Anatomy & Physiology

Question 1

What are the tunics of the eye?

Answer 1

1. Fibrous Tunics (Sclera, Cornea)
2. Vascular Tunic (Choroid, Ciliary body, Iris)
3. Retina (Pigmented layer, Neural layer)

Question 2

Where is the anesthetic injection for eye lids done?

Answer 2

submuscular areolar tissue - lies deep to orbicularis oculi

Question 3

What is the biggest oil producing gland of our body?

Answer 3

meibomian gland

Question 4

Which nerves have to be affected for palsy in eye lid + what is the consequence?

Answer 4

orbicularis muscle -> CN. VII (->ectropion lower lid, but not a ptosis)
levator muscle -> CN. III (ptosis (+))

Question 5

Which nerves of the eye reach the lid not from within the orbit?

Answer 5

facial nerve

Question 6

Do the eyelids have a good healing after trauma?

Answer 6

yes, since:
supplied by:
external carotid a. via face
internal carotid a. via orbit

Question 7

What can be used as a useful sign of infective eyelid swelling?

Answer 7

Lymphadenopathy-> preauricular node
-> submandibular node

especially viral! (adenoviral infection)

Question 8

How is swelling of conjunctiva called?

Answer 8

chemosis

Question 9

Which part of the tear film component is not affected by the conjunctiva?

Answer 9

phospholipid part

Question 10

hangi gland conjuctivada bulunmaz

Answer 10

meibomian

Mucin secretors: Goblet cells, Henle, Manz

Accessory lacrimal glands:
Krause and Wolfring

Meibomian eyelidte sebase gland

Question 11

Sensory innervation of conjunctiva?

Answer 11

ophthalmic division of trigeminal n.

Question 12

How can contact lense form ulcers in cornea?

Answer 12

d/t prevention of oxygen diffusion from tear film

Question 13

How long does the replacement of the cornea take + which cells?

Answer 13

basal cell
-> 7 days for entire corneal epithelium

Question 14

What can form a bullous keratopathy?

Answer 14

d/t endothelial cell los through ageing and cataract surgery

-> endothelial cells needed to maintain corneal dehydration: so it swells & loses transparency

Question 15

What happens in the congenital Nasolcarimal duct obstruction; “at birth watery eyes”

Answer 15

tears pass from lacrimal sac to nasolacrimal duct to nasopharyngeal cavity via inf. meatus

if not eyes become watery

acquired obstruction of nasolacrimal duct a common cause of watery eye in adults
-> can lead to cellulitic swelling just below medial palpebral ligament

Question 16

adult comes with cellulitic swelling just below medial palpebral ligament; what to think

Answer 16

acquired obstruction of nasolacrimal duct

Question 17

What does presbyopia describe?

Answer 17

failure of accomodation d/t age
-> loss of capsule elasticity
lens deformability

Question 18

Where does the aqueous humour drain?

Answer 18

through trabecular meshwork drains into schlemm’s canal

Question 19

Compare cones with rods

Answer 19

cones: at macule, fine vision and colour appreciation

rods: low light levels, movement, entire retina

Question 20

Where is the blood-retinal barrier located?

Answer 20

inner BRB: between endothelial cells of retinal vessels
outer BRB: between RPE cells

Question 21

Disruption of BRB can lead to?

Answer 21

diabetic retinopathy uveitis

Question 22

What is the blow-out fracture?

Answer 22

decompression through fracture of the floor or medial wall minimises damage to eyeball

Question 23

A fracture of the floor of the orbit can lead to abormal sensation where?

Answer 23

to the cheek
-> entry of maxillary division of 5th C.N.

Question 24

EOM innervation

Answer 24

mneomic:
SO-4, LR-6, All the rest 3

Question 25

Compare pressure on the chiasm with behind the chiasm

Answer 25

on chiasm by pituitary tumor: a bitemporal hemianopia
behind (retrochiasmal): unilateral lesion causes a hemianopia on opposite side

Question 26

What supplies the optic tracts and radiation; visual cortex; macula

Answer 26

optic tracts and radiation: middle cerebral a.
visual cortex: post. cerebral a.
macula: dual blood supply (middle & post. cerebral a.)