2. Animal Respiration

3. Function of Respiratory System To obtain and use oxygen To eliminate carbon dioxide

4. Structure and Function Nostrils - paired, external openings

5. Nostrils Species Differences –Horse--Very Pliable and Dilatable –Pig--Rigid

6. Advantages of Dilatable Nostrils Advantageous when more air is required (e.g. Running) Non-mouth Breathing

7. Structure of Nostrils Nasal Cavities –Paired –Separated by Nasal Septum, and from mouth by palate

8. Structure of Nostrils Pharynx –Common pathway for air and food Larynx –"Voice Box" –Organ of Phonation (Sound Production) –Sound produced by controlled passage of air which –causes vibration of vocal chords

9. Structure of Nostrils Syrinx –Voice Box for Birds –Located where trachea divides from bronchi Vibrating Muscles Trachea –Primary passage way to Lungs –Cartilage Rings prevent collapse of airway Alveoli –Principle site of gaseous diffusion between air and blood Lungs –Principle Organ of Respiratory System –Paired, found in Thorax Thorax expansion causes lung expansion

10. Mechanisms of respiration Respiratory Cycles –Inspiration Intake of air Enlargement of thorax and lungs –Expiration Removal of air Types of Breathing –Abdominal Diaphragmatic –Costal Rib Cage

11. Respiratory Frequency in Number of Respiratory Cycles Per Minute Varies by species –Horse – 12 –Cow – 29 –Pig – 40 –Sheep – 25 Obviously body size has a lot to do with respiration rates!

12. Respiratory Rate Increases with exercise and excitement