Human Biology - Chapter 13 Reducing the chance of pregnancy and STIs

What is Abstinence?

Abstinence is not having sexual intercourse at all.

What is periodic abstinence in the context of birth control?

Periodic abstinence is a birth control method where a female abstains from sexual intercourse during the days when fertilization is most likely, based on her ability to determine the time of ovulation.

How does periodic abstinence work as a birth control method?

Periodic abstinence relies on the female's ability to track her ovulation and avoid sexual intercourse during her fertile days to prevent pregnancy.

What is the primary factor that determines the effectiveness of periodic abstinence as a birth control method?

The effectiveness of periodic abstinence depends on the accuracy of determining the time of ovulation and correctly identifying the fertile days.

What is the basis of the rhythm method of contraception?

The rhythm method is based on the fact that an egg is available for fertilisation for only three to five days in each menstrual cycle.

In a regular 28-day menstrual cycle, when is ovulation likely to occur?

Ovulation is likely to occur on about the 14th day of a regular 28-day menstrual cycle.

How long can an egg survive unless it is fertilised?

An egg can survive for only two days unless it is fertilised.

How long can sperm survive in the female reproductive tract at most?

Sperm can survive in the female reproductive tract for four days at the most.

When should sexual intercourse be avoided if pregnancy is to be avoided using the rhythm method?

Sexual intercourse should not occur between four days before and four days after ovulation if pregnancy is to be avoided.

What is the temperature method, and how does it refine the rhythm method?

The temperature method is a refinement of the rhythm method used to predict ovulation. It involves a woman taking her body temperature each morning to determine the time of ovulation more accurately.

What happens to a woman's body temperature during ovulation?

During ovulation, a woman's body temperature experiences a sharp drop followed by a rise.

How does a woman determine when it is safe to have intercourse using the temperature method?

Using the temperature method, a woman can safely have intercourse three days after the temperature rise has occurred.

What is the primary purpose of tracking body temperature in the temperature method?

The primary purpose of tracking body temperature in the temperature method is to pinpoint the timing of ovulation with greater accuracy for fertility awareness and family planning.

What is the mucus method used for in predicting the safe period?

The mucus method is used to predict the safe period for sexual intercourse more accurately by observing changes in cervical mucus.

How does the cervical mucus change during the menstrual cycle?

Cervical mucus starts as cloudy and sticky, then becomes clearer and slippery as ovulation approaches. On the day of ovulation, there is a peak of clear mucus, followed by a return to cloudy mucus.

When is sexual intercourse considered 'safe' according to the mucus method?

Sexual intercourse is considered 'safe' when there is no cervical mucus present and more than three days have passed since the last day of clear mucus.

What is the mucus method, and how does it predict the safe period for contraception?

The mucus method involves predicting the probable time of ovulation by observing changes in the cervix's mucus. After menstruation, the vaginal opening feels dry.

What is the symptothermal method, and how does it enhance the prediction of the fertile period?

The symptothermal method combines the rhythm method with temperature and cervical mucus observations to predict the female's fertile period more accurately.

What is a FertilityMonitor, and how does it assist in tracking fertility?

A FertilityMonitor is a device developed to measure daily changes in body temperature and cervical mucus, aiding in the monitoring of fertility and ovulation

Are fertility awareness methods like the mucus and symptothermal methods highly reliable for contraception?

No, fertility awareness methods are not particularly reliable for contraception and depend on careful record-keeping.

What is lactational amenorrhoea?

Lactational amenorrhoea is temporary infertility that occurs after childbirth when a woman is fully breastfeeding and not menstruating.

What is the contraceptive method that relies on lactational amenorrhoea?

The contraceptive method that relies on lactational amenorrhoea is known as the lactational amenorrhoea method (LAM).

How does LAM work as a contraceptive method?

LAM works by suppressing ovulation through the hormonal changes induced by breastfeeding, reducing the chance of pregnancy.

When is LAM most effective as a contraceptive method?

LAM is most effective when a woman's menstrual periods have not returned, and the baby is being fully breastfed (without any food or milk supplements) and is less than six months of age.

What is coitus interruptus?

Coitus interruptus, also known as withdrawal, is the practice of removing the penis just before male orgasm to prevent ejaculation inside the female vagina

How reliable is coitus interruptus as a method of contraception

Coitus interruptus is highly unreliable as a contraceptive method due to the risk of sperm escaping in pre-ejaculatory fluids, even if withdrawal is attempted.

How do spermicides work to prevent pregnancy?

Spermicides work in two ways: They contain a substance that immobilizes and destroys sperm, and they react with moisture in the vagina to form bubbles of carbon dioxide gas, which create a physical barrier to the sperm.

What forms are spermicides available in?

Spermicides are available as creams, tablets, pessaries, or aerosol foam.

What is hormonal contraception (The pill)

Contraception that changes the hormonal levels in the female’s body

Why have oral contraceptive pills become widely used?

Oral contraceptive pills have become widely used due to their reliability and convenience.

How many main types of oral contraceptive pills are there, and what are they called?

There are two main types of oral contraceptive pills: the combined pill and the mini pill.

What substances are found in the combined pill, and what is their function?

The combined pill contains substances similar to the two female hormones, oestrogen and progesterone. They prevent the release of mature eggs, thicken cervical mucus, and alter the uterine lining to prevent pregnancy.

How long should the combined pill be taken daily during the menstrual cycle?

The combined pill should be taken daily for the first 21 days of the menstrual cycle.

What happens if the combined pill is missed for more than two days?

If the combined pill is missed for more than two days, hormone levels drop, and no protection against pregnancy will occur.

What is the purpose of the inactive pills in some brands of the combined pill?

Some brands of the combined pill use inactive pills for seven days to help maintain the daily routine and reduce the likelihood of missed pills.

What is the primary hormone in the mini pill, and what does it do?

The mini pill contains only progesterone, which thickens cervical mucus and makes it difficult for sperm to enter the uterus.

How often must the mini pill be taken, and at what time of day?

The mini pill must be taken daily at the same time each day.

What are Depo-Provera and Depo-Ralovera, and how do they work?

Depo-Provera and Depo-Ralovera are forms of hormonal contraception injected into the muscle. They work similarly to the mini pill, providing contraception for 12 weeks.

How does the injection of Depo-Provera and Depo-Ralovera compare to taking the mini pill daily?

The injection of Depo-Provera and Depo-Ralovera provides contraception for 12 weeks, while the mini pill must be taken daily at the same time each day.

What is Implanon NXT?

Implanon NXT is a soft plastic stick about 4 cm long that is inserted beneath the skin on the inner side of the upper arm for delivering progestogens.

How long does Implanon NXT provide contraception?

Implanon NXT provides contraception for three years.

How is Implanon NXT removed?

The Implanon NXT implant can be easily removed.

How long does it typically take for ovulation to return after the removal of Implanon NXT?

Ovulation usually returns within three weeks after the removal of Implanon NXT.

What is NuvaRing?

NuvaRing is a vaginal ring marketed in Australia that delivers low doses of estrogen and progesterone hormones for contraception. It is left in the vagina for three weeks and removed for one week.

How does NuvaRing prevent pregnancy?

NuvaRing prevents pregnancy by releasing low doses of estrogen and progesterone, which inhibit ovulation, thicken cervical mucus to block sperm entry into the uterus, and change the uterine lining to prevent implantation.

What are the hormones in NuvaRing and how do they compare to the combined pill?

NuvaRing contains the same hormones as the combined pill (estrogen and progesterone), producing similar contraceptive effects. However, NuvaRing eliminates the need for daily medication.

Why does the combined pill have more side effects related to estrogen than progestogen-only methods?

The combined pill contains estrogen, which is responsible for many of the side effects associated with hormonal contraception. Progestogen-only methods do not contain estrogen, resulting in fewer side effects related to estrogen.

How effective is the combined pill in preventing pregnancy when taken daily?

The combined pill, when taken daily, provides almost 100% protection against pregnancy, making it one of the most reliable hormonal contraceptives.

How has the formulation of the combined pill evolved over time, and what impact has it had on side effects?

The formulation of the combined pill has undergone changes over the years, with a significant reduction in hormone substitutes. This has led to a decrease in the incidence of side effects.

What is the most severe side effect associated with contraceptive pills like the combined pill?

The most severe side effect of contraceptive pills, including the combined pill, is an increased risk of developing blood clots in veins or arteries. This risk is small but does increase with age.

Is the combined pill safe for women over 35, and what condition should they avoid while using it?

The combined pill is relatively safe for women over 35 as long as they do not smoke. Smoking increases the risk of complications, so women who smoke should consider alternative forms of contraception.

What are IUDs, and what are they made of?

Intrauterine devices, or IUDs, are small plastic devices often containing copper that are inserted into the uterus.

How does it feel once an IUD is inserted into the uterus?

Once an IUD is inserted into the uterus, the woman or her partner does not feel it.

What purpose do the fine nylon threads attached to IUDs serve?

The fine nylon threads attached to IUDs extend through the cervix into the upper vagina, allowing a woman to check that the IUD is still in place and facilitating easy removal by a doctor.

What are the two main types of IUDs?

The two main types of IUDs are hormonal and copper-based.

What is the role of copper in some IUDs?

Copper is used in some IUDs to enhance their contraceptive effectiveness by creating a hostile environment for sperm, preventing fertilization.

What is a hormonal IUD made of, and which hormone does it release slowly?

A hormonal IUD is made up of a plastic frame with a core that slowly releases the progestogen hormone levonorgestrel.

What is the primary mechanism of action of a hormonal IUD in preventing pregnancy?

The hormonal IUD prevents pregnancy by thinning the lining of the uterus (endometrium), making it unsuitable for the implantation of a fertilized egg. It also produces thick cervical mucus, which hinders sperm from entering the uterus and reaching the egg.

In Australia, what is the commonly available hormonal IUD, and what is another term used to refer to it?

In Australia, the commonly available hormonal IUD is Mirena, which is sometimes referred to as an intrauterine system (IUS).

How does the hormone from a hormonal IUD affect ovulation in some women?

In some women, the hormone released by a hormonal IUD can stop ovulation altogether, preventing the release of an egg from the ovaries.

What are the two primary ways in which a hormonal IUD prevents pregnancy from occurring?

A hormonal IUD prevents pregnancy by making the uterine lining unsuitable for implantation and by creating thick cervical mucus that hinders sperm movement.

What is a copper IUD made of?

A copper IUD consists of a plastic frame with copper sleeves or copper wire around it.

How do copper IUDs primarily work as a contraceptive method?

Copper IUDs work mainly by inhibiting the movement of sperm and preventing them from moving through the uterus.

What additional effect do copper IUDs have on the endometrium?

Copper IUDs cause changes to the endometrium, which can prevent a fertilized egg from attaching to it.

How long can copper IUDs be used as a form of emergency contraception after unprotected sex?

Copper IUDs can be used as an effective form of emergency contraception for up to five days after unprotected sex.

What is the effectiveness rate of modern copper IUDs?

Modern copper IUDs are more than 99% effective as contraceptives and maintain their effectiveness over a long period of time.

How long does a Mirena IUD provide protection, and how does it compare to copper IUDs?

Mirena provides protection for five years, while copper IUDs are effective for up to 10 years.

Can copper IUDs be removed, and how quickly does fertility return after removal?

Yes, copper IUDs can be removed at any time, and fertility returns quickly after removal.

When might it be necessary to use emergency contraception after sex?

Emergency contraception may be needed after sex if a condom breaks, a birth control pill is forgotten, or in cases of rape.

What is the primary mechanism by which the morning-after pill works?

The morning-after pill works primarily by preventing or delaying ovulation, preventing sperm from reaching an egg, and preventing the implantation of an embryo in the uterine lining.

What are some common brand names for emergency contraceptive pills?

Some common brand names for emergency contraceptive pills include Postinor, Levonelle, and NorLevo-1.

When is the emergency contraceptive pill (ECP) most effective, and when does its effectiveness start to decline?

The ECP is most effective when taken as soon as possible after unprotected sex. Its effectiveness starts to decline after 72 hours, but it may still prevent pregnancy if taken four or five days after sex.

What are some potential side effects of emergency contraceptive pills?

Potential side effects of emergency contraceptive pills may include nausea, vomiting (although not common), headache, stomach ache, breast tenderness, dizziness, or spot bleeding from the vagina.

How does the timing of taking emergency contraception affect its effectiveness?

The sooner emergency contraception is taken after unprotected sex, the more effective it will prevent pregnancy. Effectiveness decreases after 72 hours but may still have some effectiveness if taken up to four or five days after sex.

What is sterilization as a method of birth control?

Sterilization is a permanent method of birth control for both men and women where the anatomy of the reproductive system is altered to prevent the sperm and egg from meeting.

When should the choice of sterilization as a birth control method be considered?

The choice of sterilization as a birth control method for both men and women should be considered only when no further children are wanted.

Is sterilization reversible?

While sterilization can be reversed in some people, it should generally be thought of as a permanent procedure.

What is the traditional method of male sterilization called?

The traditional method of male sterilization is called vasectom

What is removed during a vasectomy procedure?

During a vasectomy procedure, a small segment of each vas deferens is removed.

How are the cut ends of the vas deferens sealed during a vasectomy?

The cut ends of the vas deferens are typically tied or sealed with heat during a vasectomy.

Where are small cuts made during a vasectomy procedure?

Small cuts are made on each side of the scrotum during a vasectomy procedure.

What type of anesthesia is commonly used for vasectomy operations?

Most vasectomy operations are done under local anesthesia, although a general anesthetic can be used if necessary.

What is the primary surgical procedure for achieving sterilization in women?

Tubal ligation, also known as tubal occlusion, is the primary surgical procedure for achieving sterilization in women.

Describe the process of tubal ligation.

Tubal ligation involves making a small incision in the abdomen under general anesthesia, locating the uterine tubes, cutting them, removing a small piece, and tying the ends. Alternatively, metal clips may be used to crush a section of the uterine tube.

How does tubal ligation prevent pregnancy?

Tubal ligation prevents pregnancy by blocking the fallopian tubes, making it impossible for sperm to reach the egg and for the fertilized egg to reach the uterus.

What instrument may be used as an alternative to the traditional tubal ligation procedure?

An instrument called a laparoscope may be used as an alternative to the traditional tubal ligation procedure, involving a small incision near the navel to locate and manipulate the uterine tubes.

Does tubal ligation affect a woman's sexual desire?

No, tubal ligation does not result in a decrease in a woman's sexual desire. It primarily serves as a contraceptive method without impacting sexual drive.

What is castration, and how does it differ from sterilization?

Castration is the removal of the testes and differs from sterilization, which primarily involves blocking or cutting the fallopian tubes in women. Castration affects reproductive hormones and sexual characteristics and is usually performed only in specific medical circumstances.

What is oophorectomy, and how does it differ from tubal ligation?

Oophorectomy is the removal of the ovaries and differs from tubal ligation, which focuses on blocking or cutting the fallopian tubes. Oophorectomy has significant effects on reproductive hormones and body characteristics and is typically performed for specific medical reasons.

What surgical procedure in women results in sterility by removing the uterus?

A hysterectomy, which involves the removal of the uterus, results in sterility in women.

Questions 13.1 HERE

How are STIs transmitted?

STIs are transmitted through close body contact, usually involving the genital organs, and can be caused by viruses, bacteria, fungi, or parasites

Who is most at risk of contracting STIs?

Young people are most at risk of contracting STIs. In Australia, three-quarters of known cases of STIs occur in people aged 15 to 29 years.

Does contracting an STI provide immunity or reduce the likelihood of contracting the disease if exposed again?

No, for many STIs, contracting the infection once does not make a person immune or any less likely to contract the disease if exposed to infection again.

What is the most common STI?

Chlamydia

What bacterium causes chlamydia?

Chlamydia trachomatis

How does Chlamydia trachomatis reproduce?

It can only reproduce inside a living human cell.

Why is chlamydia sometimes called the 'silent infection'?

Most people infected with chlamydia show no symptoms and are unaware of their infection.

How is chlamydia treated when diagnosed?

Chlamydia can be treated with antibiotics.

How is Chlamydia trachomatis transmitted?

Chlamydia trachomatis is transmitted by vaginal or anal sex with an infected person.