Uss module 6 chpt 10 Breathing

Module 6:Wonders of My Body (II)Chapter 10 Breathing

© Copyright Star Publishing Pte Ltd

Chapter 10 Breathing

10.1 Why do we need to breathe?

10.2 How does the respiratory system work?

10.3 How does smoking affect our respiratory system?


ObjectivesExplain why breathing is important to us

(brings oxygen into the body and gets rid of carbon dioxide)

Explain the differences in composition of inhaled and exhaled air

Infer that exhaled air has a higher concentration of carbon dioxide than inhaled air, using the limewater test

Infer that exhaled air has a higher concentration of water vapour than inhaled air, using the cobalt chloride paper test


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.


What is respiration? The air that we breathe in contains oxygen which

enters the blood and is transported to body cells.

Oxygen combines with digested food molecules in body cells to release the energy stored in them.

This process is called respiration.

Carbon dioxide is produced during respiration andremoved when we breathe out.


Differences in inhaled and exhaled airThe air we breathe in is called inhaled air.

The air we breathe out is called exhaled air.


How do we test for the presence of carbon dioxide in exhaled air?

We can test the presence of carbon dioxide in exhaled air by bubbling it into limewater.

Limewater turns cloudy in the presence of carbon dioxide.


How do we test for the presence of water vapour in exhaled air?

To test for the presence of water vapour in exhaled air, we can use cobalt chloride paper.

If water vapour is present, dry cobalt chloride paper will turn from blue to pink.


Why does exhaled air contain morewater vapour than inhaled air?

The air sacs in our lungs contain a thin layer of moisture which will evaporate and be exhaled as we breathe out.


Activity Book LinkActivity 10.1Comparing the Characteristics of Inhaledand Exhaled Air


10.1 Why do we need to breathe? 10.2 How does the respiratory

system work? 10.3 How does smoking affect our

respiratory system?


Objectives Identify parts of the respiratory

system (windpipe, bronchi, lungs, ribcage, diaphragm) on a diagram and state their functions

Show an awareness of how choking can lead to death


Parts of Our Respiratory SystemThe respiratory system of the

human body consists of

(a) a windpipe(b) a pair of lungs(c) a diaphragm


Parts of the human respiratory system


Functions of the Parts of theRespiratory System

Nose

Air enters the respiratory system through the nose or the mouth.

The nose contains nasal hair that traps dust and dirt from inhaled air. © Copyright Star Publishing

Pte Ltd


Windpipe

The windpipe is a hollow tube that brings the air from the nose to the bronchi.

Mucus in the windpipe prevents dirt and dust in the inhaled air from entering the lungs.

Cells in the windpipe secrete mucus.Mucus helps to trap dust and bacteria.



Windpipe

Hair-like structures found in the windpipe help to sweep the mucus-containing dust and harmful substances out of the windpipe.

The mucus, with its trapped dust and harmful substances, is removed by spitting or by swallowing it into the stomach.


Functions of the Parts of theRespiratory SystemWindpipe

Hair-like structures found in the windpipe help to sweep the mucus-containing dust and harmful substances out of the windpipe.

The mucus, with its trapped dust and harmful substances, is removed by spitting or by swallowing it into the stomach.


inner lining of windpipe


Bronchi (singular: bronchus)

The windpipe branches into two tubes called the bronchi.

The bronchi will carry air from the windpipe to the air sacs in the lungs.



Lungs

The lungs contain many air sacs (alveoli) surrounded by blood vessels.

Oxygen in the inhaled air moves from the lungs into the bloodstream.

Carbon dioxide moves from the bloodstream into the lungs to be exhaled.


Gaseous exchange in the air sac



Ribcage

The ribcage protects the lungs and the heart.

It helps in breathing by assisting the expansion and contraction of the lungs.



Diaphragm

The diaphragm is a muscular sheet below the lungs.

It contracts to allow air to enter the lungs.

It relaxes to allow air to leave the lungs


What happens when we breathe in ( inhale )?


Activity Book LinkActivity 10.2The Respiratory System

What happens when we breathe out ( exhale )?


Activity Book LinkActivity 10.3That’s How I Breathe

ChokingThe throat is the common

passage for food and air.

It leads to two openings at the back of the mouth.

One is the gullet and the other is the windpipe.


ChokingWhen we

breathe in, air enters our windpipe.

When we swallow, food and water enter the gullet.


ChokingChoking occurs when

food or water enters the windpipe.

This prevents air from entering and leaving the lungs.

If the obstruction is not removed, the victim may choke to death.



10.1 Why do we need to breathe? 10.2 How does the respiratory

system work? 10.3 How does smoking affect

our respiratory system?


ObjectivesDiscuss the effects of

smoking/passive smoking on the respiratory system (bronchitis and lung cancer)


What are the main components of cigarette smoke?The main components of

cigarette smoke include:

(a) Nicotine(b) Tar(c) Carbon monoxide(d) Irritants


Harmful effects of cigarette smoke


Harmful effects of cigarette smoke


What is passive smoking?Even if you do not smoke, your

heart and lungs can still be damaged when you breathe in smoke from the cigarettes of smokers around you.

This is called passive smoking.


Smoking DiseasesSmoking can cause heart disease.

(a) The harmful chemicals in cigarette smoke can damage blood vessels.

(b) It also increases the formation of blood clots and fatty deposits called plaque that block the blood vessels.


Cross-section of arteries of a healthy person(left) and a smoker (right)


Smoking causes high blood pressure and heart disease

When blood vessels are blocked, blood stops flowing and oxygen cannot be transported to the heart muscles.

This results in high blood pressure and heart disease.


Fatty deposits block the flow of blood in the artery


Smoking can cause lung cancerTar in cigarette smoke is

poisonous to our cells.

It can cause cells to grow abnormally, resulting in lung cancer.


Smoking can cause bronchitisBronchitis refers to the

inflammation of the airways (e.g. windpipe, bronchi).

Our windpipe and bronchi has tiny hairs (cilia) to sweep dust and harmful substances out of it so that they do not enter our lungs.


Smoking can cause bronchitisTar in cigarettes causes these

hairs to stick together.

Harmful substances such as bacteria and dust can easily enter the lungs and cause damage to the airways.


A healthy person’s bronchus (left) and asmoker’s inflamed bronchus (right)


Smoking can cause bronchitisWhen this happens, a smoker

develops bronchitis.

This causes the smoker to cough badly and have difficulty breathing.


Activity Book LinkActivity 10.4The Harmful Effects of Cigarette Smoke

Symptoms of bronchitis


Passive SmokingPeople who inhale cigarette

smoke from smokers around them may develop lung cancer and other illnesses related to smoking.

This is because they breathe in cigarette smoke containing harmful substances that damage the lungs.



Education

Uss module 6 chpt 10 Breathing