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

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

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

Tracheal System

Gills

Gills of Fish

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

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

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

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

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.

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.

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

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