OXFORD HANDBOOK ANAT & PHYSIO

Question 1

Interpalpebral fissure length

Answer 1

30 mm wide, 10 mm high (slight higher in women)

Question 2

Resting position of upper and lowerlid

Answer 2

upperlid 2mm below superior limbus
lowerlid level with or above inferior limbus

Question 3

Does eyelid skin has subcutaneous fat?

Answer 3

NO

Question 4

how many lashes in upper and lowerlid?

Answer 4

Lashes are arranged 2-3 rows along lid margin,
above 150 on upper eyelid
75 on lower eyelid

Question 5

Meibomian gland MGs in (upper and lower lid)

Answer 5

35 upper eyelids and 25 lower eyelids

Question 6

name two horizontal canthal tendon

Answer 6

medial canthal tendon and lateral canthal tendons

Question 7

medial canthal tendon arises from

Answer 7

ant lacrimal crest and post lacrimal crest

Question 8

lateral canthal ligament inserts

Answer 8

Whitnalls tubercle (zygomativ bone)
and posteriorly with lateral check ligament

Question 9

LPS originates from

Answer 9

Orbital apex and runs forward over superior rectus (SR) to the orbital rim

Question 10

Conjunctiva (is what and comprise of)?

Answer 10

The conjunctival is a mucous membrane comprising non-keratinized epithelium, BM and stroma

Question 11

Epithelium of palpebral conjunctiva?

Answer 11

Stratified squamous form. Contains mucin secreting goblet cells and cypt of henle

Question 12

Sensation of lowerlid (nerves)

Answer 12

Infraorbital nerve (Vb)
Medial canthal region: infratrochlear branch of nasociliary (Va)

Question 13

Sensation of upper lid (nerves)

Answer 13

lacrimal, supraorbital and supratrochlear nerves (Va)

Question 14

Innervation of orbicularis, LPS and muller muscles

Answer 14

Orbicularis CN7, LPS CN3, Muller sympathetic system

Question 15

Arterial supply of lids

Answer 15

supply by three arcades form anastomoses btwn medial palpebral artery ( terminal branch of ophthalmic artery) and lateral palpebral artery (lacrimal artery)

Question 16

Marginal arcade upper and lower lid mm

Answer 16

upperlid 2mm above margin and lowerlid 4mm below the margin

Question 17

Venous Drainage Eyelid

Answer 17

superficial temporal vein - laterally
ophthalmic and angular vein - medially

Question 18

Lymphatic drainage

Answer 18

parotid glands- laterally
submandibular glands- inferiorly
anterior cervical chain inferomedial

Question 19

how many ducts run from the orbital lobe of lacrimal gland

Answer 19

12

Question 20

lacrimal gland parasymphathetic innervation schematic

Answer 20

superior salivary nucleus (pons) - greater petrosal n - synapse at pterygopalatine ganglion - zygomatic n - lacrimal n - lacrimal gland

Question 21

lacrimal puncta (location and diameter)

Answer 21

located 6mm lateral to medial canthus/ diameter 0.3mm

Question 22

superior and inferior canaliculi parameter length and width

Answer 22

vertical part (ampulla : 2mm long 3mm wide)
horizontal part (8mm long 2 mm wide)

Question 23

common canaliculi parameter

Answer 23

2mm long

Question 24

common canaliculi parameter

Answer 24

2mm long

Question 25

lacrimal sac parameter

Answer 25

12mm in length

Question 26

lacrimal sac fossa

Answer 26

posterior to medial canthal tendon lateral to ethmoid sinus

Question 27

lacrimal duct parameter

Answer 27

18 mm runs parallel to nasojugal fold (inferolaterally) fist 12 mm lies in bony nasolacrimal canal last 6mm within mucous membrane of lateral wall of nose

Question 28

which meatus lacrimal duct drains into

Answer 28

inferior meatus via ostium lacrimale

Question 29

valves in nasolacrimal system (2)

Answer 29

Rosenmuller (entry to lacrimal sac) Hasner (exit from nasolacrimal duct)

Question 30

how many glands of krause?

Answer 30

28

Question 31

how many glands of wolfring?

Answer 31

3

Question 32

% of tears drained via superior and inferior canaliculus

Answer 32

70% inferior 30% superior

Question 33

cornea act as/function

Answer 33

1) clear refractive surface 2) protective barrier to infection and trauma

Question 34

cornea horizontal diameter

Answer 34

11.7mm

Question 35

cornea vertical diameter

Answer 35

10.6mm

Question 36

cornea shape (ant and pos)

Answer 36

anterior elliptical posterior circular

Question 37

corneal stroma accounts % of corneal thickness

Answer 37

90%

Question 38

corneal proteoglycan substances (2)

Answer 38

1) chondrotin sulfate 2) keratan sulfate

Question 39

corneal transparency

Answer 39

1) active deturgence - endothelium is relative permeable -stroma swelling pressure -water passthrough homonally aquaporin eg AQP1 2) regular orientation and spacing of stromal collagen fibres

Question 40

radii of curvatuve of cornea

Answer 40

anterior surface 7.7mm and posterior surface 6.8mm