ORBIT

Question 1

The Orbital Margin is formed by the _____, ______, and ______

Answer 1

Frontal, maxillary, and zygomatic

Question 2

Walls of the Orbit

Answer 2

• Superior wall or roof
  
  • Orbital part of the frontal bone and lesser wing of sphenoid bone
• Lateral wall
  
  • zygomatic bone (frontal process) and greater wing of sphenoid bone
• Inferior wall or floor
  
  • maxilla (orbital surface), zygomatic and palatine bones
• Medial Wall
  
  • ethmoid (orbital plate), frontal, lacrimal, and sphenoid(body) bones

Question 3

Communicates with the middle cranial fossa and is bounded by the greater and lesser wings of the sphenoid

Transmits the oculomotor, trochlearm abducens, and opthalmic nerves (3 branches)

Answer 3

Superior Orbital Fissure

Question 4

Communicates with the infratemporal and pterygopalatine fossae

transmits the maxillary (infraorbital) nerve and its zygomatic branch and the infraorbital vessels

Answer 4

Inferior Orbital Fissure

Question 5

Connects the orbit with the middle cranial fossa

Formed by 2 roots of the lesser wing of the sphenoid, lies in the posterior part of the roof of the orbit, and transmits the optic nerve and ophthalic artery

Answer 5

Optic Canal

Question 6

Transmit the infraorbital nerve and vessel

Answer 6

Infraorbital goove and infraorbital foramen

Question 7

Transmits the supraorbital nerve and vessels

Answer 7

Supraorbital notch or foramen

Question 8

Transmit the anterior and posterior ethmoidal nerves and vessels respectively

Answer 8

Anterior and Posterior Ethmoidal Foramina

Question 9

Formed by the maxilla, lacrimal bone, and inferior nasal concha

Transmits the nasolacrimal duct from the lacrimal sac to the inferior nasal meatus

Answer 9

Nasolacrimal Canal

Question 10

The opthalmic nerve enters the orbit through the ___________ and divides into 3 branches

Answer 10

Superior orbital fissure

Question 11

Lacrimal nerve

Answer 11

• Enters the orbit trought the superior orbital fissure
• Enters the lacrimal gland, giving rise to branches to the lacrimal gland, the conjunctiva and the skin of the upper eyelid
• Its terminal part is joined by the zygomaticotemporal nerve that cariies postganglionic parasympathetic and sympathetic GVE fibers

Question 12

Frontal Nerve

Answer 12

• Enters the orbit through the superior orbital fissure
• Runs superior to the levator palpebrae superioris
• Divides into the
  
  • Supraorbital nerve (passes through the supraorbital notch or foramen)
    
    • supplies the scalp, forehead, frontal sinus, upper eyelid
  • Supratrochlear nerve (passes through the trochlea)
    
    • scalp, forehead and upper lid

Question 13

Sensory nerve for the eye and mediates the afferent limb of the corneal reflex.

Enters the orbit through the superior orbital fissure, within the common tendinous ring

Answer 13

Nasociliary Nerve

Question 14

Nasociliary nerve

Answer 14

• sensory nerve for the eye and mediates the afferent limb of the corneal reflex
• Enters the orbit through the superior orbital fissure, within the common tendinous ring
• Gives rise to the ff:
  
  • A communicating branch
  • Short ciliart nerves
  • Long ciliary nerves
  • posterior ethmoidal nerve
  • anterior ethmoidal nerve
    
    • internal nasal branches
    • external nasal branches
  • Infratrochlear nerve

Question 15

Comsists of the axons of the ganglion cells of the retina and leaves the orbit by passing throigh the optic canal

Carries SSA fibers for vision from the retina to the brain and mediates the afferent limb of the pupillary light reflex

Joins the optic nerve from the corresponding eye to form the optic chiasma

Answer 15

Optic Nerve

Question 16

Enters the orbit through the superior orbital fissure and divides into a superior divison, which innervates the superior rectus and levator palpebrae superioris muscle and the inferior division, which innervates the medial rectus, inferior rectus, and inferior oblique muscles

Answer 16

Occulomotor nerve

Question 17

The inferior division of the oculomotor nerve carries preganglionic parasympathetic fibers (with cell bodies located in the Edinger-Westphal nucleus) to the ________

Answer 17

ciliary ganglion

Question 18

Passes through the lateral wall of the cavernous sinus, and enters the orbit through the superior orbital fissure, and innervates the superior oblique muscle

Answer 18

Trochlear nerve

Question 19

Enters the orbit through the superior orbital fissure and supplies the lateral rectus muscle

Answer 19

Abducen nerve

Question 20

Parasympathetic ganglion situatied behind the eyeball, between the optic nerve and the lateral rectus muscle

Answer 20

Ciliary ganglion

Question 21

Branch of the internal carotid artery and enters the orbit through the optic canal beneath the optic nerve

Answer 21

Ophthalmic Artery

Question 22

Ocular and orbital vessels

Answer 22

• Central Artery of the Retina
• Long Posterior Ciliary Arteries
• Short Posterior Ciliary Arteries
• Lacrimal Artery
• Medial Palpebral arteries
• Muscular branches
• Supraorbital Artery
• Posterior Ethmoidal Artery
• Anterior Ethmoidal Artery
• Supratrochlear artery
• Dorsal Nasal Artery

Question 23

formed by the union of the supraorbital, supratrochlear, and angular veins

Receives branches corresponding to most of those of the ophthalmic artery and, in addition, receives the inferior ophthalmic vein before draining into the cavernous sinus

Answer 23

Superior Ophthalmic Vein

Question 24

Begins by the union of small veins in the floor of the orbit

Communicates with the pterygoid venous plexus and often with the infraorbital vein and terminates directly in the cavernous sinus

Answer 24

Inferior Opthalmic Vein

Question 25

Muscles of Eye Movement

Answer 25

Question 26

Medial (inward) rotation of the upper pole of th cornea, caused by the Superior oblique and superior rectus muscles

Answer 26

Intorsion

Question 27

Lateral (outward) rotation of the upper pole of the cornea, caused by the inferior oblique and inferior rectus muscle

Answer 27

Extorsion

Question 28

Fibrous ring that surrounds the optic canal and the medial part of the superior orbital fissure

Answer 28

common tendinous Ring

Question 29

The common tendinous ring is the site of origin of the 4 rectus muscle and transmits the ff structures:

Answer 29

* Oculomotor, nasociliary and abducens nerves * Optic nerve, opthalmic artery, and central artery and vein of the renina * Superior opthalmic vein plus trochlear, frontal and lacrimal nerves

Question 30

Lies in the upper lateral region of the orbit on the lateral rectus and the levator palpebrae superioris muscles

Answer 30

Lacrimal Gland * drained by **12 lacrimal ducts**, which open into the superior conjucntival fornix

Question 31

two curved canals that begin as a lacrimal punctum (or pore) in the margin of the eyelid and open into the lacrimal sac

Answer 31

lacrimal canaliculi

Question 32

Upper dialted end of the nasolacrimal duct, which opens into the inferior meatus of the nasal cavity

Answer 32

Lacrimal Sac

Question 33

Produced by the lacimal gland Pass through excretory ductules into the superior conjunctival fornix Spread evenly over the eyeball by blinking movements and accumulate in the area of the lacrimal lake

Answer 33

Tears

Question 34

spontaneous lacrimation during eating caused by a lesion of the facial nerve proximal to the geniculate ganglion.

Answer 34

Crocodile tears syndrome (Bogorad's syndrome)

Question 35

tough white fiborus tunic enveloping the posterior 5/6 of the eye

Answer 35

Sclera

Question 36

Transparent structure forming the anterior 1/6 of the external coat Responsible for the refraction of light entering the eye

Answer 36

Cornea

Question 37

Consists of an outer pigmented (dark brown) layer and an inner highly vascular layer, which invests the posterior 5/6 of the eyeball Nourishes the retina and the darkens of the eye

Answer 37

Choroid

Question 38

thickened portion of the vascular coat between the choroid and the iris and consists of the ciliary ring, ciliary processes, and ciliary muscle

Answer 38

Ciliary Body

Question 39

radiating pigmented ridges that encircle the margin of the lens

Answer 39

Ciliary processes

Question 40

consists of meridional and circular fibers of smooth muscle innervated by parasympathetic fibers

Answer 40

Ciliary muscle

Question 41

Miotic pupil that respondes to accomodation but fails to respond to light. Caused by a lesion in the midbrain and seen in neurosyphilis and in diabetes

Answer 41

Argyll-Robertson Pupil

Question 42

thin, contractile, circular, pigmented dipahragm with a central aperture

Answer 42

Iris

Question 43

The iris contains circular muscle fibers **(sphincter puppilae**) which are innervated by \_\_\_\_\_\_\_\_\_\_\_

Answer 43

Parasympathetic fibers

Question 44

The iris contains radial fibers (dilator pupillae) whoch are innervated by \_\_\_\_\_\_\_\_\_

Answer 44

sympathetic fibers

Question 45

consists of optic fibers formed by axons of the ganglion cells. These cells are connected to the rods and cones by bipolar neurons

Answer 45

Optic Disk

Question 46

yellowish area near the center of the retina on the temporal side of the optic disk for the most distinct vision Contains the fovea centralis

Answer 46

Macula (Yellow spot or Macula Lutea)

Question 47

Central depression (foveola) in the macula Avascular and is nourished by the choriocapilalry lamina of the choroid Has cones only (no rods), each of which is concerned with only one ganglion cell, and functions in detailed vision

Answer 47

Fovea centralis

Question 48

Are approximately 120 million in number and are most numerous approximately 0.5 cm from the fovea centralis Contain Rhodopsin, a visual purple pigment Are specialized for vision in dim light

Answer 48

Rods

Question 49

Are 7 million in number and are most numerous in the foveal region. Associated with visual acuity and color vision

Answer 49

Cones

Question 50

foremed by the ciliary processes and provides nutrients for the avascular cornea and lens Passes through the pupil from the posterior chamber (between the iris and the lens) into the chamber (between the cornea and the iris) and is drained into the scleral venous plexus through the canal of Schlemm at the iridocorneal angle

Answer 50

Aqueous Humor

Question 51

transparent avascular biconves structure enclosed in an elastic capsule. held in position by radially arranged zonular fibers (suspensory ligament of the lens)

Answer 51

Lens

Question 52

transparent gel called which fills the eyeball posterior to the lens (vitreous chamber between the lens and the retina)

Answer 52

Vitreous body

Question 53

The eye forms from a \_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 53

Neuroectodermal evagination of the wall of the brain and from the surface ectoderm (lens palcode), mesoderm, and neural crest cell

Question 54

Neuroectoderm of the diencephalon evagiantes to form the \_\_\_\_\_\_\_

Answer 54

Optic vesicle

Question 55

Optic cup forms the \_\_\_\_\_\_\_\_

Answer 55

Retina, iris, and ciliary body

Question 56

Optic stalk forms the \_\_\_\_

Answer 56

optic nerve

Question 57

Surface ectoderm invaginates to form the \_\_\_\_\_\_\_

Answer 57

lens placode * Which forms the lens and anterior epithelium of cornea

Question 58

\_\_\_\_\_\_ forms the sclera. portions of the cornea, vitreous body, and extraocular muscles

Answer 58

Mesoderm

Question 59

\_\_\_\_\_form the choroids, sphincter pupillae muscle, dilator pupillae muscle, anmd ciliary muscle

Answer 59

Neural Crest cells

Question 60

form the central artery and vein of the retina

Answer 60

Hyaloid artery and vein