Respiratory system Function Outline - Respiratory System I. II. III. IV. Respiratory System The function of the respiratory system is to bring in oxygen to the body and remove carbon dioxide. Function of the respiratory system Parts of the respiratory system Mechanics of breathing Regulation of breathing Biol 105 Lecture 18 Chapter 14 Breathing moves air in and out of the lungs. External respiration is the exchange of oxygen and carbon dioxide between the lungs and the blood. This type of tissue covers and lines body parts Gas transport moves oxygen and carbon dioxide between the lungs and the body tissues. Internal respiration is the exchange of oxygen and carbon dioxide between blood and the body tissues. Oxygen transport 1. 2. 3. 4. Connective Epithelial Muscle Nervous Cells lining respiratory tract Lined by pseudostratified ciliated columnar epithelial cells. The cilia sweeps mucus, germs and debris toward the throat. Mucus produced by goblet cells. Smoking damages the ciliated cells Lungs Gas diffusion Carbon dioxide transport Gas diffusion Tissue nn Co Figure 14.1 e tiv ec al e li it h Ep Ciliated cells in respiratory tract Figure 14.4a M cle us ou rv Ne s Figure 14.3 1
UPPER RESPIRATORY SYSTEM Filters, warms, and moistens air Nasal cavity Produces mucus Filters, warms, and moistens air Olfaction Functions: LOWER RESPIRATORY SYSTEM Exchanges gases Sinuses Cavities in skull Lighten head Warm and moisten air Larynx Air passageway Prevents food and drink from entering lower respiratory system Produces voice Pharynx Passageway for air and food Bronchi Two branches of that conduct air from to each lung RESPIRATORY MUSCLES Cause breathing Intercostal muscles Move ribs during breathing 1. Nasal cavity Bronchioles Narrow passageways to conduct air from bronchi to Muscle sheet between chest and abdominal cavities with a role in breathing Epiglottis Covers larynx during swallowing 1. filters the air 2. warms the air 3. moisten the air entering the lungs 4. smell (which also plays a role in the sense of taste) Lungs Structures that contain and air passageways Allow exchange of oxygen and carbon dioxide between atmosphere and blood Trachea Connects larynx with bronchi leading to each lung Conducts air to and from bronchi Alveoli Microscopic chambers for gas exchange Figure 14.2 (1 of 2) 1. Nasal cavity Figure 14.2 (2 of 2) 2. Pharynx Parts of the nasal cavity: Functions 1. Connects the to the 2. Contains vocal cords used to generate Tonsils are found here lymphatic tissue that protects against infection Contains olfactory receptor cells for the sense of smell sound 3. Prevents food from entering lower respiratory tract Sinuses air filled cavities, warm and moisten air 8-3 3. Larynx Functions - is a passageway for air, liquids, and food. (swallowing begins here). Connects the nasal cavity to the esophagus and the larynx Mucus membranes - secrete sticky mucus to trap germs & debris. 8-3 3. Larynx Structure made from cartilage Epiglottis closes the when swallowing 2
Bronchial Tree 4. Trachea Windpipe held open by concentric rings of cartilage Trachea leads to the bronchial tree: 5. Bronchi (bronchus) Function Connects the larynx to the bronchi. 6. Bronchioles 7. Alveoli (alveolus) 7. Alveoli Alveoli Sacs at the end of the bronchioles, they are surrounded by blood capillaries. Figure 14.7 Alveoli Lungs - have about 300 million The structure of the increases surface area of lung Function: It is here that the oxygen diffuses across the membrane into the capillaries, and carbon dioxide goes from the capillaries to the inside of the lungs. For to function properly they are coated with phospholipid molecules called surfactant that keep them open 8-6 Figure 14.8 What cells secrete mucus 1. 2. 3. 4. cilliated columnar epi goblet squamous epi osteocytes re na m lu co ed at li Cil Table 14.1 (1 of 2) Table 14.1 (2 of 2) pi ble go t ua Sq s ou m i ep y oc te os s te 3
11/23/2014 The tube connecting the larynx to the primary bronchi is Common passageway for air, food and drink Conducts air from the to the bronchioles 3. bronchioles 4. 3. bronchioles 4. 3. bronchus 4. alveolus bronchioles bronchioles bronchi Gas exchange takes place here Which cavity is the lung located in? Inhalation Inhalation 3. bronchioles 4. bronchioles 1. abdominal 2. pericardial 3. pleural 4. dorsal Abdominal Pericardial Pleural Dorsal Rib cage moves up and out Intercostal muscles contract contracts and flattens (a) The chest cavity increases in size, and pressure within the lungs decreases. Air flow contracts The lungs expand, and air moves in. Figure 14.9a Inhalation Exhalation Exhalation When the diaphragm and intercostal muscles contract, the of the thoracic cavity increases, causing the pressure in the lungs to decrease Inhalation is also called inspiration Exhalation Rib cage moves down and inward Intercostal muscles relax Air flow Exhalation = Expiration When the same muscles relax, of the thoracic cavity decreases, pressure in the lungs increase relaxes and moves upward The chest cavity decreases in size, and pressure within the lungs increases. relaxes The lungs recoil, and air moves out. (b) Figure 14.9b 4
Air Volumes Air Volumes The of air inhaled or exhaled during a normal breath is called the tidal Air Volumes Inspiratory reserve = forced inhalation 6000 Inspiratory reserve (forced inhalation) 5000 Tidal is usually around 500 ml Lung Volume (ml) Expiratory reserve = forced exhalation Residual is the amount of air left in the lungs after forced exhalation The of air moved into and out of the lungs is an indication of health Vital capacity is the amount of air brought in and out of the lungs during forced breathing 4000 Total lung capacity Vital capacity Tidal 3000 2000 Expiratory reserve (forced exhalation) 1000 Residual 0 Gas Exchanges in the Body Figure 14.10 (1 of 2) Carbon Dioxide Transport Oxygen Transport 1. CO2 is transported dissolved in the plasma (10%) Remember that O2 enters and CO2 leaves the lungs = External respiration Oxygen is transported on Hemoglobin. 2. CO2 is bound to hemoglobin (20%) When Oxygen is bound to hemoglobin, then it is called Oxyhemoglobin Then O2 and CO2 is exchanged between the blood vessels and tissues = Internal Respiration 3. CO2 is converted to bicarbonate ions (70%) This gas exchange is due to diffusion 8-14 Bicarbonate ions CO2 + H2O Carbonic anhydrase H2CO3 8-15 Diffusion of Gasses: Alveoli and Capillaries 8-14 Diffusion of Gasses: Capillaries and Tissues H+ + HCO3-8-14 Figure 14.11 (2 of 2) Figure 14.11 (1 of 2) 5
11/23/2014 Regulation of Breathing Important Concepts Important Concepts Normally we breath 12-15 ventilations per minute. This rate is controlled by the medulla oblongata region of the brain. Nerves transmit signal to the diaphragm and muscles. Chemoreceptors in the medulla oblongata and arteries detect levels of CO 2 and O 2 in the blood, controlling the rate and depth of breathing. Read Ch 15 What is the function of the respiratory system? What is the location and function of the all the parts of the respiratory system? What are the parts of the nasal cavity and their functions? What are the parts of the larynx and their functions? What cell types lines the, what are their functions, be able to discus how smoking effects this tissue? Where does the exchange of gases occur in the lungs? What cavity contains the lungs? What controls the rate of breathing? Be able to discuss the mechanics of breathing? 8-12 Important Concepts Definitions How is oxygen carried in the blood? How is carbon dioxide carried in the blood, know all the ways, and the which is the predominate mode? (You don t need to know the chemical equation of bicarbonate formation) What is the diaphragm and what is its function? Goblet cells, sinuses, epiglottis, surfactant, diaphragm, intercostal muscles, Inhalation/inspiration, exhalation/expiration tidal, inspiratory reserve, expiratory reserve, residual, vital capacity, hemoglobin, oxyhemoglobin, chemoreceptors 6