Respiratory System

2 levels Internal Respiration – Cellular Respiration the exchange of gases between the blood and the cells of the body. O 2 is required to break down glucose, release CO 2, 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

Passage of air

lungs-video.htm

Regulation of Breathing involuntary action under control of the medulla oblongata.

Factors affecting Breathing CO 2 chemically combines with water in the blood to form carbonic acid – H 2 CO 3 Carbonic acid releases a H + ion resulting in bicarbonate – HCO 3 - – 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 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 lungs

Close Window Respiration (Human): Processes Involved Return to Top Mechanism of BreathingMechanism of Breathing

Close Window Ventilation (Human) Return to Top VentilationVentilation

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

Close Window External and Internal Respiration (Human) Return to Top

Exchange of Gases (Human Lungs)

Close Window Control of Respiration (Human) Return to Top Controlof RespiratIonControlof RespiratIon

Close Window Lungs (Human): Circulation Return to Top

Close Window Lungs and Heart (Human): Posterior View Return to Top

Close Window Lower Respiratory Tract (Human): Lung Structure Return to Top

Close Window Lower Respiratory Tract (Human): Lung Function Return to Top LungFunctionLungFunction

Close Window Bronchioles and Alveoli (Human) Return to Top Bronchioles and AlveoliBronchioles and Alveoli

Close Window Bronchial Tree (Human): Overview Return to Top

Close Window Upper Respiratory Tract (Human): Nose and Sinuses Return to Top