anatomy Flashcards
1
Q
what is another name for the limbus
A
corneoscleral junction
2
Q
name the 3 main layers of the eye
A
fibrous outer layer
vascular middle layer
inner photosensitive layer
3
Q
what does the fibrous outer layer consist of
A
the sclera and the cornea
4
Q
role of the sclera
A
attachment site for most of the extraocular muscles
5
Q
role of the cornea
A
provides 2/3 of the refractive power of the eye
6
Q
what does the vascular middle layer consist of
A
iris
ciliary body
choroid
7
Q
anatomical position of the iris
A
lies on the anterior surface of the lens
8
Q
role of the iris
A
controls pupil diameter to control the amount of light that reaches the retina
9
Q
what are the 2 main components of the ciliary body
A
ciliary muscle attached to the lens by the ciliary process
10
Q
name the 3 main roles of the ciliary body
A
adapts the shape of the lens
anchors the lens
produces aqueous humour
11
Q
what is the choroid
A
a dense vascular bed covering most of the sclera
12
Q
role of the choroid
A
nutrition and gas exchange to the outer layers of the retina
13
Q
what is another name for the inner photosensitive layer of the eye
A
retina
14
Q
what is the fundus
A
posterior area of the eye where light is focused
15
Q
name the 3 main parts of the fundus
A
optic disc
macula
fovea
16
Q
what causes a blind spot at the back of the eye
A
optic disc
17
Q
what is the macula
A
centre of the retina where there is the greatest density of cones
18
Q
what is the fovea
A
a depression at the centre of the macula
19
Q
role of the fovea
A
high acuity vision
20
Q
name the 3 main layers of the retina (from outwards in)
A
photoreceptors
ganglion cells
axons of the ganglion cells
21
Q
where does the anterior segment of the eye lie
A
in front of the lens
22
Q
what can the anterior segment be divided into
A
anterior and posterior chamber
23
Q
where is the anterior chamber of the eye
A
between the cornea and iris
24
Q
where is the posterior chamber of the eye
A
between the iris and suspensory ligaments
25
what fills the anterior segment
aqueous humour
26
where is the posterior segment found
behind the lens
27
what is found in the posterior segment
vitreous body which contains vitreous humour
28
where is the most common location for floaters
vitreous body
29
describe the flow of aqueous humor (4)
1. ciliary body secretes it
2. circulates in the posterior chamber to nourish the lens
3. passes through the pupil into anterior chamber to nourish cornea
4. reabsorbed into scleral venous sinus
30
what is another name for the scleral venous sinus
canal of schlemm
31
where is the scleral venous sinus found
at the iridocorneal angle
32
primary arterial supply of the eyeball
ophthalmic artery
33
arterial supply of the retina
central artery of the retina
34
what does the infraorbital artery supply
structures in the floor of the orbit
35
venous drainage of the eye
superior and inferior ophthalmic veins
36
venous drainage of the retina
central vein of the retina
37
what are meninges
protective coverings of the brain and spinal chord
38
name the 3 layers of meninges in the brain
dura mater
arachnoid mater
pia mater
39
sensory supply of the dura mater
CN V
40
role of the dural mater
encloses dural venous sinuses
41
role of dural venous sinuses
drain deoxygenated blood from the brain back towards the internal jugular vein
42
what is the subarachnoid space
the space between the arachnoid mater and pia mater
43
what does the subarachnoid space contain
circulating CSF (and blood vessels)
44
role of CSF
completely surrounds the brain and the spinal chord and provides protection
45
how can we obtain a sample of CSF
lumbar puncture at L3/4 or L4/5 disc levels
46
where in the spinal chord does CSF end
inferiorly at vertebral level S2
47
role of the pia mater
completely adheres to the brain
48
what is the largest venous sinus
superior sagittal sinus
49
role of the intraventricular foramina of monroe
connects lateral ventricles to the third ventricle
50
role of the cerebral aqueduct of sylvius
connects third ventricle to fourth
51
role of the foramen of magendie and luschka
connect 4th ventricles to subarachnoid space
52
where is CSF produced
in the choroid plexus
53
what does the choroid plexus develop from
walls of the ventricles
54
where is light from the left visual field processed
in the right primary visual cortex
55
where is light from the right visual field processed
in the left primary visual cortex
56
mnemonic for remembering the innervation of the extraocular muscles
LR 6 SO4 R3
57
how many extraocular muscles do we have
7
58
name the 3 main groups of extraocular muscles
recti and oblique muscles
levator palpebrae superioris
59
role of recti and oblique muscles
eye movement
60
role of levator palpebrae superioris
superior eyelid movement
61
name the 7 muscles of the eye
levator palpebrae superioris
superior oblique
inferior oblique
superior rectus
medial rectus
lateral rectus
inferior rectus
62
where do the recti muscles originate from
common tendinous ring
63
where do recti muscles insert on the eye
onto the sclera
64
where does the superior oblique originate from
sphenoid bone
65
where does the inferior oblique originate from
orbital plate of the maxilla
66
origin of the levator palpebrae superioris
lesser wing of the sphenoid
67
insertion of the levator palpebrae superioris
skin and tarsus of the superior eyelid
68
what assists the levator palpebrae superioris in opening the eye
Mueller's muscle
69
innervation of Mueller's muscle
superior cervical chain
70
role of the vertical axis of the eye
abduction and adduction
71
role of the transverse axis of the eye
elevation and depression
72
role of the anteroposterior axis of the eye
intorsion and extorsion of the eye
73
role of the lateral rectus muscle
abduction of the eyeball
74
role of the superior rectus muscle
elevates when in abduction
75
role of the inferior rectus
depresses when in abduction
76
role of the medial rectus
adducts the eyeball
77
role of the inferior oblique
elevates when in adduction
78
role of the superior oblique
depresses when in adduction
79
what forms the roof of the orbit
frontal bone and lesser wing of the sphenoid bone
80
what forms the floor of the orbit
maxilla, palatine and zygomatic bones
81
what forms the medial wall of the orbit
ethmoid, maxilla, lacrimal and sphenoid bones
82
what forms the lateral wall of the orbit
zygomatic and greater wing of the sphenoid
83
what does the optic canal transmit
optic nerve and the ophthalmic artery
84
what does the superior orbital fissure transmit
lacrimal, frontal, trochlear, oculomotor, naso-ciliary and abducens nerves, also carries the superior ophthalmic vein
85
what does the inferior orbital fissure transmit
zygomatic branch of the maxillary nerve
inferior ophthalmic vein
sympathetic nerves
86
what supplies sensory innervation of the face
branches of CN V
87
what is another name for CN V1
ophthalmic nerve
88
what is another name for CN V2
maxillary nerve
89
what is another name for CN V3
mandibular nerve
90
what is supplied by the ophthalmic nerve
upper eyelid, conjunctiva, cornea
91
what is supplied by the maxillary nerve
skin of the lower eyelid
skin over the maxilla
92
what is supplied by the mandibular nerve
skin over the mandible and TMJ
93
what is the exception to innervation by the mandibular nerve
angle of the mandible
94
what is the corneal reflex
involuntary blinking of the eyelids elicited by stimulation of the cornea
95
why do we have the corneal reflex
protects the eyes from foreign bodies and bright lights
96
what is afferent
sensory
97
what is efferent
motor
98
sensory limb of the corneal reflex (3)
1. action potentials conducted from cornea via CN V1 branches
2. to trigeminal ganglion
3. then along CN V to pons
99
motor limb of the corneal reflex
action potentials conducted via CN VII to eyelid part of the orbicularis oculi
100
sympathetic reflex of the eye
opens eye wider to get more light in
101
parasympathetic reflex of the eye
protects the retina from bright light or when asleep
reflex lacrimation
102
what allows wide eye opening of the eye
mueller's muscle being sympathetically innervated
103
what is a mydriatic pupil
a non-physiologically enlarged pupil
104
what is a miotic pupil
non-physiologically restricted pupil
105
give an example of when we may see a miotic pupil
horners syndrome
106
when may we see a fixed pin point pupil
opiate drug use
107
when may we see a fixed dilated (blown) pupil
CN III pathology
108
describe the light reflex pathway
1. light is shined in one eye
2. action potentials reach pretectal nuclei
3. stimulates both sides of eddinger-westphal nucleus
4. generates action potentials through R+L oculomotor nerves causing both pupils to constrict
109
what happens to ciliary muscle in far vision
relaxes causing ligament to tighten and lens to flatten
110
what happens to ciliary muscle in near vision
contracts causing ligament to relax and lens to become spherical
111
what are the 3 types of tears
basal, reflex and emotional
112
role of basal tears
involved in corneal health
113
role of reflex tears
extra tears in response to mechanical or chemical stimulation
114
role of the vestibulo-ocular reflex
turns the eyes in the opposite direction to a head movement
115
what is the oculocardiac reflex
reflex bradycardia in response to tension on extraocular muscles or pressure on the eye
