Answer alveoli and blood vessels
The respiratory bronchioles have single alveoli off their walls. ... The respiratory bronchioles lead into alveolar ducts, (which are surrounded by smooth muscle, elastin and collagen), which lead into the alveolar sacs. These have several alveoli, surrounded by blood vessels - from the pulmonary system.
Explanation:
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Epiglottis
The epiglottis is a flap of cartilage the covers the entrance to the throat protecting the lungs from obstruction. It moves when we swallow to allow food in.
You would find lifeforms in these two latitudes
I believe the answer is 4 organ system<span />