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Information about Superior Oblique Muscle

Superior oblique
Rectus muscles:
2 = superior, 3 = inferior, 4 = medial, 5 = lateral
Oblique muscles: 6 = superior, 8 = inferior
Other muscle: 9 = levator palpebrae superioris
Other structures: 1 = Annulus of Zinn, 7 = Trochlea, 10 = Superior tarsus, 11 = Sclera, 12 = Optic nerve
Sagittal section of right orbital cavity.
Latinmusculus obliquus superior bulbi
subject #227 1022
Origin:annulus of Zinn at the orbital apex, medial to optic canal
Insertion:Outer posterior quadrant of the eyeball
Artery:lateral muscular branch of the ophthalmic artery
Nerve:trochlear nerve
Action:primary action is intorsion; secondary actions are to abduct (laterally rotate) and depress the eyeball (i.e. it makes the eye move outward and downward)
Dorlands/Elsevier m_22/12549898
For the abdominal muscle see: External oblique muscle

The superior oblique muscle, or obliquus oculi superior, is a fusiform muscle in the upper, medial side of the orbit whose primary action is intorsion and whose secondary actions are to abduct (laterally rotate) and depress the eyeball (i.e. it makes the eye move outward and downward). One of the extraocular muscles, the superior oblique is the only muscle innervated by the trochlear nerve.

The primary action of the superior oblique muscle is intorsion; the secondary action is depression (primarily in the adducted position); the tertiary action is abduction. A brief survey of neurology and physiology texts and websites reveals much confusion about the role of the superior oblique muscle, with many sources claiming that its role is to move the eye towards the nose. In fact, because of its positioning, it is able to rotate the eye away from the nose so that when the eye is already adducted (looking directly "inwards") its rotational action turns the pupil downwards to look towards the mouth, which many texts misinterpret as its primary action.

Usually the eye muscles do not work alone, which leads to the confusion of the primary actions. The superior oblique intorts, depresses, abducts the eye if it were to work by itself. Normally, the superior oblique, in conjunction with the medial rectus, causes the eye to ADduct.

The origin for the superior oblique is the annulus of Zinn at the orbital apex. It loops through a pulley like structure (the trochlea of superior oblique) and inserts on the posterotemporal surface of the eyeball.

It arises immediately above the margin of the optic foramen, above and medial to the origin of the superior rectus, and, passing forward, ends in a rounded tendon, which plays in a fibrocartilaginous ring or pulley attached to the trochlear fovea of the frontal bone.

The contiguous surfaces of the tendon and ring are lined by a delicate mucous sheath, and enclosed in a thin fibrous investment.

The tendon is reflected backward, lateralward, and downward beneath the superior rectus to the lateral part of the bulb of the eye, and is inserted onto the scleral surface, behind the equator of the eyeball, the insertion of the muscle lying between the superior rectus and Rectus lateralis.

Clinical significance

Superior oblique palsy is a common complication of closed head trauma. Restriction of superior oblique movement is found in Brown syndrome, leading to difficulty elevating the eye in the adducted position.

Superior oblique myokymia is an uncommon neurological condition caused by vascular compression of the trochlear nerve resulting in repeated, brief, involuntary episodes of movement of the eye.

Operations of the superior oblique include tenotomy, recession, silicone expander lengthening, split tendon lengthening, tucking, and the Harada-Ito procedure.

Additional images


Nerves of the orbit. Seen from above.

Dissection showing origins of right ocular muscles, and nerves entering by the superior orbital fissure.


External links

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
 •  • [ e]
Muscles of head and neck: the head
scalp/eyelidoccipitofrontalis (occipitalis, frontalis) - orbicularis oculi - corrugator supercilii - depressor supercilii
extraocularlevator palpebrae superioris - superior tarsal - rectus (superior, inferior, medial, lateral) - oblique (superior, inferior) - intraocular: ciliary - iris dilator - iris sphincter
earauriculares - temporoparietalis - stapedius - tensor tympani
noseprocerus - nasalis (dilatator naris) - depressor septi nasi - levator labii superioris alaeque nasi
mouthlevator anguli oris/depressor anguli oris - levator labii superioris/depressor labii inferioris - zygomaticus (major, minor) - mentalis - buccinator - orbicularis oris - risorius
masticationmasseter - temporalis - pterygoid (lateral, medial)
tongueextrinsic (genioglossus, hyoglossus, chondroglossus, styloglossus) - intrinsic (superior longitudinal, inferior longitudinal, transversus, verticalis)
soft palatelevator veli palatini - tensor veli palatini - musculus uvulae - palatoglossus - palatopharyngeus
pharynxpharyngeal constrictor (inferior, middle, superior) - stylopharyngeus - salpingopharyngeus
larynxcricothyroid - cricoarytenoid (posterior, lateral) - arytenoid - thyroarytenoid
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).
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The inferior rectus muscle is a muscle in the orbit.

Actions

It depresses, adducts, rotates laterally, and extorts the eye.

Innervation

As with most of the muscles of the orbit, it is innervated by the oculomotor nerve (Cranial Nerve III).
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The medial rectus muscle is a muscle in the orbit.

As with most of the muscles of the orbit, it is innervated by the inferior division of the oculomotor nerve (Cranial Nerve III).
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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.
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The Obliquus oculi inferior (inferior oblique) is a thin, narrow muscle, placed near the anterior margin of the floor of the orbit.

Action

Its actions are lateral rotation, elevation and abduction of the eye.
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The levator palpebrae superioris (or levator muscle of upper eyelid) is the muscle in the orbit that elevates the superior (upper) eyelid.

Structure

The levator palpebrae superioris originates on the lesser wing of the sphenoid bone, just above the optic foramen.
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The annulus of Zinn, also known as the annular tendon, circle of Zinn-Haller or common tendinous ring, is a ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit. It is the origin for five of the six extraocular muscles.
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The Trochlea of superior oblique is a pulley structure in the eye through which the superior oblique muscle passes.

Additional images




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Tarsus (from the Greek ταρσός, for "flat basket") may refer to:
  • Tarsus (skeleton), the skeletal region between the tibia and fibula and the metatarsus
  • Tarsus (eyelids)
  • The final segment of an arthropod leg

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The sclera is the opaque (usually white), fibrous, protective layer of the eye containing collagen and elastic fibers.[1] In children, it is thinner and shows some of the underlying pigment, appearing slightly blue.
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Optic Nerve may be a reference to:
  • Optic nerve, the anatomical structure;
  • Optic Nerve (comic), the comic book series;
  • Optic Nerve (1998), the seminal release from the Irish hip hop act known as Exile Eye; or

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In sciences dealing with the anatomy of animals, precise anatomical terms of location are necessary for a variety of reasons. Non-scientists often wonder why zoological and human anatomists use complex terminology to describe locations on a body, when common terms like "up",
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Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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bold refer to the diagram at right.)

In the skull (8):
  • 1-9. cranium
  • 7. mandible
''In the middle ears (6):
  • malleus
  • incus
  • stapes
In the throat (1):
  • hyoid
In the shoulder girdle (4):
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The annulus of Zinn, also known as the annular tendon, circle of Zinn-Haller or common tendinous ring, is a ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit. It is the origin for five of the six extraocular muscles.
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bold refer to the diagram at right.)

In the skull (8):
  • 1-9. cranium
  • 7. mandible
''In the middle ears (6):
  • malleus
  • incus
  • stapes
In the throat (1):
  • hyoid
In the shoulder girdle (4):
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Eyes are organs of vision that detect light. Different kinds of light-sensitive organs are found in a variety of organisms. The simplest eyes do nothing but detect whether the surroundings are light or dark, while more complex eyes can distinguish shapes and colors.
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Arteries are muscular blood vessels that carry blood away from the heart.[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life.
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The ophthalmic artery is a branch of the internal carotid artery which supplies branches to supply the eye and other structures in the orbit.

Branches

The branches of the ophthalmic artery are often subdivided into an orbital group and an ocular group [1] .
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  • Accessory nerve
  • Accessory obturator nerve
  • Alderman's nerve
  • Anococcygeal nerve
  • Ansa cervicalis
  • Anterior interosseous nerve
  • Anterior superior alveolar nerve
  • Aortic plexus
  • Auerbach's plexus
  • Auriculotemporal nerve
  • Axillary nerve

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The trochlear nerve (the fourth cranial nerve, also called the fourth nerve or simply IV) is a motor nerve (a “somatic efferent” nerve) that innervates a single muscle: the superior oblique muscle of the eye.
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Kinesiology is the scientific study of the anatomy, physiology, and mechanics of body movement, especially in humans. [1] The word kinesiology is derived the Greek "kinesis" (motion) + the suffix -ology or -logy from the greek "logos" or "logia"(meaning a field of study).
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In anatomy, internal rotation (also known as medial rotation) is rotation towards the center of the body.

The muscles of internal rotation include:
  • of arm/humerus at shoulder[1]

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Abduct is a verb meaning to carry away. Specifically, it can refer to:
  • Abduction (kinesiology) - extending a limb away from the body
  • Kidnapping

See also

  • Abduction

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Depression, in kinesiology, is the anatomical term of motion for movement in an inferior direction.

It is the opposite of elevation.

This term is often applied to the shoulders (e.g. dropping them to a normal condition after shrugging them would be depression).
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Eyes are organs of vision that detect light. Different kinds of light-sensitive organs are found in a variety of organisms. The simplest eyes do nothing but detect whether the surroundings are light or dark, while more complex eyes can distinguish shapes and colors.
..... Click the link for more information.
Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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The external oblique muscle (of the abdomen) (also external abdominal oblique muscle) is the largest and the most superficial (outermost) of the three flat muscles of the lateral anterior abdomen.
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MUSCLE (multiple sequence comparison by log-expectation) is public domain, multiple sequence alignment software for protein and nucleotide sequences.
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In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated.

It can also mean the skin which surrounds the eye of a bird.

In the adult human, the volume of the orbit is 30 ml, of which the eye occupies 6.5 ml.
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