Chapter 11: Human Reproductive System
Name: _______________________________(
) Class: ______ Date: ____________
CHAPTER MAP & OVERVIEW
Ch 11.1
THE HUMAN REPRODUCTIVE SYSTEM
Anatomy and Function of
Reproductive System
Puberty
Male
1.
2.
3.
4.
5.
PostFertilization
Female
Testis
Epididymis
Sperm duct
Glands
Penis
Structure of
Gametes
1. Sperm
1.
2.
3.
4.
5.
Ovary
Oviduct
Uterus
Cervix
Vagina
Structure & Function of:
1. Placenta
2. Amniotic Sac
3. Amniotic Fluid
4. Umbilical Cord
2. Ovum
Ch 11.2
SEXUALLY
TRANSMITTED
INFECTIONS
Prevention
Copulation &
Fertilization
Chapter 6.1.3
Menstrual Cycle
Ch 11.3
ISSUES ON SEX &
FERTILITY
Family
Planning
Premarital Sex
Birth Control
Facilitated
Reproduction
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Ch 11.1 Human Reproductive System
Learning Outcomes
Students will be able to:
1. state some of the physical changes that occur during puberty and early adolescence.
2. label on diagrams of the male reproductive system and give the functions of: testes, scrotum, sperm
ducts, prostate gland, urethra and penis.
3. label on diagrams of the female reproductive system and give the functions of: ovaries, oviducts, uterus,
cervix and vagina.
4. compare the male and female gametes in terms of size, numbers and mobility.
5. describe the menstrual cycle with reference to the alternation of menstruation and ovulation, the natural
variation in its length, and the fertile and infertile phases of the cycle with reference to
- progesterone, oestrogen (IP Classes)
- progesterone, oestrogen, follicle-stimulating hormone (LSH) and luteinising hormone (LH) (Advanced) .
6. recognise that in sexual reproduction a new individual is formed through the union of an egg and a
sperm.
7. recognise that a new individual formed through sexual reproduction receives genetic information from its
mother (via the egg) and its father (via the sperm).
8. describe fertilisation and early development of the zygote simply in terms of a ball of cells which
becomes implanted in the wall of the uterus.
9. state the function of the amniotic sac and amniotic fluid.
10.describe the function of the placenta and umbilical cord in relation to exchange of dissolved nutrients,
gases and excretory products (no structural details are required).
Ch 11.2 Sexually Transmitted Infections
Learning Outcomes
Students will be able to:
1. state the harmful consequences of sexually transmitted infections like syphilis, gonorrhoea and AIDS.
2. explain that syphilis and gonorrhoea are caused by a bacterium which is transmitted during sexual
intercourse.
3. describe the symptoms, signs, effects and treatment of syphilis, gonorrhoea and AIDS.
4. discuss the spread of human immunodeficiency virus (HIV) and methods by which it may be controlled.
Ch 11.3 Issues on Sex and Fertility
Learning Outcomes
Students will be able to:
1. discuss the consequences and issues relating to abortion and pre-marital sex.
2. describe the following methods of birth control: natural, chemical (spermicides), mechanical, hormonal
and surgical.
Advanced
1. describe some forms of facilitated reproduction in human beings. E.g: IVF.
Page 2 of 26
11.1 Human Reproductive System
All living things reproduce.
Reproduction is the biological process where new individuals (known as “offsprings”) are made
from older ones (known as “parents”)
Organisms reproduce by two primary means:
(1) Sexual Reproduction
Sexual reproduction is the biological process of forming a new individual through the fusion of the
nuclei of two very specialized cells known as gametes. The fusion process is also known as
fertilization. In cases where the two gametes involved in the fusion are distinct in form and
structure, the larger of the two gametes is known as the egg or ovum, while the smaller one is
known as the sperm.
(2) Asexual Reproduction
Asexual reproduction is the biological process of forming a new individual from a single parent
without the involvement of gametes (i.e. without fertilization).
The table below summarizes the differences between sexually and asexually reproducing organisms
Feature
Sexual Reproduction
Asexual Reproduction
No
Requires fertilization?
Yes
Number of parents
required
Usually involves two parents but
may occur within the body of a single
hermaphroditic organism
One
(hermaphrodites are organisms with
both male and female sexual
organs)
Variation in offspring?
Produces genetic variation in
offspring. (i.e. offspring may have
genetic differences between one
another)
All offspring are
genetically identical, and
are also genetically
identical to the parent
Note that while some organisms reproduce either asexually or sexually, there are many organisms
that are capable of reproducing in both manners.
We will focus on discussing about sexual reproduction in human beings.
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PUBERTY
Puberty is the developmental process where a child’s body matures into an adult body where he or
she is now capable of reproduction.
This process is triggered by:
1. Release of hormones from the brain to the gonads. The gonads are the organs
responsible for the production of sperm and eggs. In males, the gonads are the testes and
in females, the gonads are the ovaries.
2. In response to the hormonal signals from the brain, the gonads begin secreting sex
hormones (such as testosterone and oestrogen).
3. The gonads also initiate gametes production. In the testes, sperm are produced, while in
the ovaries, eggs begin maturing (premature eggs are formed in the ovaries prior to birth).
4. Other secondary sexual characteristics also begin to develop.
Secondary sexual characteristics are unique features found in each sex of a species of
organisms and they only arise in a later part of the organism’s life cycle (i.e. puberty).
In contrast, primary sexual characteristics refer to features that distinguish the two sexes from
birth. For example, presence of testes or ovaries is a primary sexual characteristic as these
organs distinguish a male from a female from birth.
The table below describes some secondary sexual characteristics in males and females.
Males
Females
Onset at age 11 to 15 years old
Onset at age 9 to 13 years old
Predominant growth of facial, underarm,
chest, abdominal and pubic hair
Predominant growth of underarm and pubic
hair
Broadening of chest and shoulders
Broadening of hips
Enlargement of penis and testes
Enlargement of breasts
Sebaceous (oil) and sweat glands become
more active, leading to acne in severe cases
Sebaceous (oil) and sweat glands become
more active, leading to acne in severe cases
Deepening of voice as larynx enlarges
Increase in weight and height
Increased muscles mass and strength;
increase in height
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ANATOMY AND FUNCTION OF THE HUMAN REPRODUCTIVE SYSTEM
The male and female reproductive systems have distinctive features.
In this section, we will examine the structure and function of the various organs in each system.
A. The Male Reproductive System
Fig. 1 Lateral view of the typical human male reproductive system.
Image taken from Pearson Education.
Structure
Function
1) Testis
•
•
Production of male gametes (sperm)
Production of male sex hormones (testosterone)
2) Epididymis
•
•
Temporary storage of sperms
Muscles in epididymis contract to ejaculate sperms
3) Sperm duct
•
Transport sperms from the epididymis to the urethra
•
Production of seminal fluid
- Alkaline to neutralize acidity in female reproductive tract
- Activates sperms by causing them to swim freely
- Nourish sperms with nutrients
•
Insertion into vagina when erected
4) Glands
P Seminal vesicles
P Prostate gland
P Bulbourethral or
Cowper’s glands
5) Penis
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Fig.2 Frontal view of the typical human male
reproductive system.
Image taken from Pearson Education.
Some physiological changes occur during sexual arousal leading to erection. The process is described
as follows:
Physiology of Erection and Ejaculation:
1) Arterioles bringing blood to the penis and its erectile tissue dilate.
2) Blood begin entering the erectile tissues and fills up the blood spaces in the erectile tissue.
3) Penis becomes turgid.
4) Epididymis contracts
5) Semen is released.
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B. The Female Reproductive System
Fig.3 Lateral view of the typical human female reproductive system.
Image taken from Pearson Education.
Fig.4 Front view of the typical human female reproductive system.
Image taken from Pearson Education.
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The table below lists the adaptation and functions of various organs in the female reproduction
system:
Structure
Function OR Adaptation
1) Ovary
•
•
Production of female gametes (ova) and release of mature ovum
Production of female sex hormones (oestrogen and progesterone)
2) Oviduct
•
•
•
Deliver mature ovum from ovary to uterus
Beating of cilia to move ovum along oviduct
Muscular, strong contractions
•
•
Muscular and elastic, to push foetus out during birth
Soft and smooth endometrium prepares for implantation of embryo
3) Uterus
3a) Endometrium
(Uterine lining)
Structural Adaptations of the Male and Female Gametes
The function of the male gamete, also known as sperm, is to deliver the male’s genetic material
to the egg by fertilizing it.
The function of the female gamete, also known as the ovum (plural: ova), is to contain the female’s
genetic material and to be fertilized by one sperm.
The diagram below illustrates the differences between the sperm and ovum:
Fig.5 Structure of the sperm (left and the egg (right). Not
drawn to scale.
Sperm image taken from
http://qwickstep.com/search/chromosomes-in-a-spermcell.html.
Image of ovum from
http://www.academiavita.org/immagini/Pubblicazioni/embrio/en
glish/colombo/FIG6.JPG
Page 8 of 26
The table below lists the structural adaptations of the sperm cell:
Structure
Adaptation
•
•
1) Acrosome
•
Contains acrosin, a protease enzyme, released by the sperm upon
contact with the membrane surrounding the ovum.
Acrosin aids in digesting away this membrane (known as zona
pellucida) which surrounds the cell membrane of the ovum.
This allows the sperm cell to penetrate the ovum during fertilization.
•
Contains the male genetic material that will eventually be combined
with the female genetic material in the ovum during fertilization.
•
The thinner cytoplasm reduces resistance to the motion of the
sperm towards the ovum.
4) Middle piece
•
•
The middle piece consists of a spiral mitochondrion.
The mitochondrion supplies energy for the beating of the tail.
5) Tail (or flagellum)
•
The tail beats to propel the sperm towards the ovum.
2) Nucleus
3) Minimal cytoplasm
Some differences between the sperm and the ovum are listed in the next table:
Sperm
Feature
1) Shape
2) Size
3) Numbers
4) Motility
5) Lifespan
Ovum
•
Three distinct regions, namely:
head, middle piece and tail
•
Spherical
•
Small, head about 2.5 μm, full
length about 40 μm
•
Large, about 120 μm
•
200 to 500 million sperm cells
per seminal discharge
•
One released on an average of
about 28 days.
•
•
Non-motile
Swept along oviduct by cilia lining
the walls of the oviduct or by
contractions of the muscles in the
oviduct walls
•
Only 48 hours (or less) if
unfertilized
•
•
Motile
Move by beating of flagella
•
•
Die rapidly in open air
Die within a few hours in the
vagina
Lifespan of 2 to 3 days in the
oviduct
•
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THE MENSTRUAL CYCLE
Menstrual Cycle Video: http://www.youtube.com/watch?v=WGJsrGmWeKE
http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/human/hormonesrev3.shtml
Oestrogen
Fig.6 Menstrual Cycle
Image taken from https://www.babycenter.com/ims/2018/06/833x469xbc-menstrual-cyclelogo_wide.png.pagespeed.ic.Pk7TLDetrQ.png
• The menstrual cycle refers to a cycle of physiological changes that occur in a fertile woman’s
reproductive system. This cycle of events is essential for reproduction to occur.
• The average period of each cycle is about 28 days.
• However, it may also range between 14 to 35 days, depending on stress levels and
lifestyle.
• The cycle is under the direct control of hormones.
• In particular, progesterone and oestrogen.
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Basic Information
Advanced
(Only Progesterone and Oestrogen)
(More Details on LH and FSH)
Menstruation, Day 1-5:
• The first day of menstruation is the first day of
menstrual cycle.
• The unfertilized egg, together with the
fragments of endometrial tissues, blood
capillaries and blood, will be removed through
menstrual bleeding as it flows from the uterus
out of the body through the vagina.
• The first day of menstruation is the first day of
menstrual cycle.
• The unfertilized egg, together with the
fragments of endometrial tissues, blood
capillaries and blood, will be removed through
menstrual bleeding as it flows from the uterus
out of the body through the vagina.
• The anterior pituitary gland secretes FSH into
the bloodstream which travels to the ovaries.
Follicle Stage, Day 6-13:
• Oestrogen causes the growth and repair of the
uterine lining (endometrium).
Effects of FSH:
• FSH stimulates the development of the
follicles in the ovaries.
• One follicle will become the Graafian follicle.
• FSH also stimulates the follicles to secrete
oestrogen.
Effects of Oestrogen:
• Oestrogen causes the growth and repair of
the uterine lining (endometrium).
High Concentration of Oestrogen:
• When oestrogen levels increase to a high
level, it inhibits the secretion of FSH, thus
preventing the development of more
follicles.
• It triggers the secretion of LH from the
anterior pituitary gland that travels in the blood
to the ovaries.
Ovulation, Day 14
• A sudden surge in LH triggers the release of the
mature ovum from one of the ovaries.
• The mature ovum then begins its passage
through the oviduct towards the uterus.
• Upon release from the ovary, the mature ovum
may only survive for 48 hours or less if it is not
fertilized.
Effects of LH:
• LH causes ovulation.
• It causes the follicular wall of the Graafian follicle
to rupture, releasing the mature ovum from one
of the ovaries into the oviduct (ovulation).
• LH causes the formation of an active corpus
luteum from the ruptured follicle.
• The corpus luteum secretes progesterone and
also some oestrogen.
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• The mature ovum then begins its passage through
the oviduct towards the uterus.
• Upon release from the ovary, the mature ovum
may only survive for 48 hours or less if it is not
fertilized.
Corpus Luteum Stage, Day 15 to 28
Effects of Progesterone
• The high concentrations of progesterone
encourages the proliferation (i.e. growth) of the
uterine lining (or endometrium).
• The progesterone maintains the thickened
uterine lining (endometrium) by causing it to
further thicken, well-supplied with blood
capillaries (vascularized) in the endometrial
tissues.
• Eventually, it will reach maximum thickness.
Effects of Progesterone
• The high concentration of progesterone
encourages the proliferation (i.e. growth) of the
uterine lining (or endometrium).
• The progesterone maintains the thickened
uterine lining (endometrium) by causing it to
further thicken, well-supplied with blood
capillaries (vascularized) in the endometrial
tissues.
• Eventually, it will reach maximum thickness.
• The thickness of the uterine lining is
maintained mainly by the relatively high
concentrations of progesterone.
• The thickness of the uterine lining is
maintained mainly by the relatively high
concentrations of progesterone.
• The proliferation of the uterine lining is to prepare
for the implantation of the fertilized egg.
• The proliferation of the uterine lining is to prepare
for the implantation of the fertilized egg.
If fertilization does not occur,
• the production of progesterone will fall sharply
and stop, thus the uterine lining cannot be
maintained in a thickened state anymore, so it
breaks down.
• The unfertilized egg, together with the
fragments of endometrial tissues, blood
capillaries and blood, will be removed through
menstrual bleeding.
• Thus, this marks the beginning of a new cycle.
• Progesterone also inhibits FSH and LH
production (ovulation).
• It also stimulates the formation of glands
secreting nutrients to prepare the endometrium
for the implantation of the embryo if there is
fertilization.
If fertilization does not occur,
• the drop in LH level in the blood causes the
corpus luteum to break down.
• When this happens, the progesterone
production stops, thus the uterine lining
cannot be maintained in a thickened state
anymore, so it breaks down.
• The unfertilized egg, together with the
fragments of endometrial tissues, blood
capillaries and blood, will be removed through
menstrual bleeding.
• Thus, this marks the beginning of a new cycle.
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If fertilization occurs,
• the menstrual cycle is disrupted.
• the fertilised egg becomes a zygote and the zygote develops into an embryo which
implants itself in the uterine lining.
• The embryo produces a hormone, hCG (human chorionic gonadotrophin), which prevents
the corpus luteum from breaking down so that the corpus luteum continues to secrete
progesterone and oestrogen until the placenta takes over the production of these
hormones.
To penetrate the ovum, the acrosome
of the sperm release acrosine to
disperse the follicle cells and digest
away the membrane.
Only one sperm nucleus enters
the ovum.
The haploid sperm nucleus
fuses with the haploid ovum
nucleus to form a fertilised ovum
known as zygote (diploid).
As soon as the sperm cell
has entered the ovum, the
membrane of the ovum
changes such that no
other sperms can enter.
The remaining sperms
which do not fertilise the
ovum will eventually die.
Take Note:
As the average lifespan of the sperm cell in the oviduct is about 72 hours or about 3 days, any
deposition of semen into the female reproductive tract 3 days prior to ovulation may suggest that
the woman can still conceive if she ovulates on Day 14.
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COPULATION & FERTILIZATION
• Copulation or sexual intercourse refers to the process of placing the male genitalia into the
female reproductive tract.
• Fertilization on the other hand refers to the fusion of the male and female gametes,
restoring the diploid number of chromosomes in the zygote.
• It is important to distinguish the two processes.
• i.e. Copulation does not necessarily lead to fertilization!!
Fertilization is the process involving the fusion of the nuclei of male and female gametes to
form the zygote. This process restores the diploid number of chromosomes.
What are chromosomes?
• Chromosomes are structures found in the nucleus of most body cells prior to cell division.
• They contain hereditary information in the form of genes.
• This genetic information is critical for determining the structure of and processes occurring
in an organism and is being passed on from generations to generations.
• Alteration to this information can be lethal or may lead to mutations.
What is meant by the diploid number of chromosomes?
• Most ordinary cells in your body possess the same number of chromosomes.
• In the case of human beings, this number is 46 chromosomes (or 2 sets of 23 chromosomes).
Any cells possessing two sets of these 23 chromosomes are described as having the diploid
number of chromosomes.
• However, gamete cells (ie. the sperm cell and the egg cell) only possess 1 set of 23
chromosomes. We describe these cells has having the haploid number of chromosomes.
• Thus, when two haploid cells, the sperm and the egg, fuse, the resulting cell, known as a
zygote, will thus possess the complete 46 chromosomes. We hence describe fertilization as a
process that restores the zygote with the diploid number of chromosomes.
• Note that different species have different diploid number of chromosomes.
• The zygote, now with 46 chromosomes, will divide repeatedly, giving rise to all the body cells
that will form the new individual. Each of these body cells will then have the diploid number of
chromosomes (except for the gametes).
• Note that this individual will also possess 23 chromosomes from the father and 23
chromosomes from the mother.
• Thus, the individual will possess a mixture of characteristics or traits from either parent.
Page 14 of 26
POST- FERTILIZATION
• After the formation of the zygote, several cycles of cell division of the zygote occurs.
• Eventually, the zygote forms a ball of undifferentiated cells.
• This ball of cells then begins to form simple tissue layers and is now known as an embryo.
• In later stages of development, the embryo starts to form distinguishable organs and we term
this as the foetus.
• The foetus is nourished and protected by several structures found in the uterus.
• The following section describes these structures.
Fig.7
Post-fertilization developments.
th
Image taken from Integrated Principles of Zoology, 13 ed., McGraw-Hill Companies (2006)
Page 15 of 26
A. Amniotic Sac and Amniotic Fluid
• The amniotic sac encloses the foetus in the amniotic cavity, which contains the amniotic
fluid.
• Functions of the amniotic fluid:
o supports and cushions the foetus while in the uterus
o absorbs shock, for example, if the mother has a fall
o protects the foetus against physical injury as it cannot be compressed
o acts as a lubricant and reduces friction in the birth canal during birth
o allows foetus to move freely during gestation
B. The Placenta
• The fetal blood system must be separated from the maternal’s system as the two systems are
functioning at different blood pressure.
• The foetus’ blood type may also be different from that of the mother. Mixing of blood of different
blood types may result in agglutination and this can be fatal.
• Functions of the Placenta:
o allows oxygen and nutrients (glucose, amino acids and mineral salts) to diffuse from
the mother’s blood into the foetus’ blood
o allows excretory products (urea and carbon dioxide) to diffuse from the foetus’ blood
into the mother’s blood
o allows antibodies (protection against diseases) to diffuse from the mother’s blood
into the foetus’ blood
o produces progesterone which maintains the uterine lining during pregnancy
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C. The Umbilical Cord
• The umbilical cord attaches the foetus to the placenta
• It contains 2 umbilical arteries and 1 umbilical vein
• Functions of the Umbilical Cord:
o umbilical arteries transport deoxygenated blood and metabolic wastes products
(urea) from foetus to the placenta
o umbilical vein transports oxygenated blood, nutrients (glucose, amino acids) and
other useful substances (antibodies, hormones) from the placenta to the foetus
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11.2 SEXUALLY TRANSMITTED INFECTIONS (STIs)
• Sexually transmitted infections (STIs) refer to
o diseases transmitted mainly through sexual intercourse
o caused by bacteria and viruses
o affect the reproductive system (may also affect other body parts)
o may not show visible signs or symptoms à pass on the disease unknowingly to their
partners.
o infections can be fatal
o Examples:, Syphilis, Gonorrhoea, Acquired Immunodeficiency Syndrome (AIDS)
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The table below summarizes some of these diseases’ cause, transmission, symptoms, effects and treatment:
STI
Gonorrhoea
Cause
Spherical bacteria
Transmission
• sexual intercourse with
infected partner
• from infected mother to
baby during birth
Symptoms
•
•
painful sensation
during urination
discharge of pus from
vagina or penis
•
•
• sharing of injection
needles with infected
person
Retrieved from:
http://www.medicaldaily.com/gonorrheasuperbug-hits-australia-powerful-newstrain-cant-be-treated-regular-std-drugs299952
Syphilis
Spiral bacteria
Effects
•
•
• transfusion of infected
blood
•
•
Human Immunodeficiency Virus
(HIV)
•
•
•
•
•
Retrieved from:
http://www.daviddarling.info/encyclopedia/
A/acquired_immune_deficiency_syndrome
.html
•
Antibiotics, but some strains
of the bacteria have
developed drug-resistance
painless sores on
penis, vagina, cervix
or mouth
non-itchy skin rashes
•
•
•
•
•
deformed joints
paralysis
insanity
death
new-born may be
deaf or with
abnormal teeth and
bone
•
Antibiotics, only effective at
early stage
weaken immune
system
loss of appetite and
weight
diarrhoea
night sweat
flu-like symptoms
•
immune system
fails
pneumonia
tuberculosis
brain infection
Kaposi sarcoma
•
Currently, no cure. Cocktail of
antiretroviral drugs is used to
prolong lifespan and improve
quality of lives of patients
Post-exposure prophylaxis
(PEP) can be used within 72
hours after a possible
exposure to HIV. PEP is very
effective but will not prevent
100% of HIV transmissions
from occurring
Retrieved from:
http://www.3d4medical.com/Syphilis-45image_RM4698.html
Acquired Immune
Deficiency
Syndrome (AIDS)
Treatment
infection of urethra
infection of oviducts
which may lead to
infertility
ectopic pregnancy
infection of newborn’s eyes which
may lead to
blindness
•
•
•
•
•
Page 19 of 26
For your information only (a.k.a. not tested):
HIV infects the helper T cells, macrophages and dendritic cells (different types of white blood cells
in the immune system).
The viral particles bind to these cells and enter the cells, utilising the cell’s mechanism in making
copies of the viral genome and proteins.
The viral particles are then assembled and exit the cells to infect more target cells.
PREVENTION OF STIs
• To reduce the risk of contracting AIDS and control its spread,
o practice monogamy or abstinence
o wear a condom during intercourse
o do not abuse drugs
o do not share instruments that break the skin (toothbrush, razors, piercing
o needles, tattoo needles) and may be contaminated with blood
o go to reliable practitioners who use sterilized/disposable instruments
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11.3 ISSUES ON SEX & FERTILITY
FAMILY PLANNING
•
•
•
Family planning is the process involving the planning of when and how many children to have.
It often involves the use of various birth control methods for the implementation of the plans.
Poor family planning may lead to unwanted or unplanned pregnancies. This has the
following consequences:
o
Financial cost of raising the child
o
Psychologically not ready to start a family
o
Struggling with career and family commitments
o
Individual aspirations or pursuits
PREMARITAL SEX
•
•
•
•
•
•
Premarital sex refers to sexual intercourse between a couple who are not married.
If the couple are teenagers, the consequences are direr.
Engaging in sexual intercourse with a teenage girl (below 16 years old) is a crime, even if the
girl gave her consent.
Premarital sex may also lead to unwanted or unplanned pregnancy.
Teenagers, being mentally, emotionally and financially not ready, are not able to cope well with
pregnancy and child-rearing.
Some even become infected with STIs.
Options for teenage pregnancy
•
Teenage girls who get pregnant have the following option:
o
carry on with the pregnancy and keep the baby
o
carry on with the pregnancy and later give the baby up for adoption
o
have an abortion
•
Each of the above options has its inherent problems:
o keeping the baby means that the girl has to stop schooling to look after the baby herself or
she may have to start looking for a job to pay for the increased expenditure
o giving up the baby for adoption can be emotionally traumatizing
o getting an abortion (even if done professionally) can be risky:
Ø infections of the uterus or oviducts which can lead to infertility
Ø accidental puncturing of the uterus which can lead to heavy bleeding or infertility
Ø weakening of cervix and uterus, especially if abortion is done repeatedly
Ø increased risk of ectopic pregnancy
Ø sense of loss, guilt, regret and depression
• Although not encouraged, abortion is still carried out for various other reasons:
o foetus is abnormal
o mother’s life is endangered if the pregnancy continues
o unwanted pregnancy resulting from rape
o unfavourable conditions such as low family income or inadequate housing
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BIRTH CONTROL
•
Couples practice birth control for various reasons:
o
Prevent unwanted pregnancy.
o
Family may be financially not ready.
o
Couple may want to pursue career development and do not have time for a child.
o
Family may already have enough children.
o
Couple may want to space out the age-gap of their children.
o
The woman may be ill and physically unsuitable to go through a pregnancy (egg
Diabetic / High Blood Pressure).
o
Reduce risk of being infected with STIs.
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Options for Birth Control
• There are many options for birth control. Some forms of birth control only prevent pregnancy
temporarily. Once the couple stops practicing these methods, they are able to get
pregnant again.
• Permanent birth control, once executed, is irreversible. The couple cannot have a baby
again.
• Medical developments had yielded more and more effective methods of birth control.
• Below are examples of some common methods. * You may want to research on newer
methods such as “Essure” / “The Patch”.
Types of
birth control
Natural
Chemical
Examples
Rhythm
method
Temporary /
Permanent
Temporary
Withdrawal
method
Temporary
Spermicide
Temporary
How it works
Effectiveness
The woman tracks
her menstrual
cycle and avoids
having intercourse
during the fertile
period.
Unreliable. The
menstrual cycle is
easily disrupted by
hormonal fluctuation
in the woman’s body.
The man
withdraws his
penis just before
ejaculation and
sperms are not
released into the
vagina.
A chemical is
sprayed in the
vagina to kill the
sperms upon entry
and render them
unable to swim up
to the oviducts.
Unreliable. Sperms
may be present in
pre-seminal fluids and
the man may not be
able to withdraw in
time.
80%. Some sperms
may be resistant to
the spermicide and
can survive the
journey towards the
oviducts.
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Types of
birth control
Mechanical
Hormonal
Examples
Condom
Temporary /
Permanent
Temporary
How it works
Effectiveness
A rubber sheath is
worn over the
penis during
intercourse and
sperms are
collected in the
condom so that
they cannot enter
the vagina.
99.9%. Microscopic
tears may be present
and sperms may leak
through.
Diaphragm
Temporary
A rubber cap is
fitted over the
cervix and act as a
barrier between
the sperms and the
ovum.
99.9%. If the cap is
not fitted properly,
sperms can still enter
the uterus and swim
up to the oviducts.
Intrauterine Device
(IUD)
Temporary
An IUD is a small t- 99%
shaped device that
is made out of
flexible plastic. The
t-shaped device is
inserted into a
woman’s uterus to
prevent pregnancy.
Pill
Temporary
Contains synthetic
female hormones
that prevent
ovulation.
Injection/Implant
Temporary
Synthetic female
hormones are
regularly injected
directly or slowly
released from an
implanted tube into
the blood stream to
prevent ovulation.
99.9%. Women were
reported to be
impregnated even
though they were put
on the Pill.
99.9%. Women were
reported to be
impregnated even
though they were put
on hormonal
treatment.
Intrauterine Device (IUD) to be inserted into the uterus by a doctor.
Image retrieved from: https://www.saintlukeskc.org/health-library/birth-control-iud-intrauterine-device
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Types of birth
control
Surgical
Retrieved
from:
Examples
Ligation
Temporary /
Permanent
Permanent
How it works
The oviducts are
cut and tied up to
prevent the sperms
from meeting the
ovum.
Effectiveness
100%.
http://www.coastalfertilityspecialists.com/coastalfertility/files/ff/ff25e278-7f1f-4ec6-9d0f-
440dadb0aa30.jpg
Surgical
Vasectomy
Permanent
The sperm ducts
are cut and tied to
prevent sperms
from being
released into the
urethra and out of
the penis.
100%
Retrieved from: https://commons.wikimedia.org/wiki/File%3AVasectomy_diagram-en.svg
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Facilitated Reproduction
There are couples who are not able to have children due to various physical conditions:
o
o
o
o
o
o
The ovaries may be defective
The oviducts may be blocked
The uterus/cervix may be too weak to sustain a pregnancy
The sperms may be weak
The man is unable to sustain an erection for penetration
The woman may be suffering from other medical conditions (eg Diabetes or High Blood Pressure)
which makes it difficult for her to conceive
As a result, these couples may turn to facilitated reproduction:
o
o
o
In vitro Fertilisation (“Test tube baby”)
In situ Fertilisation
Surrogate mother
In vitro Fertilization
•
•
•
•
•
•
The woman is given hormonal treatment to stimulate multiple ovulation and the ova are
harvested and screened for vitality.
The sperms are also collected from the man and screened for vitality.
A healthy sperm is then used to fertilise one ovum in a petri dish with the help of the
microscope.
The resulting zygote is allowed to divide before it is introduced into the uterus.
Usually, up to 3 zygotes are introduced to increase the chances of successful implantation.
If the zygote is successfully implanted, it can develop into an embryo and after 40 weeks,
the foetus is ready for birth.
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