Exam 1 Flashcards
(318 cards)
1
Q
What is the function of a somatosensory system?
A
Detects and processes body sensations (touch, temperature, pain, pressure, limb position) via extero and intero receptors
2
Q
What are steps in sensory perception
A
Detection and transduction
Transmission
Modulation
Perception
3
Q
What is the primary function of a sensory system?
A
To detect changes in the environment and relay that information to the CNS
4
Q
What are sensory receptor types?
A
Mechanoreceptors, photoreceptors, nociceptors, chemoreceptors, thermoreceptor
5
Q
Which sensory receptor is activated by mechanical forces (i.e. touch, stretch, pressure, vibration, etc)?
A
Mechanoreceptors
6
Q
What are primary receptors?
A
Specialized sensory nerves. Receptors for touch, pain, temp are specialized nerve endings
7
Q
What are secondary receptors?
A
Specialized non-neuronal cells that send a chemical signal to the sensory neuron. This includes rods and cones of the retina
8
Q
What are TRP channels?
A
Ion channels that open and close in response to a stimulus. The channel opens based on what the stimulus is.
Cation channel- permeable to Na and Ca (excitatory signal)
9
Q
What is the difference between slow and rapid adapting receptors?
A
Slow (tonic) adapting receptors have action potentials that continue to be generated at a slow rate while rapid (phasic) adapting receptors initially fire, then the action potential stops.
10
Q
Somatosensory system
A
= body sensory system (outside of the body/ muscles and joints)
11
Q
What does the somatosensory pathway include?
A
Involve 3 different neurons with 2 synapses
- synapses in the brain->thalamus-> sensory cortex
12
Q
Where are most of the sensory receptors located?
A
In the dermis
13
Q
Of the somatosensory receptors, which ones have free nerve endings?
A
Thermoreceptors and nociceptors
14
Q
Where is the sensory neurons axon found in the somatosensory system?
A
found in the dorsal root ganglion near the spinal cord
15
Q
How are merkel cells clinically relevant?
A
Merkel cell carcinomas can occur in cats (malignant) and dogs (benign)
16
Q
What are merkel cells?
A
Cells in the pressure sensitive areas of the skin that detect light touch
17
Q
What is the function of nociceptors?
A
They respond to actual or potential tissue damage
18
Q
How are thermoreceptors divided?
A
Low threshold (cold) and high threshold (warmth)
19
Q
What is the function of golgi tendon organs?
A
Help to detect the position of limbs. Provide information about muscle contraction and prevent excessive contraction
20
Q
What is the role of joint kinesthetic receptors?
A
Prevent joint and muscle damage by keeping animals from over extending or flexing their joints
21
Q
What are some first order somatosensory neurons?
A
Pseudounipolar neurons, peripheral process, cell body, central process
22
Q
What is the effect of myelination and diameter on action potential?
A
More myelination= fast action potentials travel
More diameter = faster action potentials
23
Q
What do spinal nerve roots innervate and what is the clinical significance of that?
A
Each spinal nerve segment innervates a strip of skin called dermatome. You can see where a lesion is by testing dermatome areas.
24
Q
Where do the cell bodies of the first order sensory neurons live?
A
In the dorsal root ganglion
25
What is inflammation of the dorsal root ganglion called?
Ganglioneuritis
26
Where do the sensory pathways in the spinal cord end up?
In the dorsal / lateral funiculi
27
What type of receptors are activated by light?
Photoreceptors
28
Which part of the brain is primarily associated with conscious perception of sensory stimuli?
Primary sensory cortex
29
What are the layers of the dorsal faciculus?
toward the midline of the spinal cord - where the funiculus gracilus is. The faciculus cuneatus is more toward the outside.
30
What is inflammation of nerve roots of dorsal root ganglia called?
Radiculoneuritis
31
Which half of the spinal cord contains sensory neurons and axons based on their function?
Dorsal half
32
What is the function of the spinothalamic tracts?
Relay information about pain and temperature
33
How many neurons are apart of the spinothalamic tract?
3. First, second, and third order
34
Where does the axon of the first neuron in the spinothalamic tract originate and synapse?
Its cell body originates in the dorsal root ganglion. It synapses in the dorsal horn of the spinal cord.
35
Do sensory neurons have to go all the way up to the sensory cortex?
No. Some neurons just go to the spinal cord.
36
What are some other ascending pathways besides the spinothalamic tract?
Spinoreticular tract (response to pain), spinovestibular tract (posture and balance), and spinocerebellar tract (unconscious proprioception).
37
Where is the primary somatosensory cortex located?
Caudal to the primary motor cortex
38
What is itch?
An unpleasant sensation provoking the desire to scratch.
39
Which motor neuron is responsible for the concept of whatever occurs on the right is transmitted to the left side of the brain and vice versa?
Second order neuron
40
What pathways travel from the spinal cord to brain
Spinothalamic tract and spinoreticular tract
41
True or False: itch is included in the somatosensory system
False
42
True or false: axons for itch involve C and Ad
True
43
What nerves are responsible for somatosensory innnervation of the head and what do they innervate?
Trigeminal n. (CN V): most of the head
Facial n. (CN VII): part of the ear
Glossopharyngeal n. (CN IX): throat
Spinal n. C2: part of pinna, cranial neck
44
What is the function of the nervous system?
To enable the body to respond to changes in the environment and control organs and systems
45
Describe the anatomic divisions of the nervous system
Central nervous system and peripheral nervous system
46
Describe the parts of the peripheral nervous system
Peripheral nervous system isn’t covered by bone (peripheral and cranial n. And ganglia)
47
The CNS is made up by the __________ & ____________.
Brain and spinal cord
48
True or false: Neurons are metabolically active cells.
True. They have a high demand for oxygen and energy.
49
Name the supporting cells of the CNS
Astrocytes, oligodendrocytes, microglia, ependymal cells
50
Describe the function of astrocytes
Contribute to the BBB and provide physical and metabolic support for neurons
51
Describe the function of oligodendrocytes
Make and maintain the myelin sheath
52
What is the role of microglia?
Phagocyte in the CNS
53
Kufer cell is the __________
Macrophage of the liver
54
The ependymal cells do what in the CNS?
Form the ventricular lining. They have cilia on their surface to help circulate CSF in the CNS.
55
What cell produces myelin the in PNS?
Schwann cells
56
What do the satellite cells do in the PNS?
Provide mechanical and metabolic support
57
Why is white matter white?
It consists almost entirely of myelinated axons.
It is rich in lipid (myelin). Lipid is fat and fat is white.
58
True or false: the grey matter is rich in neurons
True
59
Arborizing folds in the cerebellum are called
Folia
60
Molecular layer contains
Nerve fibers and dendrites
61
These cells are located between the granular and molecular layer of the cerebellum
Purkinje cells- a great place to find negri bodies of rabies
62
What is responsible for producing CSF?
Choroid plexus
63
What are the 3 layers of the meninges
Dura matter (tough mother)
Arachnoid
Pia (tightly covers the outside of the brain)
64
The arachnoid and pia together form whats called the __________.
Leptomeninges
65
What does the endoneurium do?
They surround each nerve fiber and Schwann cell
66
What surrounds each nerve fascicle?
Perineurium
67
What surrounds the peripheral n.?
Epineurium
68
Name the sensory systems
Somatosensory, olfactory, gustatory, visual, and vestibular
69
What are primary receptors
Specialized terminals of sensory neurons that detect touch, pain, and temperature
70
Which major somatosensory pathways transmits information about touch, pain, temperature, and body position to the cerebral cortex?
Dorsal somatosensory pathway
71
Where do first order sensory neuron axons typically branch.
On second order neurons and other interneurons that mediate local effects
72
Which ascending pathway transmits information about posture and balance to the vestibular nuclei?
The spinovestibular tract
73
The primary function of the thalamus in sensory processing is
Acting as a relay station for almost all sensory information going to the cerebral cortex
74
Where are the nuclei that contain the cell bodies of third-order neurons of the somatosensory system located?
ventral part of the thalamus
75
Where is the primary somatosensory cortex located relative to the primary motor cortex?
Just caudal to it.
76
Where do the third order neurons project in the sensory pathways?
Somatosensory cortex
77
What distinguishes the sensory pathways for the facial and glossopharyngeal nerves from the trigeminal nerve pathway?
the axons of the first order neurons travel in the facial and glossopharyngeal nerves.
The first-order neurons synapse on second order neurons in the trigeminal sensory nuclei
78
How is visceral sensation different from somatic sensation?
Somatic sensation includes sensations from skin, muscles, tendons, whereas visceral sensation pertains to internal organs
79
What type of receptors are found on visceral organs?
Enteroreceptors (or interoreceptors)
80
What is visceral pain caused by in veterinary species?
gastrointestinal or urinary tract obstruction or inflammation in the viscera (such as pancreatitis).
81
What are some signs of colic in horses?
Stretching, rolling, pawing, or kicking/biting at the flanks
82
What is the role of transient receptor potential (TRP) channels in sensory reception?
Result in depolarization in response to stimuli (Na & Ca)
83
Which receptors include rods and cones of the retina and hair cells in the inner ear?
Secondary receptors
84
What is receptor adaptation in sensory systems defined as?
Decrease in sensitivity to a prolonged stimulus. This allows the sensory system to adjust to sustained inputs.
85
In sensory systems, what is modulated based on inputs from other sensory receptors?
Sensory perception- information in sensory systems
86
The grey matter of the spinal cord is organized, based on function, into layers called ____________.
Rexed’s laminae
87
Where are the nuclei containing cell bodies of the third-order somatosensory neurons located?
In the ventral part of the thalamus
88
How are the neurons in the cortex organized regarding sensory information?
In a somatotopic map- where each part of the cortex receives information from a particular part of the body
89
What structure runs through the mandibular canal?
Inferior alveolar VAN. It will run through the mandibular foramen and exit as the mental n. through the mental foramin
90
What 4 bones make up the zygomatic arch?
The zygomatic, temporal, frontal, and maxilla bones
91
What three parts form the temporal bone?
Petrous, tympanic, squamous
92
What structures make up the temporo-mandibular joint?
The condylar process of the mandible
The squamous part of the temporal bone
93
What is the significance of the temporal lines?
They converge to form the external saggital crest and the form the rostromedial boundary of the temporal fossae which houses the temporalis m. (Major muscle of mastication)
94
What bony complex provides passage for olfactory nerves and blood vessels?
Cribiform plate
95
What is a location for dental n block that involves the infraorbital VAN?
Infraorbital foramen (becomes the maxillary formen as you move caudal
96
What major aspects does a neuro exam consist of?
Observation- what you see and hear
Hands on
97
What four areas can you localize to in the case of an intracranial lesion?
Forebrain: prosencephalon
Cerebellum: dorsal metencephalon
Brain stem: mesencephalon, ventral metencephalon, myelincephalon
Vestibular: central vs. peripheral
98
You can localize to these 4 areas when a spinal cord lesion is suspected:
C1-C5: cranial cervical spinal cord
C6-T2: cervicothoracic
T3-L3: thoracolumbar
L-S3: lumbosacral intumescense
99
Define intumescence
The area of the spinal cord where the nerves are coming off and supplying the limb (i.e. lumbosacral intumescense)
100
Define decusation and where it occurs
Occurs at the forebrain. Meaning crossing over.
The information on the right side of the brain controls the left side of the body.
101
True or False: you can get lesions just in the sensory system of the PNS.
True. You can both motor and sensory deficits occurring by themselves.
Motor deficits are called motor unit disease (or neuromuscular disease).
Sensory deficits are called sensory neuropathy
102
What is a neuropathy
A lesion to the entire nerve in the PNS (sensory and motor deficits occur together)
103
A disease to the brain is called an ____________.
Encephalopathy
104
Disease of the spinal cord is referred to as what?
Myelopathy
105
The following are examples of disease in what system?
(Neuropathy, Junctionopathy, Myopathy Axonopathy, Myelinopathy, Radiculopathy)
Peripheral nervous system
106
The sympathetic nervous system originates from where?
Hypothalamus
107
Nerves start coming off of the sympathetic nervous system starting where?
C7 (caudal cervical thoracic intumescense)
108
Which cranial nerves supply sympathetic innervation to the head, thoracic viscera, and abdominal viscera?
III, VII, IX, X
109
Of the vagus nerve and vagosympathetic trunk, which one is going toward the head?
Vagosympathetic trunk
110
What is Horner syndrome?
Lack of sympathetic innervation to the head and neck
111
How do you differentiate between upper and lower motor neurons?
Pay attention to REFLEXES, tone, and atrophy
112
Where do upper motor neurons come from?
Forebrain, brain stem, cerebellum, C1-C5 spinal cord
113
Where do lower motor neurons originate?
At the intumescense
114
What effect can an upper motor neuron lesion cause?
An exaggerated reflex response
115
What causes a decreased reflex/ tone response?
A lower motor neuron lesion/ disruption
116
What is the expected reflex and tone response of UMN vs LMN lesions
UMN- normal to increased reflexes and tone
LMN- decreased to absent reflexes and tone
117
What can occur with an C1-C5 lesion?
Increased reflexes and tone in thoracic and pelvic limbs.
No more control over LMN activity
118
What occurs with a C6-T2 lesion?
Decreased reflexes and tone in thoracic limb (LMN affected) and increased reflexes and tone in pelvic limb (UMN affected)
119
What occurs with a T3-L3 lesion?
Thoracic limb normal, pelvic limb has increased reflexes and tone
120
A lesion occurring in L4-S3 would affect the thoracic and pelvic limbs in what ways?
Normal thoracic limb function; decreased reflexes and tone in pelvic limb
121
Where is disuse atrophy seen most?
With orthopedic & UMN lesions (chronic and mild)
122
What type of atrophy is associated with a LMN lesion?
Neurogenic atrophy (acute and severe)
123
True or false: UMN & LMN differentiation includes sensory (proprioception and nociception).
False. A patient can have proprioceptive and nociceptive diseases with both
124
What tools are needed for a neuro exam?
Surface with traction, plexometer, hemostats, transIlluminator (light source), cotton balls
125
If there’s a behavior change, what part of the brain should be on the differential list?
Forebrain lesion
126
The main gait generator is the _______ _______.
Red nucleus
127
Why do dogs head press or “go, go, go”?
If there’s a forebrain lesion where you’ve lost inhibition to the red nucleus
128
In a right forebrain lesion, the ______ side of the animal’s world doesn’t exist.
Left
129
What can be observed in an animal with a right forebrain lesion
Circling to the right
130
A focal seizure localizes where?
Forebrain
131
What is the main contributor for alertness and where does it originate and project?
Ascending reticular activating system (ARAS)
- in the midbrain, sends projections to the forebrain
132
Define obtunded.
An inappropriate response to a stimulus
133
If the lesion is diffuse, a patient can become
Obtunded
134
In order for an animal to become stuporous or comatose, the lesion has to be in the
Brainstem
135
What is the significance of the Modified Glasgow coma scale?
Looks for levels of consciousness
136
If a patient has a forebrain (prosencephalon) lesion, what could be on your differential list/ observed?
Abnormal behavior from neuro abnormality
Seizures
Narcolepsy
Mentation changes- obtunded (diffuse)
137
What are the 3 types of ataxia
Proprioceptive, vestibular, cerebellar
138
What clinical signs do you see with proprioceptive ataxia?
Scuff toes/ cross over limbs- common with spinal cord disease (some degree of paresis or weakness)
139
What clinical signs do you see with vestibular ataxia?
Patients will drift to one side, may sometimes lead into the wall. Could also see a head tilt and nystagmus.
140
What ataxia is characterized by over flexion or extension of the limbs (hypermetria)?
Cerebellar ataxia
141
True or false: ataxia is predictable with every step; or regularly irregular.
False. Lameness is predictable with every step, or regullary irregular.
Ataxia is secondary to neurological disease and the gait is not predictable, or irregularly irregular.
142
Sympathetic innervation to the head comes from the
Thoracic spinal cord
143
Name the nerve fiber types
Somatic efferent, visceral afferent
General somatic afferent, general visceral afferent
Special visceral afferent, special somatic afferent
144
Name the nerve fiber types with motor function and their general innervation
Somatic efferent – somatic motor (skeletal muscle)
• Visceral efferent – autonomic motor (smooth/cardiac muscle, glands)
145
Name the nerve fiber types with sensory function unique to the head and their general innervation
• Special visceral afferent – taste and smell (chemoreceptors)
• Special somatic afferent – vision, hearing, vestibular sense
(photoreceptors, mechanoreceptors)
146
Name the nerve fiber types with sensory function similar to spinal n. and their general innervation
• General somatic afferent – somatic sensory
• General visceral afferent – visceral sensory
147
Describe the cranial nerve pathway for somatic efferent fiber type
Start in primary motor cortex (UMN), synapses in cranial n. Motor nucleus (cross nucleus)- where LMN nuclei are. Synapse with skeletal mm. @ neuromuscular junction
148
Which cranial nerves have a parasympathetic nucleus in the brainstem?
3,7,9,10
149
Which cranial n arises from the telencephalon? What is its function?
Olfactory, smell (sensory)
150
fusion of two adjacent vertebrae is a hallmark of what?
Block vertebrae
151
What is a differential causing block vertebrae?
Previous trauma with traumatic herniated disc that fused
152
What are the 3 breeds most commonly affected by hemivertebrae?
Bulldog, pug, Boston terriers
153
What are hallmarks of hemivertebrae?
Small size and wedge shaped vertebral body
154
What results from a failure of fusion of the lateral halves of the vertebral body?
Butterfly vertebrae
155
Describe transitional vertebrae and where it normally occurs
An anomaly where the vertebrae from one region take on characteristics of another region.
Lumbar sacral junction
Thoracolumbar junction
156
What type of transitional vertebrae can be seen in the lumbarsacral junction?
Sacralization of L7- where L7 partially or completely fuses to the body of the sacrum
Lumbarization of S1- transverse processes and vertebral disks form between S1 & S2
157
Describe lordosis
Ventral deviation of the spine (lo=low)
158
Describe kyphosis
Dorsal deviation of the spine (ky= high)
159
Scoliosis is what?
Lateral deviation of the spine
160
Lack of development of the vertebral arch is called what?
Spina bifida
161
The clinically significant form of spina bifida is what? What is needed to differentiate it?
Meningiomylocele
MRI or CT needed. Won’t be able to tell difference between that or the non clinical version with just radiographs.
162
Radiographic features of atlantoaxial instability include
Increased distance between the dorsal spinous process of C2 and dorsal arch of C1
Dorsal-caudal displacement of C2
163
Abnormalities of the dens include what?
Fractures, agenesis, hypoplasia
164
Endplate lysis is the hallmark Radiographic feature of what infectious disease process?
Discospondylitis
165
Osteomyelitis due to paraspinal infection is called
Spondylitis
166
What is a radiographic hallmark of spondylitis?
Bony proliferation along the ventral aspect of the vertebral body
167
What is a radiographic hallmark of spondylosis deformans?
Bone production of the annulus fibrosis between the vertebral disks
168
True or False: multiple myeloma is a plasma cell tumor.
True. It also arises from bone marrow and you’ll see multiple areas of moth-eaten lysis
169
Where do you normally see intervertebral disc disease in animals? Why?
T10 to lumbar region.
The intercapital ligament provides support to the dorsal annulus in the thoracic spine.
170
The radiographic hallmark of intervertebral disk extrusion is what?
Collapsed intervertebral disc space
171
An __________ __________ can be seen in intervertebral disc protrusion/ extrusion. This can deviate the spinal cord.
Extradural lesion
172
What is the preferred method for viewing intervertebral disc extrusion?
MRI
173
What are the common applications when you would use Brain CT and MRI?
Neurological diseases such as:
Masses, multifocal lesions, trauma, and dilated ventricular system
174
The following is an example of what? Is it typically monostotic or polyostotic?
Primary vertebral tumor
175
The following is an example of what? Is it common in animals?
Secondary (metastatic) vertebral tumor.
Not common in animals
176
CT terminology =
Attenutation
177
True or false:
Hyperattenuating= white
Hypoattenuating= black
True
178
Window represents
The range of shades of grey (HU) displayed by the image
*the example photo has a window from 1000 HU to -1000 HU
179
The central value of the HUs displayed is the ________.
Level
*the example photo has the level at 0*
180
True or false: Voxel is a picture element and has only 2 dimensions.
False! PIXEL IS A PICTURE ELEMENT AND HAS ONLY TWO DIMENSIONS (X,Y)
Voxel is a volume picture element and has 3 dimensions (X,Y,Z)
181
Thinner CT slices result in
Better spacial resolution images
182
The isotopic voxel allows for what?
Better & more accurate 3D reconstructions and volume rendering w/out resolution loss
183
Cone beam CT is more commonly used in where?
Dental applications
184
CT is a great diagnostic test for what? Give an example of when you would use CT.
Lungs: tumors, pneumonia
Nasal cavity: tumors, rhinitis
Abdomen: masses, portosystemic shunts
Bone: fractures, elbow dysplasia,
185
Some advantages of using CT are
More detailed view of anatomy
Faster and less expensive than MRI
Better for bone, lung, abdomen
186
Radiation exposure, more expensive than radiographs, poor soft tissue contrast (when compared to some other diagnostic tests) are disadvantages of
CT
187
The Z-axis in an MRI is the what?
Slice thickness axis
188
What is a major safety concern with MRI?
It is a BIG electromagnet so anything metal needs to be far away.
189
How does MRI work to produce images?
Manipulate hydrogen atoms with an external magnetic field, allowing them to penetrate the patient and produce an image
190
MRI terminology for white is
Hyper intense
191
Hypo intense is terminology for MRI meaning
Black
192
True or false
MRI= attenuation
False! MRI= intense
CT=attenuation
193
Sequences for MRI are what? What do they do?
Different ways to manipulate the magnet or for the magnet to manipulate the patient. Alters the contrast based on different properties of tissues
194
What are some spin echo sequences and their effects?
T2- fluid is bright
T1- fluid is dark
195
What is Gadolinium and its purpose in MRI?
Gadolinium is a paramagnetic rare earth metal. It detects breaks in the BBB and makes tissues more hyper intense (T1 sequence)
196
Inversion sequences include STIR and FLAIR. What do they do?
STIR- suppress fat signal
FLAIR- suppress CSF signal
197
A gradient echo called FFE (fast field echo) is great for what?
Detecting hemorrhage
198
In small animals, MRI is mainly used for
Neuroimaging
199
MRI veterinary applications include
Neuroimaging
Musculoskeletal
Cancer imaging
Vascular imaging
200
A safety concern with CT is
X-ray exposure
201
Advantages of MRI include
Better soft tissue contrast and detail
Noninvasive
202
Long scan times, require general anesthesia, and cost are disadvantages of
MRI
203
Describe the function of the inner ear
Convert mechanical stimuli (vibration, acceleration) into action potential
204
The 3 sensory parts of the inner ear are
Cochlea, semicircular canals, otolith organs
205
The cochlea detects what?
Sound (vibration)
206
Detection of angular acceleration is the function of
Semicircular canals
207
Of the three sensory parts of the inner ear, which one detects linear acceleration and position?
Otolith organs
208
Cranial nerve VIII is what? What are its 2 parts?
Vestibulocochlear; cochlear and vestibular
209
Epithelia of the sensory regions of the inner ear are made by what type of cell?
Hair cells
210
How do hair cells convert mechanical stimuli to electrical signals?
Depolarization of hair cells via potassium, release neurotransmitter (glutamate), binds to sensory neuron receptors, action potential fires if depolarization sufficient
211
Potassium concentration is high in the __________. So opening a potassium channel results in influx of potassium into the hair cell, leading to _____________.
Endolymph; depolarization
212
The organ of corti lives in the _________.
Cochlea
213
Smell pathways don’t go through the
Thalamus
214
The inferior colliculus is located where?
In the midbrain
215
The superior olive and inferior colliculus is important for what?
hearing and vision
216
The function of semicircular canals is to what?
Detect angular acceleration
217
The anterior semicircular canal detects what? It is located in the saggital plane.
Pinch
218
Posterior semicircular canal detects _____.
Roll
219
The crista ampullaris is located in the
Semicircular canal
220
The vestibular ganglia contain the cell bodies of what neuron type?
Bipolar
221
One disease process that can be associated with abnormal eye movements is
Vestibular disease
222
How can you distinguish between a change in behavior and a change in mentation?
Mentation is related to an animal's response to stimuli while behavior is not
223
_________ will have localized pain to the limb while _______ will often include other findings of neurological deficits.
Lameness; ataxia
224
(T/F) Axons transmit impulses away from the perikaryon while dendrites transmit impulse toward the perikaryon.
True
225
What structure are the arrows pointing to in the picture?
Microglia
226
10. What is the primary function of the structure?
Phagocytosis
227
Listed are the infections in different locations of the nervous system. Give the location they are indicating.
A. Meningitis
B. Encephalitis
C. Myelitis
A. Meninges
B. Brain
C. Spinal cord
228
True or false: all parts of the nervous system are sterile sites
True
229
What are the two non-immunological defenses of the nervous system?
Bone and Blood brain barrier
230
The movement of substances (including microbes) is controlled by tight intercellular junctions, astrocyte processes and pericytes surrounding the capillaries, and what else?
Specialized transport mechanisms; carrier mediated, lipid soluble substances only
231
What cell type(s) in the CNS process antigens and trigger a response in B and T lymphocytes, neutrophils, and macrophages?
Astrocytes and Microglial cells
232
What are some factors associated with increased risk of infection in general?
Age (very young/old), immunosuppression, trauma/concurrent infection
233
What are two risk factors associated with specific infections of the nervous system?
Eating spoiled silage - listeriosis; penetrating wounds - tetanus
234
What is the most common route of entry for nervous system infections?
Hematogenous
235
What are the other two routes of entry associated with nervous system infections (besides the most common)?
Retrograde movement within neurons, extension of infectious process from contiguous sites or direct penetration
236
What does vasculitis lead to?
Endothelial damage and leakage-> hemorrhage and parenchymal injury
237
Besides vasculitis, what is another result of vascular damage caused by nervous system infections?
Septic embolic and/or thrombus formation
238
(T/F) The parenchyma or meninges can be injured by direct damage or indirect damage through induction of an inflammatory response.
True
239
Neuropathy is
A disorder of a neuron (could be cell body, axon, or Schwann cells)
240
Define myopathy
Disorder of muscle fibers
241
What is junctionopathy?
Dysfunction of the neuromuscular junction
242
What does a motor unit include?
Lower motor neuron, neuromuscular junction, muscle fibers
243
What are two examples of mononeuropathy?
Radial neuropathy and sciatic neuropathy
244
Define mononeuropathy
Focal/ single peripheral nerve dysfunction
245
Multiple mononeuropathy is
Multiple nerves of one limb affected, but no other limb is affected
246
Give an example of multiple mononeuropathy
Brachial plexus avulsion
247
Polyneuropathy is
Diffuse peripheral nerve dysfunction
248
Polyneuropathy can be secondary to
Diabetes mellitus
249
Paresis vs. plegia
Paresis is decreased voluntary movement
Plegia is absent voluntary movement (paralyzed)
250
Monoparesis is
Decreased voluntary movement of a single limb
251
Monoplegia is
Complete paralysis of a single limb
252
What can anatomically cause monoparesis?
The motor unit affecting that limb (LMN cell body/ axons of LMN), sensory dysfunction (dorsal root ganglia/ sensory nn.), autonomic nerves and ganglia
253
Factors involved in neurological disease (lameness) include:
Decreased voluntary movement
Reduced reflexes
Severe atrophy
Horner’s syndrome
254
Signs of orthopedic disease (lameness) can include:
Consistency with each stride
Disuse atrophy (chronic)
Abnormalities with orthopedic exam
Normal neuro exam
255
(T/F): Some animals have both orthopedic and neurologic disease
True
256
What parts of the spinal cord does monoparesis affect
C6-T2 and L4-S3
Cervical and lumbar intumessence
257
What is the order in which cells vary in their susceptibility to injury?
Neurons> glial cells> blood vessels
258
A degenerative and reversible response to retrograde nerve root injury is
Chromatolysis (loss of Nissl substance)
259
The following is an example of what reaction pattern resulting from __________ changes in the spinal cord.
Chromatolysis; neural
260
Neuronal necrosis is a result of ___________. Known as dead red.
Hypoxia
261
Wallerian vs Wallerian-like degeneration is a tissue reaction pattern of ________. Describe them.
Axons;
Wallerian: response to trauma, occurs in a nerve fiber distal to site of injury
Wallerian-like: ischemia or degeneration similar to Wallerian but may have different mechanism or characteristics.
262
The following picture is an example of what basic tissue reaction?
Segmental swelling (spheroids)
263
Segmental swelling (spheroids) is a tissue reaction pattern of injury to an
Axon
264
(T/F): Neurons with the highest metabolic rate are the most susceptible.
True
265
What cell type accumulates inclusion bodies in response to viral or degenerative diseases?
Neurons
266
What are the consequences of necrosis of the neuropil?
Malacia -> glial scar
267
The main causes of edema in the brain and spinal cord are:
Vasogenic, interstitial, and cytotoxic (spongiform change)
268
What histologic change do you expect to see in axons?
Spheroids
269
What are two risk factors associated with specific infections of the nervous system?
Eating spoiled silage - listeriosis; penetrating wounds - tetanus
270
What does vasculitis lead to?
Endothelial damage and leakage → hemorrhage and parenchymal injury
271
The two forms of hydrocephalus are
Communicating and non-communicating
272
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
a. Staphylococcus pseudintermedius
Dogs/Cats
273
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
b. Pasteurella
(Dogs/cats)
274
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
c. Streptococcus canis
Dogs/ Cats
275
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
d. Listeria monocytogenes
276
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
e. Clostridium botulinum
Dogs, horses, ruminants
277
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
f. Enterobacteriaceae
f. Enterobacteriaceae
i. Escheria coli
ii. Klebsiella
iii. Salmonella
iv. Proteus
i. Dogs/cats, horses, ruminants, pigs
ii. Dogs/cats and horses
iii. Dogs/cats, horses, ruminants, pigs
iv. Dogs/cats
278
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
g. Beta-hemolytic Streptococci (not canis)
Horses
279
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
h. Rickettsia rickettsia, Ehrlichia canis
Dogs/cats
280
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
Clostridium perfringens type D
Ruminants
281
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
a. Streptococcus Suis
b. Histophilus somni
c. Clostridium tetani
a. Pigs
b. Ruminants
c. Dogs/cats, horses, ruminants, pigs
282
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
Non-spore forming anaerobes
i. Bacterioides
ii. Fusobacterium
Dogs/ cats for both
283
Listed below are bacteria shown to most commonly cause disease in dogs, cats AND/OR horses, AND/OR ruminants, AND/OR pigs, sort them.
l. Glaeserella parasuis
m. Nocardia, Actinomyces
n. Shiga toxin producing Escherichia coli
o. Trueperella pyogenes
l. Pigs
m. Dogs/ cats
n. Pigs
o. Ruminants, pigs
284
(T/F) Brain abscesses are more common in horses and ruminants than in dogs/cats
True
285
(T/F) Meningitis/encephalitis is more common in neonates in horses, ruminants, and pigs and is associated with failure of passive transfer.
True
286
What is the gram reaction of clostridium bacteria?
Gram positive
287
What is the atmosphere requirement of clostridial bacteria?
Strict anaerobes
288
Do clostridial bacteria form endospores?
Yes
289
(T/F) Clostridial bacteria love niches with low oxidation-reduction potential such as GIT of animals and humans for C. tetani and soil or vegetation for C. botulinum.
True
290
Are clostridial bacteria motile and gas producing?
Yes
291
What is the most common route of infection for C. tetani?
Inoculation into a wound
292
What are the primary and secondary routes C. tetani take to reach the brain?
Primary - wound → motor nerve axons → spinal cord → brain; secondary - bloodstream → brain
293
(T/F) Both C. tetani and C. botulinum produce protoxins which are inactive that need to be activated in the body to cause disease.
True
294
Which type of neurons does tetanospasmin inhibit the release of glycine and GABA from?
Inhibitory interneurons
295
The lack of inhibitory signal leads to continuous over excitation of motor neurons that manifests as what?
Increased muscle tone, rigidity and spasm → spastic paralysis
296
(T/F) Binding of tetanospasmin is irreversible and requires growth of new axon terminals and synapses.
True
297
What type of junctions do C. botulinum toxins bind to only?
Cholinergic
298
How does C. botulinum get into neurons?
Bind to presynaptic neuron via a receptor then passes through the cell membrane by receptor-mediated endocytosis
299
Inside the nerve ending, botulinum toxin blocks the release of what neurotransmitter?
The blocking of that neurotransmitter results in failure to cause a nerve action potential resulting in what type of paralysis?
Acetylcholine; Flaccid paralysis
300
What is the typical cause of death associated with botulinum?
Respiratory failure d/t paralysis of diaphragm
301
(T/F) In C. tetani infections that reach the nervous system, you see spastic paralysis in all mammalian species.
True
302
(T/F) Binding of botulinum toxin is irreversible and requires growth of new axon terminals and synapses.
True
303
Which species is the most susceptible to C. tetani infections?
Horses
304
Which species are highly resistant to C. tetani infections?
Birds and cold-blooded animals
305
You see a horse with increased temperature, heart rate, respiratory rate, and salivation, convulsive contraction of voluntary muscles, and extensor rigidity, how will they likely die?
Of the above clinical signs, which can be decreased instead and still be associated with C. tetani infection?
Death d/t spasm of muscles involved in respiration;
Heart rate, can be increased or decreased
306
What are two clinical signs that are seen with C. tetani infections associated with the eye that are not included in the list below?
increased temperature, heart rate, respiratory rate, and salivation, convulsive contraction of voluntary muscles, and extensor rigidity,
Protrusion of the third eyelid and enophthalmos
307
You find a cat in flaccid paralysis, is this a cause for concern?
Nope, they’re just living their life
308
(T/F) Trauma to the skull or spinal cord (particularly if the skin is broken) will definitely increase the risk of bacterial infection in the CNS
True
309
Risk factors for the development of nervous system infections involving very specific bacterial infections of the nervous system include
• Listeriosis
• Clostridial diseases
310
Bacterial or fungal infection of the intervertebral disks and the adjacent vertebral bones is a hallmark of
Discospondylitis
311
Incidental hosts of Parelaphostrongylus tenuis are
Sheep, goats and alpacas
312
Neurologic disease of __________________ comes from spinal cord compression and inflammation secondary to migrating nematodes
Parelaphostrongylus tenuis
313
Parelaphostrongylus tenuis is a meningeal worm of
White tail deer
314
What bacteria causes suppurative encephalitis with thrombosis and vasculitis (thrombotic meningoencephalitis or TME)
Histophilus somni
315
Describe the lesion and name the bacteria causing the disease.
Lesion: multifocal, hemorrhage, necrosis; vasculitis
Disease: Histophilus somni -> TME (thrombotic menengioencephalitis)
316
Describe the lesion and cause
Supperative meningioencephalitis
Listeria monocytogenes
317
In cattle, what bacteria is responsible for cause of necrotic laryngitis (calf diphtheria), foot rot (in the interdigital space), and liver abscesses?
Fusobacterium necrophorum
318
Fusobacterium necrophorum in sheep can cause what?
Foot scald (inflammation in the interdigital space), secondary bacteria with foot rot in small ruminants
