Chapter 46, Problem 15TYK

Summary Introduction

To review:

Whether lungs evolved once or on over several occasions.

Introduction:

Lungs are air-filled, spongy organs of respiration located on either side of the thorax. They consist of tubular branches called bronchi, which divide into smaller and narrower branches called bronchioles. The bronchioles further branch into a cluster of microscopic air sacs, called alveoli. Lungs helped animals to adapt to the terrestrial environment.