Musculus rectus inferior is a Latin term used to describe the inferior straight muscle of the eye. This muscle aids in downward movement of the eye. The pronunciation of this term can be tricky due to its Latin origin. The IPA phonetic transcription of this word is /ˈmʌskjʊləs ˈrɛktəs ɪnˈfɪərər/. The first two syllables, /ˈmʌskjʊləs/, are pronounced with stress on the first syllable. The final two syllables, /ɪnˈfɪərər/, are pronounced with stress on the second syllable.
The musculus rectus inferior, commonly referred to as the inferior rectus muscle, is one of the six extraocular muscles responsible for controlling the movement of the eyeball. It is located within the eye socket and originates from the region of the common tendinous ring.
The muscle extends downward and forward from the origin to attach to the eyeball, specifically on the lower one-sixth of the eye's anterior surface. Its main function is to rotate the eyeball downwards or depress it, allowing for the downward movement of the eye.
The inferior rectus muscle is innervated by the inferior division of the oculomotor nerve (cranial nerve III), which plays a crucial role in transmitting the signals from the brain to the muscle, enabling coordinated eye movements. This innervation also facilitates the muscle's involvement in the convergence of both eyes towards the midline, a process known as medial rotation.
Any dysfunction or impairment of the musculus rectus inferior can lead to a range of ocular conditions and symptoms, such as limited or excessive downward eye movement, double vision, or misalignment of the eyes. The muscle's significance in eye movement and the intricate interplay with other ocular muscles underscores its importance in maintaining proper vision and eye coordination.
Overall, the inferior rectus muscle is an essential component of the complex eye apparatus, working in conjunction with other ocular muscles to facilitate precise and controlled eye movements.
Origin, by a common tendon with the rectus medialis, the annulus tendineus communis or ligament of Zinn, from the lower and inner margin of the optic foramen; insertion, sclerotic coat of the eye; nerve supply, oculomotorius; action, moves eyeball downward.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.