2. Lid & Conjunctival Anatomy. Clinical evaluation.

Question 1

where does the upper and the lower eyelids meet ?

Answer 1

at the medial and the lateral canthi

Question 2

what are the layers of the eyelid?

Answer 2

skin - it is elastic and the thinnest of the body

subcutaneous tissue - loose and no fat

orbicularis oculi muscle - orbital palbepral and lacrimal - innervated by the zygomaticus and temporal branches of the facial nerve
closes the eyelid
upper lid contain levatator supplied by oculomotor nerve

fibrous layer of tarsal plate

conjuctiva - lining the lid

Question 3

what are the glands i the eyelids ?

Answer 3

meibomian gland - present in the stroma of the tarsal plate

glands of zeis - sebaceous glands open into the follicles of the eyelashes

glands of moll - near the eyelash

accessory lacrimal glands of wolfram - near the upper border of tarsal plate

Question 4

what are the blood supply innervating the eyelids ?

Answer 4

branches of the ophthalmic artery (first branch of internal carotid artery )
lacrimal artery - lateral palbebral arteries
direct from ophthalmic medial palpebral artery

viens with two plexus post tarsal which drains into the ophthalmic vein
praters opening into subcutaneous vein

Question 5

what are the sensory nerves supplying the eyelids

Answer 5

divisions of ophthalmic - infratrochlear
supratrochlear
supraorbital
lacrimal

and maxillary nerves - infraorbital - lower eyelid

Question 6

what is the function of the orbital part of the m orbicularis ?

Answer 6

forced closure of eyelids

Question 7

what is the function f the pallbearer part of the eyelid ?

Answer 7

gentle closure , blinking

Question 8

function of the eyelids

Answer 8

regularly spread the tears and other secretions on the eye surface to keep it moist, since the cornea must be continuously moist.

Question 9

what is conjuctiva ?

Answer 9

tissue that lines the inside of the eyelids and covers the sclera

Question 10

conjuctiva composed of ?

Answer 10

unkeratinized, stratified squamous epithelium with goblet cells, and stratified columnar epithelium.

Accessory lacrimal glands in the conjunctiva constantly produce the aqueous portion of tears

Question 11

what are the layers of the conjuctiva ?

Answer 11

divided into three parts

Palpebral or tarsal conjunctiva

Fornix conjunctiva -Forms the junction between the bulbar and palpebral conjunctivas: It is loose and flexible, allowing the free movement of the lids and eyeball.

Bulbar conjuctiva -tightly bound to the underlying sclera by Tenon’s capsule and moves with the eyeball movements.

Question 12

blood supply to conjuctiva ?

Answer 12

bulbar conjunctiva - ophthalmic artery
palpebral conjunctiva from the external carotid artery.

both vessels anastamoses