1. 11.1 The Function of Respiration

2. What is Respiration?
Respiration: the main function is to obtain oxygen for use by the body’s cells and to eliminate the carbon dioxide the cells produce
Inspiration: breathing in
Expiration: breathing out
Cellular Respiration: chemical reactions at the cellular level that use O2 to power all of life’s processes
It is also the fourth and final stage in respiration
Sugar/Glucose (C6H12O6)+ O2 -> CO2 + NRG + H2O

3. Continued….
External respiration: refers to the entire sequence of events in the exchange of oxygen and carbon dioxide between the external environment and the cells of the body
The air is moved in and out of the lungs so that air can be exchanged between the atmosphere (external environment) and the air sacs (alveoli) of our lungs
O2 diffuses from the air in the alveoli to the blood within the pulmonary capillaries; CO2 diffuses in the opposite direction
The blood transports O2 from the lungs to the tissues and CO2 from the tissues to the lungs
O2 and CO2 are exchanged between tissues and blood by the process of diffusion across the systemic (tissue) capillaries

5. Requirements for Respiration
You need a large surface area, called respiratory surface, in which O2 and CO2 are exchanged, and you need a moist environment for the gases to dissolve
Animals may use skin, gills or trachea to move O2 over the respiratory surface…See page 444 for various method’s

7. Gas Exchange in Aquatic Environments
O2 is dissolved in water
H2O enters the mouth and flows through the gills
Gills contain capillaries which absorb the O2 and give up the CO2
gases move along a diffusion gradient – gas moves from a region of high to low concentration
-fish, just like us, inhale oxygen and expire carbon dioxide
-fish do not have lungs like us so instead they use the capillaries in their gills

8. Gas Exchange on Land Reptiles, birds, and mammals use lungs
Diaphragm (sheet of muscle) contracts and relaxes to draw and push air out of the lungs
Inhalation: the rib cage moves up and out, diaphragm contracts and moves down. This causes the thoracic cavity to increase in size and air rushes in to fill the new space.
Exhalation: the rib cage moves down and in, diaphragm relaxes and moves up. This causes the thoracic cavity to decrease in size, and air then gets squeezed out of the lungs.

10. Respiratory Volumes
Tidal volumes: normal volume of air inhaled and exhaled
Inspiratory reserve volume: additional volume taken in when inhaling
Expiratory reserve volume: additional volume forced out when exhaling
Vital capacity: total volume inhaled and exhaled
Residual volume: the amount of air left in lungs even after forcing it all out
-get students to take a breath, take a breath and then take some more in before exhaling, take a breath and exhale and then exhale some more before inhaling

11. Spirograph

12. Homework Review 11.1 Work on your projects!!
Read over tomorrow’s lecture