**Question:** Muscles of mastication develops from

A. somites
B. neural crest cells
C. branchial arches
D. mesoderm

**Correct Answer:** A. somites

**Core Concept:** The muscles of mastication are a group of muscles that are responsible for the movements involved in chewing. These muscles are essential for the process of mastication, which is the mechanical breakdown of food in the mouth before it enters the gastrointestinal tract.

**Why the Correct Answer is Right:** The muscles of mastication develop from somites, which are paraxial mesoderm cells that form the vertebral column and adjacent structures during embryonic development. Somites give rise to the skeletal muscles of the head and neck, including the muscles of mastication. These muscles are crucial for the proper functioning of the jaw joint (temporomandibular joint) and the teeth.

**Why Each Wrong Option is Incorrect:**

B. Neural crest cells are responsible for the development of cranial nerves, ganglia, and some endocrine cells, but not skeletal muscles.
C. Branchial arches are involved in the development of structures related to the pharynx and external ear, not the muscles of mastication.
D. Mesoderm contributes to the development of various tissues and organs, but the muscles of mastication specifically develop from somites and not from mesoderm as a whole.

**Clinical Pearl:** The somites are a crucial part of the developing embryo, contributing to various structures beyond just the muscles of mastication. A thorough understanding of embryonic development helps in appreciating the complexity of human anatomy and its implications in clinical practice.

**Correct Answer Explanation:** In summary, the muscles of mastication develop from somites, which are segments of paraxial mesoderm that contribute to the formation of various skeletal structures and tissues during embryonic development. This knowledge is essential for understanding the origins of the muscles of mastication and their role in the proper functioning of the head and neck.