Neuro Flashcards
1
Q
What do oligodendrocytes myelinated?
A
Brain
2
Q
What do Schwann cells myelinate?
A
PNS
3
Q
What is a lemnisci?
A
narrow strips of fibres
4
Q
Define funiculi?
A
Rope or cord
5
Q
Define Fasciculi?
A
Bundle
6
Q
Define nuclei
A
Collection of nerve cell bodies within the CNS
7
Q
Define ganglia
A
Collection of nerve cell bodies outside the CNS and some in the CNS (In a capsule)
8
Q
What sort of information is carried on afferent fibres?
A
Sensory fibres towards CNS
9
Q
What sort of information is carried on efferent fibres?
A
Motor fibres away from the CNS
10
Q
Which direction is rostral?
A
Towards the nose (Anterior)
11
Q
Which direction is caudal?
A
Towards tail (posterior)
12
Q
What is the function of the frontal lobe?
A
Voluntary movement on opposite side of the body
Dominant frontal lobe controls speech and writing
Intellectual functioning, thought processes, reasoning and memory
13
Q
What is the function of the parietal lobe?
A
receives and interprets sensations including pain, touch, pressure and proprioception
14
Q
What is the function of the temporal lobe?
A
understanding spoken word (Wernicke’s)
Memory and emotion
15
Q
What is the function of the occipital lobe
A
Understanding visual images and meaning of written words
16
Q
What are the components of the basal ganglia?
A
Caudate nucleus
Putamen
Globus Pallidus
17
Q
What are the components of the striatum
A
Caudate nucleus and putamen
18
Q
What are the components of the lentiform nucleus
A
Globus pallidus and the putamen
19
Q
What is the function of the cerebellum?
A
Co-ordinates movement and balance
20
Q
Where does the superior cerebellar peduncle attach to?
A
Midbrain
21
Q
Where does the middle cerebellar peduncle attach to?
A
Pons
22
Q
Where does the inferior cerebellar peduncle attach to?
A
Medulla
23
Q
What are the two specialised cell types found in the CNS
A
Nerve cells (Pyramidal, stellate, Golgi, Purkinje)
Neuroglia (Astrocytes, oligodendrocytes and microglia)
24
Q
By which week does the neural tube normally close?
A
4th week
25
What condition results from failure of the neural tube to close in the spinal cord?
Spina bifida
26
What condition results from failure of the neural tube to close in the cephalic region?
Anencephalus
27
Describe the process of neuralation
Ectoderm thickens in midline in 3rd week to form neural plate
Ectoderm undergoes differential mitosis to form mid-line groove called neural groove
Groove deepens and tdetaches from ectoderm to become neural tube
Lateral to the neural plate lie presumptive neural crest cells which run dorsolaterally along the neural groove
Rostral portion of neural tube (Forms brain) grows faster than caudal portion (Forms spinal cord)
28
What do the neural crest cells go on to form?
```
Sensory (dorsal root) ganglia of the spinal cord and CN V, VII, IX and X
Schwann cells
Pigment cells
Adrenal medulla
Bony skull
Meninges
Dermis
```
29
By 5th week of development, what are the three primary brain vesicles called?
Prosencephalon (Forebrain)
Mesencephalon (Midbrain)
Rhombencephalon (Hindbrain)
30
What secondary brain vesicle does the prosencephalon become?
Telencephalon and diencephalon
31
What secondary brain vesicle does the mesencephalon become?
Mesencephalon
32
What secondary brain vesicle does the rhombencephalon become?
Metencephalon and Myelencephalon
33
What does the telencephalon form?
Cerebral hemispheres and lateral ventricles
34
What does the diencephalon form?
Thalamus
Hypothalamus
Third ventricle
35
What does the mesencephalon form?
Midbrain (Colliculi)
| Aqueduct
36
What does the metencephalon become?
Cerebellum, Pons and upper part of 4th ventricle
37
What does the myelencephalon become?
Medulla oblongata and Lower part of 4th ventricle
38
Describe the function of the hippocampus
Episodic memory
Construction of mental images
Short term memory
spatial memory and navigation
39
What are the basic components of all neurones
dendrites
cell body
axon
presynaptic terminal
40
What stain is used for myelin?
Luxor fast blue
41
What stain is used for Nissl (RER)?
Cresol violet
42
Describe the composition of myelin
70% lipid and 30% protein
43
Where are myelinated axons most commonly found?
Somatic nerves
44
Where are unmyelinated axons commonly found?
Post-ganglionic autonomic fibres, fine sensory fibres, olfactory neurones and interneurones
45
What is the function of glial cells?
Provide physical and metabolic support to neurones
46
How many axons can oligodendrocytes myelinate?
Multiple
47
How many axons can Schwann cells myelinate
Single
48
What is the function of astrocytes?
Regulate composition of extracellular fluid in CNS by removing K+ ions and neurotransmitters
Take up glutamate and convert it to glutamine and release it so can be taken back up by neurones and converted to glutamate for re-use
Stimulate the formation of tight junctions as part of the BBB
Sustain neurones metabolically by providing glucose and removing ammonia
49
What are microglia and what is their function?
Specialised macrophage like cells that perform immune functions in the CNS
- Phagocytose debris/microbes
- contribute to synaptic plasticity
50
What is the function of ependymal cells?
Line ventricles of the brain and regulate the production and flow of CSF
51
Which cells make up the BBB?
Endothelial cells, pericytes and astrocytes
52
What are the features of the blood brain barrier
Endothelial tight junctions
Astrocyte end feet
Pericytes
Continuous basement membrane
53
What is the name given to areas of the brain that lack a BBB?
Circumentricular organs ie. posterior pituitary
54
Where does the CSF circulate
Subarachnoid space
55
What is the volume of the CSF?
120mls
56
What is found in the CSF?
Protein, urea, glucose and salts
57
Where is the CSF produced?
By ependymal cells in the choroid plexus
58
How is CSF reabsorbed?
Via arachnoid granulations
59
Describe what happens in hydrocephalus?
Abnormal accumulation of CSF in the brain which leads to a build up of pressure often due to a blocked cerebral aqueduct
60
What is normal resting potential
-70mV
61
Which transporter is Important in driving neuronal membrane concentration gradients?
Na+/K+ ATPase pumps 3 Na+ out for every 2 K+ ions in via active transport
62
Where are Na+ ions concentrated in terms of the axonal membrane?
Outside the membrane
63
Where are K+ ions concentrated in terms of the axonal membrane?
Inside the membrane
64
Why is the resting axonal membrane more permeable to K+ than Na+
Because there are very few voltage gated Na+ channels open meaning few Na+ ions diffuse back into the axons whereas K+ voltage gated channels are also closed by K+ leak channels are open allowing K+ to move into the axon
65
Describe what happens during an action potential
1. Neurotransmitter binds specific ligand gated ion channels on post synaptic membrane causing Na+ influx
2. Na+ influx causes initial depolarisation which stimulates more voltage gated Na+ channels to open
3. When the depolarisation reaches the threshold potential of -55mV, depolarisation becomes a positive feedback loop with more Na+ influx causing more depolarisation
4. At +30mV, Na+ channels close and K+ channels open causing repolarisation
5. Return to negative potential causes K+ channels to close but they do this slowly allowing continued outflow of K+ which causes hyperpolarisation
66
Why are refractory periods important?
Limit the number of action potentials an excitable membrane can produce and makes them separated so that individual signals pass down the axon
67
What two factors influence the speed of propagation?
Fibre diameter and myelination
68
Why does myelination increase propagation speeds?
Less leakage of charge across myelin so local current spreads further
APs only occur at nodes of Ranvier where the concentration of Na+ channels is high enabling saltatory conduction to occur
69
What is the propagation speed in unmyelinated fibres
0.5m/s
70
What is the propagation speed in myelinated axons
100m/s
71
Describe the pathophysiology of multiple sclerosis
Degeneration of myelin and development of scar tissue which disrupts and blocks neurotransmission in myelinated axons
72
What are the symptoms of multiple sclerosis?
```
Uncontrolled eye movements
Slurred speech
Partial/Complete paralysis
Tremor
Loss of co-ordination
Weakness
Sensory numbness, prickling, pain
```
73
What happens at an excitatory synapse?
Membrane potential of the postsynaptic neurone is brought closer to threshold
74
What happens at an inhibitory synapse?
The membrane potential of the post synaptic neurone is driven further (hyper polarised) or stabilised at resting potential
75
What are the two types of synapse?
Excitatory
| Chemical
76
Describe how electrical synapses work?
Plasma membrane of pre and postsynaptic cells are joined by gap junctions
these enable local currents from arriving action potentials to flow across the junction, depolarising them membrane of the second neurone to threshold
This occurs rapidly and enables synchronised transmission
77
Where are electrical synapses most commonly found?
Brainstem neurons ie. brainstem and hypothalamus
78
Describe the structure of chemical synapses?
Plasma mem of pre and post joined by synaptic cleft
Axon of pre ends in swelling, axon terminal, which holds vesicles of neurotransmitters
79
Describe how a chemical synapse works?
AP reaches the pre-synaptic terminal and causes Ca2+ influx
Ca2+ ions cause vesicle to move to pre membrane and discharge
Neurotrans move across cleft and attach to receptor on post synaptic mem
Neurotrans removed from synaptic cleft (astrocytes)
80
What are the 5 processes of synaptic transmission
1. Manufacture (intracellular biochemical processes)
2. Storage - vesicles
3. Release - AP
4. Interact with post synaptic receptors
5. Inactivation
81
What are the two main acetylcholine receptors
muscarinic
| Nicotinic
82
What enzyme is responsible for the breakdown of acetylcholine in the synaptic cleft
Acetylcholinesterase into choline and acetate
83
What is temporal summation
Input signals arrive from the same presynaptic cell at different times and the potentials summate since there are a greater number of open ion channels
84
What is spatial summation?
Where two inputs occur at different locations in the post synaptic neurone
85
What are the 3 most common fates of neurotransmitters in the synaptic cleft
1. Actively transported back into presynaptic axon terminal
2. Diffuse away from receptor site
3. Are enzymatically transformed into inactive substances and some transported into presynaptic terminal for re-use
86
How do anaesthetics work?
Procaine and lignocaine most common
Work by interrupting axonal neurotransmission by blocking Na+ channels thereby preventing neurones from depolarising so threshold isn't met and no AP is developed to be propagated
Results in pain relief since pain isn't transmitted
87
What molecules combine in the cytoplasm to produce acetylcholine?
Choline
| Acetyl co-enzyme A
88
Why is L-DOPA given to Parkinson's Patients?
Because L-DOPA is the precursor molecule to dopamine and is freely taken up across the BBB so can enter serotonergic neurones which contain the enzymes needed to convert it to dopamine
89
What is the hearing range of a human?
20-20,000Hz
90
What is the function of the outer ear?
To collect sound, amplify and direct it
91
What is the function of the middle ear?
Transmission of sound
92
What is the function of the inner ear?
Conversion of sound into neural impulses
93
Describe the path of the external ear
Sound enters through the exterior part of the ear, the pinna
From here it enters the external auditory meatus and travels to the tympanic membrane where air molecules will push against the membrane causing it to vibrate at same frequency as the sound wave
94
Does the tympanic membrane vibrate slowly or quickly to low frequency sounds?
Slowly
95
What is the middle ear?
Air filled cavity in the temporal bone of the skull
96
Which nerve provides sensation to the middle ear
Glossopharyngeal
97
By which structure is the middle ear exposed to atmospheric pressure?
Eustachian tube which connects the middle ear to the pharynx
98
When does the Eustachian tube open?
Normally closed unless muscle movements occur during yawning, sneezing and swallowing
99
Why do changes in altitude cause ear pain?
because altitude change causes difference in pressure between the middle and external ear. This pressure can cause the tympanic membrane to stretch causing pain but can be relieved by yawning/swallowing which causes the Eustachian tube to open allowing pressure in the middle ear to equilibrate with atmospheric pressure
100
Name the three ossicle bones
Malleus
Incus
Stapes
101
Describe the transfer of tympanic membrane vibrations to the inner ear
Vibrations of TM are passed to the inner ear by the ossicles which act as a piston, coupling TM vibrations to the oval window which is much smaller than TM so force per area is greater which is required to transmit sound through fluid filled cochlear
102
How can the amount of energy transmitted to the inner be lessened?
Contraction of the tensor tympani and stapedius muscles which act reflexively to continuous loud noise to protect the inner ear
103
Which ossicle does the tensor tympani attach to?
Malleus
104
Which ossicle does stapedius attach to?
Stapes
105
What is the innervation of the tensor tympani muscle
Mandibular division of Trigeminal nerve
106
What is the innervation of the stapedius muscle
Facial nerve
107
What is the name given to the inner ear?
Cochlea - fluid filled space in the temporal bone
108
The cochlea is divided lengthways by what membranous tube structure?
Cochlea duct (SCALA MEDIA)
109
What is the fluid of the cochlea duct (scala media) called and what is its composition?
Endolymph which is high in K+ and Low in Na+
110
What is the name given to the fluid that fills the compartments either side of the cochlea duct?
perilymph - similar composition to CSF
111
What structure begins at the oval window and lies above the cochlear duct?
Scala vestibuli
112
What structure connects the middle ear to the round window and lies below the cochlea duct?
Scala tympani
113
What is the name given to the part of the inner ear where the Scala tympani and vestibuli are continuous with one another?
Helicotraema
114
Describe the transmission of sound in the inner ear?
Oval window moves in and out of the scala vestibuli which creates waves of pressure which are transmitted across the cochlea duct towards the helicotraema and the scala tympani. Pressure differences across the duct cause the basilar membrane to vibrate
115
Where does the organ of Corti lie?
on the basilar membrane which sits on the cochlear duct side closest to the scala tympani
116
Describe the properties of the base of the basilar membrane and what frequency is it sensitive to?
Narrow and stiff so sensitive to high frequency sounds
117
Describe the properties of the apex of the basilar membrane and what frequency is it sensitive to?
Wider and less stiff so sensitive to low frequency sounds
118
What are the receptor cells of the organ of Corti called
Hair cells - mechanoreceptors with stereo cilia
119
How many rows of inner hair cells do we have?
Single row
120
How many rows of outer hair cells do we have?
4-5 rows
121
Where do the inner hair cells extend to?
Extend into the endolymph and covert pressure waves caused by fluid movement in cochlear duct into receptor potentials
122
Where are the stereo cilia of the outer hair cells embedded?
Embedded in the overlying tectorial membrane and mechanically alter its movement at each point along basilar membrane
123
What happens when pressure waves displace the basilar membrane?
1. The hair cells move in relation to the stationary tectorial membrane causing the stereo cilia to bend
2. When stereo cilia bend towards the tallest member of the bundle, the fibrous connections called tip links pull open mechanically gated K+ channels causing an influx of K+ and Ca2+ from the endolymph depolarising the membrane
3. Change in voltage triggers opening of voltage gated Ca2+ channels near base of the cell which triggers neurotransmitter release
4. Bending of hair cells in opposite direction slackens the tip links, closing the channels and causing the cell to depolarise
124
What is the neurotransmitter released from hair cells?
Glutamate
125
Where does glutamate from hair cells bind to?
Protein binding sites on afferent neurones
126
Where do action potentials generated from oscillating hair cells go?
axons join to form the cochlear branch of the vestibulocochlear nerve
127
Greater frequency of action potentials generated in afferent nerve fibres from stereocili occurs when...
The sound wave has greater energy (Loudness)
128
The cochlear nerve fibres that lie within the cochlea and make direct contact with the hair cells are known as...
Spiral ganglion
129
The cochlear nerve joins the brainstem at the level of
Rostral medulla
130
After its bifurcation fro the rostral medulla, Where does the cochlear nerve end?
Dorsal and ventral cochlear nuclei which lie close to the inferior cerebral peduncle
131
From the cochlear nuclei, where do the second order neurones project to?
Superior olivary nucleus
132
Describe the pathway of auditory information from the superior olivary nucleus to the primary auditory cortex
From superior olivary nucleus, the fibres travel to the inferior colliculus of the midbrain
From here, the inferior brachium nerve carries information to the medial geniculate body of the thalamus and from there the fibres travel through the internal capsule to the primary auditory cortex on the temporal lobe
133
What functional area of the brain surrounds the primary auditory cortex?
Wernicke's area
134
What is the function of Wernicke's area
processing of language
135
Inferior colliculus and medial geniculate body are important for what sense
Hearing
136
The superior colliculus and lateral geniculate body are important for what sense?
Vision
137
Which cranial nerve runs through the middle ear and is important for taste messages from the tongue to the brain
Chorda tympani branch of the facial nerve
138
Other than the vestibulochochlear nerve, which other CN exits the cranial cavity through the internal acoustic meatus?
Facial nerve
139
Other than in the cochlea, where else can hair cells be found in the inner ear?
Vestibular apparatus
140
The vestibular apparatus is filled with what fluid?
Endolymph
141
What do the hair cells of the vestibular system detect?
Motion and position of the head
142
What does the vestibule apparatus consist of? T
3 membranous semi-circular canals and two sac like swellings, utricle and saccule which all lie in the temporal bone
143
What do the semicircular canals detect?
Angular acceleration during rotation of the head along 3 perpendicular axes
144
When are the semicircular canals of the head activated
When nodding head up and down
When shaking head from side to side
When tipping head so ear touches the shoulder
145
stereocilia in the semicircular canals are encapsulated in a gelatinous mass in the ampulla called the
Capula
146
Describe how the semicircular canals detect angular acceleration
When head moves the semicircular canals and hair cells move with it but the endolymph in the duct is not attached to skull and due to inertia remains in its original position
The moving ampulla is thus pushed against stationary fluid which causes the stereo cilia to bend and alter their rate of glutamate release
Each hair cell receptor has one direction of maximum glutamate release so when stereo cilia bend in that direct the receptor cell depolarises and when they bend in the other direction the hyper polarisation
When the head continously rotates at steady velocity, the duct fluid begins to move at same rate as the rest of the head and the stereo cilia return to resting position so hair cells are only stimulated during acceleration and deceleration
147
What is the function of the utricle and the saccule
To provide information about the linear and vertical acceleration of the head and about changes in head position relative to gravity
148
What do the hair cells of the utricle respond to?
Hair cells in utricle stand almost straight up (pointing up from floor) when standing so they respond when the head is tipped away from a horizontal plane (Head tilt) or to linear acceleration in the horizontal plane
149
What do the hair cells of the saccule respond to?
Hair cells of saccule project at right angles (pointing out from wall) to the utricle and respond when you move from lying to a standing position or vertical accelerations like on a trampoline
150
Describe how the utricle and saccule convert information in nerve impulses
Otolith membrane is gelatinous and contains calcium carbonate crystal (Otoliths) which are heavy and sit on top of hair cells.
Otoliths make the gelatinous substance heavier than the surrounding endolymph so when the otolithic material moves (ie. Linear acceleration) it pulls agains the hair cells so the stereo cilia bend and action potentials are propagated along the vestibular nerve.
when the head is still or at a continuous acceleration, the otoliths don't move so APs are constant
151
Where to the fibres of the vestibular nerve terminate?
in the vestibular nuclei of the rostral medulla
152
What is the vestibular information used for?
Control of eye movement
Proprioception
Reflexes maintaining upright posture and balance
153
What is the name given to the sensory epithelium in the saccule and the utricle?
Maculae
154
What are the 3 planes of the semicircular canals
Horizontal
Posterior
Superior
155
What do the semi-circular canals detect
Angular acceleration (Rotation)
156
What neurotransmitters are released by the hair cells in the utricle and saccule
Glutamate and aspartate
157
Which cranial nerves do the vestibular nuclei connect to to control the vesticularoccular reflex
Occulomotor
| Abducens
158
Utricle provides information about what?
Linear acceleration and head tilt
159
Saccule provides information about
Vertical acceleration
160
What frequency range is the human ear most sensitive to?
1500-4000Hz
161
The cochlear twists around what bony strcuture?
Modiolus
162
What ligament connects the stapes to the oval window?
Annular ligament
163
Which membrane separates the scala vestibuli and the scala media
Reissners membrane
164
Which membrane separates the scala tympani and the scala media
Basilar membrane
165
Reticular lamina and basilar membrane are connected by what
Rods of Corti
166
Which hair cell (Inner or outer) has the most afferent nerve connections
Inner
167
Inner cells have an important function in
Detecting sound
168
Outer hair cells have an important function in
Modifying sound
169
What is the name of the biggest stereo cilia in a bundle
Kinocillium
170
What are the three tunica (Layers) of the eye?
Fibrous tunic
Vascular Tunic (Uvea)
Sensory Tunic
171
What are the components of the fibrous tunic
Sclera
| Cornea
172
What are the components of the vascular tunic
```
Choroid
Iris
Ciliary body
- Ciliary muscle
- Ciliary processes
```
173
What are the components of the sensory tunic
Retina
| Vitreous humor
174
What is the function of the cornea
Allows the passion of light for refraction
| Must be transparent
175
What is the function of sclera?
White capsule that offers protection due to collagen component
Serves as insertion point for external eye muscles
176
What Is the effect of parasympathetic innervation on the iris
causes the sphincter pupillae muscle to contract
177
What is the effect of the sympathetic innervation on the iris
Causes the dilator pupillae to dilate
178
What is the anterior segment of the eye?
From the cornea to the lens
179
What are the two compartments of the anterior segment of the eye
Posterior chamber
| Anterior chamber
180
What Is the posterior segment of the eye
From the posterior lens to the retina
181
What is the function of the choroid
Pigmented so when light hits retina and becomes scattered the choroid absorbs it
182
What are the two components of the lens
Crystallin lens fibres
| Lens epithelium
183
What are the two components of the retina
Neural retinal layer
| Epithelial retinal layer
184
What happens in a retinal detachment
The neural and epithelial layers of the retina become separated allowing vitreous humour to seep in between the layers
185
Which part of the eye is involved in the accommodation reflex?
Cilliary muscle
186
What does the iris do?
Controls the size of the pupil which lets light into the eye
187
What does the dilator papillae muscle do?
Dilates the pupil (Sympathetic)
188
What does the spinchter papillae do?
Cnstricts the pupil (Parasympathetic)
189
What does the ciliary body do other than accommodation reflex?
Contains glandular epithelium which produces aqueous humour
190
What is the important roles of the aqueous humour
Maintains intra-ocular pressure (15mmHg)
191
What structure produces vitreous humour?
Retina
192
What are the two muscles attached to the tarsal plate?
Levatator palpibra superioris
| Obicularis oculi
193
Where in the eye are photoreceptors absent?
Optic disc (Blind spot)
194
What is the function of rod cells?
Important for vision in dim light and peripheral vision
195
What is the function of cone cells
Colour vision
196
What is the function of cone cells
Colour vision
197
What are the three layers of the tear film?
Anterior lipid layer
Middle aqueous layer
posterior mucous layer
198
Where is the anterior lipid layer of the tear film secreted from?
Meibomium gland
199
Where is the middle aqueous layer of the tear film secreted from
Lacrimal glands
200
Where is the posterior mucous layer of the tear film secreted from?
Goblet cells
201
What is the function of the anterior lipid layer of the tear film
Provides hydrophobic layer to prevent the aqueous layer evaporating
202
What is the function of the middle aqueous layer of the tear film?
Regulates transport through the cornea and prevents infection
203
What is the function of the posterior mucous layer of the tear film?
Provides hydrophilic layer that allows even distribution of the tear film
204
What are the 12 layers through which a photon must travel through the eye?
1. Tear film
2. Cornea and refraction
3. Aqueous humour
4. Lens
5. Vitreous humor
6. Ganglion cell
7. Amacrine cell
8. Bipolar cell
9. Horizontal cell
10. Cone cell
11. Rod cell
12. Pigmented epithelium
205
What branches of the internal carotid artery supply the eye?
```
Ophthalmic artery
Central retinal artery
Ciliary arteries
Lacrimal artery
Ethmoidal and eyelid artery
```
206
What branch of the external carotid artery supplies the eye
facial artery
207
Which fibres cross at the optic chiasm
Nasal portion of the retina, carrying the temporary visual field
208
Where in the thalamus do optic tracts join too?
Lateral geniculate nucleus
209
Outline the order of the visual pathway from eye to visual cortex
```
Eye
Optic nerve
Optic chiasm
Optic tract
lateral geniculate body
Optic radiation
Visual cortex
```
210
What is the name of the optic radiation that passes through the parietal lobe?
Baums loop
211
What is the name given to optic radiation that passes through the temporal lobe?
Meyer's Loop
212
What information do the superior retinal fibres of the optic radiation carry
inferior portions of the retina
213
What information do the inferior retinal fibres of the optic radiation carry?
Superior portions of the retina
214
Which lobe of the brain do the superior retinal fibres pass through?
temporal lobe
215
Which lobe of the brain do the inferior retinal fibres of the optic radiation pass through?
Parietal lobe
216
What is the effect of a lesion on the right optic nerve
Right anopia
| Right monocular blindness
217
What is the effect of a lesion on the left optic nerve?
Left anopia
| Left monocular blindness
218
What is the effect of a lesion at the optic chiasm?
Loss of temporal visual fields = Bitemporal hemianopia
219
What is the effect of a lesion on the right optic tract?
Loss of temporal field of left eye and nasal field of right eye
= Right homonymous hemianopia
220
What is the effect of a lesion on left Meyer's Loop?
Carries information from inferior retina on superior visual field so causes of loss of vision in superior nasal field of left eye and superior temporal field of right eye
221
What is the effect of a lesion to left Baum's Loop?
Carries information from superior retina on inferior visual field resulting in loss of vision in inferior temporal field of right eye and inferior nasal field of left eye
222
What is the name given t internal rotation of the eye? (Towards the midline)
Intorsion
223
What is the name given to external rotation of the eye?(Away from the midline)
Extorsion
224
What are the 6 ocular eye muscles
```
Superior rectus
Inferior rectus
Lateral rectus
Medial rectus
Superior oblique
Inferior Oblique
```
225
What are the 6 ocular eye muscles
```
Superior rectus
Inferior rectus
Lateral rectus
Medial rectus
Superior oblique
Inferior Oblique
```
226
Which muscles of the eye are supplied by oculomotor nerve?
Superior rectus
Medial Rectus
Inferior rectus
Inferior oblique
227
Which muscles of the eye are supplied by abducens nerve?
Lateral rectus
228
Which muscle of the eye is supplied by the trochlear nerve?
Superior Oblique
229
Where are the nuclei of oculomotor and trochlear CN located?
In the periaqueductal grey
230
What does the somatic nervous system innervate?
Skeletal muscle
231
Do neurones of the somatic nervous system synapse before the skeletal muscle?
No
232
What is the only neurotransmitter involved in the somatic nervous system?
Acetylcholine
233
What does the autonomic nervous system innervate?
Smooth and cardiac muscle, glands, neurones in the GIT
234
Where is the first synapse of an autonomic nerve
First nerve synapses outside the CNS in a cell cluster called autonomic ganglion
235
Whats the name of autonomic nerve between the CNS and the ganglia?
Preganglionic fibres
236
Whats the name of the autonomic nerve between the ganglion and the effector cells?
Postganglionic fibres
237
What is the neurotransmitter of the pregnaglionic fibres
Acetyl choline
238
What is the neurotransmitter of the postganglionic fibres
Acetylcholine (Excitatory) or noradrenaline (Inhibitory)
239
What are the two divisions of the autonomic nervous system?
Sympathetic and Parasympathetic
240
Where do the sympathetic nerves leave the spinal cord?
Between T1 and L2
241
Where do the ganglia of the sympathetic neurones lie?
Close to the spinal cord
242
What neurotransmitter is used by the preganglionic sympathetic fibres?
Acetylcholine acts at nicotinic receptors
243
What neurotransmitter is is used at the effect cell synapse in sympathetic fibres?
Noradrenaline acts at adrenergic receptors
244
What are the effects of the sympathetic nervous system?
```
Increased HR
Increased force of contraction
Vasoconstriction
bronchodilation
Reduced gastric secretion
Male ejaculation
Reduced gastric motility
Sphincter contraction
```
245
Where do parasympathetic nerves leave the spinal cord?
Brainstem and sacral regions of spinal cord
246
Which cranial nerves are parasympathetic
3, 7, 9 and 10 (1973)
247
Where do the ganglia of parasympathetic nerves lie?
Close to the organs that the postganglionic fibres innervate
248
What is the neurotransmitter used by preganglionic parasympathetic fibres
Acetylcholine at nicotinic receptors
249
What is the neurotransmitter used by postganglionic parasympathetic fibres
Acetylcholine at muscarinic receptors
250
What are the effects of the parasympathetic nervous system?
```
Decreased heart rate
Decreased force of contraction
Vasodilation
Bronchoconstrition
Increased gastric motility
Increased gastric secretion
Male erection
Sphincter relaxation
```
251
Describe the gross structure of a muscle
```
Muscle attached to bone by a tendon
Muscle comprises several fasciculi
Fasiculi comprise several muscle fibres
Muscle fibres comprise myofibrils
Myofibrils contrain actin and myosin myofilaments
```
252
Define a motor unit?
An alpha motor neurone and all the extrafusal skeletal muscle fibres it innervates
253
Where are the alpha motor neurones that innervate distal muscles located in the spinal cord?
Laterally
254
Where are the alpha motor neurones that innervate the proximal muscle located in the spinal cord?
medially
255
What is a major difference between neuromuscular junctions and synaptic junctions
At NMJ, every action potential in a motor neurone produces an action potential in a muscle fibre whereas at synaptic junctions, multiple EPSPs are required in order for threshold to be reached
All NMJs are excitatory
256
What is a muscle spindle?
A receptor consisting of peripheral endings of afferent nerve fibres wrapped around modified muscle fibres that monitor muscle length and rate of change of muscle length
257
What are the modified muscle fibres in a muscle spindle called
Intrafusal fibres
258
What innervates intrafusal fibres?
Gamma motor neurones
259
What does a muscle spindle detect?
The change in length of the muscle
Rate of change in length of the muscle
260
What is the name of the muscle fibres that form the bulk of the muscle and are important in generating force and movement
Extrafusal fibres
261
What are the two types of stretch receptor found in the muscle spindle?
Nuclear chain receptors
| Nuclear bag receptors
262
What is the function of nuclear chain receptors?
To detect how much the muscle has been stretched
263
What is the function of the nuclear bag receptors?
To detect the magnitude of stretch and the speed at which it occurred
264
What happens when a muscle spindle is stretched?
Activates receptor endings
| Causes the stretch reflex (Muscle contracts) and reciprocal inhibition of the antagonistic muscle
265
What is the only known monosynaptic reflex?
Stretch reflex because the afferent nerve fibres in the stretched muscle synapse directly onto motor neurones without interneurones
266
Why is a muscle contraction (Shortening) an issue for the muscle spindle detection?
Because the stretch on the intramural fibres shortens so slackening on spindle receptor reduces action potentials along afferent neurone so can't indicate further changes in muscle length while it is shortening
267
What mechanism exists to allow the muscle spindle to detect muscle length even when shortening?
Alpha-gamma coactivation - Two ends of the intrafusal muscle fibres contract during shortening of extrafusal fibres to maintain tension in central region of intrafusal fibres
268
which motor neurones control the extrafusal muscle fibres?
Alpha motor neurones
269
Which motor neurones control the intrafusal muscle fibres?
Gamma motor neurones
270
What are the three factors that determine muscle tension
The load
Muscle length
Muscle fatigue
271
Where is the golgi tendon organ located?
In the tendon of the muscle
272
How does the golgi tendon organ work?
Afferent neurone endings wrap around collagen bundles so when the muscle is stretched of extrafusal muscle contracts, the collagen bundles straighten and distort the receptor endings, activating them
273
What type of sensory afferent nerves are associated with the middle third of the muscle spindle?
Fast Type 1a
274
`Which type of sensory afferent neves are associated with the superior and inferior third of the muscle spindle?
Slow type 2
275
What type of sensory afferent nerve is associated with the glogi tendon organ?
Type 1b fibres that run to the anterior horn of spinal cord
276
What is the effect of activation of the golgi tendon organ?
Autogenic inhibition where the 1b afferent nerves will inhibit the alpha motor neurones of the contracting muscle to prevent overload of the muscle
277
Define muscle tone
degree of contraction of a muscle or the proportion of Motor units active at one time
278
What will a muscle of high tone feel like?
Firm, rigid an resists passive stretch h
279
What will a muscle of low tone feel like?
Soft, flaccid and offers little resistance to passive stretch
280
Define hypertonia
Abnormally high muscle tone
281
Hypertonia is most commonly seen in what sort of motor neurone disorder
Upper motor neurones as they inhibit motor neurones of the descending pathways
282
What is the clasp knife reflex
When spasticity occurs as in the muscles do not develop increased tone until they are stretched then after a brief period the contraction subsides
283
The clasp knife reflex is characteristic of what type of motor neurone lesion
Lower motor neurone
284
Define pain
Unpleasant sensory or emotional experience associated with actual potential tissue damage or described in terms of such damage
285
Define nociceptive pain
Pain that arises from actual or threaten damage to non-neuronal tissue due to activation of nociceptors
286
Define neuropathic pain
Pain initiated by primary lesion or dysfunction of the nervous system
287
What is a nociceptor?
Free nerve endings with no form of specialisation
288
What neurotransmitters are released at primary afferent with nociceptor endings
Substance P
| Glutamate
289
What substances released from damaged cells will activate nociceptors?
```
Neuropeptides
Bradykinin
Histamine
Cytokines
Prostaglandins
```
290
What are the two somatosensory ascending neural pathways
Anterolateral (Spinothalamic path)
Dorsal column lemniscus pathway
291
Describe the path of 1st,2nd and 3rd order neurones in the spinothalamic pathway
1st neurone enters the spinal cord on the ipsilateral side as the peripheral receptor and synapses with 2nd neurone in the CNS
2nd order neurone decussates to the contralateral side and projects in the anterolateral column to the thalamus
3rd order neurone has cell body in the thalamus and projects to the somatosensory cortex
292
What information does the spinothalamic tract carry
Pain and temperature and crude touch
293
What information does the dorsal column pathway carry
Proprioception, fine touch discrimination and pressure
294
Describe the path of the 1st, 2nd and 3rd order neurones of the dorsal column pathway
Afferent neurone (1st) enters on the ipsilateral side of spinal cord to the receptor and travels ipsilaterally in the dorsal columns
synapses with 2nd order neurone in the brainstem where it decussates to contralateral side
Synpases with third order neurone in thalamus which projects to somatosensory Cortex
295
Define acute pain
Short term pain of less than 12 weeks in duratio n
296
Define chronic pain
Continuous long term pain for more than 12 weeks of duration
297
Which primary afferent fibres are associated with the transmission of pain?
A delta
| C fibres
298
Describe the properties of alpha delta fibres in terms of their level of myelination, what information they carry, their diameter and their conduction speed
Thinly myelinated
Carry touch, pressure, temperature and FAST pain
Small diameter (1-5 micrometers)
Conduction speed is medium (5-40m/s)
299
Describe the properties of C fibres in terms of their level of myelination, what information they carry, their diameter and their conduction speed
Unmyelinated
Carry SLOW pain, temperature, touch, pressure and itch
Smallest diameter (0.2-1.5 micrometers
Slowest conduction speed (0.5-2m/s)
300
Where do the Adelta and C fibres synapse with second order neurones?
In the grey matter of the dorsal horn which is divided into reed laminae
301
What neurotransmitters do the fast pain A delta fibres release?
Glutamate
302
What neurotransmitters do the slow pain C fibres release?
Glutamate and substance P
303
What information does the trigemini-thalamic tract carry?
Pain, temperature and crude touch from the face/head and neck
304
What is the only sensation that doesn't relay at the thalamus
Olfaction
305
Which part of the brain that lies in the sylvan fissure judges the degree of pain
Insula
306
Which part of the brain is associated with the emotional response to pain?
Cingulate gyrus
307
What is the basal ganglia
Group of nuclei lying deep within the cerebral hemisphere
308
What are the main components of the basal ganglia?
Striatum (Putamen and caudate)
Globus pallidus
Subthalamic nucleus
Substantia nigra
309
Why is the substantia nigra black?
Due to the production of neuromelanin as a byproduct of dopamine production
310
What are the main functions of the basal ganglia?
Purposeful behaviour and movement
Inhibits unwanted movements
Controls posture and movement
Facilitation, integration and fine tuning of movements
311
Describe Parkinson's disease in terms of what happens to muscle tone, movement and dopamine production
Increased muscle tone
Reduced movements
Reduced dopamine production
312
Describe Huntington's disease in terms of what happens to movement, muscle tone and dopamine production
Decreased muscle tone
Overshooting movement
Too much dopamine
313
What is the precursor molecule to dopamine production
Tyrosine
314
Describe how tyrosine is converted to dopamine
Undergoes tyrosine hydroxylation and decarboxylation into L-DOPA then into dopamine
315
Describe how a lack of dopamine in PD causes lack of movement
Less dopamine means the external globus pallid us doesn't inhibit the sub thalamic nucleus so it will excite the internal globus pallidus resulting in inhibition of the thalamus and decreased movement
316
What are the two main functions of the limbic system?
Learning and regulation and transition of our emotion state into appropriate behaviour
317
What are the components of the limbic system?
```
Cingulate gyrus
Hippocampus
Parahippocampal gyrus
Anterior perforated substance
Uncus
Amygdala
```
318
The name given to the connections of the limbic system is the
Papez circuit
319
What is the function of the hypothalamus?
Coordinates drive related behaviours
320
What is the name given short term memory and where is it stored/formed?
Working memory in the prefrontal cortex
321
What are the two forms of long term memory?
Explicit
| Implicit
322
What is episodic memory and where is it coded?
Knowledge of yourself
| In the hippocampus
323
What is the semantic memory and where is it coded?
Knowledge of stuff in the lateral temporal lobe
324
What are the two types of explicit memory?
Semantic and episodic
325
What is implicit memory
Unconscious memory
326
What are the forms of implicit memory and where are they stored?
Skills/Habits = cerebellum and basal ganglia
Conditioned reflexes = cerebellum
Emotional = amygdala
327
Which part of the limbic system is responsible for the formation of new memories>
Mammillary bodies
328
What will a lesion to the anterior hypothalamus causes
inability to dissipate heat
329
What will a lesion to the posterior hypothalamus cause
Inability to retain heat
330
What will lesions of lateral tuberal nucleus cause?
Loss of hunger
331
What will lesions f he ventromedial nucleus cause?
Loss of satiety
332
What are the functions of the amgydala
Produces instinctive emotional output
| Emotional memory
333
What are the functions of the cerebellum?
```
Maintenance of posture and balance
Maintenance of muscle tone
Coordination of voluntary movement
Computes motor error and adjusts
Precise control, fine adjustment and coordination of motor activity
```
334
What are the three layers of the cerebellum from outermost to innermost
Molecular
Purkinje
Granule
335
Where does the purkinje layer of the cerebellum receive input from?
Climbing fibres
336
Where does the granule layer of the cerebellum receive input from?
Mossy fibres
337
Where do the mossy fibres originate from and what information do they carry?
Come from pons and cerebral cortex via middle cerebral peduncle and carry information on the pontocerebellar pathway
338
Where do the climbing fibres originate and what information do they carry?
From the olivocerebellar nuclei via inferior peduncle - carry proprioception and vestibular info
339
What are the 4 main afferent projections to the cerebellum
Spinocerebellar
Olivocerebellar
Vestibulocerebellar
Pontocerebellar
340
What sort of input do climbing fibres provide?
Excitatory input to the purkinje fibres and the deep cerebellar nuclei
341
the axons of which fibres are the only axons to leave the cerebellar cortex?
Purkinje fibres
342
What neurotransmitter do purkinje cells use?
GABA
343
Which cerebellar peduncle does the corticopontocerebellar tract pass through
Middle
344
Which cerebellar peduncle does the vestibulocerebellar tract pass through
Inferior
345
Which cerebellar peduncle foes the ventral contralateral spinocerebellar tract pass through
Superior
346
Which cerebellar peduncle foes the dorsal ipsilateral spinocerebellar tract pass through
Inferior
347
Which tract carries information from the lower limbs to the cerebellum
Spinocerebellar tract
348
Which two tracts carry information from the upper limbs to the cerebellum
Cuneocerebellar and rostral spinocerebellar tract
349
Describe the components of the spinal column
```
Cervical 7
Thoracic 12
Lumbar 5
Sacrum 5
33 in total
```
350
How many spinal nerves are there?
31
351
What is the name given to C1
Atlas
352
What is the name given to C2
Axis
353
Which vertebra is the vertebra prominence?
C7
354
What is unique about the structure of the cervical vertebra?
All have bifid spinous processes except c7
355
Describe the structure of thoracic vertebra?
Spinous processes are thinner and descending
Circular vertebral foramen
Have costal facets
356
Describe the structure of a lumbar vertebra?
Spinous processes are thick and broad
Vertebral body is larger as it carries more weight
Vertebral foramen is triangular
357
What are the three coverings of the spinal cord from outermost to innermost
Dura
Subarachnoid
Pia
358
Where are the two enlargements of the spinal cord?
Cervical (Segments C3-T1) = upper limbs
Lumbar L1-S3 = lower limbs
359
Describe the anatomy of the spinal cord after it ends at L1/2
Tapers into a cone (Conus medullaris) and ends in a strand of tissue called filum terminale
360
At what position do spinal nerves leave the cervical segments of the spinal cord
1 vertebra higher than their corresponding vertebra except C8 which is one below
361
At what position do the spinal nerves leave the thoracic segments of the spinal cord
1-2 vertebra below
362
At what position do the spinal nerves leave the lumbar segments of the spinal cord
3-4 vertebra below
363
At what position do the spinal nerves leave the sacral segments of the spinal cord
5 below
364
What do mixed spinal nerves divide into
Small posterior ramus
| Large anterior ramus
365
What are the three layers covering fasicles of nerves from outermost to innermost
Epineurium
Perineurium
Endoneurium
366
What are the 5 ascending spinal cord tracts
```
Fasciculus gracilis
Fasciculus cuneatus
Dorsal spinocerebellar
Ventral spinocerebellar
Spinothalamic
```
367
What are the 10 descending spinal cord tracts
```
Fasciculis proprius
Lissauers tract
Lateral corticospinal
Rubrospinal
Medial longitudinal fasciculus
medullary reticulospinal
Lateral vestibulospinal
Pontine reticulospinal
Tectospinal
Ventral corticospinal
```
368
The fascicles cuneatus carries information about what limb
Upper
369
The fasciculus cuneatus carries information about what limb
Lower
370
What information does the lateral spinothalmic tract carry
Pain and temperature
371
What information does the medial spinothalamic tract carry
Crude touch
372
where do the first and second order neurones synapse in the spinothalamic tract
Substantia gelatinous of the dorsal horn
373
Where do the second order neurone decussate in the spinothalamic tract
White anterior comissure
374
Where do the second order neurone decussate in the spinothalamic tract
White anterior commissure
375
What is the function of the descending spinal tracts
Control of movement, muscle tone
Spinal reflexes
Spinal autonomic function
376
What are the two divisions of the descending spinal tracts
Pyramidal
| Extrapyramidal
377
What are the two divisions of the descending spinal tracts
Pyramidal
| Extrapyramidal
378
What are the three ascending spinocerebellar tracts?
Dorsal spinocerebellar
Ventral spinocerebellar
Cuneocerebellar
379
What stimuli does the spinocerebellar tracts respond to?
Proprioception, touch and pressure
380
Describe the course of the ventral spinocerebellar tract
Starts in the PNS with first order neurones in the DRG
These fibres decussate to the contralateral side through the white anterior commissure and ascend to the superior cerebellar peduncle where they synapse with the cerebellar cortex
They then cross round the back to the opposing cerebellar cortex
381
Describe the path of the dorsal spinocerebellar tract
Begins in PNS with 1st order neurones in DRG
Enters CNS and synapses with Clarke's Nuclei in the 7th rexed lamina (C8-L2/3)
Ascends ipsilaterally to the inferior cerebellar peduncle where it enters the cerebellar Cortex
382
The ventral spinocerebellar tract carries information from which spinal levels
Below C8-L2/3
383
Describe the path of the cuneocerebellar tract
1st order neurones enter the DRG and synapse in the Dorsal horn grey matter then ascend ipsilaterally to the accessory cuneate nucleus before entering the cerebellar cortex through the inferior cerebellar peduncle
384
Describe the path of the spinolivcerebellar tract?
1st order neurones through DRG
Decussates contralterally to through the white anterior commissure then ascends to the inferior olivary nucleus where it crosses back over the midline to and enters the cerebellar cortex through the inferior cerebellar peduncle
385
Describe the symptoms of brown sequard disease?
Ipsilateral weakness below the lesion due to damage to the corticopspinal tract
Ipsilateral loss of proprioception below the lesion because dorsal column pathway dont decussate till medulla
Contralateral loss of pain and temperature below the lesion as spinothalamic decussate at entry to spinal cord
Ipsilateral loss of proprioception, motor and fine touch
Contralateral loss of pain, temperature and crude touch
386
How do you test cranial nerve 2?
Visual fields
Pupil reflexes
Visual acuity
Fundoscopy
387
Parasympathetic fibres of the occulomotor nerve go to where?
Edinger-westphal nucleus of the tegmenjtum, ciliary muscles, sphincter papillary mucles (Dilation)
388
Which cranial nerve maintains the open eyelid via the elevator palpebral superioris muscle?
Oculomotor
389
What does the trochlear nerve innervate?
Superior oblique muscle
390
Damage to the trochlear nerve will cause what symptoms in patients?
Double vision when looking down
391
What are the three branches of the trigeminal nerve?
1. Ophthalmic
2. Maxillary
3. Mandibular
392
Where do the trigeminal afferents meet?
Meckels cave
393
How do you test the function of the trigmeninal nerve?
Sensation the face
Muscles of the jaw
Jaw jerk reflex
Corneal reflex
394
What is the somatic motor function of the facial nerve?
Muscles of facial expression
395
What is the visceral motor function of the facial nerve?
Lacrimal glands
| Submandibular and sublingual glands
396
How do you test the motor function of the facial nerve?
```
Inspect face for weakness of asymmetry
Drooping of lower eyelids
Smile
Raise eyebrows
Puff cheeks out
Shut eyes tight
Frown
```
397
How do you test the sensory function of the facial nerve?
Touch lateral aspect of tongue with flavoured cocktail sticks and ask patient to identify the taste
398
What is the cause of bells palsy
Lesion of the facial nerve
399
How do you test the cochlear branch of the vestibulocochlear nerve?
Tuning fork
400
What is nystagmus a sign of?
Vestibular damage
401
What are the two motor functions of the glossopharyngeal nerve?
Elevate the pharynx by supplying stylopharyngeus
Secretion of the parotid gland
402
What are the sensory functions of the glossopharyngeal nerve
```
Sensation to external ear
Posterior 1/3 of tongue - touch, pain, temp
Pharynx - touch, patn, temp
Eustachian tube - touch, pain, temp
Carotid sinus, baro and chemoreception
```
403
What are the functions of the vagus nerve
```
Taste - posterior pharynx
Swallowing- muscles of pharynx and larynx except stylopharngeus
CV and GI regulation
Hunger
Fullness
Decreased HR and BP
```
404
How do yo test the function of the glossopharyngeal and vagus nerves?
Hoarseness of voice is sign of vocal cord paralysis which is caused by damage to recurrent laryngeal nerve (Derivative of vagus)
Ask patient to say AH
- Bilateral lesion of vagus and palate fails to rise
- Unilateral lesion and both palate and uvula deviate away from lesion
Absence of gag reflex suggests lesion of glossopharyngeal or vagus nerves
405
What does the accessory nerve supply?
Sternocleidomastoid
| Trapezius
406
How do you test the function of the accessory nerve
ask patient t turn head against resistance - sternoclastomastoid
Ask patient to shrug shoulders against resistance
- Trapezius
407
What does the hypoglossal nerve supply?
The intrinsic and extrinsic muscles of the tongue
408
What are the functions of the extrinsic and intrinsic musclesof the tongue
Speech, food manipulation and swallowing
409
How do you test the function of the hypoglossal nerve
Ask patient to protrude tongue
LMN lesion causes tongue to deviate towards lesion
410
What is the sensory and taste innervation of the posterior 1/3 of tongue?
Glossopharyngeal nerve
411
What is the sensory sensation of the anterior 2/3 of tongue?
Lingual branch of the V3 from trigeminal
412
What is the taste sensation of the anterior 2/3 of tongue?
Chorda tympani branch of facial nerve carried by lingual branch
413
What passes through the cavernous sinus
```
Oculomotor
Trigeminal
Ophthalmic trigeminal
Maxillary trigeminal
Carotid (internal)
Abducens
Trochlear
```
414
Which spinal levels supply the wrist and biceps reflex
C5 and C6
415
Which spinal levels supply he triceps reflex
C7 and C8
416
What spinal level supplies the knee jerk reflex
L3 and L4 keeps foot off the floor
417
What spinal level supplies the ankle jerk reflex
S1 and S2
418
What spinal level supplies everything on the front of the arm
C5 and C6
419
What spinal level supplies everything on the back of the arm?
C7 and C8
420
What spinal levels cause penis erection
S2,S3,S4 keep penis of the floor
421
Damage to Broca's area results in what sort of aphasia
Expressive aphasia where they understand what is being said and know what they want to say but can't express it in meaningful words
422
Damage to Wernicke's area results in what sort of aphasia
Comprehension aphasia where they have difficulting understanding written or spoken language but hearing and vision not impaired
Have fluent speech but may scramble words
423
What is the most common artery for a berry aneurysm to occur?
Anterior cerebral artery
424
What are the common signs of a third nerve palsy
Double vision
Down and out facing eye
Ptosis
Dilated and fixed pupil
425
What are the functions of the oculomotor nerve
Eye movement
eyelid opening
Pupil constriction
Accomodation
426
What will a lesion to the trochlear nerve cause?
Inability to depress an adducted eye
427
What will a lesion to the abducens nerve cause?
Inability to abduct the eye
428
What are the functions of the ophthalmic division of the trigeminal nerve
Sensation to the anterior of head and face (Superior 1/3) including scalp, forehead, cornea and tip of nose
429
What are the three main branches of the ophthalmic division of the trigeminal nerve?
Lacrimal
Frontal
Nasociliary
430
What are the functions of the maxillary division of the trigmeninal nerve
Sensation to middle 1/3 of face including cheek, nose, upper lip, upper teeth and palate
431
What are the functions of the mandibular division of the trigeminal nerve?
Senesation to inferior 1/3 of face including lower Lip, lower teeth, chin, jaw and anterior 2/3 of tongue
Motor to muscles of mastication and tensor tympani muscle
432
What are the functions of the facial nerve?
```
Motor to facial movement
Salivation (Submandibular and sublingual)
lacrimation
Sensation from external ear
Taste from anterior 2/3 of tongue
```
433
What are the functions of the glossopharyngeal joint
Taste and sensation from posterior 1/3 of tongue
Sensation from pharynx
Salivation
Motor to the stylopharngeus muscle
434
What is the function of the accessory nerve
Motor function to trapezius and sternocleidomastoid
435
What are the 3 sensory nuclei of the trigeminal nerve
Mesencephalic
Central pontine
Spinal nucleus
1 motor nucleus
436
What are the three nuclei of the facial nerve
Superior salivary nucleus
Motor nucleus of CN VII
Nucleus Fasciuculus solitarius
437
What are the branches of the facial nerve from the motor nucleus
```
Temporal
Zygomatic
Buccal
Mandibular
Cervical
```
438
What are the 4 nuclei of the glossopharyngeal nerve
Nucleus ambigus
Inferior salivary
Spinal trigeminal tract
Solitary tract
