Chapter 37.5, Problem 12SAQ

Summary Introduction

To draw:

The path of blood flow through heart, lungs, and body of a fish, mammals, or bird.

Introduction:

Blood is a fluid which has the property of flowing through different pathways inside the body of an organism. Blood has several components such as RBCs, WBCs, platelets and plasma. Blood act as a carrier for different types of materials like, nutrients, waste products, gases like oxygen, nitrogen, carbon dioxide.

Explanation of Solution

Pictorial representation:

Fig.1 - Path of blood flow in fish.

Fig.2: The blood flow diagram in mammals or in birds.

The pathway of blood flow in the fish is given in the diagram above. In fishes, the deoxygenated blood enters into the heart, first it goes into the atrium and then, it enters into the ventricle. From the heart it enters into the gills where the blood becomes oxygenated. The oxygenated blood goes to the all parts of the body tissues. From the body tissues is returns back to the heart.

In mammals or birds the deoxygenated blood enters into the heart through vena cava and goes to the right atrium followed by the right ventricle. From the right ventricle, the blood is entered into the lungs by the pulmonary artery. The blood is now oxygenated and enters into the left atrium followed by the left ventricle. The oxygenated blood comes out of the heart through the aorta and is transported to the rest of the body.

Conclusion

The blood is fluid in nature which continuously flows in the body of an organism like fishes, birds and mammals through a number of blood vessels present in the body.