Anatomy of Human muscles of eye.pptx

this topic from Anatomy nicely covers all the muscles of human eye

1. Dr. Krupal Modi(MPT) Assistant Professor SSPTC Kadodara. MUSCLES OF EYE

2. WHAT IS ORBIT? The orbits are bony cavities lodging the eyeballs, various muscles, nerve, blood vessels and lacrimal glands. Nature has provided orbit for the safety of the eyeball.

3. The orbits are pyramidal cavities , situated one on each side of the roof of the nose. They provides sockets for rotatory movements of eyeball. The long axis of each orbit passes backwards and medially . The medial walls are parallel to each other but the lateral walls are set at right angles to each other.

4. CONTENTS OF THE ORBIT: 1) EYEBALL 2) FASCIA: ORBITAL AND BULBAR 3) MUSCLES: EXTRA-OCULAR 4) VESSELS: OPTHALMIC ARTERY, SUPERIOR AND INFERIOR OPTHALMIC VEINS AND LYMPHATICS 5) NERVES: OPTIC, OCULOMOTOR, TROCHLEAR AND ABUDUCENT 6) LACRIMAL GLAND 7) ORBITAL FAT

5. MEDIAL SIDE LATERAL SIDE

6. Muscles of the eye gives support and mainly involves in the movement of the eye and provides better visual system . 8 MUSCLE OF EYE:

7. ORBITAL MUSCLES INTRA- OCULAR CILIARY MUSCLES EXTRA- OC U LAR INVOLUNTARY VO L UN T A R Y 1.Superior tarsal muscle. 2.Inferior tarsal muscle . 3.Orbialis 1.Levator Palpebrae Superioris 2.Superior rectus 3.Inferior rectus 4.Medial rectus 5.Lateral rectus 6.Superior oblique 7.Inferior oblique

8. Extra-ocular muscles of eyeball = Involved in movement of eyeball. Intra-ocular muscles = Controls shape of lens and size of pupil.

9. Intraocular muscles : ⦿ Ciliary muscles -helps in accommodation ⦿ Sphincter pupillae -constricts pupil ⦿ Dilater pupillae - Dilates pupil 11

10. Extraocular muscles(EOM ) : EOM Oblique muscles Superior oblique Inferior oblique Recti muscles Superior rectus Infe r ior rectus M edial rectus Lateral rectus L evator P alpebrae S uperioris 14

11. INVOLUNTARY MUSCLE: 1.Superior tarsal muscle: Deeper portion of LPS. It is inserted on the upper margin of the superior tarsus(fibrous connective tissue). It elevates upper eyelid. 2.Inferior tarsal muscle: It extends from fascial sheath of the inferior rectus and inferior oblique to the lower margin of the inferior tarsus. It possibly depresses the lower eyelid. 3. Orbitalis: It bridges the inferior orbital fissure. Action is uncertain.

12. VOLUNTARY MUSCLES: ORIGIN : The four recti arises from a common annular tendon or tendinous ring. Also known as “The annulus of Zinn”. This ring is attached to the orbital surface of the apex of the orbit. It encloses the optic canal and the middle part of the superior orbital fissure.

13. Common annular tendinous ring

14. INSERTION : The Recti muscles are inserted into the sclera at the different distances from the limbus forming spiral called Spiral of Tillaux .

15. 1) LEVATOR PALPEBRAE SUPERIORIS Origin: Orbital surface of lesser wing of sphenoid bone, anterosuperior to optic canal. Insertion : Splits in two lamina. Superior lamina ( voluntary) to Ski n o f upp e r e y elid & a nt e r ior surface of superior tarsal plate. Inferior lamina (Muller’s muscle)(involuntary) to upper margin of superior tarsus.

16. LEVATOR PALPEBRAE SUPERIORIS

17. NERVE SUPPLY- Upper division of occulomotor nerve(III cranial nerve). ACTION - Elevation of upper eyelid . APPLIED ANATOMY : Ptosis - Drooping of upper eyelid.

18. 2) SUPERIOR RECTUS MUSCLE Origin -Superior part of common tendon of zinn. Insertion -inserted into sclera by flat tendinous insertion about 7.7 mm behind sclero -corneal junction . Nerve supply -superior division of occulomotor nerve. Action : Primary action is elevation, Secondary action is adduction and Intorsion .

19. 3) INFERIOR RECTUS MUSCLE Origin -inferior part of common tendon of zinn Insertion -in the sclera 6.5 mm behind sclero corneal junction. Nerve supply - inferior division occulomotor nerve . Actions - Primary depressor. Subsidiary actions are adduction and extorsion .

20. 4) MEDIAL RECTUS MUSCLE Origin -annulus of zinn and from optic nerve sheath . Insertion - in sclera 5.5mm behind sclero corneal junction . Nerve supply -lower division of occulomotor nerve. Action - Primary adductor of the eye.

21. 5) LATERAL RECTUS MUSCLE Origin -annulus of zinn . The lateral rectus has additional small tendinous head which arises from the orbital surface of the greater wing of the sphenoid bone lateral to the tendinous ring. Insertion -in the sclera 6.9mm behind sclerocorneal junction. Nerve supply - abducens nerve (6 th cranial nerve) which enters the muscle on the medial surface. Action - Primary abductor of eye.

22. 6) SUPERIOR OBLIQUE MUSCLE Origin -body of sphenoid above and medial to optic canal. Passes along superomedial part of orbit and ends in a tendon. Insertion - the tendon passes through a fibrocartilage pulley attached to the trochlear fossa of frontal bone. The tendon then passes lateral, downward and backwards below superior rectus. It is inserted into the sclera behind equator of eyeball, between superior rectus and lateral rectus. Nerve supply -trochlear nerve(4 th cranial nerve) entering it approximately one third of the distance from the origin to the trochlea .

23. Actions : Primary action- intorsion . Subsidiary actions-abduction and depression and Adducted position-depression.

24. 7) INFERIOR OBLIQUE MUSCLE Origin - orbital surface of the maxilla, lateral to the lacrimal groove. Muscle is situated near the anterior margin of the orbit. Insertion - It is a fleshy muscle. It passes laterally, upwards and backwards below inferior rectus and then deep to lateral rectus. The inferior oblique is inserted close to superior oblique a little below and posterior to latter. Nerve supply -inferior division of occulomotor nerve enters the muscle laterally at the junction of the inferior oblique and inferior rectus muscles .

25. Actions: Primary action- extorsion . Subsidiary actions-elevations and abduction. Causes elevation only in adducted position of eyeball.

26. MUSCLE ORIGIN NERVE SUPPLY Superior rectus Annulus of zinn Occulomotor nerve Inferior rectus Annulus of zinn Occulomotor nerve Lateral rectus Annulus of zinn Abducent nerve Medial rectus Annulus of zinn Occulomotor nerve Superior oblique Annulus of zinn via trochlea Trochlear nerve Inferior oblique Maxillary bone Occulomotor nerve Levator palpebral su p 2 e /1 3 r / 2 i o 1 6 sis Sphenoid bone Muscles of the eye Occulomotor nerve 5 SO-4 LR-6

27. BLOOD SUPPLY: Arteries: Ophthalmic artery(medial and lateral branch), Lacrimal artery, anterior ciliary arteries Veins : superior and inferior orbital veins

28. ACTIONS OF MUSCLES OF EYEBALL

29. Fig: Monocular movements of the eye 2/13/2016 Muscles of the eye 39 ANATOMICAL MOVEMENT OF EYEBALL

30. MUSCLE PRIMARY ACTION SECONDARY TERTIARY SR ELEVATION INTORSION ADDUCTION IR DEPRESSION EXTORSION ADDUCTION MR ADDUCTION LR ABDUCTION SO INTORSION DEPRESSION ABDUCTION IO EXTORSION ELEVATION ABDUCTION