Related Experiment Video
Updated: Apr 14, 2026

Ocular Kinematics Measured by In Vitro Stimulation of the Cranial Nerves in the Turtle
Published on: June 2, 2018
Tendinous muscle insertions (scleromuscular junctions of the recti muscles) in patients with ocular alignment
M G Todorova1, A M Palmowski-Wolfe1, P Meyer1
1Department of Ophthalmology, University of Basel, Basel, Switzerland (Chairman a. i.: Dr. sc. nat. Norbert Spirig).
Background:
The purpose of this study was to prove the hypothesis whether the scleromuscular junction of extraocular recti muscle is tendinous.
Patients And Methods:
Muscle samples of the 41 extraocular recti muscles of 33 patients and 4 muscle-/eye-matched samples from 2 postmortem eyes, were processed for light/electron microscopy and immunohistochemistry with antibodies against desmin, smooth-muscle actin and muscle regulating proteins like myf3 and myf4 (myogenin), tenascin C and for 8 samples against collagens I to IV.
Results:
Histological examination of the muscle samples confirmed a thick collagen-structured tissue, specific for muscle tendon; without appearance of muscle tissue. This was confirmed by immunohistochemistry with antibodies against desmin, smooth-muscle actin, myf3 and myf4 (myogenin) and for eight samples with collagens I to IV. Anti-tenascin C marker was only strongly positive in the connective tissue of the blood vessel walls. Electron microscopy demonstrated collagen bundles composed of parallel oriented fibrils with a moderate amount of ground substance.
Conclusions:
The absence of contractile fibers at the sclerotendinous junction is an entirely normal finding in humans and cannot be related to ocular alignment pathogenesis.
More Related Videos
Related Concept Videos
Muscles of the Eye
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and...
Accessory Structures of the Eye
Muscles for Facial Expressions
Muscles of the Anterior Neck
Muscles that Move the Head
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
Muscle Coordination and Action
Agonists
Agonist muscles, often called prime movers, are the primary muscles responsible for producing a specific movement....

