1. Respiratory System (282-286) Process that provides oxygen to tissue cells and removes carbon dioxide from the body Two requirements for respiration 1. Surface area must be large for quick exchange of O2 and CO2 to meet body’s need 2. Moist environment because O2 and CO2 are dissolved in water

2. Respiratory Tract Extends from nose to lungs Passageway for air & site for gas exchange Lined with mucous producing and ciliated cells to capture foreign particles 2 parts: 1. Upper Respiratory Tract 2. Lower Respiratory Tract

3. Pathway of the Respiratory system AIR TRAVELS on two way pathway Upper  In mouth & nose where it’s humidified, warmed and large foreign particles removed  Passes pharynx and flap like structure epiglottis (intersection of digestive and respiratory)  Past the larynx (voice box) down cartilage lined trachea towards the lungs Lower  Into either lung through the bronchi  Then into bronchioles (smaller branch) for gas exchange in alveoli which inflate and deflate with air movement

4. Stages of Respiration Breathing air enters and leaves lungs External respiration in lungs between air and blood Cellular respiration takes place in cells production of ATP Internal respiration within body between blood and tissue fluids

5. Principle Structures Add the structures of the respiratory system to Human Systems Hal (pg 283)

6. Respiration: Let’s get specific Outcome: Explain the exchange of matter between the body and environment in gas exchange

7. Breathing movements (pg 285) Note: - Lungs and chest cavity are attached to each other but don’t rub because pleural membrane between surfaces - AIR will always move HIGH to LOW pressure - Smaller the container the more pressure, larger the container the less pressure

8. Breathing in /Inhalation Diaphragm muscle told to contract by brain (moves down) Intercostal muscles between the ribs told to contract (move up and out) Opens up chest cavity and lungs decreasing air pressure therefore sucking air in

9. Breathing in/Inhalation Air moves into the lungs. Intercostal muscles contract; rib cage moves upward. Diaphragm contracts and moves downward. Pressure in the chest cavity is lower than the atmospheric pressure, air moves into the lungs.

10. Breathing out /Exhalation Diaphragm muscle relax (back up) Intercostals muscles relax (back down and in) Closes chest cavity and lungs increasing air pressure therefore pushing air out

11. Breathing out/Exhalation Air moves out of the lungs. Intercostal muscles relax; rib cage falls. Diaphragm relaxes and moves upward. Pressure in the chest cavity is higher than the atmospheric pressure, air moves out of the lungs.

12. Respiratory Volume Under normal circumstances regular breathing doesn’t use full capacity of lungs Spirometer/respirometer- tool used to measure lung capacity Spirograph-visual representation

13. Respiratory Volume Tidal volume-volume of air that is inhaled & exhaled in normal breathing movement Inspiratory reserve volume-additional volume of air that can be taken into lungs beyond tidal volume Expiratory reserve volume-additional volume of air that is forced out of lungs beyond tidal volume Vital capacity(Total lung volume)=total volume of gas that can be moved into or out of the lungs  Vital Capacity= Tidal volume + Inspiratory volume + Expiratory volume

14. Gas Exchange (pg 288) Air diffuses from high to low pressure O 2 moves from alveoli to cells CO 2 moves from cells to alveoli Alveoli Capillary/Blood CO 2 O2O2 Capillary/Blood Cell CO 2 O2O2

15. Alveoli (pg283) 0.1 and 0.2 um in diameter, Single layer of cells thick 150 million alveoli in 1 lung (enough surface area to cover half a tennis court) Surrounded by capillaries (thin walled vessels connecting body systems to the circulation system)

16. Oxygen Exchange Diffuses from alveoli to blood to cell  Hemoglobin  Red colored respiratory pigment in blood that assists in carrying oxygen  Each red blood cell contains 250 million hemoglobin Oxygen concentration is low in cells Blood oxygen levels are high (97% saturated when leaving lungs)

17. Carbon Dioxide Exchange Diffuses from cell to blood to alveoli Carbon dioxide concentration is high in cells Blood carbon dioxide levels are low Water and carbon dioxide form bicarbonate further decreasing amount of CO2 in blood

18. Regulation of Breathing Movements (292) Breathing is involuntary action controlled by nerves of medulla oblongata in brain Specialized nerve receptors sensitive to specific chemicals (Chemoreceptor) sense accumulation of CO 2, acids and need for O 2

19. Carbon Dioxide control CO 2 chemoreceptor most sensitive and main regulators of breathing  Acid builds up if there is an accumulation of CO2 in the blood (Bicarbonate ions and hydrogen ions form carbonic acid)  Receptors pick up on accumulation and send message to brain  Brain sends message to diaphragm and rib muscles to contract  Breathing will occur/increase  If irregular breathing is occurring breathing will increase until the CO2 levels fall

20. Carbon Dioxide control Body cells use oxygen to break down organic molecules. CO2 levels rise in the cell and CO2 diffuses into the blood Chemoreceptors in the medulla oblongata detect high levels of CO2. A nerve impulse is sent to the intercostal muscles and diaphragm to increase breathing movements. CO2 is expelled faster when breathing movements increase. negative feedback

21. Oxygen control O 2 chemoreceptor less sensitive considered "back up”  receptors in carotid and aortic arteries of heart sense low O 2 levels in blood  Send message to brain  Brain sends message ribs and diaphragm they contract  breathing will occur or increase  Situations where there is low O2 in air (high altitudes) or carbon monoxide poisoning

23. Respiratory Disorders Decrease oxygen delivery to the tissues Upper Respiratory Tract infections  Caused by virus or bacteria  E.g. Tonsillitis, Laryngitis Lower Respiratory Tract Disorders  Caused by infections, obstructive pulmonary disorder (OPD), lung cancer  E.g. Bronchitis, Pneumonia, Pleurisy, Emphysema, lung cancer