Chapter 33.2, Problem 1CYL

Summary Introduction

To explain:

The four stages of gas exchange in animals with circulatory systems and lungs.

Introduction:

In large and active animals, respiratory systems involve respiratory organs that work together as a unit to allow gas exchange between body cells and atmosphere. Respiratory systems usually work in close association with circulatory systems.

Summary Introduction

To explain:

The respiratory adaptations of fish.

Introduction:

Gills are the respiratory structures of most of the aquatic animals. The simplest type of the gills is found in mollusks (nudibranch) and most of the amphibians. In general, gills are elaborately folded and branched, increasing their surface area. Just under their outer membrane, they have a dense capillaries network that carries blood close to the surface of gills. Most type of fishes has an operculum. It is a bony flap that protects the delicate gills.

Summary Introduction

To describe:

The general respiratory adaptations for life on land, and the specific adaptations of amphibians and reptiles including birds.

Introduction:

Gills were used by aquatic animals but were useless in the air. So, animals required new adaptations that would help them to transition from water to land. Respiratory structures evolved that helped land animals to carry out gas exchange.