uss module 6 chpt 12 staying healthy

Module 6:Wonders of My Body (II)Chapter 12 Staying Healthy

© Copyright Star Publishing Pte Ltd

Chapter 12 Staying Healthy

12.1 How do unhealthy habits of a modern lifestyle affect our health?

12.2 How can we maintain a healthy weight?

12.3 What are some causes of diseases?

12.4 How can malfunctioning organs be managed?


ObjectivesExamples of how modern lifestyle

can cause harm to our health (e.g. eating convenience food, prolonged computer use and listening to loud music)

State the importance of regular exercise, sufficient rest, and eating regular, balanced meals in maintaining good physical and mental health


Unhealthy habits of a modern lifestyleMany conveniences of the modern lifestyle such as

computers and fast food have made our life more comfortable and convenient.

However, they can also be harmful to our physical and mental health.

Some examples of unhealthy modern lifestyle habits are:

(a) Eating convenience food(b) Prolonged use of a computer without a break(c) Prolonged listening to loud music


Eating Convenience FoodConvenience food is

food that requires little preparation.

Some examples of convenience food are fast food such as fries and burgers, packaged food such as instant noodles, and preserved food.


convenience food such asinstant noodles is high in salt and saturated fats. Eating food like this can

lead to high blood pressure and increase the

risk of heart disease.

Convenience food Convenience food is usually factory-processed.

They are treated with chemicals or preservatives so that they can be kept for longer periods of time.

Most convenience food contains large amounts of saturated fats, salt and sugar with low nutritional value.

Taking such food regularly may result in health problems such as high blood pressure, diabetes and kidney problems


Prolonged Use of Computers Using the computer for long periods of time and the

lack of physical activity reduces our fitness level and causes many diseases that are bad for our health:

(a) The lack of physical activity increases the risk of developing obesity, heart disease and diabetes.

(b) Staring at the computer for long periods of time can damage our eyesight.

(c) Sitting for too long can also cause pain to our wrists, arms, shoulders and back.


Listening to Loud MusicThe vibrations of the noise from

loud music may affect the ear drum’s function and our ability to hear clearly and properly.

Long term prolonged listening may even cause deafness.


Ways to Stay Healthy


ObjectivesTo infer if an individual’s weight is

in the healthy range by calculating his/her BMI, and,

To describe some risks associated with over dieting and over exercising in an attempt to lose weight.


Monitoring Our Body WeightIn order to attain and maintain

the desired body weight, we can make use of the Body Mass Index (or BMI).

The BMI is defined as the person’s body mass divided by the square of the person’s height.


Body Mass Index (BMI)


BMI and the health risks


Activity Book LinkActivity 12.2Calculating BMI

What is breathing?Breathing is the physical process of

taking in air and removing it from our body.

We need to breathe to take in oxygen and remove carbon dioxide.


Issues on Weight ManagementTo maintain a healthy weight, we

should have a balanced diet that consists of the right amounts of nutrients.

We also need to ensure that there is an energy balance in our diet. The amount of energy we take in from our food should equal the amount of energy our body needs.


A balanced diet helps keep our weight healthy


If our diet contains less energy than the energy our bodies need, we will tend to be underweight.


If our diet contains more energy than the energy that our bodies need, the excess energy will be stored as fats, which will cause us to gain weight.


OvereatingWhen a person overeats, he or

she is taking in more energy than what the body needs.

The excess energy will be stored as fats. This causes weight gain. If a person gains too much weight, he or she will become overweight or obese.


Obesity The extra weight and fats in an overweight or obese

body can affect health in the following ways:

(a) The extra weight and fats put more burden on the heart. The heart needs to pump harder to push blood around the body.

(b) The fats may deposit in the arteries, restricting blood flow. This may result in heart disease.

(c) The joints at the knees need to support the heavier weight of the body. This may cause injury to the knee joints.

(d) It can lead to other health problems such as diabetes. © Copyright Star Publishing

Pte Ltd

Over-exercising and Over-dietingIn order to achieve the “perfect body”, some

people may diet or exercise too much.

Over-exercising can cause our muscles and joints to overwork. This may cause injury to our muscles and joints.

A person who over-diets may deprive the body of important nutrients. This causes the person to suffer from malnutrition. Over time, this may even cause damage to the internal organs.


Health risks associated with over-exercising and over-dieting

(a) lack of energy(b) hair loss(c) infertility(d) heart failure(e) osteoporosis(f) low blood pressure(g) low tolerance to cold(h) death


Activity Book LinkActivity 12.3Over-dieting and over-exercisingActivity 12.4Monitoring Our Body Weight

ObjectivesDiseases can be caused by viruses and

bacteriaTo investigate the effects of anti-

microbial agents on the population growth of micro-organisms

Vaccination gives protection from certain viruses

The importance of completing a prescribed course of antibiotics

Diseases can have hereditary causes (passed through parents’ genes)


Unhealthy habits of a modern lifestyleUnhealthy habits of a modern

lifestyle can lead to diseases that threaten our health.

Diseases can also be caused by:

- bacterial and viral infections- inheritance (passed down from parents to children)


Diseases Caused by Viruses and BacteriaViruses and bacteria are two

examples of a group of very tiny living things called micro-organisms.

They are too small to be seen by the naked human eye.

We will need a high-powered microscope to help us study their structures.


Electron microscopic images of Viruses and Bacteria

Electron microscopic image of E.coli - diarrhoea-causing bacteria

Electron microscopic image of coronavirus – influenza-causing virus© Copyright Star Publishing Pte Ltd

Viruses and bacteria Many viruses and bacteria do not

cause much harm to us but there are also others which can cause severe illnesses and diseases, some of which are still incurable to this day.


Some examples of diseasescaused by bacteria and viruses


Staying Free from Diseases Caused by Micro-organismsWe can protect our bodies from harmful

microorganisms by using anti-microbial agents.

Anti-microbial agents are substances that kill micro-organisms or prevent their growth.

There are three types of anti-microbial agents:

(a) Antiseptics(b) Disinfectants(c) Antibiotics


AntisepticsAntiseptics are chemicals that

are applied to living surfaces (our skin) to kill or prevent the growth of micro-organisms such as bacteria and fungi.


Examples of antiseptics

Antibacterial hand wash destroys and prevents the growth of bacteria on our hands

Antifungal cream destroys fungi on a person with athlete’s foot


Harmful microorganisms Our hands contain many harmful micro-

organisms that can make us sick.

These harmful microorganisms may enter our body and make us sick when we touch our nose or mouth with dirty hands.

Washing our hands with antiseptic soap and water can prevent the spread of diseases such as influenza.


DisinfectantsDisinfectants are chemicals

that are applied to non-living surfaces such as table tops and floors to kill or prevent the growth of micro-organisms.

Examples of disinfectants include bleach we use to clean toilets.


Hospitals use disinfectant to clean their floors and to sterilise medical equipment


Antibiotics Antibiotics are chemicals that are injected or

taken orally into our body to kill or prevent the growth of bacteria that has entered the body.

Antibiotics are only effective against bacteria. They cannot destroy viruses.

Doctors will normally prescribe a course of antibiotics for diseases caused by bacteria. Each type of bacteria is treated using a different type of antibiotic.

It is important for us to finish the course of antibiotics prescribed by the doctor.


Why must we finish a course of antibiotics? If we do not complete the course of

antibiotics, some bacteria may survive in our body.

The bacteria remaining in our body may multiply or even become stronger. If this happens, we may fall sick again and may need stronger antibiotics to destroy it.

If the bacteria become too strong, there may not be any antibiotics that can destroy them.


clear zones on the dish

where the bacterial colonies do not

grow. This means that the antibiotics

are effective against the

bacteria

Vaccinations

Antibiotics, antiseptics and disinfectants have no effect on viruses. So, how can we protect ourselves against diseases caused by viruses?

Vaccination can be used to prevent diseases caused by viruses such as flu and small pox.


Activity Book LinkActivity 12.5Effects of Anti-microbial Agents on the Growth of Microbial Cells

VaccinationsWe are vaccinated throughout our lives.

Examples of vaccinations include those against viruses that cause small pox, chicken pox, polio, rubella, mumps and measles.

For viral infections, doctors will normally advise patients to rest at home, drink a lot of water.


Activity Book LinkActivity 12.6Antibiotics and Vaccination

Hereditary DiseasesHereditary diseases are diseases

that can be passed down from one generation to the next.

Hereditary diseases are caused by mutations in our genes.

The mutated gene can be passed down from parents to their children. © Copyright Star Publishing

Pte Ltd

Examples of hereditary diseasesExamples of hereditary diseases

are:

(a) Sickle cell anaemia(b) Thalassemia(c) Colour-blindness


Sickle cell anaemiaIn sickle cell anaemia, the gene

controlling haemoglobin (the red pigment) in red blood cells may be defective at the time of the birth of a child.

This results in the formation of red blood cells that are sickle-shaped.

Sickle-shaped red blood cells cannot carry as much oxygen as normal red blood cells.


The picture shows crescent-shaped red bloodcells and some normal red blood cells of sickle cell anaemia. As there is less haemoglobin in the crescent shaped cells, the sickle–shaped cells cannot carry enough oxygen for the body.


Sickle cell anaemiaSickle-shaped red blood cells cannot

flow smoothly through blood vessels.

They may cause blockages in blood vessels.

This is a serious problem as sufferers of sickle-cell anaemia will not live long as their bodies cannot obtain sufficient oxygen.


Red blood cells showing sickleshapes due to sickle cell anaemia


ThalassemiaThalassemia is another hereditary

disease that can be passed down from parents to their young.

It also involves a mutation in the gene that makes haemoglobin.

The defective gene makes an abnormal form of haemoglobin. This causes red blood cells to be destroyed.


ThalassemiaThalassemia sufferers are therefore

anaemic (that is they do not have enough blood) as a result of low level of haemoglobin and a low count of red blood cells.

In mild forms of thalassemia, no treatment is necessary but in severe forms, patients may need blood transfusions to replace all of their blood very frequently.


Thalassemia

Red blood cells destroyed in thalassemia

Thalassemia patients require regular blood transfusions© Copyright Star Publishing Pte Ltd

Colour BlindnessColour blindness is probably one of the

most common hereditary diseases among otherwise physically healthy individuals.

Colour vision in the normal eye is controlled by a gene.

When this gene is missing or damaged, the special cells in our eyes responsible for colour vision are missing, thus the person will be colour blind.


Colour BlindnessThe most common

type is the red-green colour blindness. People who are blind to red-green colours will have difficulties differentiating between these two colours.


traffic lights that a normal person sees (left) and a colour

blindperson sees (right)

ObjectivesThe use and limitations of

technology in replacing malfunctioning organs, e.g. organ transplant and kidney dialysis


Malfunctioning OrgansDiseases can cause organs to fail.

Technology can play a part in replacing malfunctioned organs by:

(a) replacing the organ(b) replacing the function of the malfunctioned organ with artificial parts or machines (such as through the use of the pace-maker by patients with heart problems)


A pacemaker is a device thathelps maintain a regular heart beat


Kidney FailureThe kidneys are important organs in our

body. They collect waste materials from our body cells and remove them in a solution called urine.

The kidneys may fail due to a variety of reasons, from hereditary, to dietary and accidental causes.

In this case, the waste in the blood cannot be removed and may harm the other organs.


Technology and kidney failureTechnology can help kidney

patients in the following ways:

(a) kidney transplant to replace the failed kidney(b) kidney dialysis to replace the function of the failed kidney


Kidney DialysisIn kidney dialysis, the patient is connected to a

machine, which acts as an artificial kidney.


a patient undergoing kidney dialysis

Kidney DialysisThe machine removes blood from the patient

and passes the blood through a tubing which has tiny pores in it.

These pores allow waste materials to pass through them.

After the waste materials are filtered out of the blood, the purified blood is returned to the body.

A dialysis session may last a few hours, depending on the condition of the patient’s body and health.


A dialysis machine returnspurified blood back to the body


Kidney TransplantA kidney transplant involves replacing the

failed kidney with a working one.

The transplanted kidney will replace the failed kidney. Usually urine will be produced almost immediately through the new kidney after the transplant.

The donor and recipient (the patient) have to be carefully matched to ensure that once the new kidney is transplanted, there is low risk of organ rejection by the patient’s body.


Kidney transplantUsually, the donor is a close family

member or relative, or the kidney may come from an unknown donor who had just died.

After the transplant, the patient has to be closely monitored and be on medication to lower the risks of organ rejection and infection.


After a kidney transplant


Uses and Limitations of TechnologyTechnology is useful in helping

patients suffering from organ failure. However, they have some limitations too.


Uses and Limitations of Technology


uss module 6 chpt 12 staying healthy

Education