Eyelids and Conjunctiva - Week 2 Flashcards Preview

OD1 Semester 2 - Integrated Ophthalmic Sciences and Preclinical Optometry > Eyelids and Conjunctiva - Week 2 > Flashcards

Flashcards in Eyelids and Conjunctiva - Week 2 Deck (70):
1

Functions of eyelids (palpebrae) [4]

- protect eyeball from injury
------ (via lashes, cilia, via sensory, spontaneous + reflex blinking)
- maintain position of globe in orbit (without restriction of ocular rotational movement)
- maintenance of corneal surface integrity (tear distribution and drainage)
- gross regulation of incident light levels (aperture size/lashes)

** Way to remember
PAPI - Protect, Aperture, Position, (surface) Integrity

2

How many basic regions does an eyelid/palpebrae have (on surface anatomy)

2 regions: orbital and palpebral (tarsal)

3

How many sulcii are present on the eyelids (surface anatomy, in total)? What are they?

4 sulcii
- superior palpebral sulcus (top eyelid fold)
- Inferior palpebral sulcus (bottom eyelid fold)
- Malar (lateral) sulcus
- Nasojugal (medial) sulcus

4

In what common scenario does the inferior palpebral sulcus become more pronounced?

When you lack sleep

5

In respect to the eyelid margin, what are cilia?

hair. Therefore eyelashes

6

How many cilia make up the upper and lower eyelashes?

150 upper, 70 lower

7

How frequently are cilia/eyelashes replaced?

replaced every 3-5 months

8

What do Meibomium glands look like?

little dots lying on the eyelid margin (they are openings)

9

What is the Orbicularis Oculi?

is a muscle in the face that closes the eyelids.
-- i.e. It is a sphincter muscle for palpebral fissure

10

Define 'Palpebral Fissure'

The palpebral fissure is the elliptic space between the medial and lateral canthi of the two open lids. In simple terms, it refers to the opening between the eye lids

11

What type of muscle is the Orbicularis Oculi?

Striated Muscle

12

What are the 2 parts of the Orbicularis oculi muscle? And what are these parts involved with?

Orbital part: forceable lid closure
palpebral part: gentle blinking and sleep

13

What is the Orbital Septum?

Is the connective tissue sheath that forms the anterior border of the orbit

14

What are the functions of the Orbital Septum?

- separates eyelids from contents of the orbital cavity
- is an almost continuous barrier preventing the anterior-posterior spread of inflammation or blood

15

In terms of location, where do the following blend with:
A) Superior Eyelid
B) Inferior Eyelid

Superior eyelid - blends with tendon of Levator palpebrae superiosis (LPS) and superior tarsus
Inferior eyelid - blends with inferior tarsus

16

What muscles are involved in eyelid control? (3)

- Orbicularis Oculi - forceable lid closure and blinking and sleep; closes lids
- Levator Palpebrae - elevates upper lid and maintains open palpebral aperture
- Muller's Muscle - modulates lid position when eye is open


*OML - Oh My Lid!

17

What type of muscle is levator palpebrae superioris?

Striated

18

Fill in the blank: Levator palpebrae superioris (LPS) is innervated by ____?

Superior branch CNIII (cranial nerve 3)

19

Where does LPS originate from? Where does it go from there?

Arises in region of annulus of Zinn, moves forward on top of SR muscle

20

Where does LPS insert?

LPS inserts into the skin of the superior eyelid (passing through the orbicularis)

21

What does LPS give rise to?

Muller's Muscle

22

True or False: Muller's muscles are striated

False. Muller's muscles are a layer of NON-striated muscle fibres

23

Where are Muller's muscles located?

Muller's Muscles are located just behind the orbital septum

24

Which is larger? The superior palpebral muscle of muller or the inferior palpebral muscle of muller

superior is larger

25

where do muller's muscles attach?

attached to margins of tarsal plate

26

What system innervates the muller's muscles?

Sympathetic nervous system

27

For which diseases or drugs do muller's muscles hold clinical significance?

- Horner's syndrome
- Topical alpha agonists

28

What portion of the orbicularis is involved with Meibomium secretion?

The ciliary portion

29

In regards to eyelid disease, list muscular problems with the eyelid.

- ptosis, entropion, ectropion
- paralysis of orbicularis (CNVII)
- paralysis of levator (CNIII)

30

Define entropion and ectropion

Entropion - a condition in which the eyelid is rolled inward against the eyeball,

Ectropion - eyelid turned outwards, away from the eyeball

31

In regards to eyelid disease, list Eyelid gland abnormalities. [4]

- Meibomium gland dysfunction (lipid dry eye)
- Internal hordeolum (meibomium infection)
- External hordeolum (zeiss or moll infection)
- Chalazion (inflammatory, non-infective blockage of meibomium)

32

What does paralysis or orbicularis result in?

Prevents eyelid closure

33

What does paralysis of levator result in?

Drooping lid or ptosis

34

Which cranial nerves are involved with:
A) Palpebral Motor Innervation
B) Palpebral Sensory Innervation

Motor: Cranial Nerve VII - Facial nerve
Sensory: Cranial Nerve V - Trigeminal nerve

35

What are the 3 divisions of the Trigeminal Nerve? And what nerves do these divisions innervate?

1. Opthalmic Division (V1)
- lacrimal nerve (smallest)
- frontal nerve (largest)
- nasociliary
2. Maxillary Division (V2)
- infra-orbital nerve
3. Mandibular Division
- info not needed/given

36

Which nerve is larger, the lacrimal nerve, frontal nerve or nasociliary?

frontal nerve

37

Which division of the trigeminal nerve is involved with superior eyelid sensory innervation? which nerves innervate?

Opthalmic division (V1)
- mainly supra-orbital
- also supra-trochlear, infra-trochlear, and lacrimal

38

Which division of the trigeminal nerve is involved with inferior eyelid sensory innervation? Which nerves innervate?

Maxillary Division (V2)
- mainly infra-orbital

39

Name the regions and branches of the Orbicularis Oculi muscle involved with palpebral motor innervation. [2 regions, 3 branches]

Upper region: temporal & superior zygomatic branches
Lower region: lower zygomatic branch

40

Where does ocular blood supply come from?

Ophthalmic artery

41

List the major branches of the ophthalmic artery. [5]

Central retinal artery
muscular artery
lacrimal artery
short, long posterior ciliary artery
anterior ciliary artery

42

Fill in the blank: Most of the external arteries to the eyelid and adnexa come from the ________?

ophthalmic artery

43

Which 4 branches of the ophthalmic artery are the main branches involved in eyelid/palpebral blood supply?

dorsal nasal artery
supratrochlear artery (above trochlear muscle)
supraorbital artery (above orbit)
lacrimal artery (close to gland)

44

What arteries does the lacrimal artery give rise to? [1]

Lateral palpebral arteries

45

What arteries does the dorsal nasal artery give rise to, what branches?

Medial palpebral arteries
- superior and inferior branches

46

What to the lateral palpebral and medial palpebral arteries do once they reach the eyelid?

Each of them divides into 2 branches that form 2 arcades in each eyelid:
- peripheral arcade
- Marginal arcade

47

Where are the 2 arcades in each eyelid located?

Peripheral arcade: superior to tarsal plate
Marginal arcade: closer to lid margin

48

Describe the lymphatic and venous drainage of the eyelid

Venous drainage:
- Eyelid veins larger/more numerous
- Drainage into several large vessels in the face

Lymphatic drainage
- Restricted to region anterior to the orbital septum
- Drainage occurs via superficial parotid and submandibular lymph nodes

49

List the 6 major layers of the eyelid [from front to back]

1. skin
2. subcutaneous connective tissue
3. striated muscle (orbicularis)
4. submuscular connective tissue
5. tarsal plate
6. palpebral conjunctiva

50

What are the glands of Zeis & Moll, and what is their role in the skin?

They are sebaceous glands
- they produce sebum, an oily substance that coats the eyelashes/hair and keeps them from being too brittle

51

Explain the Mucocutaneous Junction

Is the transition point from skin to mucosal epithelium

52

Compared to skin, mucosal epithelium ......... [4]

- contains goblet cells
- is non-keratinised
- is thinner
- is smooth due to absence of lamina propria papillae

53

List the features of subcutaneous connective tissue [4]

- is loose collagenous connective tissue
- is traversed by filaments from the levator palpebrae tendon
- has no fat
- region of pooling -- cause black eye

54

Describe the features of the striated muscle layer of the eyelid

Orbital portion up the top, septum portion in the middle and pretarsal at the bottom

Strip of pretarsal orbicularis
- Guides Meibomian gland secretions
- More separated and posterior than pretarsal: Riolan's msucle (important for secretion)
- Pockets of muscle
- When you close eyelids = Activation of muscles = Squeezes out

55

Describe the features of the sub-muscular layer of the eyelid

Similar to subcutaneous
- Lies between orbicularis and tarsal
- Can see faint grey line (dividing lid margin)

If injured or swollen, fluid accumulation (more prominant)
- Divides anterior/posterior lid

56

Describe the features of the tarsal plate layer of the eyelid

- Thickness varies (thick centrally, thin peripherally)
- Dense fibrous CT
- Dividing line stops before lid margin = Structural importance = Superior/inferior lid margins

Maintains shape and firmness of lids
- Meibomian glands embedded

57

Describe the features of the palpebral conjunctiva layer of the eyelid

palpebral conjunctiva layer of the eyelid
- Mucous membrane (mainly cuboidal/columnar epithelium)
- Contains goblet cells - mucin
- No mucin = Can't bind

Secretes AH into tear film (10% contribution)
- Accessory lacrimal glands
- Tarsal glands of Wolfring and Klause

58

Describe the 3 zones the palpebral conjunctiva can be divided into.

1. Marginal zone: transition b/w skin and conjunctiva proper
2. Tarsal zone: thin, adherent, highly vascular (red colour)
3. Orbital zone: between tarsal upper border and fornix, loosely attached

59

list the regions of the conjunctiva

Bulbar
- limbal, - scleral
Forniceal
Palpebral
- orbital, - tarsal, - marginal

60

How far does the conjunctiva extend?-

Extends from eyelid margins anteriorly, providing a lining to the eyelids, before turning sharply upon itself to form the fornices

From here, it is reflected onto the globe, covering the sclera up to its junction with the cornea

61

True or False: The conjunctiva forms a 'sac' which opens anteriorly through the palpebral fissure.

True

62

Describe the features of the Forniceal conjunctiva.

- it forms an annular cul-de-sac
- it has 4 zones: superior, inferior, lateral, medial
- is adherent to areolar tissue
- is well vascularised

63

Describe the features of the Bulbar (ocular) conjunctiva

- thin underlying sclera visible
- tied to subadjacent structures by areolar tissue; mobile
- at about 3mm from the cornea, conjunctiva and sclera become adherent
- sensory innervation from long ciliary nerves (branches of nasociliary nerves)

64

Describe the histological structure of the conjunctiva

- epithelium = stratified columnar cells (2-5 layers)
- rests on a lamina propria (loose connective tissue)
Limbus: change to stratified squamous non-keratinised epithelium (continuous with cornea)
Goblet cells: scattered along the surface (most numerous infero-nasal)

65

Function of glands

secretion

66

What type of glands are found in eyelids? [4]

Tarsal/Meibomiam (lipid secreting)
Ciliary glands of Moll (sweat)
Glands of Zeis (sebaceous)
Accessory lacrimal glands
- Krause, Wolfring

*Way to remember
TCGA -- it's the 4 dna bases! Thymine, Cytosine, Guanine, Adenine

But instead it's tarsal, ciliary glands, glands of zeiz, accessory lacrimal

67

True or False: Making Bio flashcards is suffering and takes too long

True

68

True or False: Meibomian glands are not associated with cilia

True

69

Where is the nasojugal sulcus?

Inferior and medial/nasal.

Way to remember: it's like the lines on itachi's face from naruto. The one closest to the nose

70

What is the name of the inferior and lateral line on itachi's face under his eye?

Malar sulcus

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