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Where is the inferior rectus muscle located?
The inferior rectus muscle passes along the floor of the orbit superior to the infraorbital canal, which houses the infraorbital artery. As it inserts onto the anteromedial part of the sclera, the inferior rectus muscle is covered by the inferior oblique muscle.
What is the action of the superior rectus muscle?
The superior rectus has a primary action of elevating the eye, causing the cornea to move superiorly. The superior rectus originates from the annulus of Zinn and courses anteriorly and superiorly over the globe, making an angle of 23 degrees with the visual axis.
Where is the superior oblique muscle located?
The superior oblique muscle lies above the medial rectus, with the nasociliary nerve and the ophthalmic artery lying between them. Innervation is by the trochlear nerve, cranial nerve IV, which enters the posterior area of the muscle.
Where are the superior and inferior rectus muscles?
The superior rectus muscle is longer than other rectus muscles [3] and originates superior and lateral to the optic nerve. The origin of the inferior rectus muscle is located below the optic nerve.
How do you test for inferior rectus muscle?
To test the inferior rectus from the superior oblique, the clinician asks the patient to first look out (or lateral) to orient the visual gaze axis perpendicular to the superior oblique muscle fiber direction, then down.
How does inferior rectus move the eye?
The inferior rectus has a primary action of depressing the eye, causing the cornea and pupil to move inferiorly. The inferior rectus originates from the Annulus of Zinn and courses anteriorly and laterally along the orbital floor, making an angle of 23 degrees with the visual axis.
What is the function of superior rectus?
It is one of the extraocular muscles. It is innervated by the superior division of the oculomotor nerve (Cranial Nerve III). In the primary position (looking straight ahead), the superior rectus muscle’s primary function is elevation, although it also contributes to intorsion and adduction.
What nerve controls superior rectus?
The superior rectus is innervated by the superior division of the oculomotor nerve, which enters the muscle on its inferior face. Branches pass either through the muscle or around it to innervate the levator.
What is the main function of the superior oblique muscle?
The superior oblique is a fusiform (spindle-shaped) muscle belonging to the extraocular group of muscles. It originates near the nose. Along with the other extraocular muscles, it performs the role of controlling eye movements.
What movement does superior oblique do?
These muscles are unique in that they do not originate from the common tendinous ring, have an angular attachment to the eyeball, and they attach to the posterior aspect of the eyeball. The superior oblique functions explicitly to move the eye in the down-and-out position and intort the eye.
Where is the superior rectus located in the eye?
Superior rectus muscle (Musculus rectus superior) Superior rectus is one of the extrinsic muscles of the eye. Being located outside the eyeball but within the orbit, it belongs to a group called the extraocular muscles. This group of muscles serves to move the eyes within the orbit.
What kind of muscle is the superior rectus?
The superior rectus muscle is a muscle in the orbit. It is one of the extraocular muscles. It is innervated by the superior division of the oculomotor nerve (Cranial Nerve III).
Where is the tendon of insertion for the superior rectus located?
The tendon of insertion for the superior oblique muscle runs below the anterior part of the superior rectus muscle (see Figure 10-7 ). The superior rectus is innervated by the superior division of the oculomotor nerve, which enters the muscle on its inferior face.
Where is the rectus abdominis located in the body?
The rectus abdominis muscle is contained in the rectus sheath, which consists of the aponeuroses of the lateral abdominal muscles. Bands of connective tissue called the tendinous intersections traverse the rectus abdominis, which separates this parallel muscle into distinct muscle bellies.