Optometry Admission Test (OAT) Practice

What does the mesoderm primarily form during development?

1. Inner ear and lens of the eye

2. Muscles, skeleton, and the circulatory system

3. Lining of the digestive tract

4. Nervous system and epidermis

The correct answer is: Muscles, skeleton, and the circulatory system

The mesoderm is one of the three primary germ layers formed during embryonic development, the others being the ectoderm and endoderm. It plays a critical role in the formation of various systems and structures within the body. The mesoderm primarily gives rise to several key components, including muscles, the skeletal system, and the circulatory system, which collectively are crucial for movement, support, and transportation of materials throughout the body. Muscles develop from the mesoderm as it differentiates into myoblasts, which are the cells that fuse to form muscle fibers. The skeletal system, including bones and cartilage, also originates from the mesoderm, as mesodermal cells differentiate into osteoblasts and chondroblasts. Additionally, the circulatory system, with its components such as the heart and blood vessels, is derived from mesodermal precursors that form structures like the angioblasts. In contrast, the other choices pertain to structures developed from different germ layers. The inner ear and lens of the eye are primarily derived from ectodermal tissue. The lining of the digestive tract comes from the endoderm, which also gives rise to other internal organs. Lastly, the nervous system and epiderm