Respiratory System

2 levels

Internal Respiration – Cellular Respiration

• the exchange of gases between the blood and the cells of the body.

• O2 is required to break down glucose, release CO2 , and produces large amounts of ATP. 

• External Respiration • exchange of gases between the atmosphere

and the blood  • involves the respiratory system

Respiratory Structures and passage of air

http://videos.howstuffworks.com/hsw/16919-the-human-respiratory-system-video.htm

Passage of air

http://videos.howstuffworks.com/hsw/23914-lungs-the-structure-and-characteristics-of-lungs-video.htm

Regulation of Breathing

• involuntary action under control of the medulla oblongata.

Factors affecting Breathing• CO2 chemically combines with water in the blood to form

carbonic acid – H2CO3

• Carbonic acid releases a H+ ion resulting in bicarbonate – HCO3

-

– Lowers pH levels

– maintains proper acidic levels in the blood

• The medulla detects the changes in the pH levels• Response – increase breathing depth and rate

• This process reverses in the lungs; CO2 exhaled

The mechanism of breathing• Ventilation – mechanism of breathing in

and out

• Breathing: – Inhalation (inspiration)– air pulled into lungs– Exhalation ( expiration) – air pushed out lungs

• produced by movements of the diaphragm and the intercostal muscles

http://videos.howstuffworks.com/hsw/16925-the-respiratory-system-breathing-video.htm

Inhalation

• Diaphragm is stilumated to contract(moves downward)

• Thoracic cavity (chest cavity) enlarges; – volume increases

– Intercostal muscles (between the ribs) also contract

• Pressure in the alveoli decreases

• Air is pulled into the airways

Exhalation

• Diaphragm relaxes (moves upward)

• Volume of the thoracic cavity decreases

– Ribs and sternum moves downward

• Pressure in the alveoli increases

• Air is forced out of the lungshttp://videos.howstuffworks.com/discovery-health/14422-human-atlas-how-lungs-function-video.htm

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Respiration (Human): Processes Involved

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Mechanism of

Breathing

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Ventilation (Human)

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Ventilation

Smoking

• The tar in cigarettes causes paralysis of the cilia

• Result: the air is not filtered

• Tar builds up in lungs

Affects of Smoking Healthy Lung Smokers Lung

Emphysema

• A disease in which the alveoli of the lungs are damaged.

• This leads to a decrease in the surface area available for gas exchange

Asthma• Involves narrowing of the bronchioles • leads to recurrent attacks of

breathlessness. • Often these are triggered by an allergic

reaction

Bronchitis

• Inflammation of the bronchi

Pneumonia

• Inflammation of the lungs most often due to

• viral or bacterial infection

• Pleurisy • Inflammation of the pleura

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External and Internal Respiration (Human)

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Exchange of Gases (Human Lungs)

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Control of Respiration (Human)

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Control

of

RespiratIon

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Lungs (Human): Circulation

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Lungs and Heart (Human): Posterior View

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Lower Respiratory Tract (Human): Lung Structure

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Lower Respiratory Tract (Human): Lung Function

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Lung

Function

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Bronchioles and Alveoli (Human)

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Bronchioles and Alveoli

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Bronchial Tree (Human): Overview

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Upper Respiratory Tract (Human): Nose and Sinuses

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