A primary bronchus is the first branch off the trachea, further branching leads to the secondary bronchus and then tertiary as you get deeper into the lung.
tertiary
primary 3% secondary 17% tertiary 80%
Secondary and tertiary
secondary
14% primary, 47% secondary, 28% tertiary and 11% Quatary
Primary: 33% Secondary: 15% Tertiary: 52% Same as Philipenis'
secondary
asda is secondary
primary-81% secondary-3% tertiary-16% (includes quaternary industry which is 6% of the tertiary 16%
tertiary
Primary consumers eat primary producers(plant-eaters). Secondary consumers eat primary consumers (meat-eaters) Tertiary consumers eat secondary consumers. Quaternary consumers eat tertiary consumers.
The trachea branches off into the primary bronchus , secondary bronchus etc all the way to the alveoli.The primary bronchus is the first extension of the trachea to enter the lungs.