1. 11.1 The Function of Respiration

2. Agenda Lesson 11.1 The Function of Respiration Read p.442-449 Vocabulary Learning Check SG 166 # 1-3, SG 167 #1-3

3. Learning Goals Students will define the following terms: respiratory system, respiration, inspiration, expiration, gas exchange, ventilation, diffusion gradient, diaphragm, spirograph, tidal volume, inspiratory reserve volume, expiratory reserve volume, vital capacity, residual volume Students will list the stages of respiration. Students will list and describe the different types of respiratory surfaces and give an example for each. Students will differentiate between gas exchange on land and in aquatic environments. Students will explain the process involved in inhalation and exhalation. Students will review the different terms used to describe measures of respiration.

4. The Function of Respiration The 3 components for a Respiratory System: a) Gas Exchange surface area. (lungs, gills, skin or trachea) b) Moist and thin membrane to dissolve and diffuse gases. c) Transport medium – blood

6. The Respiratory System Respiratory System: the group of organs that provides living things with oxygen from outside the body and disposes of waste products such as carbon dioxide. Respiration: all of the processes involved in bringing oxygen into the body, making it available to each cell, and eliminating carbon dioxide as waste.

7. Respiration and Gas Exchange Stages of Respiration 1.Breathing: involves two processes: inspiration (breathing in or inhaling) expiration (breathing out or exhaling). Inspiration: the action of drawing oxygen-rich air into the lungs. Expiration: the action of releasing waste air from the lungs.

8. 2. External Respiration: This is the exchange of oxygen and carbon dioxide between the inspired air inside the lungs and the blood. This is the location of gas exchange. Gas exchange: the transfer of oxygen from the inhaled air into the blood, and of carbon dioxide from the blood into the lungs

9. 3. Internal Respiration: oxygen moves from the circulatory system into the cells of the body and carbon dioxide is diffused from the cells into the blood. 4. Cellular Respiration: oxygen is used by the cell (energy-releasing) to breakdown glucose to produce another chemical potential energy called Adenosine Triphosphate (ATP). This energy is used for cell metabolic reactions.

10. Breathing is the process by which air enters and leaves the lungs. External respiration is the exchange of oxygen and carbon dioxide between the inside of the lungs and the blood. Internal respiration is the exchange of oxygen and carbon dioxide between the blood and the body’s tissue cells.

11. Respiratory Surfaces The two requirements of a gas exchange surface area are: 1. Surface area is large enough to service the organism with enough oxygen to survive under the most extreme activity. 1. Moist and thin membrane is important. Diffusion will not take place unless the gases are dissolved in water. These gases will then move from an area from high to low concentration. (oxygen and carbon dioxide) Ventilation: the process of drawing, or pumping, an oxygen-containing medium over a respiratory surface.

12. Description of Respiratory SurfaceExample Cell membrane -direct diffusion through the plasma membrane to obtain oxygen from the surrounding environment. Single celled organisms Outer Skin -organism is larger and requires more oxygen to survive. - the earthworm’s skin acts as its gas exchange area. - the area is sufficiently large enough to support the organism -the skin is kept moist by mucous secretion. -Oxygen dissolves in the mucous and then diffuses across the skin membrane into the capillaries located just below. Earthworm

13. Description of Respiratory SurfaceExample Gills - live in an aquatic environment. -oxygen is dissolved in the water -water moves across the gills -oxygen diffuses across the gill filaments into the circulatory system Fish Tracheal System - have a tracheal system for gas exchange -a series of spiracles along their abdomen. - air enters and flows along the trachea - diffuses directly into the body and the tissue cells. Insects Lungs - a high demand for oxygen -require a mechanism to draw air into a set of lungs for gas exchange. -many alveoli in the lungs increase the surface area for gas exchange -the alveoli are surrounded by capillaries, which receives the oxygen by diffusion. Large complex organisms

14. Gas Exchange in Aquatic Environments Fish have specialized adaptations to suit their environment. The development of gills allows fish to obtain oxygen from their aquatic surroundings. The surface area is suitable to support the active life of the fish. Water enters the fish’s mouth and ventilating (pumping) it across a series of gill filaments found within the gills. As the water passes over the gill filaments oxygen diffuses (diffusion gradient) from the water across the membrane and into the capillaries found lining the gills. Carbon dioxide travels in the reverse direction.

15. Another adaptation used by fish is a counter – current exchange mechanism. Blood flows through the gills in the opposite direction to the flow of oxygen-containing water. The oxygen flows along a diffusion gradient oxygen molecules move form a region of high concentration to a low one. Because blood and water flow in opposite directions, the diffusion gradient of oxygen is kept high.

16. Gas Exchange on Land Land animals had to become adapted to their environment to maximize their gas exchange. The development of lungs was an evolutionary necessity for larger mammals to obtain oxygen.

17. The Mechanics of Breathing Air has to move from the external environment to the internal environment of the lungs. Air is not able to flow into and out of the lungs on its own. The brain: coordinates breathing movements regulates the breathing rate monitors the volume of air in the lungs monitors the gas levels in the blood 2 sets of structures the diaphragm and the intercostal rib muscles control the air pressure in the lungs.

18. Diaphragm: a sheet of muscle that separates the thoracic cavity from the abdominal cavity. Intercostal Muscles: are found between the ribs and along the inside surface of the rib cage. The diaphragm and intercostal rib muscles are able to change the volume of the chest. This change can either increase of decrease air pressure in the lungs.

19. Air Pressure in the Lungs Inspiration the diaphragm contracts (flattens) the intercostal muscles pull the ribs upward, the volume of the thoracic cavity increases. the volume increases the pressure will decrease in comparison to the atmospheric pressure. the air moves from an area of high pressure to an area of low pressure inside the lungs. Exhalation Diaphragm relaxes the intercostal muscles relax the volume of the thoracic cavity will decrease. T causes an increase in air pressure in the lungs which is greater then the atmospheric air pressure. air leaves the lungs,

21. Respiratory Volume Your normal breathing does not use the full capacity of the lungs. As your needs for oxygen increases, during exercise, you have the ability to take more air into your lungs.

22. Terms Spirograph: a graph representing the amount (volume) and speed (rate of flow) of air that is inhaled and exhaled, as measured by a spirometer. Spirometer: measures the volume of air that is inhaled and exhaled over a period of time. Tidal Volume: the volume of air inhaled and exhaled during normal breathing when the body is at rest. Inspiratory Reserve Volume: the additional volume of air that can be taken into the lungs beyond the regular tidal inhalation. Expiratory Reserve Volume: the additional volume of air that can be expelled from the lungs beyond the regular tidal exhalation. Vital Capacity: the total maximum volume of air that can be moved into and out of the lungs during a single breath. Residual Volume: the volume of air that remains in the lungs after a complete exhalation.

23. This spirograph shows typical values for human vital capacity: the maximum volume of air that can be moved into and out of the lungs during a single breath.

24. Success Criteria I am able to define the following terms: respiratory system, respiration, inspiration, expiration, gas exchange, ventilation, diffusion gradient, diaphragm, spirograph, tidal volume, inspiratory reserve volume, expiratory reserve volume, vital capacity, residual volume I am able to list the stages of respiration. I am able to list and describe the different types of respiratory surfaces and give an example for each. I am able to differentiate between gas exchange on land and in aquatic environments. I am able to explain the process involved in inhalation and exhalation. review the different terms used to describe measures of respiration.