MRCP UK EXAMINATIONS

Detailed explanation-1: -The extraocular muscles are composites of connective and muscle tissue that have embryologic origins in different locations. In the vertebrate head, connective tissue and smooth muscle is formed from the neural crest, an ectodermal structure, rather than from mesoderm, as occurs in the trunk.

Detailed explanation-2: -It has previously been suggested that extraocular muscles develop from mesoderm surrounding the head cavities and grow anteriorly into the orbit.

Detailed explanation-3: -Extraocular Muscles The four rectus muscles have their origin on the common tendinous ring (annulus of Zinn). This oval band of connective tissue is continuous with the periorbita and is located at the apex of the orbit anterior to the optic foramen and the medial part of the superior orbital fissure.