1. Respiratory System BIO 201: Organismal S&F Tony Serino, Ph.D.
Biology Department
Misericordia Univ.

2. Respiration External Respiration Internal Respiration
The exchange of gas between the blood and external environment (usually includes ventilation)
Internal Respiration
The exchange of gas between the blood and the tissues
Cellular Respiration
Burning of fuel to produce energy within cells
Ventilation (Breathing)
Movement of air in and out of the lungs

3. Primary Respiratory Organs
Skin, Gills, Oropharynx, Swim bladders, Lungs

4. Tracheal System

5. Gills

7. Gills of Fish

8. Counter Current Exchange
Also function in excretion of nitrogen wastes in all fish, and salt excretion in marine species

9. Swim Bladders
Evagination of pharynx; two kinds: those with pharynx connection and those without
Functions:
Hydrostatic organ –maintains neutral buoyancy
Sound Production
Respiratory organ – may be primitive function; retained in those bladders that maintain connection to pharynx; allows air gulping

11. Gas gland –delivers oxygen to bladder
Ovale gland –reabsorbs O2 to blood

12. Terrestrial Respiratory Organs
Divided into:
Upper Respiratory Tract
Includes: nostrils (nares), nasal cavity, and nasopharynx
Lower Respiratory Tract
Includes: larynx, trachea, bronchi, and lungs
Conducting Air passages include: nares to terminal bronchioles
Move air to respiratory membrane
Condition the air
Moisten, Warm, Clean

13. Trachea and Bronchi Trachea Tertiary Bronchi Primary Bronchi
Secondary Bronchi
Trachea
Tertiary (segmental) bronchi lead to each lung broncho-pulmonary segment
Bronchi continue to divide at least 20 more times.

14. Bronchioles Air passages less than 1 mm in diameter are bronchioles.
Alveoli:
Lots of Surface Area
Highly vascular
Thin walls
Air passages less than 1 mm in diameter are bronchioles.
The terminal bronchioles are the last of the purely conducting air passages.

16. Parabronchial System of Birds
Many air sacs penetrate bones making them less dense

17. Air Flow in Bird Lung
Allows lungs to exchange air in both inhalation and exhalation phases