Chapter 47.2, Problem 2LO

Summary Introduction

To explain: The advantage of countercurrent flow.

Introduction: Gas exchange is the physical process by which gases move passively by the diffusion across a surface. Gases are constantly produced and consumed by metabolic and cellular reactions in most living things. Most larger organism have a small surface area to volume ratios and the specialized structures such as pulmonary alveoli, gills, and spongy mesophyll gives the larger area needed for the effective exchange of gas.