RESPIRATORY SYSTEM EXCHANGE OF GASES PowerPoint® Lecture Slide Presentation by Robert J. Sullivan, Marist College RESPIRATORY SYSTEM EXCHANGE OF GASES Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.

What is Human Respiration? The human respiratory system allows one to obtain oxygen, eliminate carbon dioxide. Breathing consists of two phases, inspiration and expiration Inspiration- the process of taking in air Expiration- the process of blowing out air

Human Respiratory System Figure 10.1

Organs in the Respiratory System STRUCTURE FUNCTION nose / nasal cavity  warms, moistens, & filters air as it is inhaled pharynx (throat)  passageway for air, leads to trachea larynx  the voice box, where vocal chords are located trachea (windpipe)  keeps the windpipe "open"  trachea is lined with fine hairs called cilia which filter air before it reaches the lungs bronchi  two branches at the end of the trachea, each lead to a lung bronchioles  a network of smaller branches leading from the bronchi into the lung tissue & ultimately to air sacs alveoli  the functional respiratory units in the lung where gases are exchanged

Components of the Upper Respiratory Tract Figure 10.2

Upper Respiratory Tract Functions Passageway for respiration Receptors for smell Filters incoming air to filter larger foreign material Moistens and warms incoming air Resonating chambers for voice

Components of the Lower Respiratory Tract Figure 10.3

Lower Respiratory Tract Functions: Larynx: maintains an open airway, routes food and air appropriately, assists in sound production Trachea: transports air to and from lungs Bronchi: branch into lungs Lungs: transport air to alveoli for gas exchange

Gas Exchange Between the Blood and Alveoli Figure 10.8A

Respiratory Cycle Figure 10.9

Breathing Regulation Involuntary Have Chemoreceptors in walls of arteries that detect CO2 levels High CO2 levels in blood detected and send message to respiratory center of brain (Medulla) Medulla send message to diaphragm and rib muscles to increase rate and depth of breath Low pH of blood also stimulates medulla

External vs. Internal Respiration Gas exchange in alveoli with capillaries Internal Gas exchange in capillaries with body cells

Oxygen transport In lungs oxygen combines with Hemoglobin to form oxyhemoglobin

Structure of hemoglobin

Oxygen Transport Oxygen released in locations of low O2 concentration Carbon monoxide has greater binding ability to hemoglobin than oxygen

Carbon Dioxide Transport 70% as Bicarbonate in plasma CO2 + H20  H2CO3  H++ HCO3- carbonic bicarbonate acid Carbonic Acid Buffering system

Carbon Dioxide Transport 20% as carbaminohemoglobin CO2 + Hb HbCO2 (HbCO is carboxyhemoglobin)

Carbon Dioxide Transport 10% as free CO2 in plasma

Carbon Dioxide Transport

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Respiratory volumes tidal volume: air inhaled or exhaled in one quiet breath inspiratory reserve volume: air in excess of tidal inspiration that can be inhaled with maximum effort expiratory reserve volume: air in excess of tidal expiration that can be exhaled with maximum effort residual volume: air remaining in lungs after maximum expiration, keeps alveoli inflated

Measurement of Lung Capacity Figure 10.10A

Malfunctions & Diseases of the Respiratory System asthma severe allergic reaction characterized by the constriction of bronchioles  bronchitis inflammation of the lining of the bronchioles emphysema condition in which the alveoli deteriorate, causing the lungs to lose their elasticity pneumonia condition in which the alveoli become filled with fluid, preventing the exchange of gases lung cancer irregular & uncontrolled growth of tumors in the lung tissue

Four Respiration Processes Breathing (ventilation): air in to and out of lungs External respiration: gas exchange between air and blood Internal respiration: gas exchange between blood and tissues Cellular respiration: oxygen use to produce ATP, carbon dioxide as waste

Perfusion and Ventilation https://www.youtube.com/watch?v=Czl1OQ_4ht8

Oxygen Dissociation Curve Click on the numbered sections on the graph for an explanation of what happens at each stage Oxygen Dissociation Curve Saturation of Haemoglobin / % Partial Pressure of Oxygen/ kPa 2 4 6 8 10 12 20 40 60 80 100 5 4 3 The red blood cells transport the oxygen to respiring tissues. The partial pressure of oxygen in these tissues is low, as the oxygen is being used for respiration. Under conditions of a lack of oxygen (low partial pressure of oxygen), the haemoglobin yields its oxygen to the respiring cells – we refer to this as dissociation. Haemoglobin’s properties allow it to bind with a lot of oxygen at a high partial pressure of oxygen, but at low partial pressure, only a limited amount binds to it. The partial pressure of oxygen is high and the haemoglobin reaches saturation. The red blood cells collect oxygen in the capillaries surrounding the lungs. Show/ hide titles Show/ hide scale 2 Show/ hide line 1