming, too. - Small buds that will grow into your baby\'s arms and legs also appear this week. - Blocks of mesodermal tissue will form the spine and muscles Week5 - the umbilical cord has formed. - digestive tract and lungs continue to form. - face is taking shape. The mouth, nostrils, ears, and eyes are some of the facial features that become more defined this week. - arm bud that developed just last week has a hand on the end of it, which looks like a tiny paddle. Week6 - fingers and toes are just beginning to form this week, and the arms can even flex at the elbows and wrists. - The eyes are becoming more obvious because they've begun to develop pigment in the retina. - Also, the intestines are getting longer and there isn't enough room for them in the baby's abdomen, so they protrude into the umbilical cord until week 12. - By now, the beginnings of the buds that will develop into genitals have made their appearance, although they\'ve not yet developed enough to reveal gender Week 7 - The tail has shrunk and almost disappeared by this week. - head has been growing --- it\'s quite large compared with the rest of the body and it curves onto the chest. - Embryo measures 16 to 18 mm and weighs around 3 grams. - The tip of the nose has developed and can be seen in profile, and flaps of skin over the eyes have begun to shape into eyelids, which will become more noticeable in the next few weeks. - The digestive system continues to develop. The anus is forming, and the intestines are growing longer. - Internal reproductive features, such as testes and ovaries, start to form this week. - May make some first movements this week as muscles develop, but mother won\'t be able to feel them for several more weeks. Week 8 - All vital organs have been formed and are starting to work together. - Separation of fingers and toes - disappearance of the tail takes place. - Tooth buds form inside the mouth - Testes will begin producing testosterone. - Congenital abnormalities are unlikely to develop after week 10. - This also marks the end of the embryonic period --- in general, the embryo now has a distinctly human appearance and starting next week your baby will officially be considered a foetus. The foetal period- The fetal period is mainly a period of growth, both of the overall fetus, and of the internal organs. After the 8th week, the fetus takes on a typically human appearance.Over 90% of the adult body structures are already established and can be recognised. During the fetal period these organs undergo further growth and differentiation (organogenesis). A screenshot of a computer Description automatically generated 1. Mother in 1^st^ trimester: - Menstruation stops - Morning sickness ( in about 75% of cases) - Swollen and tender breasts - Tiredness - Giddiness - Increased frequent of urination. 2. Mother in 2^nd^ and 3^rd^ trimester: - In the second trimester the mother feels the first movements of the child. - The abdomen starts to become noticeably larger after about the 5^th^ month, also due to internal organs such as stomach, liver, intestines being forced upwards and outwards. - Other signs are likely to include: - Weight gain - Backache - Frequent urination - Varicose veins & hemorrhoids - Edema (swelling due to fluid retention) - Constipation. 3. Pyscological changes include: - Above normal levels of progesterone & estrogen - A blood volume increases of almost 50% (increase in size of heart) - Pressure on bladder leads to increased frequency of urination - Changes of mood due to changes in hormonal balance - Increased functioning of the heart, kidneys and respiratory system - Risk of gestational diabetes - Risk of increased blood pressure. 12.4birth and infant development Gestation is the period of pregnancy, parturition is the end of g period and is the expellation of foetus from mothers body, but the events that take place before that is labor. Childbirth, or labour, is preceded by a rise in the levels of estrogen and oxytocin in the mother's bloodstream. Labour begins with contractions of the muscular walls of the uterus. These contractions start at the top of the uterus and sweep down to the cervix. As labour progresses contractions become stronger and more frequent. Labour is divided into three stages **First Stage - Dilation of the Cervix** -contractions force the baby's head into the cervix, stretching it until the head enters the birth canal (the vagina). -Each contraction become strong and occur about every 30 minutes -This the beginning of the birth process and the contractions are known as \`labour pains'.  **Second Stage - Expulsion** -The baby moves into a face-down position -Contractions become stronger and closer together, forcing the baby through the birth canal. -At this stage the 'waters' usually 'break' (i.e. the amnion bursts and releases the amniotic fluid). This may occur much earlier in labour, or occasionally, may not until the foetus is ready to be born. -Full dilation of the cervix to birth, last from 20 minutes to 2 hours. -Head of foetus is downward in over 90% birth. This position allows the foetus to begin breathing even before it is completely free of the birth canal. **Third Stage - The placental stage** -A final contraction of the uterus expels the placenta, umbilical cord and membranes (the **after-birth**) from the mother's body. -The baby continues to breathe with its own lungs, even though it is connected to the placenta by its umbilical cord. -Amnion, chorion and placenta are still inside the uterus. -Umbilical cord is clamped, tied in two places and then cut between the ties. -The arteries and veins within the umbilical cord contract (after being cut), and after a few days, the stump of the cord dries up and falls away. The navel, or umbilicus, is that which remains. -Uterus continues to contract, and about 5 mins after delivery, the placenta, other membranes and remains of the umbilical cord are expelled. These are called the \`afterbirth'. Changes at birth: - At birth the respiratory system starts to function and the digestive system becomes fully functional. - Important changes occur in the blood circulatory system. - Before birth the fetus receives nutrient-rich blood from its mother via the placental circulation. - Although the fetus swallows amniotic fluid before it is born, the digestive system does not become fully functional until after birth. - After birth, breathing begins and the pulmonary circulation is activated. 12.5 Disruptions too foetal development: - Congenital disorders -- defects or diseases that are present at birth - Environmental factors affecting the foetus during the uterine development - Teratogens -- toxic substances that causes physical defects in the developing embryo (eg. some hormones, antibiotics, oral anti-coagulants, anti-convulsants, anti-tumour drugs, thyroid drugs, thalidomide, LSD (lysergic acid diethylamide) and marijuana - Environmental factors may not change the gene but how the gene is expressed - Placenta can allow many dangerous organisms and chemicals to pass from mother to foetus (eg. some viruses) - Infections -- rubella, maternal diet, alcohol, smoking, chemicals (thalidomide) **[CHAPTER 13:]** 13.1 Measures taken to prevent a woman from having a child is called contraception. 1\) Abstinence is not having sexual intercourse, only option that has no risk of pregnancy or side effects 2\) detection of ovulation- some methods is relying on determining the time of ovulation, she will not partake in sexual activity during the days where fertilization is most likely, known as periodic abstinence or safe period technique. Many ways of determining safe period too have sex like: -rhythm method-an egg is only available during a period of 3-5 days in each menstural cycle, ovulation occurs on the 14^th^ day. As the egg can survive for only 2 days unless its fertilized, a sperm can only survive in a female reproductive tract at four days most, you shouldn't have sex 4 days before and after ovulation, to be safe do 5 days in case egg wasn't released exactly on day 14. However most women do not have exactly the same cycles each month so rhythm method is used along with others. -tempreture method- similar too rytm of predicting ovulation. Female takes body temp each morning too determine accurate time of ovulation. Ovulation is accompanied by a sharp drop and rise in temp. woman knows she can have sex 3 days after temp rise occurs. -mucus method- method of observing mucus from vagina. Immediately after menstruation vaginal opening feels dry, as ovulation approaches mucus can be detected, at first cloudy and sticky, but as cervix stretches more mucus become clearer and slippery. On the day of ovulation is the peak of clear mucus, once it becomes cloudy again then safe. It is safe more than 3 days after last clear mucus day or when no more mucus. -symptothermal methods- combination of temp, mucus and rhythm method. Fertility monitor too track changes in body temp and cervical mucus 3\) **Lactational amenorrhoea method (LAM)--** temporary infertility that follows child birth. When a woman is fully breastfeeding, she is not menstruating. Breastfeeding affects the production of hormones so ovulation is suppressed. This means of contraception is known as LAM. **4) Coitus interruptus** -- the man withdraws the penis before male orgasm so ejaculation takes place outside the female vagina. **5) Douching** -- washing out the vagina after intercourse. 6\) mechanical barriers- something manmade and physcically inbetween man and womans parts. These devices are moderately effective, especially if used in combination with a chemical barrier. -condom- made from thin latex rubber that is rolled onto erect penis just before intercourse, pretty effective in prevention of semen entering vagina, unless it teras or slips of after ejaculation. Condoms have a additional advantage in providing protection against sexually transmitted infections such as HIV/AIDS. -diaphragm- thin rubber cap that must fit perfectly onto of the vagina, usually used with spermicidal cream to increase effectiveness, should be left in at least 6 hours after intercourse -Cervical cap- a smaller version of diaphrgm that must sit perfectly over cervix. -Female condom-lubricated shealth that lines vagina. The closed end must sit over cervix and other open side must sit over loose folds of skin surrounding entrance too vagina. Effective and gives protection over sexually transmitted infection 7\) spermicides-works in two ways: contain substance that disables and destroys sperm and react with moisture in vagina to form bubbles of carbon dioxide gas which form a physical barrier to sperm. These are available as cream, tablets or foam. Unreliable on its own but effective along with others 8\) hormonal contraception for women- one of the most effective ways is by changing hormonal levels in woman -contraceptive pill- 2 types of oral pills. "Combined pill" contains substances similar too the 2 female hormones oestrogen and progestrogen. When taken daily for first 21 days of menstural cycle the sub hormones prevent release of mature eggs from ovary. Mucus become thick and sticky making difficult for sperm too travel through. The sub hormones also change the lining of uterus so less receptive too implantation of embryo. If these pills aren't taken for 2 or more days the hormone levels drop and no more protection. Second type of pill is called "mini pill" contains only progesterone sub, progestrogen. This hormone makes cervix mucus thick so sperm cant enter uterus changes lining which makes difficult for fertilized egg too implant. Depo-provera and depo-ralovera are forms of those hormones that are injected into a muscle of upper arm or buttock. Lasts for 12 weeks and works like mini pill -hormone implants- another way of delivering progestrogens is using a Implanon NXT, soft plastic stick inserted on the inner side of the upper arm, slowly releases progeterogen into body and provides contraception for 3 years. Implant can easily be removed and ovulation usually returns within 3 weeks. -vaginal ring- oestrogen and progesterone can also be delivered by a VR. Soft plastic ring placed inside vagina, realese low doses of the hormones. Left in for 3 weeks. These small realese of hormones prevent ovulation, cause the mucus too thicken, and lining of uterus too change. VR has same hormones as combined pill and has same effects, but woman doesn't have too take pill every day. Despite the risk of side effects, combined pill is the most reliable contraceptives available, if taken daily it's almost 100% effective. In time the hormone sub levels have decreased lessening the side effects. Highest risk of a combined pill is ithe use in it increases change of developing a blood clot in a vein or artery. Although small. Risk increases with age. Women over 35 using combined pill is safe as long as they don't smoke. 9\) hormonal contraception for men- Implantation of hormone testosterone beneath the skin every four months. May be combined with an injection of progesterone every three months and effective in suppressing sperm production. Some side effects are still monitored 10)intrauterine devices (IUDS)- small plastic devices, inserted into uterus. Not felt by woman or partner. Australian IUDS have a nylon thread attached which extends too cervix for woman too check if still in place and easy rmoval by doctor/ 2 types, hormonal and copper: -hormonal IUD- made with plastic frame with core which slowly releases progestrogen hormones. In Australia only 1 type called , mirena,IUS intrauterine system. The way it works is it releases hormones at a steady rate making lining of uterus, endometrium (inner lining of womb) thin and unsuitable for implantation of fertilized egg. Hormone also stimulates thicker cervix mucus, in some women IUD stops ovulation all together. -copper IUD- also consist of plastic frame but with copper sleeve or copper wiring around it, two types in Australia. Mainly work by inhibiting the movement of sperm through uterus. They causes changes too endometrium too stop implantation, because of this copper IUDS are a way of emergency sontraception up too 5 days after unprotected sex. Mirena provides protection for up too 5 years whereas copper IUDS show effective for up too 10. Devoces can be removed anytime and can return fertility quite quickly. 11\) emergency contraception for women- sometimes its needed for prevention of pregnancy after sex. This could be if condom breaks, slips, pill is forgotten and if rape occurs. The morning after pill was mostly taken as 2 progestrogen, but now a single one. The sooner the pill is taken the more effective it will be, effectiveness is reduced 72 hours after unprotected sex. Works by preventing or delaying ovulation, preventing sperm from reaching egg, prevents implantation of egg on lining. Few side effects, nausa, vommitingbreast tenderness, dizziness, spot bleeding and stomach ache. In Australia concern that morning after pill can be purchased over the counter by local pharmacist, parents may be unaware of this. Copper IUD can be used as emergency contraception 12\) sterilisation- permanent method of birth control for both men and women, where the anatomy is altered so sperm and egg never meet. This choice should only be considered if no more children are wanted, it can sometimes be revesed but considered permenant. -male sterilisation- called a vasectomy. Involves the removal of a small piece of vas deferens. Small procedure, small cut is made on each side of scrotum, small segment is removed from each vas deferens and cut ends are tied or sealed with heat, cuts in scrotum are then closed, most operations are done under local anesthesia but general can be used. Doesn't result in reduction of sexual desire or pleasure. A new non surgical way is being tested right now technique involves injecting gell into vas deferens too block the path of sperm. -female sterilisation- usually achieved by tubal ligation, operation is reletivley simple, only a short stay in hospital, under general anesthetic, small insision made in abdomen and uterine tubes are located. Each tube is cut and a small piece removed, ends are tied, alternatively a instrument called laparoscope u=is used, passed into abdominal cavity and through a small cut at lower edge of navel, once inside the doctor crushes that section of uterine tube with metal clips making it impossible for sperm too reach egg, no decrease in pleasure or desire Castration is the removal of testes and oophorectomy is removal of ovaries, have harsh effects on sexual drive, womens also referred as hysterectomy. 13\) Ethical issues- catholic church and other Christian faiths hold view that only acceptable method is abstinence from intercourse when fertilization is most likey too occur. Some believe that methods that allow fertilization but no implantations are wrong. Their arguments are what if a embryo becomes human moment of fertilization, time of implantation or later stage of embryonic development. These decisions are too be made personally and not let sciene tellll us. A close-up of a chart Description automatically generated 13.2 Sexually transmitted infections (stis) are also referred too sexually transmitted diseases (stds) infections that are transmitted by close body contact with genetial organs, caused by viruses, bacteria, fungi, parasites that are passed from a infected person too partner during sexual activity. Young people are most at risk, no vaccine readily available 1)chlamydia- the most common sti, caused by highly specialised bacteria, this can only reproduce inside a living human cell, making difficult for isolation. Most people show no symptoms and are unaware, can be treated with antibiotics. Chlamydia infection- transmitted by vaginal or anal sex with infected person. Both men and women may be infected. Men may develop a infection of the urethra known as non specific urethritis which has symptoms of yellow mucus like discharge from penis and burning sensation when passing urine. If the infection in males isn't treated the bacteria can spread too the epidiymis where it causes inflammation called epididymitis, causes pain and swelling of epidymis. Can lead to infertility is both testes are infected, however epi in both testes are very rare. Most infected women have no symptoms and wont know they have chlamydia making it dangerous because if left untreated it leads too infertility, eye infection, and arthritis. Some women show symptoms of pelvic inflammotery disease, inflammation of pelic region such as uterus and tubes. If left untreated leads too infertility. Implantation of embryo outside uterus a ectopic pregnancy may occur. If infected women is pregnant, 70% child will be effected. Results in nose and throat infections, pneumonia and high risk of baby born premature and stillborn. Diagnosis and treatment of chlamydia- Chlamydia infection can be diagnosed through a urine test in both males and females, or more accurately via swabs from the vagina, cervix, or penis. If the infection caused by Chlamydia trachomatis is confirmed, antibiotics are the standard treatment, although the bacteria may not be completely eliminated from the body. Researchers are exploring a vaccine that would help the body tolerate the bacteria, potentially preventing negative symptoms like infertility. However, a human vaccine is still at least a decade away. 2\) gonorrhoea- infectious disease that mainly effects the mucous membrane of excretory and reproductive systems, the rectum and occasionally eyes and throat. Caused by disease Neisseria gonorrhoeae transmitted during sexual intercourse, effects males and females symptoms appear 2-10 days after infection, in females may not be recognised, period inbetween appearance of infection is called incubation period. \- in males, bacteria enters urethra during sexual intercourse with infected partner. After incubation, inflammatory happens causing burning pain while peeing. Later yellow discharge of pus from penis, if untreated urethra may be permentantly constricted, difficult urinating, may spread too other organs of body causing arthritis or heart and eye issues. -in females. Considered more serious since no early symptomscan be unrecognised in 70% of women. Bacteria enters vagina during sexual intercourse, urethra or cervix is infected usually no pain so any pus produced is considered normal vaginal discharge. Women may leave for months before pain becomes recognised. If untreated the infection spreads too oviducts and blockages causing infertility. A pap smear every now and then is advised too seek infections. Oral sex with infected person can cause throat infection. Because female gonorreal infection is vaginal and in cervix. A woman pregnant naturally when child is born infects their eyes causesing maybe blindness. Antibiotics are used for a cure and normally result in a easy and effective way if treatment is done early enough. 3\) syphilis- known as the pox caused by thin flexible bacteria. disease is normally contracted by direct sexual contact and effects men and women in the same way. Can only survicve a brief amount of time outside human tissue so infections by indirect contact are rare. -stages of infection if unreated 1\. primary stage begins when syphilis bacteria enters througha small break in skin, like sexual intercourse with infected person. Bacteria multiplies and spreads through body, first symptoms are small sores, usssually appear on sex organs and occur on skin like fingers eyelids or lips. These heal after 3-8 weeks giving infected person false sense of clean. 2\. follows a few weeks later may be delayed by 12 monthss, large range of symptoms, rashes, sores, mild fevers, disorders of bones and eyes. Patient is highly infectious in this stage, lasts about 2 years and goes away on its own. 3\) latent stage (hidden stage)- no noticeable symptoms may last many years and sometimes rest of their life, in this stage cant be passed onto others however if secondary symptoms occur then can be passed. 4\) late teritary stage- may result in syphilitic heart disease, blindness, insanity, weakened blood vessels. Can be up too 5-40 years after infection occurs. If a woman is pregnant they can get antibiotics but if bacteria enters feocal circulation theres no stopping too it muktiplying Treatment- surgery in later stages but usually antibiotics 4\) Genital herpes- is a common sti caused by herpes simplex. There are 2 forms of herpes type one ( produces cold sores on lips and can also do genitals) and type 2 (produces blisters on genital organs). Both are spread by skin too skin contact so it can come from genital, oral or anal sex. 1^st^ episode is the most painful, blisters develop on penis of males and labia or vagina of females, may also be accompanied with a flu like symptoms. Blisters break and form ulcers, healing may take 1-2 weeks but sometimes the virus will then pass into nervous system which it will remain for life. The virus can infect the skin or mucous membrane of sex organs at any time reoccurrent periods are usually short and less painfull, even if no symptoms it can still be spread. Can be transmitted from mother too newborn during birth causing life threatening illnesses. No way of removing it permanently but there is treatment for pain and the blisters, absitence should be taken too avoid spread too others. Antiviral drugs can be prescribed, again don't cure you but can make it less harsh and shorten the attack. 5\) genital warts- found on the genitals but can be found in the anus and throat. Can be flat or raised or coliflower growths caused by HPV virus, more than a 100 types, some tyes can appear on skin and sometimes genitals but sexual intercourse may not be the cause. Genital warts are passed on by infected partner as they could be inside hidden, a newborn is at risk when delivered through vagina. Some types can cause cervix cancer but genital warts don't cause cancer. **6) Human immunodeficiency Virus (HIV)**- HIV weakens the body's immune system so infected person is susceptible to infection by other micro-organisms and to some forms of cancer. Almost all cases lead to acquired immune deficiency syndrome (AIDS). HIV is a retrovirus, containing a RNA (ribonucleic acid) core rather than DNA. Unable to reproduce by itself, it infects white blood cells (T lymphocytes) in the host cell. Virus uses an enzyme called reverse transcriptase to converts its RNA to DNA which then multiplies to infect more T cells. Over sustained period of time, immune system weakens considerably and all types of infections set in, and cancer may develop. -spread- HIV/AIDS is pandemic, meaning it can spread to all parts of the world. Body fluids in which the virus is present must be passed through the body's bloodstream or in contact with mucous membranes. These body fluids include blood (including menstrual blood), seminal fluid (including pre-ejaculatory fluid), vaginal and cervical fluids and breast milk. Unless blood is present, virus is not found in sufficient amount to be infectious in urine, faeces, vomit, tears, sweat or saliva. HIV may be spread by unprotected sexual intercourse, sharing of needles or syringes with infected persons, infected mother to child during pregnancy or through breastfeeding, blood transfusions, skin-piercing implements. -diagnosis and treatment of HIV- If infected with HIV, post-exposure prophylaxis (PEP) treatment may be used. This treatment consists of a course of drugs taken for a month within 3 days of exposure to HIV. Not 100% effective but prevent viral replication. Other tests include determining the viral load and determining antibody count in blood. No cure for HIV/AIDS but some antiviral drugs can be used. 7\) Trihomoniasis- An infection caused by a protozoan *Trichomons vaginalis*. Causes inflammation of the mucous membranes of the vagina in women and of urethra in men. Can cause some discomfort and vaginal discharge but in men, no symptoms can be discerned. Can be cured quickly with medications. Can be spread by vaginal intercourse and use of condom can prevent infection. 8\) pubic lice and scabies- Can cause intense itching in the genital area. Pubic lice are insects called *Phthirus pubis*. Confined to anal and pubic area. Scabies caused by a mite. *Sarcoptes scabei* (Arachnida class). Found in genital region, wrists, finger webs and infected areas become very itchy. Both transmitted by sexual contact. Can be treated using skin lotions to kill insects, mites and eggs. 9\) control of sexually transmitted infection- the identification, treatment and tracing can help Prevention- abstinence is the only method of somplete prevention however practicing safe sex can help be more effective. Safe sex also means making sure bodily fluids don't enter eachothers bodies. For vigal and anal the use of a condom helps tremendously, and for oral sex condom or a dental damn a thin square of latex can be used as a barrier. If infected cover that area until treated. Treatment and contact tracing of STIs- there are special clinics and most public hospitals by tracing sexual partners the clinics aim too locate and prevent people from unknowingly having the disease.