1. The Respiratory System
SBI 3U
January 14th, 2013

2. The Respiratory System
Exchange of oxygen and carbon dioxide between an organism and its external environment
Respiratory system: supplies oxygen to cells and removes carbon dioxide
CO 2 and breathing rate

3. More Respiratory Functions
Defends body against foreign pathogens
Controls pH levels
Produces sounds for speaking
Helps maintain homeostasis

4. Components of Respiration
Ventilation or breathing
Inhalation and exhalation
Lungs: specialized structures for respiration (large surface area)

5. Components of Respiration
External Respiration
Exchange of gases across the respiratory surface between air sacs or alveoli and the blood
Respiratory surface – where oxygen diffuses into organism and CO2 diffuses out

6. Components of Respiration
Internal Respiration
Exchange of gases between the blood in capillaries and individual cells in the tissues
Oxygen diffuses out of blood and CO2 diffuses in

7. Components of Respiration
Occurs in the mitochondria
Glucose as fuel

8. Anatomy of Respiratory System
Upside down tree!
Begins with nasal cavity and ends at alveoli
Consists of: nose, nasal cavity, pharynx, larynx, trachea, smaller conducting passageways, and lungs

9. Nasal and Oral Cavities
21% of every air inhalation is oxygen
Inhalation from mouth vs. nose
Nasal cavity: lined with mucus-secreting cells; helps to moisten and filter incoming air
Oral cavity

10. The Pharynx Pharynx: common path for both air and food
Trachea/epiglottis
Larynx at top of trachea

11. The Larynx Adam’s apple Produces sound
Vocal chords: two highly elastic folds inside larynx

12. The Trachea Windpipe Allows air to pass from pharynx into lungs
Tough, flexible, c-shaped cartilage rings surrounds the trachea

13. Respiratory Structures Within the Chest Cavity
Trachea divides into 2 branches: right and left bronchi
Left bronchus  Left lung
Right bronchus  Right lung
Lungs
Bronchi branch into smaller tubes called bronchioles
Alveoli

14. Respiratory Structures Within the Chest Cavity
Bronchioles enter in a cluster of tiny hollow air sacs called alveoli
150 million alveoli in each lung!
Occur in clusters
Gas exchange