why is lateral rectus called muscle of divorce

What is the anatomy of the lateral rectus?

Anatomical terms of muscle. The lateral rectus muscle is a muscle on the lateral side of the eyeball in the orbit. It is one of six extraocular muscles that control the movements of the eye. The lateral rectus muscle is responsible for lateral movement of the eyeball, specifically abduction.

What happens if the lateral rectus muscle is paralyzed?

The lateral rectus muscle will be denervated and paralyzed and the patient will be unable to abduct the eye. For example, if the left abducens nerve is damaged, the left eye will not abduct fully.

Why does the abducens nerve innervate only the lateral rectus?

Since the abducens nerve only innervates the lateral rectus, other extraocular muscles will not be affected. Therefore, the muscle that is functionally antagonistic to the lateral rectus will overpower it and pull the eyeball on their side.

How far does the lateral rectus innervate the inferior rectus?

It then enters the medial surface of the lateral rectus to innervate it. The insertion of the lateral rectus muscle is around 8 mm from the insertion of the inferior rectus muscle, around 7 mm from the insertion of the superior rectus muscle, and around 10 mm from the corneal limbus. [3]

Which muscle is called muscle of marriage?

Sartorius muscleOriginAnterior superior iliac spine of the pelvic boneInsertionanteromedial surface of the proximal tibia in the pes anserinusArteryfemoral arteryNervefemoral nerve (sometimes from the intermediate cutaneous nerve of thigh)9 more rows

What is the purpose of lateral rectus muscle?

The lateral rectus is one of the seven extraocular muscles. These muscles control every movement of the eye; usually, one muscle moves the eye in one direction, and the combination of all of them allows the eye to move in every direction.

What is the function of the medial and lateral rectus?

The medial rectus is an adductor, and functions along with the lateral rectus which abducts the eye. These two muscles allow the eyes to move from side to side.

How can you distinguish between medial and lateral rectus?

The lateral rectus (LR) is flat muscle located alongside the lateral wall of the orbit. The sixth cranial (abducens) nerve provides innervation of the muscle. The medial rectus (MR) is located alongside the medial wall of the orbit.

What is the primary function of the lateral rectus muscles quizlet?

The lateral rectus muscle is a muscle in the orbit. It is one of six extraocular muscles that control the movements of the eye (abduction in this case) and the only muscle innervated by the abducens nerve, cranial nerve VI. Its function is to bring the pupil away from the midline of the body.

What nerve serves the lateral rectus muscle?

abducens nerveThe abducens nerve (cranial nerve VI) exits the brainstem from the pons-medullary junction and innervates the lateral rectus muscle.

How does the lateral rectus move the eye?

The lateral rectus muscle is responsible for lateral movement of the eyeball, specifically abduction. Abduction describes the movement of the eye away from the midline (i.a. nose), allowing the eyeball to move horizontally in the lateral direction, bringing the pupil away from the midline of the body.

Is the lateral rectus muscle horizontal or vertical?

Medial and lateral rectus muscles have only horizontal actions. The medial rectus muscle is the primary adductor of the eye, and the lateral rectus muscle is the primary abductor of the eye.

Where is the lateral rectus located?

The lateral rectus muscle arises from the common tendinous ring and runs anteriorly and across the lateral part of the orbit to insert at the lateral side of the eyeball. Like other straight muscles, the lateral rectus is named by its position within the orbit relative to the eyeball.

Which eye muscle is used to make you look cross eyed?

Oblique (Eye) Muscles.

What are the muscles that move the eye called?

There are six extraocular muscles that move the globe (eyeball). These muscles are named the superior rectus, inferior rectus, lateral rectus, medial rectus, superior oblique, and inferior oblique.

How do you test lateral rectus muscle?

The lateral and medial rectus muscles are tested by asking the patient to look to the right then to the left. The actions of the superior and inferior rectus muscles are isolated by testing them when the optic axis is aligned along the orbital axis, (requiring the patient to look laterally) one eyeball at a time.

What is the function of the inferior rectus muscle?

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 controls the movement of the eye?

The brain exerts ultimate control over both voluntary and involuntary eye movement. Three cranial nerves carry signals from the brain to control the extraocular muscles.

Which nerve is responsible for lateral eye movement?

Abducens nerveAbducens nerve (CN VI) The abducens nerve innervates the lateral rectus muscle of the eye. It is responsible for lateral eye movements. Injury to this nerve prevents such movement. Injury to this nerve can cause double vision.

How do you check lateral rectus muscle?

0:204:04Clinical testing extraocular muscles tutorial - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo how will you clinically test these two muscles. And their associated cranial nerves to do that weMoreSo how will you clinically test these two muscles. And their associated cranial nerves to do that we take them look at their actions well the lateral rectus a B ducts the eye.

What is the lateral rectus?

The lateral rectus is on the right side of the image. Figure showing the mode of innervation of the Recti medialis and lateralis of the eye. The lateral rectus muscle is a muscle on the lateral side of the eyeball in the orbit. It is one of six extraocular muscles that control the movements of the eye. The lateral rectus muscle is responsible ...

What is the disorder of the lateral rectus muscle?

In addition, another disorder associated with the lateral rectus muscle is Duane Syndrome. This syndrome occurs when the sixth cranial nerve which controls the lateral rectus muscle does not develop properly.

What causes the abducens nerve to be damaged?

Damage to the abducens nerve by trauma can be caused by any type of trauma that causes elevated intracranial pressure; including hydrocephalus, traumatic brain injury with intracranial bleeding, tumors, and lesions along the nerve at any point between the pons and lateral rectus muscle in orbit.

What is the sixth nerve palsy?

A sixth nerve palsy, also known as abducens nerve palsy, is a neurological defect that results from a damaged or impaired abducens nerve. This damage can stem from stroke, trauma, tumor, inflammation, and infection. Damage to the abducens nerve by trauma can be caused by any type of trauma that causes elevated intracranial pressure; including hydrocephalus, traumatic brain injury with intracranial bleeding, tumors, and lesions along the nerve at any point between the pons and lateral rectus muscle in orbit. This defect can result in horizontal double vision and reduced lateral movement. The lateral rectus muscle will be denervated and paralyzed and the patient will be unable to abduct the eye. For example, if the left abducens nerve is damaged, the left eye will not abduct fully. While attempting to look straight ahead, the left eye will be deviated medially towards the nose due to the unopposed action of the medial rectus of the eye. Proper function of the lateral rectus is tested clinically by asking the patient to look laterally. Depending on the underlying cause of the lateral rectus palsy, some improvement may occur naturally over time. While the prognosis for a lateral rectus palsy onset by a viral illness is generally positive, the prognosis for an onset of trauma or tumor is quite poor. Ultimately, nerves are not very good at regenerating or healing themselves, so if the damage is severe there will be permanent damage.

Why is my left eye deviated towards the nose?

While attempting to look straight ahead, the left eye will be deviated medially towards the nose due to the unopposed action of the medial rectus of the eye. Proper function of the lateral rectus is tested clinically by asking the patient to look laterally.

Which nerve exits the pontomedullary junction of the brainstem?

These neurons project axons as the abducens nerve which exit from the pontomedullary junction of the brainstem, travels through the cavernous sinus and enter the orbit through the superior orbital fissure. It then enters the medial surface of the lateral rectus to innervate it.

Where does the lateral rectus originate?

The lateral rectus originates at the lateral part of the annulus of Zinn, also known as the annular tendon or common tendinous ring, and inserts into the temporal side of the eyeball.

Where does the lateral rectus muscle originate?

The lateral rectus muscle has its origin on both limbs of the common tendinous ring and the spina recti lateralis, a prominence on the greater wing of the sphenoid bone. The lateral rectus muscle parallels the lateral orbital wall until it passes through a connective tissue pulley just posterior to the equator of the globe; at this point it follows the curve of the globe to its insertion. 34,35 The insertion parallels that of the medial rectus and is approximately 6.9 mm from the limbus, and the length of the tendon is approximately 8.8 mm. 5

Which muscle innervates the lateral rectus?

CN VI innervates the lateral rectus muscle; damage results in ipsilateral paralysis of lateral gaze. CN IV innervates the superior oblique muscle; damage results in inability to look in and down (most conspicuous when climbing stairs, stepping off a curb, reading in bed). CN III (oculomotor nuclei) innervates the medial rectus, superior rectus, inferior rectus, and inferior oblique muscles (damage results in paralysis of the ipsilateral medial gaze) and also innervates the levator palpebrae superioris muscle (damage results in profound ptosis). The ciliary ganglion gives rise to postganglionic parasympathetic axons that supply the pupillary constrictor muscle and the ciliary muscle; damage results in a fixed and dilated pupil that does not constrict for the pupillary light reflex and does not accommodate to near vision.

What nerves are involved in the lateral rectus?

The abducens (sixth) nerve supplies the lateral rectus muscle. Selective involvement of the abducens nerve anywhere along its pathway leads to isolated weakness of abduction of the affected eye. Destruction of the abducens nucleus in the brain stem results in a conjugate gaze paralysis (ipsilateral) because, in addition to oculomotor neurons, the nucleus contains interneurons destined for the contralateral medial rectus nucleus. The trochlear (fourth) nerve supplies the contralateral superior oblique muscle, which turns in and depresses the eye. Patients with superior oblique weakness note an increase in diplopia with head tilt toward the side of weakness and often tilt their head in the opposite direction. At rest, there is slight upward deviation of the involved eye, and downward movement is impaired when the affected eye is turned in. Patients typically complain of diplopia when reading or going down stairs. The third (oculomotor) cranial nerve supplies the remaining ocular muscles. Involvement of the third nerve nucleus in the midbrain always produces at least some bilateral oculomotor weakness; the superior rectus division of the nucleus supplies the contralateral superior rectus muscle (all other divisions supply ipsilateral muscles). Peripheral third nerve paralysis can result from lesions damaging the structure anywhere from its course within the ventral midbrain to where it enters the orbit through the superior orbital fissure. When complete, third nerve palsy produces a widely dilated pupil, severe ptosis, and an externally deviated eye held in position by unopposed contraction of the lateral rectus muscle. In such conditions, the continued trochlear action reveals itself by intorsion of the eye when the subject attempts to look down.

What is the differential diagnosis of 6th nerve palsy?

The differential diagnosis of sixth nerve palsy includes any situation where the ipsilateral medial rectus fails to relax (early injury, orbital blowout fracture, myopathy, thyroid orbitopathy), or congenital dysinnervation such as Duane syndrome. In Möbius syndrome congenital hypoplasia of cranial nerve nuclei includes at least CN VI and CN VII, and often many others including CN V and CN VIII.

What nerve innervates the lateral rectus muscle of the eye?

The abducens nerve innervates the lateral rectus muscle of the eye. It is responsible for lateral eye movements. Injury to this nerve prevents such movement. Injury to this nerve can cause double vision. Owing to its lengthy nature, multiple areas of the nerve have the potential to be damaged, whether at its nucleus or along cranial bone areas. It is difficult to locate the area of damage. But if this nerve is damaged, other cranial nerves are frequently also injured.18 Injury to this nerve occurs at a rate of 0.4%–4.1%. 21

What are the six ocular muscles?

The six ocular muscles—superior, inferior, medial, and lateral recti and superior and inferior obliques—are responsible for movements of the globe ( Fig. 1-7 ). Cranial nerve VI innervates the lateral rectus, which abducts (turns out) the eye. Cranial nerve IV innervates the superior oblique, which abducts, depresses, and intorts (rotates in) the eye. Cranial nerve III innervates the medial rectus, inferior rectus, superior rectus, and inferior oblique muscles. The medial rectus adducts (turns in) the eye, the inferior rectus depresses the eye, the superior rectus elevates the eye, and the inferior oblique abducts, elevates, and extorts (rotates out) the eye. Cranial nerve III also innervates the levator muscle, which is responsible for lid elevation. (The cardinal movements of the eye are shown in Fig. 1-8 .)

Which axons are innervated by the abducens and oculomotor nucle?

requires the coordinated action of the lateral and medial rectus muscles, which are innervated by the abducens and oculomotor nuclei (medial rectus subdivision), respectively. The afferent limb of the H-VOR is conveyed by the horizontal semicircular canal ampullary nerves. These axons form monosynaptic excitatory contacts with cells in the ipsilateral MVN and vLVN ( McCrea et al., 1987a,b ), which in turn send glycinergic inhibitory ipsilateral projections and excitatory glutamatergic contralateral inputs to abducens motor and internuclear neurons ( Spencer and Baker, 1992 ). Medial rectus motoneurons in the oculomotor complex receive the monosynaptic excitatory input from ipsilateral vLVN via the ascending tract of Deiters (ATD) ( Muskens, 1913; Gacek, 1971 ), and the disynaptic excitatory input from the contralateral abducens internuclear neurons via the ascending MLF ( Highstein and Ito, 1971 ). The ipsilateral projection from vLVN to the oculomotor complex carried in ATD constitutes a notable exception to the overall VOR connectivity scheme which otherwise embodies inhibitory ipsilateral and excitatory contralateral projections The ATD conveys projections to medial rectus motoneurons, and also includes a contingent of fibers, probably from a separate vLVN neuronal population, that continues rostrally to terminate in the thalamus ( Highstein and Holstein, 2006 ).

What is the action of the lateral rectus?

Action. The action of the lateral rectus is to abduct the eye (see figure 1) 1. Unlike most of the other extraocular muscles, it has no significant contribution to movement in the other ocular axes.

Where is the lateral rectus?

Lateral rectus runs anteriorly on the medial surface of the eye and inserts into the lateral surface of the sclera just posterior to the junction of cornea and sclera 2.

What does the rectus mean?

Rectus comes from the Latin rectos, meaning straight 1. oculomotor nerve palsy. as the lateral rectus and superior oblique muscles are the only extraocular muscles not supplied by the oculomotor nerve, the unopposed force generated by these muscles results in depression and abduction of the affected eye. abducens nerve palsy.

Which nerve supplies the rectus?

Lateral rectus is unique among the extraocular muscles in being supplied by the abducens nerve.

Where does the word "rectus" come from?

Rectus comes from the Latin rectos, meaning straight 1.

Which muscle is responsible for abduction?

The lateral rectus muscle is one of the six extraocular muscles that control eye movements. It is responsible for abduction and is the only muscle that is innervated by the abducens nerve (CN VI).

What nerve innervates the lateral rectus?

The sixth nerve or the Abducens nerve is often referred to as the lover's nerve because the nerve innervates the muscle “Lateral Rectus”, a muscle whose contraction used to facilitate nonverbal communication between lovers in a conservative setup.

Which muscle rotates the eye ball sideways?

The contraction of the lateral rectus muscle rotates the eye ball sideways (laterally).

What muscle is used to move the eye inward?

Relating to the lateral rectus muscle that called divorce muscle because the lovers eye communicates indirectly through the movement of eyeball laterally to see the girl and that cause divorce .Medial rectus called marriage muscle because when you decide to chose you wife you should concentrate your eye to the girl you want and that occur throug medial rectus that move the eye inward .

What is Sartorius called?

Sartorius is called the honeymoon muscle. Apparantly whatever happens in honeymoon requires the sternous use of this muscle (lateral rotation of thigh). So It is named after it.

How many recti are there in the eyeball?

The eyeball has an assortment of muscles attached to it that assist and facilitate its movement. They are four recti and two obliques, as demonstrated in the picture.

Overview

Structure

Function

Clinical significance

Additional images

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