Chapter 11) Gas exchange in humans

Gas exchange

Movement of oxygen into blood and carbon dioxide out

Alveoli

Tiny air sacs where gas exchange happens

Diffusion

Movement of particles from high to low concentration

Trachea

Tube carrying air to and from lungs

Bronchus

Airway leading into each lung

Bronchioles

Smaller airways inside lungs

Ventilation

Movement of air into and out of lungs

Diaphragm

Muscle that flattens to draw air in

Intercostal muscles

Muscles between ribs that move ribcage

Inhalation

Breathing in (air enters lungs)

Exhalation

Breathing out (air leaves lungs)

Surface area

Large area of alveoli for efficient gas exchange

Thin walls

Short distance for diffusion in alveoli

Moist surface

Helps gases dissolve for diffusion

Concentration gradient

Difference in concentration that drives diffusion

Larynx

Voice box that produces sound and keeps airway open