Respiratory Circulatory Systems Respiratory System Respiration Involuntary event

Respiratory & Circulatory Systems

Respiratory System • Respiration: Involuntary event • O 2 enters cells where it’s used for aerobic cell respiration (making ATP!) • CO 2 eliminated

Diffusion of gases only works when you are very small or very flat

• Amphibians & earthworms use integument (skin) for respiration • Must stay moist

• Fish extract O 2 from water with gills, thin filaments • Diffusion of O 2 from high to low areas to enter blood

Insect respiration separate from circulatory O 2 enters through spiracles

Human (mammalian) Respiratory System

Human (mammalian) Respiratory System • Pulmonary ventilation • Air enters nasal cavity

Human (mammalian) Respiratory System • Pulmonary ventilation • Air enters nasal cavity • Passes through pharynx & larynx to enter trachea

Human (mammalian) Respiratory System • Pulmonary ventilation • Air enters nasal cavity • Passes through pharynx & larynx to enter trachea • Divides into 2 primary bronchi in left & right lungs

Human (mammalian) Respiratory System • Pulmonary ventilation • Air enters nasal cavity • Passes through pharynx & larynx to enter trachea • Divides into 2 primary bronchi in left & right lungs • Primary bronchi branch into secondary, tertiary & terminal bronchi & then finally into bronchioles

Human (mammalian) Respiratory System • Pulmonary ventilation • Air enters nasal cavity • Passes through pharynx & larynx to enter trachea • Divides into 2 primary bronchi in left & right lungs • Primary bronchi branch into secondary, tertiary & terminal bronchi & then finally into bronchioles • Bronchioles subdivide into alveolar ducts which are surrounded by alveoli & alveolar sacs where gas exchange occurs with capillaries

O 2 carried by hemoglobin found in red blood cells Heme group contains iron