Breathing - Ambition, Respect, Care and...

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Breathing


Aerobic respiration

Glucose is an important

substance that contains

stored chemical energy.

When glucose reacts

with oxygen, energy is

released. This is called

aerobic respiration.

All living organisms need a constant supply of energy. This

is because life processes, such as growing, use energy.

Most living things, including some micro-organisms, therefore

need a constant supply of oxygen to gain energy from food.


The exchange of gases

Aerobic respiration is the process of releasing energy

through the oxidation of glucose molecules:

Oxygen is breathed

into the lungs and is

transported in blood.

oxygencarbon

dioxideglucose + + water ( energy)+

Carbon dioxide and water are formed

as waste products in cells. They can

be excreted when we breathe out.

The respiratory system carries out gas exchange. It is made

up of the lungs, intercostal muscles, diaphragm and airways.


Parts of the respiratory system


Label the respiratory system


Why do we breathe?

Fish do this by keeping

a continuous stream of

oxygenated water

moving over their gills.

Animals need to ensure that a constant supply of oxygen is

able to diffuse into the blood and that any waste carbon

dioxide can diffuse out quickly.

In mammals and birds,

the process of ventilation

allows the stream of gases

to move to and from the

site of gas exchange.


Model of ventilation


The mechanism of ventilation


Explain the terms


The bell jar and the lung

In humans, the volume and pressure can be changed by the

movement of both the diaphragm and the ribcage.

lung

pleural membranes

The bell jar model of the lungs is limited because the

rubber sheet (representing the diaphragm) is the only way

to alter the volume and pressure of the chest cavity.

This occurs because of

the pleural fluid. This

fluid adheres the outer

walls of the lungs to the

chest cavity by water

cohesion, so that the

lungs expand with the

chest while breathing.

chest

cavity


Gases moving in and out of the blood


Spirometry


Spirometric terms


Exercise, respiration and ventilation

Energy is used up by the active

muscles during exercise.

The rate of respiration must

therefore increase to supply

enough energy to the muscles.

This means that more oxygen

must be breathed in and more

carbon dioxide breathed out.

the arteries supplying the muscles dilate?

During exercise, why does:

the heart rate increase

the rate and depth of breathing increase


Running and breathing rates


Carbon dioxide

One way the brain deals with

a build up of carbon dioxide

during exercise is by increasing

the rate of breathing.

The brain can detect the level of carbon dioxide in cells.

This increases the rate of gas

exchange and the removal of

carbon dioxide from the lungs.

When the level of carbon dioxide

increases during exercise, the brain

must coordinate ways to prevent the

levels reaching toxic levels.


Keeping the airways clear

The walls of the trachea and bronchus contain goblet cells,

which secrete mucus made of mucin. This traps micro-

organisms and debris, helping to keep the airways clear.

The walls also contain

ciliated epithelial cells,

which are covered on

one surface with cilia.

These beat regularly to

move micro-organisms

and dust particles along

with the mucus.

The epithelial cells contain many mitochondria to provide

energy for the beating cilia.


Why are respiratory diseases common?

Do you know anyone who has asthma?

Respiratory diseases are very common.

One reason for this is because the lungs are essentially a ‘dead end’. Any particles that are not removed by the mucus and cilia remain in the alveoli and damage the thin walls of these delicate structures.

This is evident from the lungs of a

smoker, which turn black from the

accumulation of trapped particles.


Diseases have different causes


Lung cancer and smoking


Replacing body parts

Doctors and scientists have developed ways to replace body

parts when they stop functioning due to disease or trauma.

Sometimes, replacement

body parts can be

transplanted from a donor.

Lungs, hearts, kidneys,

livers and corneas are

examples of biological

replacement parts.

Mechanical replacement parts are also used. These might

be put inside the body, for example heart pacemakers.

Larger mechanical parts, such as lung machines and

artificial ventilators, must be used outside the body.


External artificial aids

Artificial ventilators, and machines to maintain heart and kidney function, are used outside the body.

This can limit patient mobility:

Some are used intermittently,

such as dialysis machines.

Patients are able to move

around normally between

treatment sessions.

Others must be continuously

attached to the patient. For

example, artificial ventilators are

needed until patients regain the

ability to breathe for themselves.


Asthma

Asthma is a chronic condition in which the airways narrow

and become inflamed, limiting airflow. It can be triggered by

allergens, dust, exercise, stress, infections etc.

Asthma causes difficulty

breathing, wheezing and

chest tightness, and can be

mild or life-threatening.

Inhalers are used treat asthma.

They contain bronchodilators,

such as salbutamol, to reduce

the narrowing of the airways.

Corticosteroids can also be

used to stop an asthma attack.


Asthma attack


Events during an asthma attack


Glossary


Multiple-choice quiz

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