Transcript - Your Best Wellness Tips

REPRODUCTION
10 CMH
Integrated Science
What is Reproduction?

The process by which new
organisms are generated.

There are two means of reproducing: asexual and
sexual reproduction.
Asexual Reproduction
 Does not involve the fusion of sex cells.
Parts of the parents form the offspring.
 Only one parent is needed.
Advantages
 Reproduce in large amount very
quickly.
 No need to search for a mate.
 Desirable characteristics can be
artificially bred into a population.

Farmers can now produce high-yield or disease –
resistant crops and livestock.
Disadvantages
 All the offspring are clones.

A poor quality parent will produce poor quality
offspring.

There is a lack of variation.
Sexual Reproduction
 Requires a male and a female.
 Male sex cell is called sperm and female the
egg(ovum).
 The two sex cells must join during fertilization.

Fusion of the gametes forms a single
cell called zygote.
Advantages of Sexual Reproduction
 Offspring are different both from each other and
to parents.

It produces variation in the offspring so
organisms gradually change or evolve.

There will always be a proportion
of organisms which can survive
unfavourable changes, so the
population is less likely to die out.
Disadvantages of Sexual Reproduction
 Mating partners must be available.

Fewer offspring are produced.
Movement of Sperm

During ejaculation, the sperm cells leave the epididymis
and flow through the vas deferens towards the penis.

The epididymis passes through the prostate gland and
seminal vesicles.

These structures bathe the sperm
cells with seminal fluids.

This mixer is called semen.
Structure of the Sperm
 The head is where the nucleus is.
 Tip of head contains a small sac called the
acrosome.
 Acrosome contains hydrolytic
enzymes.
 This is responsible for burrowing
through egg during fertilization.
 The neck area contains lots of
mitochondria.

Mitochondria generate energy.

The tail allows sperm cell to swim
through vagina and uterus.
Female Reproductive System
•Make the female gametes (egg cells)
•Receive
the sperm cells from male for fertilization.
•Maintain
an environment suitable the implantation of an
embryo.
•Provide
everything needed for the development of foetus.
•Deliver
baby to the outside world.
Female Reproductive System
 the
parts of the female reproductive system are
located in the pelvic region.
Vagina
 the entrance to the inner parts
 It is a muscular channel
 Receives penis at copulation
 Passage for baby at birth
The ovary
 Where
egg cells are produce.
 Site for oestrogen production.
 About ten thousands ova are present at birth.
 Only about 400 will develop fully (1 per month/14 to 45).
 Ova
develop inside follicles.
 Mature follicle is called graafian
follicle.
 When ripe it moves to ovary’s
surface.
 Egg
live for 3-4 days after ovulation
 It move along the oviduct by the beating of cilia.
Fertilizations
 The fusion of a sperm with an ovum.
 This occurs in the oviduct.
 About 3-5 cm3 of semen expelled from penis
 Contains
between 180 and 500 million
spermatozoa.
 Spermatozoa
 Sperm
swim up the oviduct.
enter head first, losing its tail as it does so.
 The
acrosome produce enzymes which help penetrate
the ovum.
 Only
one sperm can enter
the ovum.
 The resulting zygote has
contents of both male and
female nuclei ,which is fuse.
Implantation
 The
corpus luteum continues to produce progesterone.
 Progesterone prepares the uterus wall for the zygote.
 Uterus wall thickens.
 Zygote now divides into a ball of cells and stick into the
wall of the uterus.
Pregnancy
 The
thick wall of uterus is called the placenta
 It has rich blood supply stimulated by oestrogen and
progesterone.
 The
placenta is formed mainly from the embryo
and partly from the mother’s tissue.
 There
is no joining of the maternal and fetal red
blood cells.
A
thin layer of cells
acts as a barrier,
separating maternal
and fetal red blood
cells.
 Nicotine, alcohol
and other drugs and pathogens
do pass across the placenta to cause harm.
 Nutrients
and oxygen diffuse from maternal
blood capillaries to embryo.
 Carbon
dioxide and other waste materials diffuse
from the embryo to mother.
Umbilical cord
 Carries nutrients in veins to fetus and waste in
artery from fetus.
 The
cord runs from the embryo’s abdomen to
the placenta.
Amnion
 A sac of water.
 Membrane enclosing fluid, protecting fetus from
shock and allowing movement.
 The water distributes pressure evenly around
fetus.
N.B
A fetus moves its limbs from the age of about 16
weeks onwards.
After two months, the human form of the fetus is
recognizable.
At three months the sex can be seen.
Birth follows about nine months after fertilization
(37-40) wks.
The birth Process
Stage one
 The uterus muscles start to contract to start the labour
process.
 Baby stimulates the release of
the hormone oxytocin.
 Rhythmic contractions of the
uterus cause amnion to break.
 The fluid will now pass out.
Stage two
 Increasing contractions of the uterine muscle
push the baby through the cervix and then the
vagina.
Stage 3

Finally the baby is expelled head first

The mother bending forward

Holding her breath, aids this, to push the diaphragm on
top of the uterus.
After Birth
 The umbilical cord is cut and tied so that the
remains form the navel on the abdomen.

The placenta and membranes are shed from the
mother and are called the afterbirth.
Medical Abortion
Surgery

The lining of the uterus, including the
embryo is removed by suction

The uterus lining can also be scrap away
Drugs
 Drags can be use, which kill the
embryo and make her go into
labour.

She gives birth to the dead embryo.
Disadvantages of abortion

High risk of blood loss during the
surgical procedure.

Surgery can cause diversion of blood
flow to different organs.
Disadvantages of abortion

Increases risk of developing depression,
guilty feeling and anxiety.

Medical instruments may cause uterus
injury and infection.
Reasons for abortion
 The woman is not healthy enough to
carry a healthy baby and give birth to it.

Woman feels that she will not be able to
look after and support the baby.
Woman may not want her family or
friend to know that she has become
pregnant.
 Getting pregnant was an accident.

What is cancer?

This is the uncontrolled growth of the
cells in the human body and the ability of
these cells to migrate from the original
site and spread to distant sites.
Disorders of the female reproductive
system
Ovarian cancer
 Begins in the ovaries.
 More common in women over 50.
 Very hard to detect
early.
 There is no or just mild
symptoms until it is in
an advanced stage and
difficult to treat.
Signs and symptoms

Heavy feeling in pelvis.

Pain in lower abdomen.

Weight gain or loss.

Abnormal periods.

Unexplained back pain that gets worse.

Gas, vomiting or loss of appetite.
Treatment
Chemotherapy

This is when medicines are used to
destroy cancer cells and can cause side-
effects, including tiredness and feeling
sick or vomiting.
Radiotherapy
 This is when radiation is used to destroy
cancer cells.
Cervical cancer

Can be detected at an early stage by
cervical smears.
Causes
Should be taken by those most at risk,
such as:
 Women who have
sex with many partners.



Start having sex at a
early age.
Have been infected with sexually
transmitted disease.

Cause by a virus (human papilloma
virus, HPV) that is sexually transmitted.

Using birth control pills for 5 or more
years.
Symptoms
 irregular vaginal bleeding.
 vaginal discharge with an unpleasant odor.
 watery vaginal discharge.
 vaginal discharge tinged with blood.
 pelvic or back pain.
What is breast cancer?
 Breast cancer is a malignant tumor that starts in
the cells of the breast.
 A malignant tumor is a group of cancer cells that
can grow into (invade) surrounding tissues or
spread to distant areas of the body.
Symptoms
 A lump in the breast or underarm that persists
after your menstrual cycle.
 Swelling in the armpit
 Pain or tenderness in the breast.

A noticeable flattening or indentation on the
breast.

Any change in the size, contour, texture, or
temperature of the breast.

Unusual discharge from the nipple that may be
clear, bloody, or another color
Prostate Cancer
 When cancerous cells begins to develop in the
prostate.
 Usually occurs in older men.

Diet is a contributing factor in reducing the risk
of prostate cancer.
What are the symptoms of prostate cancer?
 The patient urinates more often
 The patient gets up at night more often to urinate
 He may find it hard to start urinating
 He may find it hard to keep urinating once he has
started
 There may be blood in the urine
 Urination might be painful
 Ejaculation may be painful
 Achieving or maintaining an erection may be
difficult
Menstruation
 At puberty (12 to 13) a girl begins what is called
her menstrual cycle.

About every 28 days, blood and other particles
from the uterus lining are expelled out.

Usually over over 4 to 5 days.
Ovulation
 A woman born with all of the sex cells she will
ever make.

The eggs are in an immature state.

A follicle in one of the ovaries begins to develop
or mature.

After menstruation the follicle mature and
releases oestrogen.

Oestrogen causes the
uterus lining to become
thicker, containing a lot
of blood and blood
vessels.

This is called endometrium.

Its purpose is to provide an environment that will
sustain the growing fetus.
This continues for about
2 weeks.
 The hormone luteinising
(LH), then triggers the
release of a mature egg
from the follicle.

Breast Feeding
 During pregnancy the mammary glands enlarge.

It get prepared to secrete milk.

Shortly after birth the baby will
suck at the nipples.