Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NBEO Part 1 > Anatomy > Flashcards

Anatomy Flashcards

1
Q

What is Rieger syndrome associated with?

A

Telecanthus

Rieger syndrome can present with various developmental abnormalities.
Dental = few and small teeth
Facial = maxillary hypoplasia, nasal bridge, hypertelorism (eyes set wide apart)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does the term ‘pental’ refer to?

A

Few & small teeth

Pental is a term used in dental anomalies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is hypertelorism?

A

Eyes are set far apart

Hypertelorism is characterized by an increased distance between the eyes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List the layers of the eyelid.

A

1.Skin
2. Subcutaneous Areolar Layer
3. Orbicularis Layer
4. Submuscular areolar layer
5. Orbital septum
6. Posterior muscular system
7. Tarsal Plate
8. Palpebral conjunctiva

These layers serve different functions and structures within the eyelid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is entropion?

A

Turning inward of the eyelid

Entropion often leads to irritation of the eye due to eyelashes rubbing against the cornea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does telecanthus refer to?

A

Abnormally increased distance between medial canthi

Telecanthus is a condition that can affect the appearance of the eyes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is poliosis?

A

Whitening of the eyelashes

Poliosis can be associated with various conditions, including genetic disorders.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is madarosis?

A

Loss of eyelashes

This condition can be caused by various factors, including trauma or disease.
Such as MGD, blepharitis, lid disease, sebaceous gland carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is trichiasis?

A

Turning inward of eyelashes

Trichiasis is often secondary to conditions like entropion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is phthiriasis palpebrarum?

A

Infection of the eyelashes caused by Phthirus pubis

  • pubic crab lice
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the skin layer of the eyelid.

A

Thin layer containing fine hairs, sweat glands, and sebaceous glands

This layer is unique as it is the thinnest skin in the body and contains no fat.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the subcutaneous areolar layer contain?

A

Loose connective tissue and levator aponeurosis

The levator aponeurosis is crucial for eyelid elevation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the orbicularis layer?

A

Contains the palpebral portion of the orbicularis oculi

The orbicularis oculi is a muscle responsible for closing the eyelids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a characteristic of the eyelid skin?

A

Contains no fat

This anatomical feature contributes to the eyelid’s flexibility and function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the role of the eyelid?

A

Keeps the eyeball divided into anterior & posterior portions

The eyelid protects the eye and maintains moisture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which cranial nerve is responsible for eyelid expression?

A

CN VII (facial nerve)

CN VII innervates the muscles responsible for facial expressions, including the eyelids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens during paralysis of CN VII?

A

Causes a brow to be lowered on the affected side and can lead to lagophthalmos

Lagophthalmos refers to the inability to close the eyelids fully.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the two portions of the orbicularis oculi?

A
  • Orbital portion
  • Palpebral portion

These portions serve different functions in eyelid movement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the function of the orbital portion of the orbicularis oculi?

A

Used for forced closure of the eyelids

The orbital portion attaches to the orbital margins and extends outward.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the function of the palpebral portion of the orbicularis oculi?

A

Used for spontaneous and reflex blinking

This portion helps in gentle eyelid closure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the muscle of Riolan?

A

Most superficial portion of the orbicularis oculi that keeps the lid margin tightly applied to the globe

Also known as the pars ciliaris.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the gray line?

A

A groove located between the eyelash insertions and the meibomian glands

It serves as a surgical landmark during lid repair.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What condition results from paralysis of the orbicularis oculi?

A

Ectropion

Ectropion is characterized by the lower eyelid drooping away from the globe.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the muscle of Horner?

A

Consists of fibers from the orbicularis that help drain tears into the lacrimal sac

Also referred to as the pars lacrimalis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the anatomical origin of the muscle of Horner?

A

Originates from the posterior lacrimal crest and fascia of the lacrimal sac

It encircles the canaliculi to assist in tear drainage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does paralysis of the orbicularis oculi lead to?

A

Drooping of the lower eyelid and potential eversion of the lid

This can also lead to discomfort and red eye due to improper eyelid function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Fill in the blank: The gray line divides the lid into _______ and posterior portions.

A

anterior

This anatomical feature is important for surgical procedures.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the submuscular areolar layer?

A

Thin layer of loose connective tissue between the orbicularis and the orbital septum

Contains the levator aponeurosis and the palpebral portion of the main lacrimal gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the function of the orbital septum?

A

Serves as a barrier to the orbit in the upper and lower eyelids

Prevents fat from falling onto the lid margins and keeps infections localized to the anterior portion of the eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

True or False: The orbital septum protects the lacrimal sac from infection.

A

False

The lacrimal sac is anterior to the attachment of the orbital septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does preseptal cellulitis refer to?

A

An infection that occurs anterior to the orbital septum

Commonly seen in cases of eyelid infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is orbital cellulitis?

A

An infection that occurs posterior to the orbital septum

More serious than preseptal cellulitis, often involving the orbit itself

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the components of the posterior muscular system of the eyelid?

A

Superior levator palpebrae muscle, superior tarsal muscle, inferior tarsal muscle

These muscles control eyelid elevation and positioning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Where does the superior palpebral levator muscle originate?

A

From the lesser wing of the sphenoid at the orbital apex

It serves as the main retractor of the upper eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the role of Whitnall’s ligament?

A

Serves as a fulcrum for the levator muscle

Changes the course of the muscle, allowing it to perform its function effectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Fill in the blank: The levator muscle extends into the eyelid as a fan-shaped tendon known as the _______.

A

levator aponeurosis

This tendon sends fibers anteriorly through the orbital septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the significance of the medial and lateral horns of the levator aponeurosis?

A

The lateral horn attaches to Whitnall’s ligament; the medial horn merges with the medial palpebral ligament

Important for the structural integrity and function of the eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the clinical implication of CN III palsy on the eyelid?

A

Results in ptosis, or drooping of the upper eyelid

CN III is responsible for innervating the levator palpebrae muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the function of the levator palpebrae superioris?

A

Elevates the upper eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What forms the superior palpebral furrow?

A

Insertion of the levator aponeurosis into the skin of the upper eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What forms the inferior palpebral furrow?

A

Indirect attachment of the inferior rectus muscle into the skin of the lower eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What separates the tarsal and orbital portions of the eyelid?

A

Eyelid furrows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the role of the Muscle of Muller?

A

Provides minor retraction of the upper eyelid and widens the palpebral fissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Which receptors does the Muscle of Muller respond to?

A

Alpha-1 adrenergic receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is another name for the Muscle of Muller?

A

Superior tarsal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Where does the inferior tarsal muscle originate?

A

Fascial sheath of the inferior rectus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What causes mild upper lid ptosis in Horner’s syndrome?

A

Lack of sympathetic innervation to the Muscle of Muller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the result of CN III palsy?

A

Significant upper lid ptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What condition can cause a ‘stare appearance’ in patients?

A

Thyroid eye disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the normal interpalpebral fissure distance in adults?

A

10-12 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Which cranial nerve opens the eye?

A

Cranial Nerve III (CN III)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Which cranial nerve closes the eye?

A

Cranial Nerve VII (CN VII)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

______ is the smooth muscle innervated by the sympathetic nervous system that raises the eyelid.

A

Muscle of Muller

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

True or False: Cocaine can maintain the eye being open.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the effect of sympathetic input on pupil dilation?

A

Will not dilate the pupil in the absence of sympathetic input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

List the adrenergic receptors available to bind norepinephrine.

A
  • A1
  • A2
  • B1
  • B2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is the primary function of the Meibomian glands?

A

To produce the anterior lipid layer of the tear film

Meibomian glands are large sebaceous glands located within the tarsal plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How many Meibomian glands are approximately in the upper eyelid?

A

About 25 Meibomian glands

There are approximately 20 glands in the lower eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What type of tissue composes the tarsal plate?

A

Dense irregular connective tissue

This tissue provides rigidity to the eyelids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What are the two layers of the palpebral conjunctiva?

A
  1. Epithelial layer
  2. Stroma

The epithelial layer contains goblet cells that produce mucin for the tear film

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Where are goblet cells predominantly found?

A

In the inferonasal fornix and on the bulbar conjunctiva

Most concentrated temporally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What does the stroma of the palpebral conjunctiva contain?

A

Superficial lymphoid layer and deep fibrous layer

The superficial lymphoid layer is immunologically active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is the function of the Glands of Zeis?

A

To lubricate the eyelashes

They are modified sebaceous glands associated with eyelash follicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

True or False: The Glands of Moll are modified sebaceous glands.

A

False

Glands of Moll are modified apocrine glands located near the lid margin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Fill in the blank: The upper and lower tarsal plates combine to form the _______.

A

Medial and lateral palpebral ligaments

The medial palpebral ligament attaches to the maxillary bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What type of immune cells are found in the superficial lymphoid layer of the conjunctiva?

A

IgA, macrophages, mast cells, PMNs, eosinophils

This layer is very immunologically active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are the accessory lacrimal glands located in the fornices of the conjunctiva called?

A

Glands of Krause

They are considered merocrine glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is exocytosis?

A

A process where cells secrete substances by expelling them from vesicles, allowing the cells to remain intact.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are the Glands of Wolfring?

A

Accessory lacrimal glands that are larger and less numerous than the glands of Krause, located predominantly in the tarsal conjunctiva.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What type of glands are the Meibomian glands and glands of Zeis?

A

Holocrine glands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What type of glands are the Glands of Moll and goblet cells?

A

Apocrine glands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What type of glands are the accessory lacrimal glands?

A

Merocrine glands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

During holocrine secretion, what happens to the cell?

A

The whole cell is shed into the lumen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

During apocrine secretion, what occurs?

A

A portion of the plasma membrane buds off the cell and enters the lumen for secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

In merocrine secretion, how do cells secrete their substances?

A

Cells secrete their substances by exocytosis and remain completely intact after secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

True or false
There are more glands of Krause than Wolfring

A

True
* more glands of Krause but wolfing glands are larger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is the orbicularis oculi?

A

A muscle of the eyelids with concentric fibers that act as a sphincter to close the eyelids

It consists of palpebral and ciliary portions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Which nerve innervates the orbicularis oculi?

A

Zygomatic branch of the facial nerve

It provides voluntary motor innervation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What type of innervation does the muscle of Muller receive?

A

Involuntary motor innervation from the sympathetic nervous system

This muscle assists in elevating the upper eyelid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What branches supply sensory innervation to the upper eyelid?

A

Frontal (supraorbital and supratrochlear) and lacrimal branches of V1 (ophthalmic nerve)

These branches are responsible for sensory perception in the upper eyelid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Which branches innervate the lower eyelid?

A

Infraorbital and zygomaticofacial branches of V2 (maxillary nerve)

These branches provide sensory innervation to the lower eyelid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What is the role of the infratrochlear nerve?

A

Innervates the medial aspect of the upper and lower eyelids

It branches from the nasociliary nerve of V1.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What arteries supply the deeper eyelid tissue?

A

Lateral and medial palpebral arteries, branches of the ophthalmic artery

These arteries are crucial for blood supply to the eyelids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Where are the palpebral arcades located?

A

In the submucosal areolar layer of the upper and lower eyelids

They are formed by the union of the medial and lateral palpebral arteries.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What are the two main types of palpebral arcades?

A

Marginal palpebral arcades and Peripheral palpebral arcades

Marginal palpebral arcades are located closest to the eyelid margin, while Peripheral palpebral arcades supply the fornices and the posterior conjunctiva.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What is the role of the anterior ciliary arteries?

A

Provide circulation to the bulbar conjunctiva and the ciliary body

This explains why patients with uveitis can experience circumlimbal injection and decreased aqueous humor production in the involved eye.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

Which arteries supply the superficial areas of the eyelid?

A

Facial artery

The facial artery branches off the external carotid artery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What condition can lead to circumlimbal injection?

A

Uveitis

Uveitis can cause inflammation leading to circumlimbal injection and decreased aqueous humor production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Fill in the blank: The _______ supplies circulation to the deeper eyelid structures.

A

Arcades

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

True or False: The veins of the eyelids drain into the palpebral and ophthalmic arteries.

A

False

The veins of the eyelids drain into the palpebral and ophthalmic veins, not arteries.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What is the function of the medial palpebral artery?

A

Supplies circulation to the medial aspect of the eyelid

It is a branch of the ophthalmic artery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What is the approximate volume of aqueous humor in the anterior chamber?

A

200 microliters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

List the main branches of the external carotid artery that supply the eyelids.

A
  • Facial artery
  • Lacrimal artery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What do the superior and inferior marginal arcades supply?

A

The eyelid margins

They are important for vascular supply to the eyelid.

95
Q

Circumlimbal injection

A

Enlargement of episcleral vessels in the region of the CB

96
Q

What does EKC stand for?

A

Epidemic Keratoconjunctivitis

97
Q

What are the symptoms of Epidemic Keratoconjunctivitis?

A
  • burning
  • Itching
  • FBS
  • Tearing
  • Photophobia
98
Q

What is the self-resolving time frame for EKC?

A

2-3 weeks

99
Q

What type of lymphatic drainage occurs in the conjunctiva?

A

Lateral lymphatics drain into the parotid (preauricular) lymph nodes; Medial lymphatics drain into the submandibular lymph nodes

100
Q

True or False: Simple bacterial conjunctivitis presents with preauricular lymphadenopathy.

A

False

101
Q

True or false
Epidemic keratoconjunctivitis has positive preauricular lymphadenopathy?

A

True

102
Q

What is the primary function of the eyebrows?

A

protection and facial expression

103
Q

What reflex do the cilia of the eyebrows and eyelashes elicit?

A

blink reflex

104
Q

What muscle is the main elevator of the eyebrows?

A

Frontalis

105
Q

Fill in the blank: The frontalis muscle helps to compensate for _______.

A

ptosis

106
Q

What does the corrugator muscle do?

A

Medial depressor of the eyebrow

107
Q

What is the function of the procerus muscle?

A

Pulls the skin between the eyebrows downward for an appearance of menace or aggression

108
Q

Where does the procerus muscle originate?

A

on the nasal bone (bridge of the nose)

109
Q

What is the primary lateral depressor of the eyebrow?

A

Orbicularis Oculi

110
Q

What is a key characteristic of the frontalis muscle?

A

Fibers run vertically to raise the eyebrow for a look of surprise or attention

111
Q

What type of wrinkles does the corrugator muscle produce?

A

vertical wrinkles of the forehead

112
Q

What appearance does the corrugator muscle create?

A

a look of concentration

113
Q

What is the role of the Orbicularis Oculi muscle?

A

to depress the eyebrow laterally

114
Q

What is Parinaud’s oculoglandular syndrome characterized by?

A

significant preauricular and submandibular lymphadenopathy

115
Q

Where is the lacrimal gland located?

A

In a fossa on the temporal side of the frontal bone

116
Q

What are the two portions of the lacrimal gland?

A

Orbital and palpebral portions

117
Q

What type of gland is the lacrimal gland?

A

Tubuloalveolar exocrine gland

118
Q

How does the lacrimal gland release its products?

A

Via merocrine secretion

119
Q

What supplies blood to the lacrimal gland?

A

Glandular branches of the lacrimal artery

120
Q

How is the lacrimal gland drained?

A

By the lacrimal vein

121
Q

What is unique about the lymphatic vessels of the lacrimal gland?

A

They are the ONLY lymphatic vessels of the orbit

122
Q

Where do the lymphatic vessels of the lacrimal gland drain?

A

Into the parotid lymph nodes

123
Q

What type of innervation does the lacrimal gland receive?

A

Parasympathetic innervation from the lacrimal nerve of the pterygopalatine ganglion of CN VII

124
Q

What does parasympathetic stimulation of the lacrimal gland cause?

A

Secretion of the aqueous layer of the tears

125
Q

Do sympathetic nerve fibers innervate the lacrimal gland?

A

Yes, some sympathetic nerve fibers follow the lacrimal artery

126
Q

What is acute dacryoadenitis?

A

An infection and/or inflammation of the lacrimal gland

127
Q

What can acute dacryoadenitis result in?

A

Acute swelling and discomfort in the upper lateral eyelid

128
Q

What causes acute dacryoadenitis?

A

Staphylococcus infection

129
Q

What is a chronic cause of dacryoadenitis?

A

Sarcoidosis

130
Q

What are accessory lacrimal glands?

A

Glands that have the same histological makeup as the main lacrimal gland

131
Q

Name two types of accessory lacrimal glands.

A

Glands of Wolfring and glands of Krause

132
Q

Where are accessory lacrimal glands located?

A

In the subconjunctival tissue from the fornix up to the tarsal plate

133
Q
A

Make sure you know the anatomy of nasolacrimal drainage system!

134
Q

What are the 2 divisions of lacrimal gland?

A

Palpebral and orbital
* divided by tendon of levator (SLP)

135
Q

What are lacrimal puncta?

A

Small openings located within a ring of connective tissue called the lacrimal papilla

136
Q

What is the function of the lacrimal papilla?

A

Responsible for keeping the puncta open

137
Q

What is the length of the canaliculi?

A

10 mm long

138
Q

What type of epithelium lines the canaliculi?

A

Stratified and pseudostratified epithelium

139
Q

Describe the path of the canaliculi.

A

Initially runs vertically 2 mm, then travels medially 8 mm before joining the common canaliculus

140
Q

What prevents back flow into the canaliculi?

A

The angle at which the common canaliculus enters the lacrimal sac

141
Q

What muscle surrounds the canaliculi?

A

Muscle of Horner

142
Q

What is the role of the muscle of Horner during eyelid closure?

A

Contracts the canaliculi to assist in tear drainage

143
Q

Where is the lacrimal sac located?

A

Within a fossa in the medial orbital wall formed by the lacrimal and maxillary bones

144
Q

What is the length of the lacrimal sac?

A

10-12 mm long

145
Q

What type of epithelium lines the lacrimal sac?

A

Double epithelium with superficial columnar and deep basal layers

146
Q

What additional structures are found in the lacrimal sac?

A

Microvilli and goblet cells

147
Q

What is the lacrimal sac continuous with?

A

The nasolacrimal duct

148
Q

What is located posterior to the lacrimal sac?

A

The orbital septum and the check ligament of the medial rectus

149
Q

True or False: The lacrimal sac is less susceptible to infection due to its position.

A

False

150
Q

What does NLDO stand for?

A

Nasolacrimal duct obstruction

151
Q

What is a common cause of unilateral tearing in adults?

A

Involutional stenosis (age)

152
Q

What is Jones I testing used for?

A

To assess nasolacrimal duct function

153
Q

What condition can untreated nasolacrimal duct obstruction lead to?

A

Dacryocystitis

154
Q

What is dacryocystitis?

A

An infection of the lacrimal sac

155
Q

What anatomical features form the nasolacrimal duct?

A

Posterior lacrimal crest of the maxillary bone and the inferior concha

156
Q

How long is the nasolacrimal duct?

A

15 mm

157
Q

What lines the nasolacrimal duct?

A

Double epithelium, microvilli, and goblet cells

158
Q

Where does the nasolacrimal duct terminate?

A

Inferior meatus of the nasal cavity

159
Q

What is the function of the Valve of Hasner?

A

Prevents back flow of nasal fluids into the lacrimal drainage system

160
Q

What structures are contained within the orbit?

A

Globe of the eye, extraocular muscles, optic nerve, connective tissue, and adipose tissue

161
Q

What is thyroid eye disease?

A

An autoimmune response against the connective tissue and adipose tissue within the orbit

162
Q

What symptoms are associated with thyroid eye disease?

A

Swelling, inflammation, proptosis, lid retraction, EOM restrictions, optic nerve compression

163
Q

What are the two compartments of adipose tissue in the orbit?

A
  • Intraconal adipose tissue
  • Extraconal adipose tissue
164
Q

Where is intraconal adipose tissue located?

A

Within the muscle cone of the four recti muscles

165
Q

Where is extraconal adipose tissue found?

A

Outside the muscle cone between the EOMs and the walls of the orbit

166
Q

What are extraocular muscles?

A

Extrinsic muscles of the eye that attach to the sclera

167
Q

Fill in the blank: The nasolacrimal duct is lined with a _______.

A

Double epithelium

168
Q

True or False: The nasolacrimal duct is involved in the drainage of tears.

A

True

169
Q

What is denser in extraocular muscles (EOMs)?

A

Blood supply and nerve supply

EOMs have a denser blood supply and a more finely tuned nerve supply.

170
Q

What combination of muscle fibers allows EOM movements to be faster and more fatigue resistant?

A

White (fast) and red (slow but sustaining) muscle fibers

This unique combination contributes to the performance of EOMs.

171
Q

Where does the superior rectus muscle originate?

A

Common tendinous ring anterior to the superior orbital fissure

It inserts 7.7 mm from the limbus.

172
Q

What connects the sheath covering the superior rectus?

A

Sheath of the superior levator palpebrae and connective tissue of the superior conjunctival fornix

These connections raise the lid when the eye is in up gaze.

173
Q

Where does the inferior rectus muscle originate?

A

Common tendinous ring at the infraoptic tubercule

It inserts 6.5 mm from the limbus.

174
Q

What structure does the sheath of the inferior rectus combine with?

A

Sheath of the inferior oblique muscle

This forms the suspensory ligament of Lockwood.

175
Q

What does the suspensory ligament of Lockwood attach to?

A

Inferior tarsal plate, zygomatic bone, and lacrimal bone

It provides support for the globe.

176
Q

Where does the lateral rectus muscle originate?

A

Common tendinous ring at the spina recti lateralis

It inserts 6.9 mm from the limbus.

177
Q

What anchors the lateral rectus muscle?

A

Lateral check ligament to Whitnall’s tubercule

This is located on the zygomatic bone of the orbit.

178
Q

Where does the medial rectus muscle originate?

A

Common tendinous ring

It inserts 5.5 mm from the limbus.

179
Q

What anchors the medial rectus muscle?

A

Medial check ligament to medial orbital septum and other structures

This includes the bone behind the posterior lacrimal crest, the caruncle, and the plica semilunaris.

180
Q

Superior rectus

Innervated by CN?
Origin?
Insertion?
Primary, secondary and tertiary actions?

A

CN III
origin: common tendinous ring
Inserts: 7.7 mm from limbus
1. Elevation
2. Intorsion
3. ADDuction

181
Q

Inferior rectus

Innervated by CN?
Origin?
Insertion?
Primary, secondary and tertiary actions?

A

CN III
origin: common tendinous ring
Insertion: 6.5mm from limbus
1. Depression
2. Extorsion
3. ADDuction

182
Q

What is the insertion distance of the Superior Rectus muscle from the limbus?

A

7.7 mm

The Superior Rectus (SR) inserts furthest from the limbus compared to other recti muscles.

183
Q

What is the insertion distance of the Lateral Rectus muscle from the limbus?

A

6.9 mm

The Lateral Rectus (LR) inserts at 6.9 mm from the limbus.

184
Q

What is the insertion distance of the Inferior Rectus muscle from the limbus?

A

6.5 mm

The Inferior Rectus (IR) inserts at 6.5 mm from the limbus.

185
Q

What is the insertion distance of the Medial Rectus muscle from the limbus?

A

5.5 mm

The Medial Rectus (MR) inserts closest to the limbus at 5.5 mm.

186
Q

Where do all recti muscles originate from?

A

Common Tendinous Ring (CTR)

All recti muscles originate from the CTR.

187
Q

What anatomical structure is considered the physiological origin of the Superior Oblique muscle?

A

Trochlea

The trochlea changes the direction of action for the Superior Oblique.

188
Q

Where does the Inferior Oblique muscle originate?

A

Maxillary bone

The Inferior Oblique originates anteriorly at the maxillary bone, posterior to the medial orbital rim.

189
Q

What is the primary action of the Lateral Rectus muscle?

A

Abduction

The primary action for the Lateral Rectus is abduction of the eye.

190
Q

What is the primary action of the Medial Rectus muscle?

A

Adduction

The primary action for the Medial Rectus is adduction of the eye.

191
Q

What is the primary action of the Superior Rectus muscle?

A

Elevation

The primary action for the Superior Rectus is elevation of the eye.

192
Q

What is the primary action of the Inferior Rectus muscle?

A

Depression

The primary action for the Inferior Rectus is depression of the eye.

193
Q

What is the primary action of the Superior Oblique muscle?

A

Intorsion

The primary action for the Superior Oblique is intorsion of the eye.

194
Q

What is the primary action of the Inferior Oblique muscle?

A

Extorsion

The primary action for the Inferior Oblique is extorsion of the eye.

195
Q

True or False: The primary action for the obliques is extorsion.

A

False

The primary action for the obliques is intorsion.

196
Q

Fill in the blank: The superior and inferior obliques are responsible for pure _______ and _______ respectively when the eye is adducted.

A

depression, elevation

This occurs when the eye is adducted 51-5 degrees towards the midline.

197
Q

Fill in the blank: The superior and inferior recti muscles are responsible for pure _______ and _______ respectively when the eye is abducted.

A

elevation, depression

This occurs when the eye is abducted 23 degrees away from the midline.

198
Q

What are the primary and secondary actions of the Superior Oblique muscle?

A

Primary: Intorsion, Secondary: Adduction

The Superior Oblique muscle primarily intorts the eye and can secondarily adduct.

199
Q

What are the primary and secondary actions of the Inferior Oblique muscle?

A

Primary: Extorsion, Secondary: Abduction

The Inferior Oblique muscle primarily extorts the eye and can secondarily abduct.

200
Q

What are the two muscular branches from the ophthalmic artery that supply the EOMs?

A
  1. Superior lateral branch
  2. Inferior medial branch

These branches are responsible for supplying different extraocular muscles.

201
Q

Which extraocular muscles are supplied by the superior lateral branch of the ophthalmic artery?

A

SR, LR, SO

SR = Superior Rectus, LR = Lateral Rectus, SO = Superior Oblique.

202
Q

Which extraocular muscles are supplied by the inferior medial branch of the ophthalmic artery?

A

MR, IR, IO

MR = Medial Rectus, IR = Inferior Rectus, IO = Inferior Oblique.

203
Q

What minor arteries may provide blood supply to the EOMs?

A

Lacrimal artery, supraorbital artery, infraorbital artery

These arteries contribute to the blood supply but are not the main sources.

204
Q

Which cranial nerve innervates the superior rectus muscle?

A

CN III (superior division)

CN III is the oculomotor nerve.

205
Q

Which muscles are innervated by the inferior division of CN III?

A

IR, IO, MR

IR = Inferior Rectus, IO = Inferior Oblique, MR = Medial Rectus.

206
Q

Which cranial nerve innervates the lateral rectus muscle?

A

CN VI

CN VI is the abducens nerve.

207
Q

Which cranial nerve innervates the superior oblique muscle?

A

CN IV

CN IV is the trochlear nerve.

208
Q

What is the orbital fascia also known as?

A

Periorbita or orbital periosteum

This fascia plays a crucial role in the structure of the orbit.

209
Q

What is the primary composition of the orbital fascia?

A

Dense connective tissue

This composition provides support and structure within the orbit.

210
Q

What does the orbital fascia provide support to?

A

Blood vessels within the orbit

It also serves as a point of attachment for muscles, tendons, and ligaments.

211
Q

How is the orbital fascia related to the dura mater?

A

Continuous with the dura mater surrounding the brain and optic nerve

This connection occurs within the optic canal.

212
Q

What is the role of the anterior orbital fascia?

A

Forms the orbital septum and prevents prolapse of orbital fat

It also acts as a barrier against orbital infections.

213
Q

Fill in the blank: The orbital fascia contributes to the formation of the _______.

A

CTR (common tendinous ring)

This structure is significant for muscle attachments.

214
Q

What does the orbital fascia cover besides the bones of the orbit?

A

Lacrimal gland, lacrimal sac, nasolacrimal canal

This coverage is essential for the function of the lacrimal system.

215
Q

What forms the base of the cranium?

A

The body of the sphenoid bone

The sphenoid bone has a middle portion known as the body, which is crucial for cranial structure.

216
Q

Where is the optic canal located in relation to the sphenoid bone?

A

Just lateral to the center of the sphenoid body

The optic canal is essential for the passage of the optic nerve and ophthalmic artery.

217
Q

What is the sella turcica?

A

A depression in the body of the sphenoid bone that houses the pituitary gland

The sella turcica is a key anatomical feature relevant for endocrine function.

218
Q

What lies superior to the pituitary gland?

A

The optic chiasm

This relationship is important for understanding visual field deficits caused by pituitary tumors.

219
Q

What visual field defect can result from damage to nasal retinal fibers due to a pituitary tumor?

A

Bitemporal hemianopsia

This condition occurs when the fibers that cross at the optic chiasm are affected.

220
Q

What are the two wings of the sphenoid bone?

A

Lesser wing and Greater wing

Each wing has specific anatomical connections and features.

221
Q

What does the lesser wing of the sphenoid connect with?

A

The frontal bone

This connection helps form the roof of the orbit.

222
Q

What structures are contained within the optic canal?

A

Optic nerve and ophthalmic artery

These structures are vital for vision and blood supply to the eye.

223
Q

What does the greater wing of the sphenoid connect with?

A

The zygomatic bone

This connection helps form the lateral wall of the orbit.

224
Q

What are the three important foramina located in the greater wing of the sphenoid?

A

Foramen rotundum, Foramen ovale, Foramen spinosum

Each foramen has a specific function related to nerve and artery passage.

225
Q

What does the foramen rotundum transmit?

A

Maxillary division (V2) of the trigeminal nerve

This foramen is crucial for sensory innervation to the mid-facial region.

226
Q

What does the foramen ovale transmit?

A

Mandibular division (V3) of the trigeminal nerve and the lesser superficial petrosal nerve

This foramen is essential for motor innervation to the muscles of mastication.

227
Q

What does the foramen spinosum transmit?

A

Middle meningeal artery

This artery supplies the meninges and is important for cranial blood supply.

228
Q

What is the Superior Orbital Fissure (SOF)?

A

An opening between the greater and lesser wings of the sphenoid bone

The SOF allows passage for several cranial nerves and vascular structures.

229
Q

What lies just posterior to the Superior Orbital Fissure?

A

Cavernous sinus

This structure is significant for venous drainage and cranial nerve relationships.

230
Q

What is the Common Tendinous Ring (CTR)?

A

A circular band of connective tissue that lies just anterior to the SOF

The CTR serves as the origin for the recti muscles of the eye.

231
Q

What is another name for the Common Tendinous Ring?

A

Annulus of Zinn

This alternative name is often used in anatomical contexts.

232
Q

Which cranial nerves pass through both the SOF and the CTR?

A

CN III, CN VI, Nasociliary nerve

These nerves are crucial for ocular function and control.

233
Q

True or False: The sympathetic root of the ciliary ganglion travels with the nasociliary nerve.

A

True

This relationship is important for understanding autonomic innervation to the eye.

NBEO Part 1 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions