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Respiration 1. Unifying Concepts 2. Structure and Function of Respiratory Surfaces 3. Human Respiratory System - 3 phases of gas exchange 4. Structure and Function of the Human Respiratory System 5. Negative pressure breathing 6. Role of Hemoglobin 7. Lung damage - Smoking Unifying Concepts of Animal Respiration – Recall that cellular respiration uses oxygen and glucose to produce water, carbon dioxide, and energy in the form of ATP. • Cells need a constant supply of oxygen and must continuously dispose of CO2. • The respiratory system facilitates this gas exchange. The Structure and Function of Respiratory Surfaces – Gas exchange occurs at the respiratory surface. • This surface must be large enough to take up oxygen for every cell in the body. • Different types of organisms have different types of respiratory surfaces. – Some animals use their entire outer skin as a respiratory surface. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Figure 23.15a – In aquatic environments, the respiratory surfaces are found in the gills. • Water is constantly pumped across the gills to facilitate gas exchange. – In most land-dwelling animals, the respiratory surfaces are folded into the body. • The surfaces open to the air through narrow tubes. – Insects breathe using tracheae, an extensive system of internal tubes that branch throughout the body. – Lungs are the most common respiratory surface of terrestrial organisms. • The lungs are located in only one part of the body. • The circulatory system transports oxygen from the respiratory surface to the rest of the body. The Human Respiratory System – In the human respiratory system, there are three phases of gas exchange. The Structure and Function of the Human Respiratory System – Our lungs are located in the chest cavity. – Air moves sequentially through the body from the mouth and nose to the bronchioles. • The bronchioles are the smallest branches of the tubes within the lungs. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings Figure 23.17 Figure 23.18 http://media.pearsoncmg.com/bc/bc_0media_bio/bioflix/bioflix.htm?eb3exchange Figure 23.19 – You can consciously speed up or slow down your breathing, • But you don’t always consciously control your breathing. – Most of the time, automatic control centers in the brain regulate breathing. – The breathing control centers increase or decrease breathing rate in response to CO2 levels in the blood. Figure 23.20 The Role of Hemoglobin in Gas Transport Figure 23.22 How Smoking Affects the Lungs – Every breath you take exposes your respiratory tissues to potentially damaging chemicals. • One of the worst sources of airborne pollutants is tobacco smoke.