Nervous System Flashcards
1
Q
Define ataxia
A
Incoordination
2
Q
Define nociception
A
Perception of painful stimuli
3
Q
Define paresis
A
Weakness due to a nervous system lesion
4
Q
Sympathetic is…
A
Fight or flight
5
Q
Parasympathetic is…
A
Rest and digest
6
Q
Central nervous system branches
A
Brain and spinal cord
7
Q
Peripheral nervous system branches
A
Cranial nerves and spinal nerves
8
Q
What are the functional regions of the spinal cord
A
- Cervical
- Cervical intumescence
- Thoracolumbar
- Lumbar intumescence
- Caudal regions
9
Q
The left side of the brain controls the…
A
Right side of the body
10
Q
Dorsal root fibers of the PNS are…
A
Sensory (afferent) fibers
11
Q
Ventral root fibers of PNS are…
A
Motor (efferent) fibers
12
Q
What does the somatic nervous system innervate
A
Striated muscle
13
Q
What does the autonomic nervous system innervate
A
Smooth muscle
14
Q
What makes myelin
A
Schwann cells
15
Q
What layers of the covering of the brain make up the meninges
A
Dura matter, arachnoid, & pia mater
16
Q
What are the parts of the forebrain
A
Cerebrum & thalamus
17
Q
Frontal lobe: controls
A
Motor cortex and association areas
18
Q
Parietal lobe: controls
A
Somatosensory
19
Q
Temporal lobe: controls
A
Audition, learning, memory
20
Q
Occipital lobe: controls
A
Vision
21
Q
Rhinencephalon: controls
A
Olfaction, learning, memory
22
Q
Limbic system: controls
A
Behavior/emotion
23
Q
Basal nuclei: controls
A
Extrapyramidal motor system
24
Q
What connects the left and right cerebral hemispheres
A
The corpus callosum
25
What is the basal nuclei and what does it do
A region located at the base of the brain composed of 4 clusters of neurons
It modifies the cortical initiation of voluntary movement
26
What are the 5 sections of the cerebral cortex
1. Frontal lobe
2. Parietal lobe
3. Temporal lobe
4. Occipital lobe
5. Rhinencephalon (olfactory)
27
What are the two divisions of the cerebrum
1. Cerebral cortex
2. Subcortical structures
28
All sensory information except for ___ synapse in specific thalamic nuclei
Olfaction
29
Describe the flow to CSF through cerebral ventricles
Lateral ventricle -> intraventricular foramen -> third ventricle -> mesencephalic aqueduct -> fourth ventricle -> lateral aperture -> central canal
30
The ____ is the most prominent structure and makes up the floor of lateral ventricle
Hippocampus
31
What is medial to the two cerebellar hemispheres
Cerebellar vermis
32
What connects the cerebellum to the brainstem
The peduncles (three bundles of fibres)
33
What are the cerebellar hemispheres known as
Neocerebellum
34
What is the cerebellar vermis known as
Spinocerebellum
35
What are the three sections of the brainstem
The midbrain, pons and medulla oblongata
36
The ___ is the rostral part of the brain stem
The midbrain
37
Visual reflexes are located in the ___
Rostral colliculus
38
Auditory reflexes are in located in the ___
Caudal colliculus
39
Where can you find the motor nucleus of the trigeminal nerve
The pons
40
What cranial nerves are located in the medulla oblongata
Cranial nerves VI - XII
41
What is the obex
The most caudal point in the fourth ventricle
42
What cranial nerve nucleus is found in the pons
Cranial nerve V
43
What cranial nerves are found in the midbrain
Cranial nerve III and IV
44
Define what makes up white matter
Neuroglia & bundles of axons coated with myelin sheath
45
Define what makes up gray matter
Masses on neuronal bodies and axons and neuroglia
46
Bundles of axons (of neurons) are called ___ in the PNS and ___ in the CNS
Nerves in the PNS
Tracts/pathways in the CNS
47
Bundles of cell bodies (of neurons) are called ___ in the PNS and ___ in the CNS
Ganglia in the PNS
Nuclei in the CNS
48
Most axons of neurons are myelinated and part of the ___
White matter
49
Most cell bodies of neurons are unmyelinated and part of the ___
Gray matter
50
There are NO ___ neurons in the PNS
Somatic motor neurons
51
Define axon
Long cytoplasmic process that transmits impulses (efferent)
52
Define dendrites
Cytoplasmic process off the cell body that receive impulses (afferent)
53
Direction of communication: sensory afferent neurons
PNS --> CNS
54
Direction of communication: motor efferent neurons
CNS --> PNS
55
Direction of communication: interneurons
Transmit information between neurons in the CNS
56
What is the term for neuronal RER
Nissl substance
57
Name 4 glial cells in the central nervous system
1. Astrocytes
2. Microglia
3. Oligodendroglia
4. Ependymal cells
58
Name 2 glial cells in the peripheral nervous system
1. Schwann cells
2. Satellite cells
59
Which glial cells create the BBB
Astrocytes
60
Which glial cells form the myelin sheath
Oligodendrocytes
61
Which glial cells are known as the brain macrophages
Microglia
62
Which glial cells lines the ventricles of the brain and spinal cord
Ependymal cells
63
Which glial cells create a neurilemma around the axons in the PNS
Schwann cells
64
What is different about Schwann cells and oligodendrocytes
One Schwann cells creates the myelin sheath around the section of one axon, whereas oligodendrocytes can surround several axons
65
Which spinal nerves make up the cervical intumescence
C6-T2
66
Which spinal nerves make up the lumbar intumescence
L4-S3
67
Which point is the widest in the cervical intumescence
C8
68
In the spinal cord, the dorsal horn is __ and the ventral horn is __
Dorsal = sensory
Ventral = motor
69
What are the 3 tract divisions of the spinal cord
Dorsal funiculus
Lateral funiculus
Ventral funiculus
70
What are the spinal cord segment numbers in the dog
C8, T13, L7, S3
71
What are the spinal cord segment numbers in the horse
C8, T18, L6, S5
72
The majority of spinal cord segments are positioned __ to their corresponding vertebrae
Cranial
73
What does the cauda equina refer to
The spinal roots innervating the sacrum and tail
74
Where does the spinal cord end in dogs
L6/7
75
Where does the spinal cord end in horses
S1/2
76
Name two locations you can obtain cerebrospinal fluid
Altano-occipital joint or lumbosacral area
77
List the 4 functions of cerebrospinal fluid
1. Protection & buoyancy
2. Excretion of waste products
3. Nutrition
4. Chemical buffer
78
Where is CSF produced
In the leptomeninges and the choroid plexuses of the lateral, 3rd and 4th ventricles
79
Where is the main site of absorption of cerebrospinal fluid
The arachnoid villus
80
What are the 5 main blood supplies to the brain
1. Rostral cerebral arteries
2. Middle cerebral arteries
3. Caudal cerebral arteries
4. Rostral cerebellar arteries
5. Caudal cerebellar arteries
81
In the brain, blood flows from __
Ventral to dorsal
82
Which artery supplies most of the cerebral hemispheres
The middle cerebral artery
83
Which artery is the principle input to the brain
The internal carotid artery
84
What is the rete mirabile
A network of vessels located in the cavernous sinus
85
What are the 3 trunks of arterial supply to the spinal cord
1. Ventral spinal artery
2. Dorsolateral spinal arteries
3. Spinal arteries
86
Define the BBB
The selective barrier between the circulating blood and the parenchyma of the nervous system
87
Name the 3 venous sinuses in the brain
1. Dorsal sagittal sinus
2. Transverse sinus
3. Cavernous sinus
88
Where can you find upper motor neurons
In all divisions of the brain
89
Where can you find lower motor neurons
In the brainstem and spinal cord
90
In which cranial nerves are axons from somatic motor neurons NOT found
CNI, CNII and CNVIII
91
What do LMNs innervate
Skeletal muscle fibers
92
What are the functions of UMNs
Initiate, regulated, modify and terminate the activity of LMNs (they control LMNs)
93
Loss of inhibitory UMN function results in...
Increased muscle tone and spinal reflexes
94
Loss of facilitatory UMN function results in...
Paresis or paralysis
95
Function of alpha motor neurons
Innervate extrafusal muscle fibers (contraction ones)
96
Function of gamma motor neurons
Innervate intrafusal muscle fibers (stretch receptor ones)
97
What are the 4 important somatic reflexes of the neurological exam
1. Patellar
2. Palpebral
3. Flexor
4. Cutaneous trunci
98
What are the 3 signs of a lower motor neuron lesion
1. Poor/absent reflexes
2. Neurogenic muscle atrophy
3. Decreased muscle tone
99
What are the 3 neurons of a sensory system
1. Spinal ganglion
2. Nucleus in brain stem/spinal cord
3. Thalamic nuclei (contralateral)
100
Which sensory system has a separate pathway from temperature, touch, and special senses
Nociception
101
What are sensory receptors?
Dendrites of sensory neurons
102
What are the 3 neurons in the 3 neuron pathway of vision
1. Bipolar cell in retina
2. Ganglion cell of retina
3. Lateral geniculate nucleus
103
What are the 3 neurons in the 3 neuron pathway of audition
1. Spiral ganglion of CNVII
2. Cochlear nuclei
3. Nucleus in thalamus
104
What is the sensory pathway for nociception
The spinothalamic pathway
105
Define proprioception
The sense of relative position of the head, neck and limbs
106
Define the location of conscious proprioception
Contralateral cerebral cortex
107
Define the location of subconscious proprioception
Motor coordination in the cerebellum
108
Define the location of vestibular proprioception
Balance in the inner ear and vestibular nuclei in the brainstem
109
Where do afferent tracts of conscious proprioception receptors end
The forebrain
110
Where do afferent tracts of subconscious proprioception receptors end
The cerebellum
111
The cerebellum is a ___ structure
Sensory
112
What are the 3 primary inputs to the cerebellum
1. Proprioceptive information from spinal cord (from muscle spindles and golgi tendon organs)
2. Vestibular system
3. Forebrain motor planning centers
113
Where are the 2 outputs of the cerebellum to
1. UMN nuclei of brain stem
2. Forebrain motor centres
114
What are the only two neurons in each spinocerebellar pathway
1. Neuron in spinal ganglion
2. Neuron in spinal cord dorsal grey column
115
Muscle spindles respond to __
Stretch
116
Golgi tendon organs respond to __
Force (muscle tension)
117
Where is the vestibular ganglion located
The petrous temporal bone
118
What are the two types of fluid found in the vestibular labryrinth
Perilymph and endolymph
119
What are the two groups of receptors in the vestibular labyrinth
1. Saccule & utricle
2. Crista ampullaris
120
Macula in the saccule detect __
Vertical position and movement
121
Macula in the utricle detect __
Horizontal position and movement
122
The vestibular system facilitates ___ and inhibits ___
1. Ipsilateral antigravity muscles
2. Contralateral antigravity muscles
123
What is the central pattern generator
A network of neurons (or even single neuron) that is able to exhibit rhythmic activity in the absence of sensory input
124
In what two ways can neural rhythmicity arise
1. Interactions among neurons
2. Interactions among currents in individual neurons
125
How do CPGs drive spinal motor neurons
By raising and lowering their membrane potentials rhythmically
126
What are the functional areas of the neocortex
Visual, motor, auditory, and olfactory
127
CN I location
Rhinencephalon
128
CN II location
CNS
129
CN III location
Midbrain
130
CN IV location
Midbrain
131
CN V location
Motor nucleus in pons
Sensory part in brainstem column
132
CN VI location
Rostral medulla oblongata
133
CN VII location
Rostral medulla oblongata
134
CN VIII location
Medulla oblongata
135
CN IX location
Column in medulla oblongata
136
CN X location
Column in medulla oblongata
137
CN XI location
Column in medulla oblongata
138
CN XII location
Column in medulla oblongata
139
What is the lateral geniculat nucleus
A category of sensory projection nuclei of the thalamus that plays an essential role in normal visual processing
140
The ___ pupillary light reflex is stronger
Direct
141
What is the menace response
Consists of the animal blinking in response to a gesture
142
Which nerves control the extraocular muscles
CN III, IV, and VI
143
Which extraocular muscles are supplied by CN III
Levator palabrae superiosis, dorsal/medial/ventral recti, and the ventral oblique muscles
144
Which extraocular muscles are supplied by CN IV and what is the function
Dorsal oblique
Intorts eyeball
145
Which extraocular muscles are supplied by CN VI and what are their functions
Lateral rectus m (lateral movement)
Retractor bulbi (retracts bulb)
146
What cranial nerves are involved in the vestibulo-ocular reflex
CN III, IV, and VI
147
Which nerve (and which part) supplies the hearing apparatus
The cochlear portion of CN VIII
148
What stimulates the cochlear nerve
Pressure waves in the fluid in the inner ear stimulate the hair cells in the cochlea
149
Which nerve(s) innervate the masticatory muscles
The motor nucleus of CN V and the mandibular branch of CN V
150
Which nerve(s) innervates the muscles of facial expression
The motor nucleus of CN VII
151
CN III ___ the eye
Opens (levator palpebrae superioris)
152
CN VII __ the eye
Closes (orbicularis oculi)
153
Which cranial nerves are found in the nucleus ambiguus
CN IX, X, XI
154
What do the cranial nerves of the nucleus ambiguus supply
The striated muscles of the pharynx, larynx and esophagus
155
The recurrent laryngeal nerve is a branch of which cranial nerve
CN X
156
Which nerve innervates the intrinsic and extrinsic muscles of the tongue
The hypoglossal nerve
157
Which nerve(s) is responsible for taste
CN VII and IX
158
Which nerve(s) is responsible for tongue sensation
CN V
159
What do LMNs regulate
Muscle tone and bulk
160
Name 3 signs of paresis due to LMN dysfunction
1. Decreased muscle tone
2. Decreased reflexes
3. Neurogenic muscle atrophy
161
How does the cerebellum coordinate tone and movement of the head, body and limbs
By modulating the activity of upper motor neurons
162
What do most ataxic cases have?
A spinal cord lesion and compression of conscious proprioceptive and spinocerebellar tracts
163
Name two areas of the cerebellum you would see lesions that would cause UMN/LMN issues
Purkinje cells and floculonodular lobe
164
List 4 clinical signs of cerebellar disease
1. Ataxia
2. Hypermetria & increased tone
3. Tremor
5. Normal mentation
165
In nystagmus, slow eye movement is in the direction __ to head movement
Opposite
166
Damage to ascending proprioceptive tracts causes __
Ataxia
167
Damage to descending motor tracts causes __
Increased reflexes/UMN paresis
168
List 3 functions of the forebrain
1. Interpretations of sensory impulses
2. Motor function
3. Planning & organization
169
What does ARAS stand for
ascending reticular activating system
170
What does the ARAS do
Determines arousal levels, regulates sleep
AND functions as a triage system to rank the incoming information in terms of importance
171
List signs of forebrain lesions
1. Behavior changes
2. Changes in mentation
3. Central blindness
4. Conscious proprioceptive deficit
5. Circling/head aversion towards side of lesion
6. Seizures
172
List signs of brainstem lesions
1. Conscious, subconscious proprioceptive & UMN deficits
2. Nociception reduction in the head
3. Decreased arousal
4. Cranial nerve dysfunction
173
Where do you find the ARAS system
The brainstem
174
Define seizure
A paroxysmal transitory disturbance of brain function that originates in the forebrain, starts suddenly, ceases spontaneously and has a tendency to reoccur
175
What is the difference between conscious and reflex responses to a nociceptive stimulus
A reflex response does not mean the patient has good nociception, lack of conscious nociception is when there is a problem
176
List 4 functions of the brainstem
1. Motor & sensory
2. Afferent & efferent tracts
3. Role in regulating cardiac respiratory function
4. Consciousness & sleep cycle (ARAS)
177
The direction of a nystagmus is defined as the direction of the ___
Fast phase
178
How are transitions between different gaits generated
By varying the network's driving signal and/or by altering internal oscillator parameters
179
The rubrospinal tract is responsible for which phase of locomotion
The protraction phase
180
Stimulation of what evokes walking, trotting and galloping
The mesencephalic motor region
181
Define the autonomic nervous system
A system which includes the enteric nervous system, has upper and lower motor neurons and sensory and motor pathways
182
How many neurons are their in the autonomic nervous system
3 (1 UMN, 2 LMN)
183
Where are the two LMNs in the autonomic nervous system
1st in CNS (presynaptic)
2nd in ganglion (postsynaptic)
184
In the autonomic nervous system, presynaptic LMNs are ___ and post synaptic LMNs are ___
Presynaptic are myelinated
Postsynaptic are unmyelinated
185
What are the divisions of the autonomic nervous system
Sympathetic and parasympathetic
186
What is the enteric nervous system
Postsynaptic parasympathetic neurons
187
What neurotransmitter causes pupil dilation
Noradrenaline
188
What neurotransmitter causes pupil constriction
Ach
189
What are 4 clinical signs of horner's syndrome
1. Pupil constriction
2. Retraction of globe
3. Drooping
4. Protrusion
190
Which cranial nerve supplies parasympathetic signals to the pupil
CN III
191
What is the 'boss' of the ANS
The hypothalamus
192
What are the two noradrenaline receptors
Alpha (constricts) and beta (dilates)
193
What are the two ach receptors
Nicotinic (presynaptic) and muscarinic (postsynaptic)
194
What is the innervation to the detrusor muscle
The pelvic nerve (parasymp)
195
What is the innervation to the inner urethral sphincter
Hypogastric nerve (symp)
196
What is the innervation to the external urethral sphincter
Pudendal nerve (somatic)
197
Which animal does not have cilia
The cat
198
Which extraocular muscles are innervated by CN III
Dorsal, ventral and medial recuts
Ventral oblique
199
Which glands produce the lipid part of tears
Meibomian glands
200
Which glands produce the aqueous part of tears
Lacrimal and nictitans glands
201
Which cells produce the mucus part of tears
Conjunctival goblet cells
202
What is found in the outer layer of the ocular tunic
The sclera and cornea
203
What is found in the middle layer of the ocular tunic
The iris, ciliary body and choroid
204
What are the 4 layers of the cornea
1. Epithelium
2. Stroma
3. Descemet's membrane
4. Endothelium
205
__ drugs dilate the pupil
Mydriatic
206
___ drugs constrict the pupil
Miotic
207
Dilator muscles of the eye are under ___ innervation
Sympathetic
208
Constrictor muscles of the eye are under ___ innervation
Parasympathetic
209
What secretes aqueous
Ciliary processes
210
What is the iridocorneal angle
Where the majority of the aqueous humor leaves the eye
211
The lens fibers meet each other to form ___
Suture lines
212
Define homeothermic
Body temperature maintained within narrow limits
213
Define poikilothermic
Body temperature varies with that of surroundings
214
Heat energy moves __ temperature gradients
Down
215
Small animals have ___ heat loss per unit mass
Greater
216
Define the thermoneutral zone
The ambient temperature range where a mammal can maintain constant core temperature without expending extra energy
217
What mediates the control of blood flow to dermal capillaries to help regulate heat loss
SNS
218
What is non-shivering thermogenesis
Increasing heat production by increasing metabolic rate (action on brown adipose tissue)
219
What is the only effective means of heat loss if ambient temperature is greater than body temperature
Evaporation
220
Fever occurs when...
The set point of the hypothalamic thermoregulatory center is increased
