Contenu connexe Similaire à Extraocularmuscles 160315042629 Similaire à Extraocularmuscles 160315042629 (20) Extraocularmuscles 1603150426293. CONTENTS OF ORBIT
Eyeball
Fascia bulbi
Muscles
Vessels
Nerves
Lacrimal gland
Orbital fat
6. • ANNULUS OF ZINN -
common tendinous ring
• Attachments
• Forms a muscle cone
RECTI MUSCLES - origin
8. RECTI MUSCLES - Insertion
Inserted into 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
10. SUPERIOR OBLIQUE – Insertion
Behind the equator on sclera in posterosuperior
quadrant, between the superior and lateral rectus
12. INFERIOR OBLIQUE – Insertion
Behind the equator on sclera in posterior quadrant,
between the superior and lateral rectus
13. Three cranial nerves
3. Trochlear nerve2. Abducent nerve1. Oculomotor nerve
Superior obliqueLateral rectus
1. Superior rectus
2. Medial rectus
3. Inferior rectos
4. Inferior oblique
5. Levator pelpebrae
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
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
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 – Oculomotor Nerve
Involuntary part – Sympathetics
Action :
Elevation of upper eye lid
LEVATOR PALPEBRAE SUPERIORIS
23. Abnormal deviation of eyeball is known as
Squint (Strabismus)
Damage to Abducent nerve - Medial
Squint
Damage to Occulomotor nerve - Lateral
Squint and Ptosis-Dropping of Eyelid
Damage to Trochlear nerve - diplopia
while looking downwards
Medial Squint
Lateral Squint and Ptosis