Week 3: Optic Nerves Part 1 Flashcards
(119 cards)
1
Q
What are the components of the clinical neurologic exam?
A
subjective interview
mental status
cranial nerves
sensory exam
motor exam
functional task analysis
2
Q
What are the 12 cranial nerves?
A
- Olfactory
- optic
- oculomotor
- trochlear
- trigeminal
- abducens
- facial
- vestibulocochlear
- glossopharyngeal
- Vagus
- spinal accessory
- hypoglossal
3
Q
The cranial nerves are considered to be part of the PNS. What 2 nerves are the exception to this rule?
A
CN 1 and 2 (olfactory and Optic)
4
Q
The cranial nerves are part of the ___________ nervous system?
A
peripheral
5
Q
Even though the cranial nerves are part of the PNS, they have:
A
central structures involved in their pathways
6
Q
Almost all the cranial nerves target structures are located (ipsilaterally/contralaterally):
A
ipsilaterally
7
Q
A peripheral nerve has layers which are the:
A
Epineurium
Perineurium
Endoneurium
8
Q
What is the outermost layer of nerve that binds fascicles together and contains blood vessels?
A
Epineurium
9
Q
What does the epineurium of the peripheral nerve do?
A
binds fascicles together and contains blood vessels
10
Q
The perineurium of the peripheral nerve binds:
A
groupings of axons into fascicles
11
Q
The _________________ binds groupings of axons into fascicles.
A
perineurium
12
Q
What layer is a delicate layer of connective tissue surrounding single axon fibers
A
Endoneurium
13
Q
The endoneurium is a delicate layer of:
A
connective tissue surrounding single axon fiber
14
Q
What are the 4 somatic motor cranial nerves?
A
3, 4, 6, 12
15
Q
What are the 5 branchial motor cranial nerves?
A
5, 7, 9, 10, 11
16
Q
What are the parasympathetic nerves of the cranial nerves?
A
3, 7, 9, 10
17
Q
What are the somatosensory cranial nerve neurons?
A
5, 7, 9, 10
18
Q
What are the special sensory cranial nerves?
A
vestibulocochlear
19
Q
What are the visceral sensory cranial nerve?
A
7, 9, 10
20
Q
What is the saying for sensory, motor, and both?
A
Some
Say
Marry
Money
But
My
Brother
Says
Big
Brains
Matter
More
21
Q
CN 1 is the:
A
Olfactory Nerve
22
Q
Olfaction is:
A
the chemical interaction between air molecules and chemoreceptors within the membranes of receptor cells in nasal cavity.
23
Q
Olfaction, in short, means:
A
smell
24
Q
The olfactory epithelium is the:
A
sensory organ of the nose
25
What structures can be found in olfactory epithelium?
olfactory sensory receptor cells (hair cells)
supporting cells
basal stems
olfactory glands
26
The olfactory nerve pathway must start with:
odor molecules entering the nasal cavity and dissolving into nasal surface mucus.
27
When discussing the olfactory nerve pathway, the odor molecules must dissolve in the nasal surface mucus. After that, what occurs next?
The dissolved odor molecules inside the nasal surface bind to ligand gated chemoreceptors located on 1st order neurons.
28
The 1st order neuron is AKA
Olfactory nerve.
29
The 2nd order neuron is the:
olfactory tract
30
Once the odor molecules bind to the ligand gated chemoreceptors located on the 1st order neuron, the nerve then:
penetrates skull via the small foramina (cribriform plate) in the ethmoid bone and synapse within the olfactory bulb
31
Once the olfactory nerve penetrates the skull via the small foramina in the ethmoid bone, it synapses within the:
olfactory bulb.
32
The olfactory bulb is an _____________ structure that travels (rostrally/caudally) to synapse with the ________________ tract.
ovoid; caudally; olfactory
33
Once the olfactory bulb travels caudally to synapse with olfactory tract, it projects to:
multiple cortical structures, both ipsilaterally and contralaterally
34
When the olfactory bulb synapses with the olfactory tracts and projects to multiple cortical structures, this connects smell with:
odor discrimination, emotions, memory, decision making and more.
35
The CN 2 is the:
optic nerve
36
The optic nerve carries:
information about visual input from the retina to the brain
37
What are the major accessory structures (without mentioning what nerve allows it to occur)?
Eyebrows
Eyelashes
Eye lid
Extraocular muscles
Ciliary muscles
lacrimal apparatus
38
What nerve allows the eye lid to close?
What nerve allows the eye lid to open?
CN VII facial nerve
CN III Oculomotor nerve
39
What nerves are a part of the extraocular muscles of the optic nerve?
CN III, IV, and VI
oculomotor, trochlear, abducens
40
What nerves control the ciliary muscles of the optic nerve?
CN 3
Oculomotor
41
What nerve controls the lacrimal apparatus of the optic nerve?
CN VII (facial nerve)
42
Regarding the anatomy of the eye, what functions to bend light to focus image on the retina?
The lens
43
Regarding the anatomy of the eye, what is between the lens and retina, holds retina in place and contains phagocytes to remove floating debris?
vitreous humor (within the vitreous body).
44
Regarding the anatomy of the eye, what are the functions of the vitreous humor?
holds retina in place
it is between the lens and retina
Contains phagocytes to remove floating debris
45
Regarding the anatomy of the eye, what is between the cornea and lens?
anterior cavity
46
The anterior cavity of the eye is between the cornea and lens and contains:
aqueous humor
47
Define the aqueous humor of the eye that exists between the cornea and lens?
filtered blood plasma that nourishes lens and cornea
48
What are the names of the meninges in the eye?
Fibrous outer layer
vascular middle layer
Retinal inner layer
49
What are the 2 components of the fibrous outer layer?
The sclera and cornea
50
What are the 3 components of the vascular middle layer?
choroid layer, ciliary body, iris.
51
What are the 3 functions of the sclera in the fibrous outer layer of the eye?
it attaches the eye to the eyelid
is the epithelium of CN II
holds tendons of extraocular muscles
52
What is the function of the cornea of the fibrous outer layer?
controls and focuses incoming light
53
The outermost lens of the eye exists in the fibrous outer layer and is called the:
cornea
54
The vascular middle layer contains the:
choroid
ciliary body
iris
55
The choroid of the vascular middle layer is a special structure that holds the:
blood vessels
56
The ciliary body of the vascular middle layer contains the:
ciliary processes
57
What do the ciliary processes of the ciliary body in the vascular middle layer do?
it helps suspend the lens
58
What do the ciliary muscles of the ciliary body in the vascular middle layer do?
They constrict and dilate the pupils
59
The ciliary body of the vascular middle layer contains two important structures called:
ciliary processes and ciliary muscles
60
The iris of the vascular middle layer contains _________ muscle fibers that act on the \_\_\_\_\_\_\_\_\_\_\_.
smooth; pupil
61
What does the iris of the vascular middle layer do?
contains smooth muscle fibers that act on the pupil
62
How many layers are in the retinal inner layer?
7
63
What are the layers of the retinal inner layer?
Pigment epithelium
Photoreceptor layer
Outer and inner nuclear and plexiform layers
ganglion cell layer
Optic disc
Macula lutea
64
What are the 2 layers of the photoreceptor layer?
Rods and cones
65
Define the function of the rods in the photo receptor layer of the retinal inner layer:
Dim light vision
produce gray images
low acuity
66
Describe the functions of the cones in the photoreceptor layer of the retinal inner eye:
bright light vision
produces color images
high acuity
67
What are the specialized areas of the retinal inner layer?
the optic disc and the macula lutea
68
The optic disc in the specialized area of the retinal inner layer is the site where:
the optic nerve and blood vessels enter/ exit the eye
69
If there are no receptor cells in the optic discs, this creates a:
blind spot
70
What structure in the specialized area of the retinal inner layer is considered to be the visual axis?
Macula Lutea
71
The Macula Lutea contains a structure called the ________ \_\_\_\_\_\_\_\_\_\_, which means cones only.
central fovea
72
What specialized area of the retinal inner layer contains a structure that has the highest visual resolution in the eye?
macula lutea
73
1st order neurons in the pathway of the optic nerve contain the:
retinal bipolar cells (which have the rods and cones)
74
In the 1st order neuron of the retinal bipolar cells, these gather at the optic _______ and synapse with the optic \_\_\_\_\_\_\_
disc; nerve
75
The 2nd order neurons of the optic nerve pathway have retinal __________ cells that converge to form optic nerve
ganglion cells
76
1st order neurons in the optic nerve has:
retinal _______ cells
2nd order neurons in the optic nerve has
retinal ________ cells
retinal bipolar cells
retinal ganglion cells
77
What happens at the 2nd order neurons of the optic nerve?
First: the **retinal ganglion cells** are **converging with the retinal bipolar cells** to form the optic nerve
Then: it travels out of the eye socket and heads **intracranially** through optic canal.
The last thing to happen in the 2nd order neuron is that it travels **medially** and **converges** with **contralateral optic nerve** at the optic chiasm
78
What happens to the nasal visual fibers in the 2nd order neuron of the optic nerve?
these cross over and continue contralaterally
79
what happens to the temporal visual fibers of the 2nd order neurons at the optic nerve tract?
these remain on the ipsilateral sides
80
Majority of fibers from 2° optic tract neurons travel and terminate on the:
lateral geniculate nucleus of the thalamus
81
MINORITY of fibers from 2° optic tract neurons travel to what 2 structures?
superior colliculus and pretectal nucleus in midbrain
82
The minority fibers of 2° neurons that go to the superior colliculus of the optic tract will go to what 2 areas?
primary and supplementary visual areas
numerous brainstem areas
83
Of the minority fibers from the 2° optic tract neurons that go to the pretectal nucleus in the midbrain, where will they go next?
primary and supplementary visual areas
parasympathetic nuclei controlling the pupils
84
What are the 3rd order neurons of the optic nerve?
Thalamus projects to occipital lobe via the optic radiations
85
At the 3° neuron, the thalamus projects to the occipital lobe via:
optic radiations
86
At the 3rd order neurons, the right visual field consists of the _____ temporal and _______ nasal retinal input.
left and right
87
At the 3rd order neurons, the left visual field consists of _______ temporal and _______ nasal retinal input
right; left
88
In the 3rd order neurons of the optic tract, the right visual field, which is the left temporal and right retinal input, ultimately ends up at the:
left primary visual cortex
89
In the 3rd order neurons of the optic tract, the left visual field, which is the right temporal and left retinal input, ultimately ends up at the:
right primary visual cortex
90
What muscles innervate the oculomotor nerve?
medial rectus
superior rectus
inferior rectus
inferior oblique
91
The medial rectus performs:
adduction
92
The superior rectus performs:
elevation and intorsion
93
The inferior rectus performs:
depression and extorsion
94
The inferior oblique performs:
extorsion and elevation
95
The trochlear nerve is innervated by the:
superior oblique
96
The superior oblique performs:
intorsion and depression
97
The abducens nerve is innervated by:
the lateral rectus
98
The lateral rectus performs:
abduction
99
The 1st degree neuron of the oculomotor nerve originates:
in the nuclei found in the MIDBRAIN
100
The 1st order neuron of the oculomotor nerve originates in the nuclei found in the midbrain. What are the names of the 2 nuclei and what are their branches?
Oculomotor nucleus: Somatomotor branch
Edinger - Westphal Nucleus: Parasympathetic branch
101
After the oculomotor nerve originates in the nuclei found in the midbrain, it exits through a fissure and splits into superior and inferior divisions. What is the fissure it exits through and what structures are in the superior and inferior divisions?
**Fissure**: superior orbital fissure
**Superior division structures:** _Contralateral superior rectus_ and the _levator palpebrae_ (which elevates the eyelid)
**Inferior division structures**: inferior rectus, medial rectus, inferior oblique
102
After the 1st order neuron of the oculomotor neuron exits the skull and splits into different divisions, it goes to the 2nd order neuron.
At the 2nd order neurons, the pathway goes through the ___________ \_\_\_\_\_\_\_\_\_\_\_\_\_ neurons and project to muscles that are in charge of:
ciliary ganglion neurons (parasympathetic nuclei)
muscles that are in charge of: accommodation and pupil constriction
103
ciliary ganglion neurons, especially when referring to the oculomotor nerve pathway, are _______________ nuclei.
parasympathetic
104
The accommodation response applies to which 2 nerves?
Optic and oculomotor nerves
105
True or false: The accommodation response is a reflex response.
FALSE. This is not a reflex response. It simply occurs when visual objects moves from far to near
106
What is the response called when objects move from far to near?
the accommodation response
107
The accommodation response occurs when pupillary ______________ + accommodation of the ________ muscle + _____________ of eyes occurs due to the extraocular muscles.
constriction; ciliary; convergence
108
How does the accommodation response start?
By following the entire pathway of the optic pathway.
This means: retinal cells go to → primary visual cortex in the occipital lobes.
109
If we are talking about the accommodation response, it starts by following the entire pathway of the optic pathway. This means it starts at the retinal cells and goes to the primary visual cortex in the occipital lobe. Describe the pathway that occurs from here.
The start of the true association cortex will start at the visual association cortex → Superior colliulus and pretectal area → oculomotor nucleus and Edinger - Westphal Nucleus to send bilateral motor output.
110
Discussing the accommodation pathway, at the end of the pathway, the oculomotor nucleus and Edinger - Westphal Nucleus send bilateral motor output to:
* EOM's
* Len's Sphincter muscles
* ciliary ganglia
111
The trochlear nerve and the abducens nerve both only have:
first order neurons
112
What is the pathway at the 1st order neuron of the Trochlear nerve?
1. Signal travels from the trochlear nucleus in the midbrain and projects contralaterally
2. Decussate before exiting dorsal midbrain
3. Travels through the superior orbital fissure
113
What is the 1st step in the 1st order neuron of the trochlear nerve pathway?
Signal travels from the trochlear nucleus in the midbrain and projects contralaterally
114
What is the 2nd step in the 1st order neuron of the trochlear nerve pathway?
Decussate before exiting dorsal midbrain
115
What is the 3rd step in the 1st order neuron of the trochlear nerve pathway?
Travels through superior orbital fissure to the superior oblique muscles
116
What is the abducens nerve pathway?
1. Travels from the abducens nucleus (PONS)
2. Exits brainstem and exits through dura via Dorello's Canal
3. Travels rostrally to the superior orbital fissure and continues to lateral rectus muscles.
117
What is the 1st step in the 1st order neuron of the abducens nerve pathway?
the nerve travels from the abducens nucleus
118
What is the 2nd step in the 1st order neuron of the abducens nerve pathway?
Exits the brainstem and travels through the dura via Dorello's Canal
119
What is the 3rd and last step in the 1st order neuron of the abducens nerve pathway?
Travels rostrally to the superior orbital fissure and continues to the lateral medial rectus
