Anatomy Flashcards
(171 cards)
1
Q
Which cranial nerves travel through the lateral wall of the cavernous sinus at the level of the pituitary fossa? (3 things)
A
- 3
- 4
- 5th (V1 + V2)
2
Q
Which cranial nerve travels through the cavernous sinus?
A
6
3
Q
What is the supratrochlear nerve derived from?
A
Frontal nerve (branch of Ophthalmic nerve (CN V1))
4
Q
What does the supratrochlear nerve supply? (2 things)
A
- Skin of medial eyebrow
- Forehead
5
Q
Where are goblet cells most abundant in conjunctiva? (2 things)
A
- Fornices
- Plica semilunaris
6
Q
What does conjunctival stroma contain?
A
Rich vascular network
7
Q
What type of cells does conjunctival epithelium contain?
A
MHC class II dendritic cells
8
Q
How does conjunctival epithelium vary?
A
Stratified squamous to stratified columnar epithelium
9
Q
What are the anatomical zones of the trabecular meshwork?
A
- Innermost uveal meshwork
- Corneoscleral meshwork
- Outermost cribriform meshwork
10
Q
Which zone of the trabecular meshwork has the highest resistance to aqueous outflow?
A
Cribriform meshwork (adjacent to Schlemm’s canal)
11
Q
What is the effect of anterior ciliary muscle contraction on aqueous outflow?
A
Increases outflow by opening trabecular meshwork
12
Q
What are functions of trabecular meshwork cells? (2 things)
A
- Maintain hydration of trabecular connective tissue
- Phagocytic capacity
13
Q
Where does the nucleus of the third cranial nerve (oculomotor nerve) reside?
A
Midbrain
14
Q
Where does the nucleus of the fourth cranial nerve (trochlear nerve) reside?
A
Midbrain
15
Q
Where does the nucleus of the sixth cranial nerve (abducens nerve) reside?
A
Pons
16
Q
What is the correct order of the five layers of Bruch’s membrane (from retina to sclera)? (5 layers)
A
- RPE basement membrane
- Inner collagenous zone
- Elastic layer
- Outer collagenous zone
- Choriocapillaris basement membrane
(aka elastic sandwich - elastic layer in middle of collagenous zones as “bread” on either side
17
Q
What are the different parts of Orbicularis oculi muscle?
A
Orbital
Palpebral
18
Q
Where does the orbital portion of the orbicularis oculi arise from?
A
Medial palpebral ligament.
19
Q
Where does the palpebral portion of the orbicularis oculi originate from?
A
Medial palpebral ligament.
20
Q
How do the orbital fibres of the orbicularis oculi run?
A
Circumferentially in an elliptical fashion around the orbital margin.
21
Q
Where do the palpebral fibres of the orbicularis oculi pass?
A
Within the eyelid, anterior to the orbital septum and tarsal plate.
22
Q
Where is cerebrospinal fluid (CSF) produced?
A
By the choroid plexus in the:
Lateral ventricles
Third ventricle
Fourth ventricle
23
Q
What is the pathway of the Oculomotor nerve (CN3) BEFORE the Ciliary ganglion?
A
Pre ganglionic PS fibres → via branch of its inferior division → Ciliary ganglion
24
Q
What is the pathway of the Oculomotor nerve (CN3) AFTER the Ciliary ganglion?
A
Ciliary ganglion → Post-ganglionic PS fibres via Short Ciliary Nerve
25
What do the PS fibres of the Oculomotor nerve (CN3) supply) (3 things)
1. Choroid
2. Ciliary muscle
3. Sphincter pupillae
26
What does the INFERIOR division branch of the Oculomotor nerve (CN3) supply? (motor) (3 things)
1. Inferior oblique
1. Inferior rectus
1. Medial rectus
27
What does the SUPERIOR division branch of the Oculomotor nerve (CN3) supply? (motor) (2 things)
1. Superior rectus
2. Levator palpebrae superioris
28
What is the Anterio-posterior diameter of the adult eye?
23-25mm
29
Which is the strongest orbital wall?
Lateral
30
Which is the weakest orbital wall?
Anterior Medial (Lamina Papyracea)
It's paper thin
NB: Thin like papyrus
31
Which is thicker, the Anterior or Posterior Lens Capsule?
Anterior
32
Which has a stronger refractive power, lens or cornea?
Cornea
(70% of eyes refractive power)
33
What are the shapes of the sutures of the lens?
Anterior: Y shaped suture
Posterior: Inverted Y shaped suture
34
Which Lens capsule has lens epithelium under it?
Anterior ONLY
(NOT posterior)
35
What 2 arteries does the Trochlear Nerve (CN 4) pass OVER and UNDER?
OVER: Superior Cerebellar Artery
UNDER: Posterior Cerebral Artery
36
At what angle are nerve fibres in the Optic tract rotated?
90 degrees
37
Where does the muscle belly of Levator Palpebrae Superioris pass in relation to Superior Rectus?
Forward + Above
38
What does the Medial Horn of the Aponeurosis of the Levator Palpebral Superioris become?
What does it insert into?
Becomes: Medial Palpebral Ligament
Inserts into: Frontolacrimal Suture
39
What is on the inferior aspect of the Levator Palpebrae Superioris?
Muller's Muscle
40
What nerve branch is the Levator Palpebrae Superioris supplied by?
Superior division of Oculomotor Nerve (CN 3)
41
What spiral shows the distances of the insertion of the EO muscles from the limbus?
Spiral of Tillaux
42
What is the distance from Limbus to Medial Rectus Muscle?
5.5mm
(Spiral of Tillaux)
43
What is the distance from Limbus to Inferior Rectus Muscle?
6.5mm
(Spiral of Tillaux)
44
What is the distance from Limbus to Lateral Rectus Muscle?
6.9mm
(Spiral of Tillaux)
45
What is the distance from Limbus to Superior Rectus Muscle?
7.7mm
(Spiral of Tillaux)
46
What are the different types of glands around the eye? (3 things)
1. Eccrine glands
2. Apocrine glands
3. Holocrine glands
47
What is an example of Eccrine glands?
Sweat gland
48
What is an example of Apocrine glands?
Moll's glands
(associated with hair follicles)
49
What are examples of Holocrine glands? (3 things)
1. Meibomian glands
2. Sebaceous glands
3. Glands of Zeis
50
Where in the nose does the Nasolacrimal duct open?
Through an ostium partially covered by a mucosal fold (Valve of Hasner)
51
Where does the Nasolacrimal duct drain?
Inferior nasal meatus
(under inferior turbinate)
52
What is the Vitreous most firmly attached to?
Vitreous base
(Recall Q)
53
Where does the Lateral Geniculate Nucleus send most of its fibres to?
Visual cortex (aka Area 17)
54
What month of gestation does myelination of Optic Nerve begin?
7th month
55
When does myelination of Optic Nerve complete?
1 year after birth
56
Where does Myelination of the Optic Nerve terminate anatomically?
@ Lamina Cribrosa
(So optic disc + retina not myelinated)
57
What cells are responsible for myelination of optic nerve?
Oligodendrocytes
58
What is the Cornea permeable to?
Lipid soluble subtances
59
What is the Refractive Index if Descemets Membrane the same as?
Corneal endothelium RI
60
How does Descemet’s Membrane change with age?
Thickens
61
Where does Cornea get majority of its nutrition?
Aqueous
62
Where does Cornea get 10% of its nutrition from?
Limbal capillaries + Tear film
63
Remember the diagram of the Intracanalicular portion of Optic Nerve?
Yes
64
What is the Optic Nerve accompanied by in the Intracanalicular portion? (2 things)
Ophthalmic artery
Sympathetic nerves
65
What does the Optic Nerve have in its orbital portion?
S shaped bend
66
Where does the subarachnoid space terminate around the Optic Nerve?
Posterior surface of Sclera
67
The optic nerve passes through the ______ ring near the _______
Tendinous
Orbital apex
68
The optic nerve passes through the ______ ring near the _______
Tendinous
Orbital apex
69
What is the pterygopalatine fossa?
Distribution centre for main vessels and nerves of middle third of face
70
What are the contents of the pterygopalatine fossa? (3 things)
1. Maxillary artery
2. Maxillary nerve (CN V2)
3. Pterygopalatine ganglion (PS)
71
What cells of the Choroid Plexus produces the CSF?
Modified ependymal cells
72
Blockage of what can cause communication hydrocephalus in terms of CSF?
Arachnoid granulation
73
How does the Ventricular system communicate with the subarachnoid space?
Via roof of 4th ventricle
74
What is the main route of absorption of CSF?
Through Arachnoid Granulations in Superior Sagittal Sinus
75
Where does CN4 (Trochlear) enter orbit via?
Superior Orbital fissure
SO4
76
What is the innervation of the different Extraocular muscles?
Lateral Rectus: 6
Superior Oblique: 4
Others: 3
LR6 SO4 O3
77
What is the innervation of the different Extraocular muscles?
Lateral Rectus: 6
Superior Oblique: 4
Others: 3
LR6 SO4 O3
78
Know the EO muscles
79
Know the EO muscles and nerves from posterior view
80
What does paralysis of Orbicular Oculi muscle result in?
Widening of palpebral fissure
81
What muscle is responsible for frowning?
Procerus
82
Which muscle is responsible for vertical glabellar wrinkles?
Corrugator
83
Which muscle is responsible for vertical glabellar wrinkles?
Corrugator
84
Why is lateral brow ptosis more common in elderly?
Frontalis is deficient laterally
85
What layer is Outer Capillary Plexus of Retina contained in?
Inner Nuclear Layer
86
What side is the nucleus that innervates each of the EO muscles?
Levator Palpebrae Superioris: Fused
Superior Rectus + Superior Oblique: Contralateral
All others: Ipsilateral
87
What epithelium lines Nasolacrimal duct?
Stratified columnar ciliated
88
What is the line at the termination of Descemets membrane?
Schwalbe’s line
89
Where is the cornea thicker?
Periphery
90
Where is the cornea thicker?
Periphery
91
Where is the cornea thicker?
Periphery
92
What are the muscles of facial expression innervated by?
Facial nerve CN 7
93
What are the muscles of mastication innervated by?
Trigeminal nerve CN 5
94
What are the muscles of mastication? (2 things)
Temporalis
Masseter
95
What is the suspensory ligament of Lockwood?
Hammock-like ligament supporting the globe
96
What structures make up the suspensory ligament of Lockwood? (4 things)
1. Inferior rectus sheath
2. Inferior oblique sheath
3. Medial check ligament
4. Lateral check ligament
97
What are longer, rods or cones?
Rods
98
What layer is closest to the RPE microvilli?
Photoreceptor outer segments
99
What bone is the Cribriform plate part of?
Ethmoid bone
100
What nerves run through Cribriform plate?
Olfactory nerve (CN 1)
101
Where does the Trochlear Nerve (CN 4) pass in relation to tendinous ring?
Through Superior Orbital Fissure but ABOVE tendinous ring
102
Where does the Lacrimal Nerve (branch of CN V1) pass in relation to tendinous ring?
Through Superior Orbital Fissure but ABOVE tendinous ring
103
Where does the Frontal Nerve (branch of CN V1) pass in relation to tendinous ring?
Through Superior Orbital Fissure but ABOVE tendinous ring
104
What structures travel within Superior Orbital Fissure but ABOVE tendinous ring? (4 things)
1. Lacrimal Nerve
2. Frontal Nerve
3. Superior Ophthalmic Vein
4. Trochlear Nerve
105
What are the divisions of contents of the Tendinous Ring? (2 things)
1. Optic canal contents
2. Superior Orbital Fissure contents
106
What are the contents of the Tendinous ring in the Optic canal? (2 things)
1. Optic nerve (CN 2)
2. Ophthalmic artery
107
What are the contents of the Tendinous ring in the Superior Orbital Fissure? (4 things)
1. Sup division of Oculomotor Nerve (CN 3)
2. Nasociliary Nerve (branch of CN V1)
3. Inf division of Oculomotor Nerve (CN 3)
4. Abducens Nerve (CN 6)
108
What is the only structure in the Superior Orbital Fissure that is BELOW the Tendinous ring?
Inferior Ophthalmic vein
(also found in inferior orbital fissure)
109
What are the contents of the Inferior Orbital Fissure? (6 things)
1. Inferior Ophthalmic vein
2. Ganglionic branches (from Pterygopalatine ganglion to Maxillary Nerve)
3. Infra orbital Nerve (branch of CN V2)
4. Infra orbital Artery
5. Infra orbital Vein
6. Zygomatic Nerve (branch of CN V2)
110
What EO muscle does intortion?
Superior Oblique
111
What EO muscle does extortion?
Inferior Oblique
112
What is Medial Orbital Wall composed of? (4 things)
1. Maxilla
2. Lacrimal
3. Ethmoid
4. Sphenoid
MLES
113
What is the order of the components of Medial Orbital Wall from Anterior to Posterior?
1. Maxilla
2. Lacrimal
3. Ethmoid
4. Sphenoid
MLES
114
What is Inferior Orbital Wall composed of? (3 things)
1. Maxilla
2. Zygomatic
3. Palatine
115
What is Superior Orbital Wall composed of? (2 things)
1. Frontal
2. Lesser wing of Sphenoid
116
What is Lateral Orbital Wall composed of? (2 things)
1. Zygoma
2. Greater wing of Sphenoid
117
What are the different types of Ciliary Muscle? (3 things)
1. Longitudinal (external) (aka Brucke's)
2. Radial (middle)
3. Circular (internal) (aka Muller's)
118
What ciliary muscle attaches to Scleral Spur?
Longitudinal (external)
119
What ciliary muscle attaches to Corneoscleral trabeculae?
Radial (middle)
120
How does the inner circular muscle of ciliary body run?
Runs around ciliary body like a sphincter
121
What are the Apices of RPE in closest approximation?
Photoreceptor outer segment
122
What is the Embryological origin of Corneal stroma?
(Recall)
Neural crest
123
What is corneal stroma mostly comprised of?
(Recall)
Type 1 collagen
124
Which layer of corneal stroma has greater mechanical strength? Anterior or deeper?
Why?
(Recall)
Anterior stroma
Because anterior lamellae thinner + more interwoven
125
How is arrangement of fibrils in Corneal stroma different to that of Sclera? (3 things)
(Recall)
Corneal stroma:
1. Highly organised
2. Regular spacing
3. Parallel lamellae
= All contribute to transparency
(Sclera less regularly organised)
126
Trochlear nerve (CN 4) pierces dura to enter what wall of cavernous sinus? (easy one)
Lateral
127
What is the Tentorium cerebelli?
Dural fold separating cerebrum + cerebellum
128
What is Trochlear nerve (CN 4) in relation to Tentorium cerebelli?
CN4 travels anteriorly and below free edge of Tentorium cerebelli
129
What is the centre for visual fibre synapses?
Lateral geniculate body
130
What is difference between Congruous and Incongruous hemianopia?
Congruous: symmetrical visual field loss in both eyes
Incongruous: Asymmetrical visual field loss in both eyes
131
What causes Congruous vs Incongruous hemianopia?
Congruous: Lesion in Optic radiations / occipital cortex
Incongruous: Lesion in Optic tract / Lat geniculate nucleus
132
Where is the main visual centre?
Calcarine sulcus
(sulcus @ medial aspect of occipital lobe)
133
Which colliculi are involved in light reflex?
SUPERIOR colliculi
(midbrain structure)
134
What artery supplies most of Posterior visual pathway?
Posterior cerebral artery
135
What artery supplies the Retina + Extracranial Optic Nerve in Visual pathway?
Ophthalmic artery
136
What artery supports the Intracranial Optic Nerve + Optic chasm in Visual pathway? (3 things)
1. Anterior cerebral artery
2. Anterior communicating artery
3. Superior hypophyseal artery
137
What artery supports the Intracranial Optic Tract in Visual pathway? (2 things)
1. Posterior communicating artery
2. Anterior choroidal artery
138
What artery supports the Lateral Geniculate Nucleus in Visual pathway? (2 things)
1. Anterior choroidal artery
2. Posterior choroidal artery
139
What artery supports the Optic radiation in Visual pathway? (2 things)
1. Middle cerebral artery
2. Posterior cerebral artery
140
What artery supports the Primary visual cortex in Visual pathway?
Posterior cerebral artery
141
Where is mitotic activity most in Lens epithelium?
Equatorial region (aka germative zone)
142
What cell type is Lens epithelium?
Simple cuboidal
143
What is volume of vitreous?
4ml
(80% of eye volume)
144
What bone is Optic Canal located in?
Lesser wing of sphenoid bone
145
What connects Lateral ventricles to 3rd ventricle?
Foramen of Munro
146
What connects 3rd and 4th ventricles?
Aqueduct of Sylvius
147
How wide is Ciliary body?
5-6mm
148
What does Ciliary body extend to anteriorly + posteriorly?
Anterior: Scleral spur
Posterior: Ora serrata
149
What is Anterior part of Ciliary body called?
Pars Plicata
150
What is Posterior part of Ciliary body called?
Pars plana
151
What is Bowmans membrane?
Layer just underneath corneal epithelium
152
How thick is Bowmans membrane?
8-12 um
153
If Bowmans membrane is injured what happens?
Replaced by scar tissue from stromal keratocytes
(cannot regenerate)
154
What is Lamina Vitrea?
aka Bruchs membrane
Layer between Retina + Choroid
155
Where is Retina in relation to choroid?
Retina is more inside
156
What is Lamina Fusca?
Inner portion of sclera
157
What is Lamina cribrosa?
Part of Sclera that allows optic nerve to pass
158
What is Lamina Densa?
Part of BM of Corneal epithelium
159
Which EO muscle has shortest muscle belly?
Superior oblique (32mm)
others are 37-40mm
160
Which part of ciliary processes actively secretes Aqueous humour?
NON-pigmented epithelium
161
What bone does the Foramen Ovale pierce?
Greater wing of sphenoid
162
What nerve innervates lacrimal gland?
Trigeminal nerve (CN V)
the secretion from the lacrimal gland contains IgA
parasympathetic innervation originates in the lacrimatory nucleus
a layer of myoepithelial cells surrounds each acinus
163
What Ig does lacrimal gland secretion contain?
IgA
164
Where does PS innervation originate for the lacrimal gland?
Lacrimatory nucleus
165
What epithelial cells surround each acinus of lacrimal gland?
Myoepithelial cells
166
Where does CN 7 exit brainstem?
Cerebellopontine angle
167
What are the phagocytic cells of the CNS?
Microglia
168
What drains into the Superior Meatus?
Posterior ethmoidal sinus
169
What drains into the Middle Meatus? (3 things)
1. Anterior ethmoidal sinus
2. Frontal Sinus
3. Maxillary Sinus
170
What drains into the Inferior Meatus?
Nasolacrimal duct
171
Where does the Olfactory nerve terminate?
Primary olfactory cortex
