Extraocular muscles

Extraocular muscles

1. EXTRAOCULAR MUSCLES

2. IMPORTANT LANDMARKS

3. CONTENTS OF ORBIT
Eyeball
Fascia bulbi
Muscles
Vessels
Nerves
Lacrimalgland
Orbital fat

4. EXTRAOCULAR MUSCLES

5. Voluntary
muscles
Involuntary
muscles
Extraocular
muscles
LPS
Recti muscles
Oblique muscles
Superior tarsal muscle
Inferior tarsal muscle
Orbitalismuscle

6. •ANNULUS OF ZINN -
common tendinous ring
•Attachments
•Forms a muscle cone
RECTI MUSCLES -origin

7. Medial Rectus
Lateral Rectus
Superior Rectus
Inferior Rectus
RECTI MUSCLES -origin

8. RECTI MUSCLES -Insertion
Insertedinto sclera
In front of equator
•Distance from cornea
MR = 5.5mm
IR = 6.5mm
LR = 6.9mm
SR = 7.7mm
5mm
6 mm
8 mm
7 mm

9. Superior Oblique
SUPERIOROBLIQUE-origin

10. SUPERIOROBLIQUE–Insertion
Behind the equatoron sclera in posterosuperior
quadrant, between the superior and lateral rectus

11. Inferior Oblique
INFERIOROBLIQUE-origin

12. INFERIOROBLIQUE–Insertion
Behind the equatoron sclera in posterior quadrant,
between the superior and lateral rectus

13. Three cranial nerves
3. Trochlear nerve2. Abducentnerve1. Oculomotornerve
Superior obliqueLateral rectus
1.Superior rectus
2.Medial rectus
3.Inferior rectos
4.Inferior oblique
5.Levatorpelpebrae
NERVE SUPPLY OF EOM

14. ACTION OF INDIVIDUAL MUSCLES
Adduction-MR
Abduction-LR
In Abducted eye
Elevation-SR
Depression-IR
In Adducted eye
Elevation-IO
Depression-SO

15. MOVEMENTS-DUCTIONS
Elevation
Depression
Abduction
Adduction
Intorsion
Extorsion
•Elevation & Depression –Around the transverse axis
•Adduction & Abduction –Around the vertical axis
•Intortion& Extortion –Around the anteroposterioraxis

16. drepression
elevation
1.Primary position
MOVEMENTS-VERSIONS (CONJUGATE)

17. Convergence (simultaneous movement nasally)
Divergence (simultaneous temporal movement)
MOVEMENTS-VERGENCE

18. DUCTIONS -MUSCLES PRODUCING
•Elevation –Superior rectus & Inferior oblique
•Depression –Inferior rectus & Superior oblique
•Intortion–Superior rectus & Superior oblique
•Extorsion–Inferior rectus & Inferior oblique
•Adduction –Medial ,Superior & Inferior recti
•Abduction –Lateral rectus, Superior & Inferior oblique
RECTI -Adduct
OBLIQUES –Abduct
SUPERIORS –Intort
INFERIORS -Extort

19. Levatorpalpebraesuperioris
LEVATOR PALPEBRAE SUPERIORIS -Origin
Undersurfaceof
lesser wing of
sphenoid

20. •Upper lamina : Skin of
upper eyelid
•Middle lamina: Superior
tarsus(Muller’s)
•Lower lamina: Superior
conjunctival fornix
LEVATOR PALPEBRAE SUPERIORIS -Insertion

21. Nerve Supply:
Voluntary part –OculomotorNerve
Involuntary part –Sympathetics
Action:
Elevation of upper eye lid
LEVATOR PALPEBRAE SUPERIORIS

22. CINICAL TESTING

23. Abnormal deviation of eyeball is known as
Squint (Strabismus)
Damage to Abducentnerve -Medial
Squint
Damage to Occulomotornerve -Lateral
Squint and Ptosis-Dropping of Eyelid
Damage to Trochlearnerve -diplopia
while looking downwards
Medial Squint
Lateral Squint and Ptosis

24. PTOSIS
Drooping of upper eyelid
•Complete ptosis
•Partial ptosis