Reproduction- upper primary science

Reproduction

Reproduction is the process by which living things give rise to offspring of the same kind

The male reproductive system

Parts of the male reproductive system

Parts	Functions
Testis	Produce sperms, the male gametes and male hormones
Scrotum	Bag that hold and protect the testis
Sperm duct/ Vas deferens	Carries sperms from the testis to urethra
Urethra	Passage for both semen and urine
Penis	Deposits sperms into the vagina
Epididymis	Stores sperms

 

The female reproductive system

Parts of the male reproductive system

Parts	Functions
Ovaries	They produce eggs or ova (singular Ovum) a female gamete Produce hormones  such as estrogen The process of process of producing ova is called ovulation
Oviduct/Fallopian tube	This is where fertilization takes place Fertilization is the union of male and female gametes
Uterus/womb	This is where the fetus develops
Cervix	This is the lower part of uterus. It allows sperms into the uterus Retains the fetus in the uterus before birth
Vagina/birth canal	It is where sperms are deposited It is a tube through which the baby passes during parturition/giving birth

A sperm

It is a male reproductive cell. Sperms are produced in testes.

The Ovum

It is the female reproductive cell

The egg is produced in the ovary.

The process of releasing an egg from the ovary into a fallopian tube is called ovulation. It occurs every 28 days.

Egg remain alive for 2 days. If not fertilized, the egg and the thickened walls of the uterus come out of the body in form of blood by the process of menstruation.

Fertilization in human beings

This is the union of female (ovum) and male gamete (sperm) to form a zygote. It occur in the upper part of the Fallopian tube.

Immediately after fertilization a woman is said to be pregnant or to have conceived.

After fertilization ovulation and menstruations stop until after child birth

Types of fertilization

• Internal fertilization is the fusion of male and female gametes inside the female body, for example in human being, birds and reptiles.
• External fertilization is the fusion of male and female gametes outside the female body for example in amphibian and fish.

Implantation

This is the attachment of the zygote to the walls of the uterus. Immediately after implantation, the zygote becomes an embryo.

An embryo develops into a fetus after 6 to 8 weeks

The fetus develops and at birth is called a newborn baby.

Placenta

This is an organ of attachment between the mother and the fetus

Functions of the placenta

1. Prevents mixing of blood of the mother and fetus.
2. Supplies Oxygen, water, amino acid, glucose and other essential minerals from the mother to the fetus
3. Allows transfer of Carbon dioxide, urea and other wastes from fetal blood to mother’s blood.
4. Prevents certain pathogens from entering fetal blood
5. Produces HCG a hormone that support development of fetus.
6. It allows certain maternal hormones to cross to the fetus.

Why should mothers and fetal blood not mix?

1. To prevent blood incompatibility due to different blood group
2. To prevent incompatibility due to different rhesus factors
3. To prevent infections from the mother attacking the fetus
4. To protect the fetus from high blood pressure of the others blood

 Umbilical cord

This is a flexible tube that connects the fetus at the abdomen to the placenta

Functions of the umbilical cord

• Transports food nutrients and oxygen from the mother to fetus
• Transports waste products from the fetus to the mother

The amniotic fluid

This is a clear jelly-like liquid that surrounds the fetus.

• Protects the fetus against shock resulting from external force.
• Prevents the fetus from getting dry
• Reduces friction between the fetus and the uterus
• Allows movement of the fetus in the amniotic sac.
• Acts of lubricant during birth

Signs of pregnancy

• Breasts become soft, tender and sensitive
• Abdomen enlarges
• Menstruation stops
• Morning sickness such as vomiting and nausea in the morning

Gestation period

This is the period between implantation and child birth. In humans it is about 9months

Stages of child birth

• Labor pains – caused by contraction of the uterine wall.
• Dilation – widening of the cervix
• Bursting of amniotic membrane
• Parturition or birth
• Tie and cut the umbilical cord. Tying of umbilical cord prevent excess fetal bleeding.

Breast feeding

This is the feeding of a baby with milk from the breast. It is advisable that a baby is exclusively breast fed for 6months.

 

Importance of breast feeding

• Breast Milk Provides Ideal Nutrition for Babies.
• Breast Milk Contains Important Antibodies.
• Breastfeeding May Reduce Disease Risk like allergies
• Breast Milk Promotes a Healthy Weight.
• Breastfeeding May Make Children Smarter.
• Breastfeeding May Help You Lose Weight.
• Provide bond pair between a baby and child

 

Ante –natal care

This is the care provided by skilled health-care professionals to pregnant women and adolescent girls in order to ensure the best health conditions for both mother and fetus during pregnancy.

Importance

Good antenatal care includes regular screening which can detect and prevent early complications such as, infections, hypertension and pregnancy diabetes; which can dramatically affect the fetus.

 

 

Services provided at ante-natal care

1. Provides women and their families with appropriate information and advice for a healthy pregnancy, safe childbirth, and postnatal recovery, including careof the newborn, promotion of early, exclusive breastfeeding, and assistance with deciding on future pregnancies in order to improve pregnancy outcomes.
2. Ultrasound scan
3. Provide deworming tablets
4. Checking pressure of pregnant mother
5. Urinalysis – checking for infections in urine
6. Checking fetal heart rate

Treatment of diseases

Family care to pregnant women.

• Provide a balance diet
• Show them love
• Give them enough rest
• Give appropriate dressing

 

ADOLESCENCE

What is adolescence?

Adolescence is the period between childhood and adulthood, a period within which both boys and girls become sexually mature and are able to reproduce. This period of adolescence is also known as puberty.

Changes that take place during adolescence

The changes that occur during adoles­cence can be either physical or emotional. Below are the physical changes that occur in boys and in girls.

  

Physical changes in girls

1. The breasts enlarge
2. Hips broaden
3. There is rapid growth
4. Hair grows in the groin and armpit region
5. The oil glands of the skin produce more oil and pimples may be seen on the face
6. Eggs are formed and released from the ovary in a process called

The egg may be fertilized leading to birth of a child. If the egg is not fertilized, the uterus sheds blood in what is known as the monthly periods or menstruation.

Physical changes in boys

1. Shoulders broaden
2. They have hair (beards) on the chin
3. The voice breaks
4. The rate of growth increases
5. There is growth of hair in the groin, armpits, chest and legs
6. They start to produce sperms in the testis, which are able to fertilize eggs leading to birth
7. The oil glands of the skin produce more oil and pimples may be seen on the face.

Disadvantages of becoming a parent at an early age.

• Drop out of school
• Failure to look after one’s children.
• The child may not be ready for marriage
• Teenage pregnancy may lead to fistula
• May lead to obstructed delivery.

 

Infertility

Infertility means not being able to get pregnant after one year of trying (or six months if a woman is 35 or older). Women who can get pregnant but are unable to stay pregnant may also be infertile.

 

Infertility in men is most often caused by:

 

1. A problem called varicocele (VAIR-ih-koh-seel). This happens when the veins on a man’s testicle(s) are too large. This heats the testicles. The heat can affect the number or shape of the sperm.
2. Other factors that cause a man to make too few sperm or none at all.
3. Movement of the sperm. This may be caused by the shape of the sperm. Sometimes injuries or other damage to the reproductive system block the sperm.
4. Sometimes a man is born with the problems that affect his sperm. Other times problems start later in life due to illness or injury. For example, cystic fibrosis often causes infertility in men
5. importance

 

Infertility in women is most often caused by:

1. Failure of ovulation

 

1. Damage to fallopian tubes such blocked fallopian tubes due to pelvic inflammatory disease, endometriosis, or surgery for an ectopic pregnancy

 

1. Damage to uterus such as uterine fibroids, which are non-cancerous clumps of tissue and muscle on the walls of the uterus.
2. Problems with the cervix, some women have a condition that prevents sperm from passing through the cervical canal
3. Age can contribute to infertility because as a woman ages, her fertility naturally tends to decrease.
4. Some women have polyps and fibroids that interfere implantation

Incorrect frequency and or timing of intercourse may make conception unlikely and couples may need to be counselled on the most appropriate time when ovulation is likely.

Family planning

The method whereby a couple chooses when to have children according to their income.

Advantages or importance of family planning

Prevents unwanted pregnancy

Leads to child spacing.

Allows the uterus to repair before the next pregnancy

 

Methods of contraception include:

• long-acting reversible contraception, such as the implant or intra uterine device (IUD)
• Hormonal contraception, such the pill or the Depo Provera injection.
• Barrier methods, such as condoms.
• Emergency contraception.
• Fertility awareness.
• Permanent contraception, such as vasectomy and tubal ligation.

 

Disadvantages of big families

(a) Large family size leads to scarcity of basic services like food, health, clothing and shelter.

(b) Lack of basic amenity like food leads to malnutrition which affects the health of children.

For revision questions download PDF below

Reproduction upper primary

Sponsored by The Science Foundation College +256 753 802709

Compiled by Dr. BbosaScience +256 778 633 682