Primary Lessons in Physiology Author:Jane Taylor Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: LESSON THIRD. The Muscles of the Body. How many muscles are there in the human body ? It is supposed that there are not less than four hundred and fifty... more ». What is a muscle ? It is a piece of flesh. Is all flesh, then, muscle ? All the lean flesh in the body is, and this is divided into parts 5 and each part, or number of parts, united into one, is called a muscle. Of tvhat shape is a muscle ? It is long, round, and fine, like a thread. Sometimes a muscle is made up of a number of these long, fine strings of flesh ; as a skein of thread is made of a number of threads. To what are the muscles fastened ? The bones. What is the use of muscles ? They are the instruments by which we move the different parts of the body; for by them we perform every motion. How do they enable us to move ? They have the power of contracting, by which their two ends are drawn nearer to each other, thus moving the bones to which they are attached. This contracting power is subject to the will, and we exercise it when we please, without knowing how we do it. A piece of India-rubber contracts after having been stretched out, springing back to its original form. So the muscles become shorter at one time and longer at another, whenever we employ them to move the bones of the body. What is the color of the muscles ? Deep red. What appearance do they give to the body ? A full, plump appearance. When an animal has lost the greater part of its flesh, or what isthe same thing, its muscle, it looks thin and shrunken. Is a muscle the same as a cord ? No 5 a cord is white, gristly, and much more difficult to pull into pieces. Muscle is simply lean flesh, and gives form and protection to the body. v chapter{Section 4LESSON FOURTH. Muscular Effects of Ha...« less