Chapter 11, Problem 9SAEQ

Summary Introduction

To review:

1. The muscles developed from the somitomers.

2. The major groups of pharyngeal arch muscles.

3. The three constrictor muscles involved in squeezing swallowed food through the pharynx to the esophagus.

Introduction:

Muscles are developed from mesoderm. During the second month of development, myotomes and splanchnic mesoderm develop. Somitomers are the cells that originate from the paraxial mesoderm. These cells are the first seven myotome-like structures that are loose masses of paraxial mesoderm. Body muscles can be categorized in four functional groups based on the origin of development.