Chapter 47, Problem 1PL

The middle layer of an artery and vein contains mostly
a. connective tissue.
b. simple squamous epithelium.
c. smooth muscle.
d. nervous tissue.

Summary Introduction

Introduction:

In most animals, the heart is a muscular organ that draws blood of the circulatory system through the blood vessels. In humans, the heart is located in the middle part of the chest, between the lungs. In humans, other mammals and birds, the heart is divided into 4 chambers: the upper left and right atria and the lower left and right ventricle.

Answer to Problem 1PL

Correct answer: 

The correct answer is option (c) smooth muscle.

Explanation of Solution

Explanation/justification for the correct answer: 

Option (c) smooth muscle. The smooth muscle lacks non-striated muscle. The smooth muscle usually forms the subsidiary tissue of blood vessels and hollow internal organs (stomach, bladder, and intestine). It is seen in the veins and arteries. So, this is the correct option.

Explanation for incorrect answer: 

Option (a) connective tissue. Connective tissue is located everywhere, including another body tissue and the nervous system. So, this is an incorrect option.

Option (b) simple squamous epithelium. They are seen in alveoli, glomeruli, capillaries, and other tissues where rapid increase is required. So, this is an incorrect option.

Option (d) nervous tissue. Nervous tissue is seen in Peripheral Nerves everywhere in the body and the Central Nervous System organs, brain, and spinal cord. So, this is an incorrect option.

Conclusion

The middle (or intermediate) layer of an artery and veins includes only smooth muscle. Hence the correct answer is option (c) smooth muscle.