Central Nervous System (Exam II) Flashcards
1
Q
What are the 4 major lobes of the brain? What do they control?
A
- Frontal (Personality, planning, thinking, etc.)
- Parietal (Sensory info processing, somatosensory cortex)
- Occipital (Vision primarily)
- Temporal (Right and Left, Hearing and Language)
2
Q
What are the 3 neuron types found in mammals? Which one is not in mammals?
A
- Multipolar
- Pseudounipolar
- Bipolar
True Unipolar not found in mammals.
3
Q
Which neuron type is the most common? What is the defining trait of these?
A
- Multipolar
- This is the “decision making” neuron.
4
Q
What is the purpose of pseudounipolar cells? Where are pseudounipolar neurons found? What is the purpose of the nucleus in these cells?
A
- Sensory information processing.
- They are found in ganglia
- The nucleus mainly just provides cell support.
5
Q
Where are bipolar neurons found?
A
- Eyes and ears (i.e. retinas and cochlear/vestibular structures of the ears.)
6
Q
At resting state, are V-G Na+ channels of most somatic sensory nerve receptors open or closed? What changes this state?
A
- V-G Na+ channels are closed at Vrm.
- Changes by stretch or pressure opens V-G Na+ on your somatic sensory nerves. This is how we perceive our sensory information.
7
Q
The Telencephalon is also known as what?
A
The cerebrum
8
Q
The Diencephalon controls what functions of the brain? What incredibly important structure is located here?
A
- Hypothalamus
- Automated functions are controlled in the diencephalon (I.e. infection response, body temp, etc.)
9
Q
What other name does the midbrain go by?
A
Mesencephalon
10
Q
What are the three structures of the brain stem in descending order?
A
- Midbrain (mesencephalon)
- Pons
- Medulla Oblongata
11
Q
What does the cerebellum control?
A
- Complex movement coordination (I.e. sports, driving a car, etc.)
12
Q
Where does the spinal cord terminate?
A
Around L1 to L2
13
Q
What information does the anterior horn of the spinal cord process?
A
Motor
14
Q
What information does the lateral horn of the spinal cord process?
A
Visceromotor
15
Q
What information does the posterior horn of the spinal cord process?
A
Sensory
16
Q
What differentiates vertebral arteries in the C-spine area from vertebral arteries throughout the rest of the spinal column?
A
Vertebral arteries in the c-spine area are protected by the cervical vertebrae.
17
Q
Which spinal nerves are necessary for breathing?
A
C3, C4, and C5
18
Q
Spinal nerves flow out alongside which bony structures?
A
Transverse Processes
19
Q
What foramen do vertebral arteries pass through?
A
The tranverse foramen
20
Q
What bony structure of the spine allows for “head swivel”? Which vertebrae is this structure located on? Where does this structure attach to?
A
- Dens Process
- C2 Axis
- C1 Atlas: Dens Facet
21
Q
Which two facets fit to the base of the skull, connecting the skull with the vertebrae?
A
The right and left superior articular facets
22
Q
What is another name for the C1 Vertebrae? How about the C2 Vertebrae?
A
- C1 = Atlas
- C2 = Axis
23
Q
What are the 3 main arteries that feed the spinal cord?
A
- Anterior Spinal Artery
- Right Posterior Spinal Artery
- Left Posterior Spinal Artery
24
Q
What thoracic arteries feed the main vertebral arteries? Are these normally located next to each other?
A
Posterior and Anterior Segmental Medullary Arteries.
No, they are normally staggered.
25
Which two vascular structures sit inside the Anterior Fissure of the spinal cord?
Anterior Spinal Artery and Anterior Spinal Vein
26
How many large veins run off the spinal cord? Where are they located?
4 run off the spinal cord. 1 anteriorly and 3 posteriorly.
27
How many pairs of spinal nerves run through the cervical spine? How many vertebrae are located in the c-spine?
8 pairs of nerves
7 vertebrae
28
How many pairs of spinal nerves run through the Thoracic spine?
12 pairs of nerves
29
How many pairs of spinal nerves run through the Lumbar spine?
5 pairs of spinal nerves
30
How many pairs of spinal nerves run through the Sacral spine?
5 pairs of spinal nerves
31
How many pairs of spinal nerves run through the Coccygeal spine?
1 pair
32
Spinal nerves emerge _____ respective vertebrae. Which spinal nerve is the exception and why?
Below
Spinal nerve 1 exits above the C1 Atlas
33
Why do vertebrae get larger as we progress from the cervical spine to the Lumbar spine?
Vertebrae become larger to account for more weight to hold.
34
What is scoliosis? Does it usually present with any other conditions? Is it hereditary?
Scoliosis is left or right abnormal curvature of the spine
It usually presents with a degree of kyphosis
Yes, it is hereditary.
35
What spinal condition could affect ventilation?
Excessive Thoracic Kyphosis could prevent adequate thoracic expansion and compress the heart as well.
36
What consequences are there when excessive kyphosis or lordosis of the spine is treated with spinal fusion?
Metal fusing plates in the spine prevent normal shock absorption and lung expansion.
37
What is the joint where C1 meets C2, and rotation of the skull occurs, called?
Atlanto-Axial Joint
38
Which portion of the Vertebrae is the weight supporting portion?
The Vertebral body
39
Which spinal nerve runs on top of it's respective vertebrae as opposed to below?
Spinal Nerve 1.
Comes out above C1
40
What structural difference of the spinous process would differentiate cervical vertebrae from other vertebrae?
Biphid Spinous Processes
41
Which two vertebrae have no disc in between them?
C1 and C2
42
What differentiates newborn spinal curvature and adult spinal curvature? What does this do to a toddler's gait?
Newborn spinal curvature is mostly kyphotic.
This means that a toddler's spine development, not being complete yet, makes them unstable and prone to falling.
43
Where do spinal nerves exit out of the spinal cord space? What two bony structures are above and below this exit space?
The intervertebral foramen
The superior pedicle and the inferior pedicle
44
What are the portions of the sternum in descending order?
Manubrium
Sternal Angle
Sternal Body
Xyphoid Process
45
Which ribs are known as “true” ribs? Why?
Ribs 1-7 because the cartilage directly connects to the sternal bone
46
Which ribs are known as “false” ribs? Why?
Ribs 8-10
This is because the cartilage on these ribs attaches to the cartilage of the ribs above
47
Which rib connects to the sternal angle?
Rib 2
48
Which ribs are known as “floating” ribs? Why?
Ribs 11 and 12
This because these ribs have no connection to the sternum
49
What is the purpose of rib cartilage?
Flexibility for breathing
Shock absorption
50
From a top down view, what general shape would a lumbar vertebral body possess?
Kidney bean shape
*need to verify*
51
From a top down cut view, what shape do the vertebral body's of thoracic vertebrae have?
Heart shape
52
What is the purpose of the flattened portion of the vertebral body on the thoracic vertebrae?
This provides room for the thoracic Aorta
53
Where do spinal nerves exit out of the vertebral foramen? What is directly above and below this exit site?
Spinal nerves exit out of the interveterbral foramen.
Directly above is the pedicle of the superior vertebrae
Below is the pedicle of the inferior vertebrae
54
What procedure makes access into the spinal column much more difficult?
Spinal fusion surgery.
55
What are two treatments for disc herniation? What is the problem with one of these?
1. Discectomy (less invasive)
2. Spinal Vertebral Fusion (last resort) more tension is placed on discs above and below, precluding them for the same problem later. Fusion usually has to be extended.
56
What is a really good, non-invasive way to treat back pain?
Physical Therapy (duh)
Strengthening of core muscles and hamstrings takes strain off of the vertebrae's job in stabilizing the back.
57
Where are the most common sites of disc herniation?
L3 - Sacrum
58
What two functions does the CSF provide to the spinal cord?
1. Nutrient support (glucose and such)
2. Shock absorption
59
What are the 3 layers of the spinal meninges in order of superficial to deep? Is there any space in between these layers? If so, what inhabits this space?
1. Dura Mater
2. Arachnoid Mater
3. Pia Mater
There is the Arachnoid space in between the arachnoid mater and the pia mater for blood vessels and CSF.
60
Where does the lumbo-sacral enlargement occur?
T11 - L1
61
What is the name of the tip of the spinal cord? Does this differ in newborns and adults?
Conus Medularis
Adults CM terminates at L1
Newborns CM terminates at L2
62
What is the range of the Cauda Equina?
L3 - S5
63
What condition would occur from blocking the arachnoid granulations? What is this?
**Communicating Hydrocephalus**
Communicating hydrocephalus is characterized by CSF that can't exit the CNS but all the ventricles are unblocked.
64
How much CSF circulates at any given time?
150cc
65
How much CSF is produced every day?
450cc
66
Is there a pump for CSF fluid? When is CSF produced most?
No CSF flow is passive.
When asleep or under anesthesia
67
What is the pH range for the CSF?
7.31 - 7.32
68
Are there proteins in the CSF? What does CSF fluid with proteins look like?
Proteins shouldn't be in the CSF
If there are proteins in the CSF, it will be cloudy
69
What is the K+ concentration of the CSF?
- 40% plasma concentration
(Ex. Serum Plasma k+ = 4, then CSF K+ = 2.4)
70
What is the Chloride concentration of the CSF?
15% greater than the plasma
71
What is the glucose level of the CSF? Is insulin used for glucose transport in the brain?
60 mg/dL
No, concentration gradient is required
Neurons need constant supply of O2 and glucose.
72
What is the pCO2 of the CSF?
≈ 47 mmHg
73
What is the bicarbonate level of the CSF?
20
74
What changes in this plasma electrolyte greatly effect the CSF?
Na+
75
What electrolyte is involved in the constant inhibitory effect exhibited by the brain? What neurotransmitter works in tandem with this electrolyte?
Cl-
GABA
76
What is the average adult male brain mass?
1350 grams
77
How much of Cardiac Output is utilized by the Brain? What is the takeaway from this?
12 - 15%
This is a large percentage of CO going to a single small organ.
78
What is the equation for cerebral blood flow?
50cc/ 100g/ min
79
What 4 stimuli cause an increase in blood flow to the brain?
1. ⇡ CO2
2. ⇡ Adenosine
3. ⇣ O2
4. ⇡ H+
80
What is the major driving force for determining cerebral blood flow?
MAP
81
CPP = \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
MAP - ICP
82
What is normal ICP?
5 -10 mmHg
83
Describe what autoregulation means?
The ability of the body to compensate for a Low MAP to a High MAP. Ex:
1. Lower Limit of Autoregulation (LLA) = 60 mmHg
2. Upper Limit of Autoregulation (ULA) = 140 mmHg
84
What is another name for the blood pressure autoregulating system of the brain?
The Myogenic Response
85
What would chronic hypertension due to the brain's autoregulation capability? What other consequences should be considered?
It would shift it to the right so that the Upper Range of Autoregulation was higher (160mmHg rather than 140)
This adjustment makes the brain unable to compensate for hypotension. (Think Valley Stroke)
86
What are the components that utilize the most energy in the brain?
**Electrophysiology = 60%** (think action potentials and signaling)
**Homeostasis = 40%** (cell division, protein replacement, etc.)
87
What CNS energy expenditure component can be limited? By which drugs and by how much (percentage wise)?
* Electrophysiologic Component (signaling)
* Barbiturates, inhaled anesthetics, propofol
* 60% decrease.
88
Which drugs do not affect CNS energy expenditure?
Nitrous Oxide and Ketamine
89
What is the equation for calculating brain O2 demand? How much O2 is used by the brain relative to the rest of the body?
3.5ml O2 / 100g/ min
Around 20% of all O2 usage comes from the brain.
90
How much O2 does the body, as a whole, use every minute?
250 ml
91
Why might one get latent results from a spinal tap done in the lumbar cistern?
The CSF located there is not as “fresh”.
92
What structure does the cerebral aqueduct run through?
The Brainstem
93
Where is the most common site of CSF blockage?
The cerebral aqueduct of sylvius
94
What happens if the cerebral aqueduct becomes blocked? What is this condition known as? What is the treatment?
Ventricles 1,2, & 3 will become enlarged
Non-Communicating Hydrocephalus
Ventriculostomy to drain CSF
95
How is CSF created in very very basic terms? What stops CSF production?
Na+ is pumped out of circulation, followed by Cl-, and then H2O.
Nothing (CSF production doesn't stop unless you're dead)
96
What artery is arguably the worst to get a stroke in? Why?
The MCA (Middle Cerebral Artery)
The MCA feeds both the middle of the brain and the anterior of the brain through the Anterior Cerebral Artery
97
Which communicating arteries are a part of the Circle of Willis? Which are not?
A1 and P1 are parts of the circle of Willis
A2 and P2 are outside of the circle of Willis
98
What is the most common brain bleed for young people? What is the most common artery affected?
Epidural Hematoma's w/ skull bone fracture
Middle Meningeal Artery
99
What usually causes epidural hematoma's? What are the usual symptoms?
Trauma
N/V, Balance issues, weakness
100
Which brain bleed can have a delayed or quick onset? give an example of a delayed onset.
Subdural hematomas
Old person falls → develops symptoms a few days after fall
101
Who is most affected by subdural hematoma's?
Old people and young children (aspect of shaken baby syndrome)
102
Where does bleeding most often occur from subdural hematoma's?
Venous Sinuses or vessels that feed the sinuses
103
What are 5 risk factors for subarachnoid hemorrhage?
* Age
* HTN
* ETOH
* DM
* ↑ cholesterol
104
Which brain bleed usually has a rapid onset? What is the usual cause?
Subarachnoid hemmorhage
Usual causes are aneurysm's that “pop” from trauma
105
What are the treatment's for subarachnoid hemmorhage?
1. Clip
2. Coil
3. Stent
106
What is the most common form of hemorrhagic stroke?
Sub-Arachnoid Hemorrhage
107
What makes veins in the CNS different than other portions of the body?
Veins in the CNS are more durable and rigid due to their characteristic of being extensions of the dura mater.
108
Do large veins in the head have valves? What is the consequence of this?
No, this means that backflow can occur
109
How much smooth muscle do cranial veins possess?
Trick question, no smooth muscle. Only small veins in the pia mater may have some smooth muscle.
110
Where would one measure brain oxygen use?
What would normal parameters be?
What would an abnormal parameter be?
* Internal Jugular Vein
* 70 - 75% SvO2
* 60 % SvO2 or less would be dangerous
111
What portion of the population have a larger right jugular vein?
65%
112
What's the difference between tracts and nerves?
Tracts are collections of axons in the CNS
Nerves are collections of axons in the PNS
113
What 3 things makes C7 unique among cervical vertebrae?
* No Biphid process.
* No Carotid Artery runs through its foramen.
* Longest spinous process (usually palpable).
114
What is another name for the C7 vertebrae?
Vertebra Prominens
115
What are two portions of the Dorsal Column Medial Lemniscus Pathway? What information do the two portions transmit?
Fasciculus Cuneatus - Upper Body Sensation
Fasciculus Grascilis - Lower Body Sensation
116
What sensory information does the DCML pathway transmit? How fast is the signal propogation?
* High Fidelity Sensory
(pinpoint touch, pressure, vibration, think hands)
* Very Fast
117
Where does crossover of the DCML pathway occur?
Crossover occurs at the Lemniscal Decussation of the Medulla Oblongata
*need to verify*
118
Do any of the signals from the DCML interact with the gray matter of the spinal cord?
No
*need to verify*
119
What structure organizes sensory information from the DCML and directs it to the appropriate processing region of the cerebrum?
Ventrobasal Complex of the Thalamus
120
Where does sensory pain information crossover in the CNS?
How does this compare to regular sensory information?
Pain crosses over at spinal cord.
Sensory information crosses over at Medulla/Pons.
121
Describe the path of a general motor signal through the corticalspinal tracts starting with the cortex.
1. Cortex
2. Internal Capsule
3. Ventrobasal Complex of Hypothalamus
4. Medulla Pyramids
5. Medulla Decussation
6. Lateral Corticospinal Pathway
122
How much information is transmitted through the Lateral Corticospinal Pathway?
How does this compare to the Anterior Corticospinal Pathway?
* Lateral Corticospinal = 90% of motor output
* Anterior Corticospinal = 8-9% of motor output
123
What portion of motor information never crosses over at the pyramidal decussation or further down in the spinal cord?
1-2%
124
Where does motor output crossover for the lateral corticospinal tract occur?
Medulla Pyramidal Decussation
125
What are the two main paths of the Pyramidal Tracts? Which is the primary?
* Lateral Corticospinal Tract (Primary)
* Anterior Corticospinal Tract
126
Where does crossover occur for the Anterior Corticospinal Tract?
The level of activity initiation
(Ex. Signal going to calf muscle, crossover occurs at spinal nerve controlling calf)
127
What are the two Spinocerebellar Tracts?
Anterior Spinocerebellar Tract
Posterior Spinocerebellar Tract
128
What information is carried by the spinocerebellar tracts?
Feedback on the Coordination of movement.
129
What structure senses information for the Posterior SpinoCerebellar Tract?
Spindle Fibers in the Skeletal Muscle
130
What is the structure of spindle fibers and how does this relate to the information they transmit?
Where is this information sent primarily?
* Spring-like structure that “senses” contraction/stretch of muscle.
* Information is sent primarily to the Posterior Spinocerebellar tract.
131
Are muscle spindle fibers myelinated or unmyelinated? What does this mean in terms of pathophysiology?
* Spindle fibers are myelinated.
* Spindle fibers can be affected by demyelinating pathologies such as MS or Guillan Barre.
132
What sensors located in tendons send information to the spinocerebellar tract on muscle contraction?
Which spinocerebellar tract is this information primarily sent to?
* Golgi Tendon Stretch Sensors
* Anterior spinocerebellar tract.
133
Where do the Anterior (Ventral) spinocerebellar tracts end?
Superior Cerebellar Peduncle
134
Where do the Posterior (Dorsal) spinocerebellar tracts end?
Inferior Cerebellar Peduncle
135
What are the two divisions of the Spinothalamic (Anterolateral) Tracts?
Lateral Spinothalamic - Fast pain - A-δ
Anterior Spinothalamic - Slow pain - C
136
Where are A-δ fibers found in the spinothalamic tract?
What neurotransmitter(s) is used by this pathway?
How precise is the information delivered by this pathway?
* Lateral Pathway
* Glutamate
* Very precise (detailed pinpoint info)
137
Where are C-fibers found in the spinothalamic tract?
What neurotransmitter(s) is used by this pathway?
How precise is the information delivered by this pathway?
* Anterior Pathway
* Glutamate, Substance P, CGRP
* Imprecise (think stomach pain)
138
What two sensory receptor types run alongside C-fibers?
What is the consequence of this?
Thermoreceptors and Vibration receptors
\*When slow pain is “activated” you can feeling heat, cold, tickles, and itching\* (needs verification)
139
Which two neurotransmitters are slower to release, bind, and breakdown? Which neurotransmitter is faster in all aspects?
CGRP & Substance P = Slow
Glutamate = Fast
140
Which lamina are associated with slow pain?
Which tract is utilized with these lamina?
What is another name for this tract?
Lamina II, III, and V
Anterior Spinothalamic Tract
“Paleospinothalamic Tract”
141
Which lamina are associated with fast pain?
What tract is utilized with this lamina?
What is another name for this tract?
Lamina I
Lateral Spinothalamic Tract
Neospinothalamic Tract
142
Where does fast pain processing occur?
What processing occurs alongside it?
Ventrobasal Complex of Hypothalamus
Sensory Information from DCML
143
Where does slow pain cross over at? What tract carries this information?
Anterior White Commissure
Anterior Spinothalamic Tract
144
Why is there poor localization of slow pain?
Only 15% of the signal progresses to the parietal lobe for higher level of processing.
145
Where are both fast pain and slow pain processed?
Where does most of slow pain signalling terminate?
How does this compare to fast pain signaling?
* Hypothalamus
* Most slow pain signaling terminates in the pons.
* Fast Pain → Ventrobasal complex of hypothalamus → Parietal Lobe
146
What brain structure determines wakefulness and emotion processing?
Where is this structure located?
Reticular Formation
Interior of Brainstem (spans medulla, pons, and midbrain)
147
What would two byproducts of chronic pain processing be? Why?
Feeling shitty and Sleeping shitty.
Wakefullness and Emotions are processes in Reticular formation of brainstem alongside C-fiber pain.
148
Where does fast pain processing crossover?
Are these axons carrying this information myelinated all the way through?
Lamina X
Yes, even through Lamina X
149
What are the 4 extrapyramidal tracts?
What are all 4 of these extrapyramidal tracts characterized by?
1. Vestibulospinal
2. Olivospinal
3. Reticulospinal
4. Rubrospinal
All are CNS efferent outputs to spinal cord.
150
What information is pertinent to the Vestibulospinal Tract?
Eye fixation w/ muscle coordination during acceleration
151
What information is pertinent to the Olivospinal Tract?
Cerebellar output to coordinate movement
152
What information is pertinent to the Reticulospinal Tract?
What would occur with injury to this tract?
Maintenance of Muscle Tone
Crazy Movement (flaccidity or jerkiness)
153
What information is pertinent to the Rubrospinal Tract?
Modulation of Voluntary Movement
154
What does DIC stand for in the context of the CNS?
What does the DIC do?
What activates the DIC?
* Descending Inhibitor Complex
* Pain suppression system from CNS output
* Brain or hormones activate DIC
155
Where are two origins for a DIC signal?
1. Periventricular Nuclei
2. Periaqueductal Gray Matter
156
Where does the DIC synapse at?
Which portion of the DIC specifically?
What is released at this synapse?
* The DIC synapses at the synapse of the 1st nociceptor and the 2nd signaling neuron.
* 3rd Order Enkephalin Neurons.
* Enkephalin
157
How do enkephalins decrease pain?
1. Enkephalins bind to receptors on the pre-synaptic neuron and the post-synaptic neuron
2. ↑ pK+
3. ↑ Action Potential Threshold
158
How would physical damage to a free nerve ending cause an action potential?
1. ↑ K+
2. ↑ H+
3. Physical damage to cell (crushing, burning, etc.) would cause an increase of both of the above, thus causing a Na+ influx.
159
What three factors will indirectly augment a pain response?
1. Histamine
2. Prostaglandins
3. NO
160
How do opiates treat pain?
Opiates bind to receptors on the nociceptor and the synapsing neuron and **↑ pK+ **
161
What other receptor is relevant (besides µ, δ and κ) in decreasing pain on the presynaptic nociceptor?
What drug would be relevant in utilizing this receptor?
* α-2
* Dexmedetomidine
162
What 3 organs lack pain receptors?
Lungs - specifically alveoli and small airways
Brain - \*Glial cells\* (need to verify)
Liver - specifically inside the parenchyma
163
What 5 areas in lecture were described as having a lot of pain receptors?
1. Dura Mater/ Meninges
2. Blood Vessels (i.e. coronary arteries)
3. Joints
4. Bones
5. Periosteum
164
What drug class preceded SSRI's?
What usage do these drugs have now?
* Tricyclic Antidepressants
* Used to treat chronic pain and chronic arousal
165
What are the two glutamate receptors?
What ion(s) are influxxed by these two receptors?
1. AMPA - Na+
2. NMDA - Na+ & Ca++
166
What ion blocks NMDA receptors?
What removes this block?
What influxxes once the block is removed?
1. Mg++
2. AMPA depolarization “ejects” Mg++
3. Na+ & Ca++ influx
167
What occurs after after Ca++ influx from NMDA receptors?
1. ↑ PKC
2. ↑ iNOS
3. ↑ NO
4. ↑ COX-2 → ↑PG
168
How do Prostaglandins affect the pain signaling process?
Prostaglandins produced in the 2nd neuron increase release of glutamate by the 1st nociceptor.
169
What compound in the pain signaling process potentiates pain, causing it to become worse, and also influences chronic pain development?
How does this compound do this?
↑ NO
↑ NO = ↑ NMDA receptors = ↑ pain sensing
170
What two components of the pain cycle increase pain by increasing glutamate release?
Of these two, which increases glutamate sensitivity?
NO and PG's
NO
171
In what two ways do inhalational anesthetics inhibit pain?
1. **Systemic ↑ pK+**
2. Activation of periventricular nuclei and periaqueductal gray matter to **release enkephalins.**
172
How long before the chronic pain potentiation process starts to occur?
1 hour
173
Which two NMDA receptor antagonists were talked about in lecture?
Ketamine
Nitrous Oxide
174
Describe the dissociative nature of ketamine.
Ketamine is dissociative because it is a non-competitive NMDA receptor antagonist. This means it blocks signaling between neurons in the pain signaling system.
175
What toxin is a known NMDA receptor antagonist and is especially unhealthy for children?
Lead
176
Why does lead poisoning affect children more than adults?
Children are still in the process of developing of creating NMDA receptors and forming synapses.
177
Which receptors are strongly associated with memory and learning?
NMDA receptors
178
In which lamina do the 2° neuron of the DIC interface with the 3° neuron of the DIC?
Lamina 1, 2, 3
(dependent on fast pain or slow pain)
179
Where does crossover occur for the DCML?
Lower Medulla
*need to verify*
180
What is the termination point for the posterior spinocerebellar tract?
Inferior Cerebellar Peduncle
181
What is the termination point for the anterior spinocerebellar tract?
Superior Cerebellar Peduncle
182
Which sensors give feedback to the Posterior Spinocerebellar Track?
Muscle Spindle Feedback
183
What sensors give feedback to the Anterior Spinocerebellar Tract?
Golgi Tendon Feedback
184
What type of nerve fiber usually reduces pain in Lateral Inhibition?
A-β
185
Differentiate Parietal and Visceral pain. Which is localizable?
Parietal - pericardium, peritoneum, (essentially fibrous coatings. Parietal is localizable.
Visceral - Deep organ interior. Not localizable.
186
Why is visceral pain usually felt above where the pain is actually occuring?
Pain info is fed into SNS chain and is routed up a couple of levels. So signal is not localized well.
187
Which type of pain works in conjunction with stretch receptors and lines up with dermatomes.
Parietal Pain
188
What 3 examples of referred pain were given in class?
Where is the pain felt for each of these?
* Myocardial Infarction - left shoulder/arm
* Kidney Infection - lower back
* Appendicitis - umbilicus
189
What is the primary characteristic of where referred pain is felt?
Why is this?
Referred pain is felt **above** the site of injury/inflammation.
This is due to the signal traversing the SNS up a couple of interneurons. \*better phrasing needed\*
190
What are the two generalized causes of pain that were discussed in lecture?
Inflammation and Muscle Spasms.
191
What 5 factors lead to pain felt from inflammation?
* ↑ H+
* Ischemia
* Bradykinin release
* Poor Nutrient delivery
* Proteolytic enzyme release (lysosome necrosis)
192
What causes pain in the case of muscle spasms?
Excessive contraction causing acidosis and ischemia.
193
Of Parietal and Visceral tissues/organs which has the larger pain receptor density?
Parietal
194
At which vertebral level would appendicitis be felt for Parietal pain?
At which vertebral level would appendicitis be felt for Visceral pain?
Parietal = L-1 dermatome
Visceral = T-10 dermatome
195
How is an individual's pain threshold determined in a pain study?
What would categorize as a low pain tolerance?
What would categorize as a high pain tolerance?
Thermal probe at 45°C on hand.
High Tolerance ≈ 50° C
Low Tolerance ≈ 40° C
196
What concept is the basis for acupuncture?
Lateral (or Surround) Inhibition
197
What passes through the Tract of Lissauer?
What does NOT pass through the Tract of Lissauer?
All Sensory information
Pain information
198
How is the Tract of Lissaeur best described?
Myelinated Interneurons where multiple levels of the spinal cord are connected.
199
What occurs during a stretch reflex?
In response to a stretch (say the quads):
1. Contraction of Quads occurs to normalize length
2. Antagonistic muscles (hamstrings) are relaxed.
200
What receptor is associated with the stretch reflex?
Muscle Spindle Sensor
201
What reflex keeps us from placing too great of a load on our muscles?
What sensor is used in this reflex?
Tendon Reflex
Golgi Tendon Stretch Sensors
202
Give an example of the Tendon Reflex using the biceps and triceps as an example.
1. A 400lb weight is caught (much too heavy)
2. Biceps relax.
3. Triceps contract (to speed movement away from trigger).
203
What is the primary purpose of the Flexor Reflex?
What should be known about this reflex and the Tract of Lissaeur?
To withdraw from pain.
Pain sensors activated use tract of Lissaeur to activate multiple neurons quickly to contract muscle away from pain. (\*wordy\*)
204
Which reflex involves communication up/down multiple levels of the spinal cord as well as across the cord?
Crossed Extensor Reflex
205
What feeds the radicular arteries of the neck?
How many radicular arteries does the cervical spinal cord have?
Vertebral Arteries
1-3 Radicular Arteries (usually 3)
206
In what surgery is the Great Radicular Artery relevant?
What consequences could occur from blocking of the Great Radicular Artery?
Is it better to have a GRA thats higher or lower?
* Aortic Aneurysm repair.
* Prolonged Ischemia of the GRA = Paralysis
* ↑ GRA = Better
207
How is Spinal Cord Perfusion Pressure Calculated?
CordPP = MAP - Cord CSF Pressure (5-10 cmH20)
208
Which 3 arteries perfuse the cervical Posterior Spinal Arteries?
1. Vertebral Arteries
2. Anterior Inferior Cerebellar Artery
3. Posterior Inferior Cerebellar Artery
209
In Brown-Sequard Syndrome which 3 consequences would you expect to see from transection of half of the spinal cord?
1. Loss of Motor ipsilateral of the injury
2. Loss of Sensation ipsilateral of the injury
3. Loss of Pain contralateral the injury
210
How can horrible pain from terminal cancer be treated?
Cordectomy of the spinothalamic tracts to sever pain sensation.
211
What happens to ICP when the aorta is clamped?
Can this be counteracted?
* It increases by 10cmH20
* A prophylactic spinal tap can be done during aneurysm repair to lower pressure. Controversial.
212
Which spinal tracts are inhibitory to motor function?
What can loss of these tracts cause?
Non-pyramidal tracts
Skeletal Muscle Rigidity (Decorticate & Decerebrate)
213
What is a shingles infection?
What virus causes this?
How is the pain in this infection?
* An infection of the Dorsal Root Ganglia
* Herpes Zoster
* Painful (follows dermatomes)
214
What is Tic Douloureux?
Can this be treated?
* Overactive and painful Cranial Nerve 5 (Trigeminal) and Cranial Nerve 9 (Glossopharyngeal).
* CN 5 can be cut but CN 9 is too hard to access.
215
Which neurotransmitter is **always** inhibitory in the spinal cord?
Glycine
216
Which neurotransmitter is excitatory and utilized in our pain pathways?
Glutamate
217
Which neurotransmitter is the main inhibitory transmitter of the CNS?
What would happen without this neurotransmitter?
GABA
Seizures, rampant electrical activity, etc.
218
GABA receptors always increase cell wall permeability to _______ and to a lesser degree \_\_\_\_\_\_\_.
Cl-
K+
219
What electrolyte might be utilized for pain control?
What are three theories as to how this might work?
* Mg2+
1. NMDA receptor blocking
2. Ca2+ receptor antagonism
3. Blocking Na+ Channels
220
Which drugs potentiate GABA?
EtOH, Benzo's, and Barbiturates
221
What is the difference between Barbiturates and Benzodiazepines in regards to GABA potentiation?
Which is considered more dangerous?
Barbiturates are direct GABA Agonists.
Benzodiazepines potentiate endogenous GABA.
Barbiturates are far more dangerous, especially when used with another CNS depressant.
222
AcetylCholine, in regards to the CNS, typically makes one more \_\_\_\_\_\_\_.
Thus, AChEsterase Inhibitors would do what?
Aware, Awake, etc.
AChE inhibitors would potentiate CNS awareness.
223
Which type of ACh receptors are found in the CNS?
What other receptor are they similar to?
* muscarinicACh Receptors
* Histamine1 Receptors
224
How does benadryl makes you sleepy?
Why do new antihistamines not have a drowsiness effect?
Benadryl crosses the BBB blocks mACh receptors.
New antihistamines are too large to cross the BBB.
225
Regarding the Pyramidal Tracts, where does crossover occur for:
1. Lateral Corticospinal Pathway?
2. Anterior Corticospinal Pathway?
1. Lateral Corticospinal Crossover: Medulla
2. Anterior Corticospinal Crossover: Spinal Cord
226
Regarding the Pyramidal Tracts, where does crossover occur for:
1. Lateral Corticospinal Pathway?
2. Anterior Corticospinal Pathway?
1. Lateral Corticospinal Crossover: Medulla
2. Anteriro Corticospinal Crossover: Spinal Cord
