Orbit, Extraocular Muscles And CN 3 4 6

Question 1

Thinnest wall of Orbit

Answer 1

Medial Wall

Question 2

Medial wall of the orbit is formed by

Answer 2

u

S ~ body of Sphenoid

M ~ Maxilla

L ~ Lacrimal

E ~ Ethmoid

Question 3

Fracture is seen in the which wall of the orbit

Answer 3

Floor of the Orbit

Question 4

Lateral wall of Orbit Formed by

Answer 4

Zygomatic Bone

Greater Wing of Sphenoid

Question 5

Roof of the orbit is formed by

Answer 5

Frontal Bone

Lesser wing of Sphenoid

Question 6

Floor of the Orbit is Formed by

Answer 6

Maxilla Bone

Zygomatic Bone

Palatine Bone

Question 7

Optic Canal Transmit and Present in Which Bonw

Answer 7

In the Lesser Wing of Sphenoid

Ophthalmic Artery

Optic nerve with Meninges

Question 8

Superior Orbital Fissure Is divided into

Answer 8

Superolateral Part

Intermediate Part

Inferomedial Part

Question 9

Structures Passing Through Superolateral Compartment of Superior Orbital Fissure

Answer 9

L ~ Lacrimal nerve

F ~ Frontal nerve

T ~ Trochlear nerve

Superior Ophthalmic Vein

Question 10

Structures Passing Through Intermediate Compartment of Superior Orbital Fissure

Answer 10

SO ~ Superior division of Oculomotor nerve

N ~ Nasociliary nerve

I ~ Inferior division of oculomotor nerve

A ~ Abducent nerve

Question 11

Structures passing through Inferomedial Compartment of Superior Orbital Fissure

Answer 11

Inferior Ophthalmic Vein

Question 12

Inferior Orbital Fissure transmitting

Answer 12

Infraorbital Nerve (continuation of Maxillary Nerve)

Zygomatic Branch (of Maxillary Nerve)

Question 13

Recti ~ means

Answer 13

Straight

Question 14

Origin of 4 Rectus Muscles

Answer 14

Common Tendinous Ring

Question 15

Origin of Inferior Oblique Muscle

Answer 15

Floor of The Orbit (Maxilla Bone)

Question 16

Angle of Superior Rectus and Medial Rectus on which side to Visual Axis

Answer 16

Lateral to Visual Axis

Question 17

Main Action of Superior Rectus Muscle

Answer 17

Elevation on abducted eye

Other Actions;
Adduction

Intorsion

Question 18

Main action of Inferior Rectus Muscle

Answer 18

Depression on abducted eye

Other Actions;
Adduction

Extortion

Question 19

Intorsion of the eye ball refers to

Answer 19

Inward movement of the eyeward

Question 20

Intorsion is done by ____________ muscles

Extorsion done by __________
muscles

Answer 20

Superior muscles ~ intorsion

Inferior muscles ~ extorsion

Question 21

Superior and Inferior Oblique Muscles are attached behind the _____________

Answer 21

Equator of eye ball

Question 22

Angle of Superior and Inferior oblique is on which side of the Visual Axis

Answer 22

Medial to Visual Axis

Question 23

Main Action of Superior Oblique Muscle is

And other actions

Answer 23

Depression on adducted eye

Other Actions;
Abduction

Intorsion

Question 24

Main Action of Inferior oblique muscle

And other actions

Answer 24

Elevation on adducted eye

Other Actions;
Abduction

Extorsion

Question 25

Elevation on Abducted Eye is done by __________ Muscle

Answer 25

Superior Rectus Muscle

Question 26

Elevation on Adducted Eye is done by __________ Muscle

Answer 26

Inferior Oblique Muscle

Question 27

Depression on abducted eye is done by ___________ Muscle

Answer 27

Inferior Rectus Muscle

Question 28

Depression of adducted eye is done by _________ Muscle

Answer 28

Superior Oblique Muscle

Question 29

Adduction is done by Main Muscle - Other Muscle -

Answer 29

Main Muscle - Medial Rectus Other Muscle - Superior and Inferior Rectus

Question 30

Abduction is done by Main Muscle - Other Muscle -

Answer 30

Main Muscle - Lateral Rectus Other Muscle - Superior and Inferior Obliue

Question 31

Nerve Supply To Extra Ocular Muscles ~ mnemonic

Answer 31

SO4 LR6 Remaining3

Question 32

Functional columns of 3rd nerve

Answer 32

GSE - to supply Extraocular Muscle GVE - to supply Sphincter Pupillae and Ciliaris Muscle Parasympathetic column from Edinger Westfall Nucles

Question 33

3rd and 4th Nerve is passing b/w _________ Arteries

Answer 33

Posterior Cerebral Artery and Superior Cerebellar Artery

Question 34

Before entering the Orbital Cavity 3rd Nerve is divided into

Answer 34

Superior and Inferior Division Then both enters through superior orbital fissure in the common Tendinous ring

Question 35

Superior Division of Oculomotor nerve is supplying

Answer 35

Levator Palpebrae Superioris Superior Rectus Muscle

Question 36

Medial Rectus Inferior Rectus Inferior Oblique Muscles supplied by

Answer 36

Inferior division on Oculomotor nerve

Question 37

GVE ~ Parasympathetic Component of Oculomotor Nerve reach Ciliary Ganglion via

Answer 37

Nerve To Inferior Oblique

Question 38

Parasympathetic Fibres from Ciliary Ganglion via ___________ Nerve, Supplies _______ and ________ Muscle

Answer 38

Via Short Ciliary Nerves Ciliaris Muscle (95% fibres) and Sphincter Pupillae (5%)

Question 39

Oculomotor Nucleus is located in the Midbrain at the level of

Answer 39

Superior Colliculus

Question 40

Fibres Supplying the ___________ Muscle, is crossing to the opposite side within the nucleus and joins with the oculomotor Nerve

Answer 40

Fibres coming to Superior Rectus Muscle

Question 41

Lesion to the Right Oculomotor Nucleus Which side of the Superior Rectus Muscle will be affected?

Answer 41

Both side Superior Rectus Muscles will be affected Lesion in one nucleus will affect crossing of opposite side fibres too

Question 42

Changes In Accommodation Reflex

Answer 42

1. Medial Convergence of eyeball ~ by medial Rectus 2. Construction of Pupil ~ Sphincter Pupillae 3. Increase in Thickness of Lens ~ Ciliary Muscle

Question 43

The sole Property of 3rd Cranial Nerve

Answer 43

Accommodation Reflex

Question 44

Features of 3rd Nerve Palsy P P D p D O Reflexes ~

Answer 44

P ~ Ptosis (LPS) P D ~ Pupils Dilated p D O ~ Down d/t Superior Oblique Out d/t Lateral Rectus Loss of Light Reflex Loss of Accommodation

Question 45

Cranial Nerve with Dorsal Exit Internal Decussation ~ Supply contralateral side Longest IntraCranial Course Slender/Smallest Nerve

Answer 45

Trochlear Nerve

Question 46

Exit of Trochlear Nerve from the midbrain at the level of

Answer 46

Inferior Colliculus

Question 47

Nerves Passing between Superior Cerebellar Artery and Posterior Cerebral Artery

Answer 47

3rd and 4th Cranial Nerves

Question 48

Features of 4th Nerve Injury

Answer 48

Loss of Intorsion Extorted Eye Ball To correct extorsion Head Tilt ~ to Opposite side

Question 49

Location of Abducens Nucleus

Answer 49

Lying under Facial Colliculus

Question 50

Nerve with longest Intradural course

Answer 50

Abducens Nerve

Question 51

Dorello’s Canal is situated Between And is formed by

Answer 51

Between Apex of the Petrous Temporal Bone and Clivus Formed by Petrosphenoid Ligament

Question 52

Under Raised Intracranial Pressure the Abducent Nerve is irritated by

Answer 52

Apex of the Petrous-Temporal Bone

Question 53

Most Common Nerve to get affected in the Raised Intracranial Pressure

Answer 53

6th Cranial Nerve

Question 54

Nerve passing through (space) the cavernous sinus

Answer 54

6th Cranial Nerve