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The Respiratory System

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BTEC Sport

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Lear

ning

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Learning objectives

The structures of the respiratory system and their functions

The mechanisms of breathing

How gases are exchanged during breathing

The composition of inhaled and exhaled air

What we will learn in this presentation:

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The respiratory system

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The respiratory system

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The nasal passages and lungs

Air is drawn into the body via the nose or mouth. There are advantages to breathing through your nose:

Air then travels through the larynx, trachea (windpipe), bronchi (one bronchus to each lung) and bronchioles to the alveoli, where oxygen passes into the bloodstream.

the air is warmed so that it is closer to body temperaturetiny hairs and mucus in the nose filter the air, preventing larger dust and pollen particles reaching the alveolimucus moistens the air, making it easier for the alveoli to absorb.

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When you breathe in:

intercostal muscles between the ribs contract, pulling the chest walls up and outthe diaphragm muscle below the lungs contracts and flattens, increasing the size of the chestthe lungs increase in size, so the pressure inside them falls. This causes air to rush in through the nose or mouth.

Mechanisms of breathing – inspiration

Diaphragm contracts and moves down

Intercostal muscles pull ribs

up and out

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Mechanisms of breathing – inspiration

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Mechanisms of breathing – expiration

When you breathe out:

Intercostal muscles between the ribs relax so that the chest walls move in and down.The diaphragm muscle below the lungs relaxes and bulges up, reducing the size of the chest. The lungs decrease in size, so the pressure inside increases and air is pushed up the trachea and out through the nose or mouth.

Diaphragm relaxes and bulges up

Ribs move in and down

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Mechanisms of breathing – expiration

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Gas exchange at the alveoli

The alveoli are bunches of tiny air sacks inside the lungs.

Each individual sack is called an alveolus.

When you breathe in, they fill with air.

The alveoli are covered in tiny capillaries (blood vessels).Gases can pass through the thin walls of each alveolus and capillary, and into the blood stream. Gases can also pass from the blood stream, into the alveolus.

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Gas exchange at the alveoli

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Composition of inhaled and exhaled air

Gas Amount in inhaled air

Amount in exhaled air

Oxygen

Carbon dioxide

Nitrogen

Water vapour

17%

3%

79%

Large amount

21%

Very small amount

79%

Small amount

What are the main differences between inhaled and exhaled air?

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Can you remember all these keywords?

Larynx

Trachea

Bronchus / Bronchi

Bronchioles

Alveoli

Diaphragm

Intercostal muscles

How The Cardiovascular & Respiratory Systems work together in the body

http://www.youtube.com/watch?v=EtPA_Y9_p5I

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Exam-style questions

1. Log on to www.stjosephsnewrybtecsport.weebly.com, download and complete ‘The Respiratory System Homework’.

• Can be completed within the MS Word document and printed, or

• Can be printed and completed in pen.