1. The Respiratory System Functions & Anatomy
Equine Science
Ms. Weller

2. What is the Respiratory System?
Organs that deliver oxygen to the circulatory system for transport to the cells in the animal’s body

3. Functions Provides oxygen to tissues and cells
Removes carbon dioxide from the body
Controls body temperature
Eliminates water (as vapor)
Aids in voice production

4. Anatomy Nostrils Nasal Cavity Pharynx Larynx Trachea
Bronchi (Bronchial Tubes)
Lungs
Bronchioles
Alveoli

5. Nostrils External openings of the respiratory tract
Lead into nasal cavity
Shape and size varies amongst species

6. Nasal Cavity Air is warmed and moistened Dust particles filtered out
Site of smelling (olfactory receptors located in turbinate bones)
Separated from the mouth by a hard and soft palate

7. Pharynx
Passages of nostrils and mouth join here (air and food cross paths)
Epiglottis: keeps food from going to the lungs (valve-like)
Short, funnel-shaped tube
Filled with mucus membrane and ciliated cells to remove more impurities

8. Larynx Vocal chords Composed of cartilage structures
Vibrate when air passes over
Produces the neighing, whinnying or nickering sound
Composed of cartilage structures
Located in the middle of the neck
Controls breathing
Prevents inhalation of foreign objects into the lungs

9. Trachea Windpipe (single tube)
Wall lined with series of c-shaped rings of cartilage (rigid)
Help to maintain the shape of the passage during breathing
Enters chest cavity
Contributes to the cleansing function of the respiratory system

10. Bronchi The branches the trachea divides into to connect to the lungs
Contribute to the cleansing function of the respiratory system
Branch into bronchioles inside the lungs

11. Lungs Elastic, spongy material Cone shaped
May be incompletely divided into several lobes
Located in thoracic cavity
Greatly expand when filled with air

12. Bronchioles Smaller branches of the bronchi
The first few contribute to the cleansing function of the respiratory system
Terminate in the alveoli

13. Alveoli Tiny air sacs that are the end of bronchioles
Have very thin walls
Surrounded by tiny blood capillaries
Exchange of gases occurs here through diffusion

14. Diaphragm Body partition of muscle and connective tissue
Separates the thoracic cavity from the abdominal cavity

15. Terms Respiration: the act of breathing
Inspiration: inhalation brought about by a contraction of the diaphragm and an outward rotation of the ribs
Expiration: expulsion of air effected by a relaxation of muscles and a contraction of rib and abdominal muscles

16. Stats Average lung capacity = 1.5 cubic feet of air
Normal breathing rate (at rest) = 8-16 times per minute
Inhales approximately 250 cubic inches of air at each respiration