Neuro 3: spinal cord and brain Flashcards
(186 cards)
1
Q
The spinal cord is the center of what
A
spinal reflexes
2
Q
what does spinal cord transmit
A
nerve impulses btw PNS & CNS
3
Q
What does the reflex arc consist of
A
- stimulus (input)
- integration/ modulation (interneuron)
- Response (effector motor output neuron)
4
Q
Where is foramen magnum
A
cranium
5
Q
Where is conus medullaris
A
end of spinal cord between L1and L2
6
Q
What length does spinal cord travel
A
from foramen magnum (cranium) to the conus medullaris
-~0.5 - 1 m in length
7
Q
What anchors spinal cord in place
A
Denticulate ligament
8
Q
What is the Filum Terminale of spinal cord
A
-a fibrous extension that originates frm the PIA mater of the conus medullaris & attaches to the posterior facet of the coccyx
9
Q
What is the Cauda Equina (Horses tail)
A
End of the spinal cord
10
Q
Where is a spinal tap done in spine
A
btw L4-L5
-low risk of damaging spinal cord
11
Q
Why is spinal tap done
A
assess for certain diseases like meningitis
12
Q
Where is the Epidural space
A
btw vertebrae & spinal Dural sheath
-filled with fat that absorbs shock & isolates the spinal cord
13
Q
How many nerves emerge from the spinal cord and from where
A
31 pairs of spinal nerves
- Cervical (8)
- Thoracic (12)
- Lumbar (5)
- Sacral (5)
- Coccygeal (1)
14
Q
What are the 2 enlargements in the spinal cord where the upper and lower appendages are represented
A
- cervical enlargement
- Lumbar enlargement
15
Q
What separates the spinal cord into left & right
A
- Posterior (dorsal) median sulcus
- Anterior (ventral) median fissure
- anterior sulcus is wider
16
Q
What is White Matter
A
-called a funiculus (columns)
-named after its position:
2 posterior (dorsal)
2 lateral
2 anterior (ventral) columns
17
Q
What is Gray Matter
A
- called horns
- shaped like butterfly or H
- gray commissure (location where 2 objects join) ensures communication btw the 2 sides: 2 dorsal, 2 lateral horns, 2 ventral
18
Q
What type of neurons are in Dorsal Horn
A
all interneurons
19
Q
what type of neurons are in Lateral horn
A
motor neurons of sympathetic nervous system, serving viscera
-ventral horn: mainly somatic motor neurons, some interneurons
20
Q
Where are the Ascending pathways
A
external / on the periphery of spinal cord
-sensory, afferent
21
Q
where is the Descending pathways
A
internal in spinal cord
-motor, efferent
22
Q
What is the medulla
A
it is a waystation for ascending and descending tract systems and is highly myelinated
23
Q
What do some groups scattered throughout the medulla do
A
play roles in sensory system
24
Q
What does the autonomic reflex center of the medulla do
A
- maintains homeostasis
- houses the cardiovascular center, respiratory center
25
What happens when you get a lesion on the medulla
= "locked in syndrome"
- all muscles are paralyzed except eye muscles
- consciousness is intact
26
What are 6 features of the medulla
- solitary nucleus
- pyramids
- medial leminiscus
- internal arcuate fibers
- nucleus gracillis and cuneatus
- inferior olive
27
What is the other name of the medulla
myelencephalon
28
What is the solitary nucleus of medulla
- the nucleus is embedded in the solitary tract
| - involved in gustation
29
What are pyramids of medulla
-voluntary motor movement
30
what are internal arcuate fibers of medulla
-fibers of decussation
31
what is nucleus gracillis and cuneatus
-nuclei of proprioception (kinesthesia; body ability to sense movement, action, location) of lower and upper appendages
32
What is inferior olive of medulla
-motor coordination
33
What is the medial leminiscus of medulla
tract carrying proprioceptive ( sense of self-movement and body position) information
34
Why is it that damage to tract (or brain) above the medulla will affect the opposite side of the body
because medulla is point of decussation (crossing over of information) for the pyramids and the medial leminiscus
35
What is the Pons
- structure that bridges inputs and outputs with the cerebrum and cerebellum
- translates as "bridge"
36
What is another name for the Pons
metencephalon
37
what are 3 features of the Pons
1. superior Olive
2. Cranial nerve nuclei
3. Pontine Reticular formation
38
What is the superior Olive of the Pons
auditory processing pathway
39
What is cranial nerve nuclei of the pons
```
abducens
auditory
facial
trigeminal
vestibular
```
40
what is pontine reticular formation
sleep and wakefulness / arousal
41
What is structure of cerebellum
- translates as "the little brain"
- has 3 lobes
- right and left hemispheres separated by structure called vermis
42
What are the 3 lobes of the cerebellum
1. anterior lobe
2. posterior lobe
3. flocculonodular lobe
43
what does the anterior lobe of the cerebellum do
coordinates movement
44
what does the posterior lobe of the cerebellum do
coordinates movement
45
what does the flocculonodular lobe do
- communicates w/ the internal ear
| - equilibrium organs
46
what are the 4 functions of the cerebellum
- fine motor movement
- procedural memory
- balance
- aspects of speech and language
47
What are the 3 layers of cerebellar cortex in order from outside to inside
1. Molecular
2. Purkinje layer
3. Granule layer
48
what does molecular layer of the cerebellum contain
parrallel fibers and stellate
49
What does the purkinje layer of cerebellum contain
-large purkinje cells
50
What does the granule layer of the cerebellum contain
-small granule cells and fibers
51
How many tract systems bring input and output to the cerebellum
3 tract systems
52
what are the 3 tract systems into/out of the cerebellum
- inferior cerebellar peduncle
- middle cerebellar peduncle
- superior cerebellar peduncle
53
what info does the inferior cerebellar peduncle handle
input from medullar and spinal cord
54
what info does the middle cerebellar peduncle handle
input from the pons
55
what info does the superior cerebellar peduncle handle
- output of cerebellum to the thalamus
56
What is the midbrain
a multi-modal hub of interaction
| - vision, hearing, and movement converge here
57
what is another name for the midbrain
mesencephalon
58
How many sections can the midbrain be separated into at its greatest size
3 sections
- Tectum
- Tegmentum
- Crus
59
What is Tectum section of midbrain
- upper portion
| - visual and hearing reflex sensations
60
what is tegmentum section of midbrain
- middle portion
| - reward system
61
what is Crus section of midbrain
- lower portion
| - white matter conduction
62
What are 6 features of midbrain
- Corpora Quadigemina "the 4 bodies" on the superior surface
- Red nucleus
- Nuclei involved on the light reflexes
- substantia nigra " black substance"
- ventral tegmental area
- Raphe nuclei
63
What is the corpora quadrigemina "the 4 bodies" on the superior surface of the midbrain
```
2 superior colliculi
-visual light reflex
-saccadic eye movements
2 inferior colliculi
-auditory relay
```
64
what is red nucleus of midbrain
- motor coordination
| - lesion produces Holmes tremor
65
what is nuclei involved on the light reflexes of midbrain
- oculomotor nucleus
- nucleus of the posterior commissure (consensual light reflex = both pupils constricting at the same time)
- edinger-westphal nucleus (pupil constriction)
66
What is substantia nigra "black substance"
broken down into multiple parts:
- Compacta: DOPAMINE and is involved in reward
- Reticulata: Inhibition of dopamine & suppression of motor movements
- depletion of the compacta is seen in Parkinson's disease
67
What is ventral tegmental area of midbrain
- dopamine secretions
| - involved in addiction
68
What is Raphe nuclei of midbrain
-serotonin creating nucleus
69
What are the 3 structures that make up thalamus / diencephalon
1. Thalamus (master integrator)
2. Hypothalamus (hormone regulation, emotion)
3. Epithalamus (Pineal) (circadian rhythm = biological clock)
70
The thalamus is the largest portion of what
the diencephalon ~ 80%
71
What are the functions (7) of the 12 nuclear groups of the thalamus
- sense of timing
- learning
- motor skills
- sensory integration
- memory
- cortical arousal
- personality
72
Hypothalamus is made up of many nuclei what are 4 of them
1. VMH (ventromedial hypothalamus)
2. Mammillary bodies
3. Infundibulum
4. center for regulation of physical functions playing a role in homeostasis
73
What is function of VMH
eating
74
what is function of mammillary bodies
relay for the emotional circuit
75
what is function of infundibulum
stalk connecting the hypothalamus to pituitary
76
what does center for regulation of physiological functions regulate
- homeostasis
- water balance
- emotional reactions
- sleep-wake cycle
- body temp
- endocrine functions
- food intake
77
What are the 2 components of the epithalamus
- pineal gland
| - habenula
78
What is the role of the pineal gland
- role in sleep-wake cycle
| - creation of melatonin (neurotransmitter)
79
What is the role of Habenula
- pain, learning, sleep
| - involved in depression
80
What is the basal ganglia
a collection of nuclei that serve 2 main functions
81
what are 2 main functions of the basal ganglia
1. movement
| 2. reward/ addiction (most cells are dopaminergic)
82
What are the 3 primary structures involved with motor movement of basal ganglia
1. Caudate (movement linked to parkinsons. lesion = chorea like movement)
2. Putamen
3. Globus Pallidus (movements of laughter)
83
What is the nucleus in basal ganglia that is involved with addiction
nucleus accumbens
84
What is the nucleus of Meynert in the basal ganglia
- located in basal forebrain
| - contains brain's acetylcholine (severely depleted in alzheimers and other dementias - fronto-temporal)
85
What is the purpose of white matter tracts within the cerebrum / cerebral cortex
connect different areas
86
What are the 3 types of white matter association
1. commissural
2. Association
3. Projection
87
What does the commissural type of white matter connect
connects regions btw the left and right hemispheres
88
What does the Association type of white matter do
transmits info inside the same cerebral hemisphere
89
What does the projection type of white matter do
links the cortex to the rest of the nervous system and also to the receptors and effectors
90
Where are there several large projection and commissural tracts
the cerebral cortex
91
What is the Corpus Callosum
# translate to large body
- largest commissural fibers connecting the L and R hemisphere
- Sexually dimorphic (larger posterior portion in females)
92
What is the anterior commissure
connects the anterior 2/3 of the temporal lobes
93
What are the 3 capsules in brain which conduct info up/down and front/back of the brain called
- internal capsule
- external capsule
- extreme capsules
94
What is the cerebral cortex
the outer most layer of the brain
-made up of 4 lobes
and gyri and sulci
95
how many gyri and sulci can be seen on an individual brain
~176
- highly variable
- 3 consistent landmarks
96
what are the 3 consistent landmarks of the gyri and sulci
- superior (medial) longitudinal fissure
- the lateral (Sylvian) sulcus
- central sulcus (of Rolando)
97
What are Gyri
elevations or ridges within and along the brain
98
What are Sulci
Valleys or depression within and along the brain
99
How many layers does the cerebral cortex have
6 layers
| -thickness ranges from 2 to 5 mm
100
What are 6 functions of cerebral cortex
1. consciousness
2. Sensory processing
3. Motor processing
4. Emotion
5. Memory
6. Language
101
What are the 3 functional break downs of the cerebral cortex
1. primary or receptive cortex
2. secondary
3. tertiary
102
What is the function of the primary or receptive cortex
- directly receive thalamic input
| - damage to these areas produce loss of sensory modality(i.e. blindness, deafness...)
103
what does damage to the secondary cortex result in
agnosia
| -person detects the stimuli but does not recognize it or the meaning
104
What is function of tertiary cortex
-multimodal and involve the most sophisticated of human potentials (i.e. reasoning, thought, etc..)
105
What are the 3 large sulci that serve as landmarks for the division of the brain
- sylvian sulcus (lateral sulcus)
- Central sulcus (fissure of Rolando)
- superior longitudinal fissure (medial longitudinal fissure)
106
What does the Sylvian Sulcus divide
the temporal lobe from the frontal lobe
107
what does the central sulcus separate
frontal lobe from the parietal lobe
108
what does superior longitudinal fissure divide
the brain into left and right hemisphere
109
Which hemisphere has more gray matter
Left
110
which hemisphere has more white matter
Right
111
What are the functions of the Left hemisphere (7)
- language
- memory encoding
- sense of self
- logic
- analytical
- serial processing
- active thought
112
What are the functions of the right hemisphere (9)
- some language
- autobiographical memory
- mathematics
- spatial processing
- creativity
- dreaming
- pattern recognition
- emotion
- parallel processing
113
What are the 4 superficial lobes of the cerebral cortex
1. frontal
2. parietal
3. Occipital
4. temporal
114
What are the 2 internal / buried lobes
1. insula
| 2. limbic lobe
115
what is the limbic system
a collection of sub-cortical structures
116
what are the 3 structures of the limbic system
1. Hippocampus
2. Amygdala
3. Cingulate
117
What is the function of the limbic system
- emotion
- memory
- bonding
- default-mode
118
What is the Hippocampus
- known as the "Gateway to memory"
| - H.M. removed it and could not form new memories
119
What is structure of hippocampus
- divided into 3 sectors called the CA fields (CA1, CA2, CA3 and Cornu ammonis)
- formed continuously w/ a gyrus called the dentate gyrus
- very low resistance / electrically labile (common are for seizures)
120
What is the Cingulate
- area of the bonding
- highly influenced by oxytocin
- involved in orgassm
121
What is Amygdala
- named as such bcs of its appearance (amygdala = almond)
- sits directly in front of the hippocampus
- emotional quality to memories
- involved w/ fear and aggression
122
What is the Insula
```
Buried beneath the cortex
Named the Island cortex
Perception of taste
Responsible for visceral sensations
Region of disgust
Internal representation of the self
```
123
Where is occipital lobe located
most posterior aspect of the brain and most of it is hidden in the
calcarine fissure
124
What are the 2 stream of white matter that visual information passes through in occipital lobe
- the dorsl stream (parietal/ where)
| - the ventral stream (temporal / what)
125
What are 2 features of the occipital lobe
- Primary visual cortex (area 17)
| - Secondary association cortex (Area 18)
126
What is primary visual cortex (area 17)
AKA the striate cortex involves awareness of what is being seen
-lesion = blindness
127
what is secondary association cortex (area 18)
- involved w/ recognition of movement and colour
| - lesion = visual agnosia ( one can see the object but cannot recognize it)
128
Where is the parietal lobe located
extends posteriorly from the central sulcus until it reaches the occipital lobe
129
What are the primary areas of the parietal lobe
somatosensory integration and recognition(ability to associate touch and sensation together)
130
what are the secondary areas of the parietal lobe
integration of visual-tactile-auditory input (put the 3 together to get full picture)
131
What is the tertiary areas of the parietal lobe
language function
132
What are the features of the primary cortex of the parietal lobe
Area 1,2,3:
- primary projection area for touch, proprioception (recognize position of body) and pain
- Lesion here = loss ability to recognize body position, estimate weights, tell diff in temp
133
How is input from body represented in the parietal lobe
as a homunculus
134
What is a homunculus
translates to "little man" in lating
- is a representation of the human body enlarging/ highlighting the areas with the most sensory nerves
- face, hands, testicles, uterus, legs
135
What is in the secondary association cortex of the parietal lobe
- area 5,7: (recognize and understand body image)
| - area 19: (movement of eyes to visual stimuli)
136
What is in the tertiary cortex of the parietal lobe
- area 39 (angular gyrus): involved w/complex language function
- area 40 (supramarginal gyrus): intimately involved w/ language and symbolic processing capacity
137
What are the2 most electrically unstable portions of the brain that are contained in the temporal lobe
- hippocampus
| - amygdala
138
What is temporal lobes main association
sense of self
139
what are the primary areas of the temporal lobe:
auditory, vestibular processing
140
What are the secondary areas of the temporal lobe
auditory, visuospatial recognition
141
What is tertiary areas of the temporal lobe
language processing
- L side = interpretation of words
- R side = interpretation of tone
142
What are some features of the temporal lobe
- experience of hearing (area 41,42 Heschl's gyrus)
- auditory receptive area (area 22)
- recognition and meaning of what is said (area 22)
- vestibular (bowels) experience (area 52)
- stimulation: dizziness, sense of spinning around, hallucinations (area 52 associates with intoxication)
143
What is the structure of the frontal lobe
- extends from the central sulcus anteriorly (front/ think forehead)
- largest portion of the brain
- divided functionally into motor region and prefrontal cortices (the largest cortical region is on the surface)
144
When is there a relative increase in metabolic activity within the prefrontal region
under normal conditions of thinking
145
When is there no increase in metabolic activity while thinking in the prefrontal cortex
Pt's diagnosed with schizophrenia
146
When is there hypofrontal metabolic activity in the prefrontal cortex
in Alzheimer's disorder it is a chronic issue
147
What are the Motor features of the frontal lobe (4)
- Primary motor strip
- Premotor and supplementary motor region
- Frontal eye fields
- Broca's area
148
What is the primary motor strip (area 4) of frontal lobe responsible for
- major output to spinal cord
| - output arranged in a homunculus, parrallel to somatosensory pattern in the parietal lobe
149
What is the premotor and supplementary motor region (area 6) of frontal lobe responsible for
-organization and initiation of motor sequences
150
What is the frontal eye fields (area 8) of frontal lobe responsible for
-voluntary control of eye movements
151
What is the Broca's area (area 44,45) of frontal lobe responsible for
- involved w/ translation of image of the words into their motoric equivalents that allow vocalization
- left hemisphere: syntax (structure of sentences)
- right hemisphere: tone
152
What are the functions of the orbitofrontal region of frontal lobe
- integration of planning w/ emotional behaviour
- lesion: evokes restless, impulsive, antisocial, loss of self concern, decresed normal self-awareness
- over-stimulation: OCD
153
What are the functions of the prefrontal regions (3) (frontal lobe)
Allows planning, organization and self-monitoring of one’s behaviour
Controls attention, concentration, and ability to change set quickly
Modulates inhibition of irrelevant or inappropriate behaviours
Lesions: apathy, akinesia, mutism, disturbances in sphincter control (urinary and bowel)
154
What are the functions of the dorsolateral region of frontal lobe (areas 9-12)
-involved w/ symbolic reasoning, synthetic reasoning, thinking in a traditional sense
155
What info is carried on the ascending tract
sensory information carried up to the brain
156
What info is carried on the descending tract
motor info carried to the muscles
157
What are the 6 areas in order of the corticospinal descending pathway
1. premotor cortex and motor cortex
2. internal capsule
3. Crud cerebri (midbrain)
4. pons
5. Medulla
6. posterior lateral white column (spinal cord)
158
What happens to corticospinal descending pathway as it goes through the medulla
- it decussates (cross to form an X/ cross over) 90%
| - other 10 % stays on same side and = anterior corticospinal tract
159
What is the function of the corticospinal tract
-sends info re: skilled, voluntary motor movement from motor/ premotor cortex to the spinal cord
160
What happens if you get a lesion on the corticospinal tract
Voluntary movement compromised at the levels of the lesion and below. If the damage occurs within the spinal cord, impairments are ipsilateral. If the occur above the pyramidal decussation, all effects are contralateral.
161
What is the route of the ascending pathway / spinothalamic (5)
1. substantia gelatinosa (decussation)
2. spinathalamic tract
3. internal capsule
4. VPL (vetropostereolateral) thalamus
5. somesthetic cortex (areas 3,1,2, parietal lobe)
162
What are functions of spinothalamic tract
1. Anterior: light touch, contact info
2. Lateral: info regarding pain and temp
(a lesion to this tract would impair the above)
163
Does spinothalamic or corticospinal tract carry infor re: tactile or proprioceptive input
no neither do
164
The medial lemniscus carries sensory info via ascending pathway from what areas of the body
1. arms
- fasciculus cuneatus
- nucleus cuneatus
2. legs
- fasciculus gracilis
- nucleus gracilis
165
Where does the medial lemniscal system decussate
at caudal medulla
166
What is the path of the medial lemniscal system after it decussates
- medial lemniscus
- internal capsule
- VPL (ventroposterolateral) thalamic nucleus
- somesthetic cortex
167
What is function of the medial lemniscal system
delivers tactile and proprioceptive input to the brain
168
What is the neurotransmitter systems
systems in brain that have diff receptors (receivers) and activators (neurotransmitters or drugs that activate receptors)
169
What is the lock and key mechanism of neurotransmitters
it means there is a specific activator for a specific receptor
-same as hormones
170
What is receptor sensitization
- receptors can be occluded (or burried in memebrane), which reduces # expressed = decresing cells sensitivity for compounds that activate that receptor
- increased expression = increased sensitivity
171
What is tolerance in neurotransmitters
- repeated exposure = down regulation in receptors / desensitization
- more of the compound now needed to repeat effect
172
What is agonist in neurotransmitters
- drugs that can activate specific receptors
173
what is antagonists in neurotransmitters
-drugs that block the activation of specific receptors
174
What are cholinergic drugs
acetyl choline
- critical for communication btw neurons & muscle cells
- involved in attention
- nicotine acts on specific cholinergic receptors
175
What are serotoninergic drugs
serotonin (5-HT)
- involved in mood stability, aggression, sleep, gastrointestinal funct.
- certain receptor subtypes (5-HT2A/C) activated by LSD
176
When is serotonin found to be disfunctioning
```
psychiatric disorders (depression, anxiety, schizophrenia, OCD)
-decreased circulation of serotonin in brain often = depression
```
177
What are opioid drugs
- involved in pain and euphoria
| - receptors in pain sensing limbic (emotion) areas
178
What are the endogenous agonists of opioids
enkephalin and endorphin peptides
179
what are the exogenous agonists of opioids
morphine, heroin, codein
180
What are adrenergic drugs
Adrenalin/Epinephrine = fight or flight response
Noradrenalin/norepinephrine = focused attention, sleep
-Involved in depression, anxiety and ADHD
181
What are Dopaminergic drugs
Dopamine
-Reward/addiction and involuntary motor movements
(Gamblers addicted to the behaviour bcs provides a release in dopamine;
They likely have lower than norm levels of dopamine to start)
-Involved in Parkinson’s and Schizophrenia
182
What are GABAergic drugs (gamma amino butyric acid)
-Inhibitory
-GABAa receptor subtype operates on Cl- channel:
When activated, increases influx of Cl-, hyperpolarizing the membrane, making it more difficult for there to be an action potential
-Target of barbituates (anesthetic and anti-convulsant), benzodiazepines (anti-anxiety)
183
What is the neurological disease STROKE
- hemorrhaging
- cells in area will loose blood supply and die
- symptoms depend on where in CNS occurs
184
What is neurological disease traumatic brain injury (TBI)
- Could result in tissue damage, swelling or internal bleeding
- Common symptoms: dizziness, headaches, loos of consciousness (at the time of)
- New research has shown that remaining active is important to recovery
185
What is neurological disease Parkinson's disease
- Cell death occurs in the substantia nigra in the midbrain
- Decreased dopamine to basal ganglia
- Most common symptoms are motor problems (tremors)
186
What is neurological disease schizophrenia
- Very complex
- Individuals have psychotic episodes (Lose touch with reality)
- Brains are structured differently
- Common treatments are anti-dopaminergic drugs
