Key Terms
Primary function
Gas exchange (O2 in, CO2 out) + perfusion (delivery of O2 and nutrients to tissues).
Without adequate perfusion
All body systems are at risk; cells die.
Right lung
3 lobes (upper, middle, lower) Left lung: 2 lobes (upper, lower) - shaped to include cardiac notch (space for heart)
Compliance
Lungs' ability to accommodate deep and shallow breaths.
Elastic recoil
Ability to return to normal size/shape after inspiration.
Location
Mediastinum (space between lungs in thoracic cavity).
DIFFUSION
Molecules move from HIGH concentration to LOW concentration. No energy required.
Inspiration
Diaphragm and intercostal muscles CONTRACT; thoracic space enlarges; alveolar pressure drops; air flows IN.
Expiration
Respiratory muscles RELAX; elastic recoil reduces thoracic space; intrapulmonary pressure momentarily exceeds atmospheri
Normal blood pH
7.35 to 7.45
Process
Renin (kidney) + angiotensinogen = angiotensin I; angiotensin I + ACE (produced in lung capillaries) = angiotensin II.
Angiotensin II
Powerful vasoconstrictor; increases blood pressure.
Medulla oblongata
Primary respiratory center; signals respiratory muscles for ventilation.
Pons
Controls respiratory rate.
Dyspnea
Subjective feeling of shortness of breath. Rated 0-10.