Structure and Function
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. With the head facing straight and the eyes facing straight ahead, the eyes are said to be in primary gaze.
What happens when the medial rectus muscle contracts?
Contraction of the medial rectus pulls the eye towards the nose (adduction or medial movement). Contraction of the lateral rectus pulls the eye away from the nose (abduction or lateral movement).
What would damage to the medial rectus affect?
The medial rectus is part of a group of skeletal muscles called the extraocular muscles of the eye. Extraocular muscle disorders, such as extraocular muscle palsy, can cause an individual to experience symptoms of visual confusion, vertigo, oscillating or rapid image movement, or double vision.
What is the location of the medial rectus muscle?
Like the other eye muscles, inferior oblique is named by its position within the orbit, relative to the eyeball. It occupies the inferior aspect of the orbit, encircling the lower portion of the eyeball. The primary action of this muscle is to elevate and abduct (laterally move) the eyeball.
What is the action of the medial rectus?
Function. When contracting, each medial rectus muscle adducts the eyeball, i.e. pulls the eye medially. This action is important in two types of ocular movements; conjugate and disconjugate. Conjugate movements are when both eyeballs move in the same direction.
What is the medial rectus medial to?
Medial rectus | |
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Origin | annulus of Zinn at the orbital apex |
Insertion | 5.5 mm medial to the limbus |
Nerve | inferior division of the oculomotor nerve |
Actions | adducts the eyeball (makes it move inwards) |
Why are eyes constantly moving?
However, because we have such a smooth, clear view of the world, it can be easy to overlook how much hard work our eyes and brain have to do to create this experience. Actually, our eyes are constantly moving in order to provide the brain with new information about the world around us.
What nerve controls medial Eye Movement?
The oculomotor nerve innervates the medial rectus muscle (adductor of the eye), superior rectus and inferior oblique muscles (elevators of the eye), and inferior rectus muscle (depressor of the eye).
Why do my eyes move from side to side?
Nystagmus is a vision condition in which the eyes make repetitive, uncontrolled movements. These movements often result in reduced vision and depth perception and can affect balance and coordination. These involuntary eye movements can occur from side to side, up and down, or in a circular pattern.
What is medical rectus?
Reviewed on 3/29/2021. Rectus: Usually refers to the rectus abdominis, a large muscle in the front of the abdomen that assists in the regular breathing movement and supports the muscles of the spine while lifting and keeping abdominal organs such as the intestines in place.
What artery supplies medial rectus?
The superior rectus is supplied by branches of the ophthalmic artery and the lacrimal artery (1 to 5 pedicles). The medial rectus is supplied by branches of the ophthalmic artery and the inferior muscular artery (5 to 9 branches).
What is medial rectus recession?
Overview. Recession of the medial rectus is a measured retroplacement of the muscle from its original insertion. It is the easiest and most effective way of weakening the medial rectus and is the most commonly performed procedure in strabismus management.
Where is the superior rectus muscle?
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 is the function of superior rectus?
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.
What muscle moves to the left eye to the left?
The lateral rectus is an extraocular muscle that attaches to the side of the eye near the temple. It moves the eye outward.
What muscle elevates the eyeball?
The first of these muscles, the superior rectus muscle, elevates the eye, allowing the eye to look up. The antagonist of the superior rectus muscle is the inferior rectus muscle, which depresses the eye, allowing the eye to look down.
What are marriage muscles?
7-Muscle of marriage – medial rectus.
Which muscle contracts when you pucker your lips?
The circular muscle around our mouth is Orbicularis Oris and this muscle brings our lips together so we can pucker up for a kiss!
Which muscles are obliques?
Oblique muscle refers to two abdominal muscles – the external and internal obliques. These provide trunk flexion and rotation. The external oblique is the thickest and runs from the lower ribs to the iliac crest.
What cranial nerve is responsible for movement of the medial rectus superior rectus inferior rectus and inferior oblique muscles?
The Oculomotor Nerve or Cranial Nerve III. The oculomotor nerve provides motor innervation to the levator palpebrae superioris, the superior, medial and inferior rectus muscles, and the inferior oblique muscle. All these muscles insert directly onto the globe and move the eye within the orbit.
What is dancing eye syndrome?
Dancing eye syndrome (DES) or Opsoclonus myoclonus syndrome (OMS) is a very rare neurological condition which usually develops in the second or third year of life. The syndrome gets its name from the very unusual and characteristic eye movements, which are almost always present.
Can eyes cause vertigo?
The extra stress on the eye muscles can cause them to quiver, which can lead to light-headedness or dizziness. Eye misalignment that causes dizziness can be so slight that it is often overlooked in routine eye exams.
Why do I feel funny when I move my eyes?
Oscillopsia usually occurs as a result of conditions that affect eye movement or alter how parts of the eye, inner ear, and brain stabilize images and maintain balance. It often links to types of nystagmus, which is a condition that causes abnormal or involuntary eye movement.
What part of the brain controls eye muscles?
The occipital lobe is the back part of the brain that is involved with vision.
What cranial nerve controls neck and shoulder movements?
The accessory nerve (cranial nerve XI) controls the muscles of the shoulder and neck.
Which rectus muscle inserts nearest to the limbus?
Insertion relationships
The tendon of the medial rectus muscle inserts 5.5 mm posterior to the limbus along the medial aspect of the globe. Next most posterior in its insertion is the inferior rectus, which inserts 6.5 mm posterior to the inferior limbus.
What is unspecified Papilledema?
Papilledema is a serious medical condition where the optic nerve at the back of the eye becomes swollen. Symptoms can include visual disturbances, headaches, and nausea. Papilledema occurs when there is a buildup of pressure in or around the brain, which causes the optic nerve to swell.
What is inferior rectus?
The inferior rectus is one of the seven extraocular muscles and is primarily responsible for depressing the eye (downgaze). The inferior rectus is one of the four rectus muscles, which also include the superior rectus, the medial rectus, and the lateral rectus.
Which two arteries meet within the rectus sheath?
The superior and inferior epigastric arteries anastomose with each other at the level of umbilicus after entering into the rectus sheath. The space between the right and left rectus abdominis muscles is filled with the thickening of the anterior wall of the rectus sheath.
How many rectus muscles are there?
These muscles are the four rectus muscles—the inferior, medial, lateral, and superior recti—and the superior and inferior oblique muscles.
What is lacrimal artery?
49927. Anatomical terminology. The lacrimal artery is an artery of the orbit around the eye. It arises close to the optic foramen, and is a branch of the ophthalmic artery. It accompanies the lacrimal nerve along the upper border of the lateral rectus muscle.
What supplies blood to the muscles of the eye?
The primary blood supply for all of the extraocular muscles are the muscular branches of the ophthalmic artery, the lacrimal artery, and the infraorbital artery. The ophthalmic artery has two muscular branches, which are the superior and inferior muscular branches.
Which artery supplies blood to the brain eyes and forehead?
The left common carotid artery is the second main branch and arises directly off the aorta. The left and right carotid arteries carry blood and oxygen to the brain and head and face.
What is strabismus surgery called?
Strabismus surgery | |
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Specialty | ophthalmology |
What is ESO deviation?
A tendency for the eyes to turn inward, prevented by binocular vision.
How is strabismus surgery done?
STRABISMUS SURGERY
Rather, a small incision is made on the clear membrane covering the white part of one or both eyes. Through this incision, the appropriate surgery is then performed on the surface of the eye to eliminate the strabismus. The inside of the eyeball is not entered during this type of surgery.
What cranial nerve innervates the medial rectus muscle?
The third cranial nerve supplies the levator muscle of the eyelid and four extraocular muscles: the medial rectus, superior rectus, inferior rectus, and inferior oblique. These muscles adduct, depress, and elevate the eye.
Is the superior rectus smooth muscle?
Superior rectus | |
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Origin | annulus of Zinn at the orbital apex |
Insertion | 7.9 mm superior to the corneal limbus |
Nerve | oculomotor nerve |
Which is the strongest extraocular muscle?
The medial rectus had the strongest trend between increasing diameter and motility restriction, followed by the inferior rectus and the superior muscle group (comprised of the superior rectus and levator palpebrae superioris).