Central Nervous System Flashcards
1
Q
What is the anatomical planes of the brain?
A
The brain can be viewed in three ways
2
Q
What are the three ways the brain can be viewed?
A
Coronal/Frontal Plane
(Para)sagittal/(para)median Plane
Transverse, horizontal or axial plane
3
Q
How is the nervous system organised on an anatomical level?
A
- Central Nervous System
- Peripheral Nervous System
4
Q
What does the central nervous system contain?
A
Brain and Spinal cord
5
Q
What does the peripheral nervous system?
A
Cranial nerves and Spinal nervers
6
Q
What does the functional level of the nervous system contain?
A
- Somatic Nervous System
- Autonomic Nervous System
7
Q
What does the somatic nervous system control?
A
Control of movement
External environment
8
Q
What doe the automatic nervous system control?
A
Internal environment
Homeostasis
9
Q
What are the subunits of the automatic nervous system?
A
Sympathetic
Parasympathetic
Enteric
10
Q
What are the two types of cells?
A
- Neurons
- Glia
11
Q
What is the structure of a neurone?
A
Dendrites
Soma (Cell body)
Axons
12
Q
What are the synapse involved in neurones?
A
Transmission of information
Involves neurotransmitter
Pre synaptic neurone to post synaptic neurone
13
Q
What is the function neurone?
A
Afferent neuron
Interneurons
Efferent Neurons
14
Q
What is an afferent neurone?
A
Receive information from sensory organs and then transmit to CNS
15
Q
What is the interneurone?
A
Acts as an intermediary in passing signals between two other neurones
16
Q
What is an efferent neurone?
A
Send impulses from the central nervous system to your limbs and organs
17
Q
What is the characteristics of a glia?
A
- Outnumber neurones by 2-10 times
- Haves processes, but no dendrites or axons
18
Q
What is the function of a glia?
A
- Not directly involved in information processing
- Structural matriculates, homeostasis, protection
19
Q
What are the different types of glia?
A
- Microglia
- Macroglia
- Ependyman cells
20
Q
What does the macroglia include?
A
- Astrocytes
- Oligodendrocytes
21
Q
What are different parts of a spinal cord?
A
- Spinal nervers
- Grey matter
- White matter
22
Q
What is the spinal nerve made out of?
A
- Dorsal root
- Ventral root
23
Q
What does the dorsal root contain?
A
- Afferent neurons
- Somas in dorsal root ganglion
24
Q
What does the ventral root contain?
A
- Motor neurons
- Somas within spinal coord
25
What does the grey matter include?
- Dorsal horns
| - Ventral horns
26
What is the dorsal horns?
- Afferent neurones from sensory receptors
| - Origin of ascending pathways to the brain
27
What is the ventral horns?
- Motor neurones
| - Innervate skeletal muscle
28
What does the white matter include?
- Ascending tract
| - Descending tract
29
Where does the information involved in the ascending tract of white matter go?
The brain
30
What does the ascending tract of the white matter include?
- Dorsal columns
- Spinothalamic
- Spinocerebellar
31
What is the dorsal columns?
Fine touch and proprioception
32
What is the spinothalamic?
Pain, coarse touch, temperature and pressure
33
What is the spinocerebellar?
Receptors in joints and muscles
34
What does the descending tract of the white matter include?
Lateral corticospinal tract?
35
What is the lateral corticospinal tract?
Voluntary movement
36
In the spinal nerve is the sensory info (involved with the dorsal root) joined to the motor info (involved with the ventral root)?
No they are separated
37
What is more excitable a neurone or glia?
Neurone
38
When is a microglia cell activated?
When a pathogen is present
39
What is the ependymal cell?
Epthial cells lining the ventricle
40
When are astrocytes (involved with the macroglia cell) activated?
In homeostasis and forms blood brain barrier (selectively allows chemicals into the brain)
41
What are the components of the brainstem?
- Medulla oblongata
- Pons
- Midbrain
42
What is the does the brainstem connect?
The spinal cord to the brain
43
What is the vital function of the brainstem?
Control breathing and level of arousal
44
What does the ascending fibre of the brainstem function?
Sensory
45
What does the descending fibre of the brainstem function?
Motor
46
What is the cerebellum structure?
- Cerebellar cortex
- White matter
- Peduncles
47
What are the components of the peduncles?
- Superior (Midbrain)
- Middle (Pons)
- Inferior (Medulla)
48
What is the function of the cerebellum?
- Movement coordination
- Muscle tone
- Equilibrium
- Posture
49
What are the two components that make up the diencephalon?
- Hypothalamus
| - Thalamus
50
What is the function of the hypothalamus?
- Autonomic (homeostasis)
- Limbic (emotions)
- Neuroendocrine (pituitary gland)
51
What does the hypothalamus contain?
Several nuclei
52
What does the thalamus contain?
Several nuclei
53
What is the thalamus a gateway to?
The cortex
54
What part of the diencephalon get input from most areas of the CNS?
Thalamus
55
What is the function of the thalamus?
- Sensory
- Motor
- Cognitive
56
What does the cerebral hemisphere made out of?
- Grey matter
| - Whute matter
57
What is the largest part of the brain?
Cerebral hemisphere
58
What makes up the grey matter in the cerebral hemisphere?
- Cerebral cortex
| - Basal ganglia
59
What makes up the white matter in the cerebral hemisphere?
- Corpus callous
- Corona radiata
- Internal capsule
60
What is the basal ganglia made up of in the cerebral hemisphere?
- Caudate
- Putamen
- Globus pallidus
61
What does the basal ganglia do?
Control of movement, posture and muscle tone
62
Finish the sentence:
| The cerebral cortex is highly...
convoluted
63
What are the different types of convolutes that make up the cerebral cortex?
- Gyrus
- Sulcus
- Fissure
64
Describe the gyrus in the cerebral cortex:
Ridge of cortex
65
Describe the sulcus. in the cerebral cortex:
Shallow groove
66
Describe the fissure in the cerebral cortex:
Deep sulcus
67
What are the different lops in the cerebral hemisphere?
- Frontal
- Parietal
- Temporal
- Occipital
- Insula
68
What are each lobe divided into?
Different functional areas
69
What are the primary areas of the cerebral hemisphere?
- Motor cortex
- Somatosesonsory cortex
- Auditory cortex
- Visual cortex
70
What does the motor cortex control?
Voluntary movement
71
What does the somatosensory cortex control?
Somatosensation
72
What does the auditory cortex control?
Hearing
73
What does the visual cortex control?
Seeing
74
What are the secondary areas of the cerebral hemisphere?
- Broca's area
| - Wernicke's area
75
What is the Broca's area?
Language expression
76
What is the Wernicke's area?
Language comprehension
77
What are the higher order areas of the cerebral hemispheres?
- Multimodel Integration
- Attention
- Recognition
- Decision making
- Personality
78
What is the function of the frontal lobe?
Judgement, motor planning and personality
79
What is the function of the visual association?
Object recognition
80
What is the function of the posterior parietal?
Spatial awareness
81
What makes up the white matter of the cerebral hemisphere?
Corona radiate and internal capsule
82
What does the corona radiata connect the cerebral cortex with?
- Basal ganglia
- Thalamus
- Spinal cord
83
What is the cranial nerves?
Majority carry sensorimotor information
84
Where can you find the cranial nerves?
Innervate the head and neck
85
What is the cranial nerves made up off?
Twelve pairs with point of attachments
86
How do we identify the twelve pairs of cranial nerves?
- Individual names
| - Roman number
87
Finish the sentence:
| The cranial nerves is a complex system of linked chambers surrounding...
deep brain structures
88
What is the I cranial nerves?
Olfactory nerve
89
What is the II cranial nerve?
Optic nerve
90
What is the III cranial nerve?
Oculomotor nerve
91
What is the IV cranial nerve?
Trochlear nerve
92
What is the V cranial nerve?
Trigeminal nerve
93
What is the VI cranial nerve?
Abducent nerve
94
What is the X cranial nerve?
Vagus nerve
95
What is the XI cranial nerve?
Spinal accessory nerve
96
What is the XII cranial nerve?
Hypoglossal nerve
97
What is the IX cranial nerve?
Glossopharyngeal nerve
98
What is the VIII cranial nerve?
Vestibulacochlear nerve
99
What is the VII cranial nerve?
Facial nerve
100
What is the ventricular system?
A complex system of linked chambers surrounding deep brain structures
101
What is the choroid plexus part of?
The ventricular system
102
What is the choroid plexus?
- Produces the cerebrospinal fluid
| - Invagination of the pia matter
103
What is meant by invagination?
A cavity or pouch formed by being turned inside out or folded back
104
Where is the choroid plexus located?
In the lateral, third and fourth ventricles
105
What does the choroid plexus appear as?
Spongy-like apperance
106
What is continuously secreted and reabsorbed in the ventricular system?
The cerebrospinal fluid
107
What is the function of the cerebrospinal fluid?
Homeostasis and protection
108
What is the circulation pathway of the cerebrospinal fluid?
Lateral ventricle to the third ventricle to the fourth ventricle to the subarachnoid space
109
What reabsorbed the cerebrospinal fluid?
The arachnoid villi
110
What covers the brain and the spinal cord?
Meninges
111
What is meninges function?
Protection
112
How many layers of membranes does meninges have?
Three
113
What are the three layers of membranes of the meninges?
- Dura mater
- Arachnoid mater
- Pia mater
114
Describe the dura mater of meninges:
- Fibrous
| - Loosely attached to the CNS
115
Describe the arachnoid mate:
- Collagenous
| - Blood vessels and CSF
116
Describe the pia mater:
- Very thin
| - Firmly attached to the surface of the CNS
117
What is the Falx cerebri of the meninges?
Sagittal plane between the two cerebral hemispheres
118
What is the tentorium cerebelli?
Horizontal plane between the occipital lobes and cerebellum
119
What is the flax cerebri above?
The corpus callosum
120
What is the tentorium cerebelli continuous with?
Continuous with the falx cerebri
121
What is the dural venous sinuses?
- In the falx cerebri and tentorium cerebelli
| - Venous drainage of the brain
122
What is a synapse?
A specialised junction where a neurone contacts and communicates with another neurone or cell (muscle or gland)
123
What are the types of synapse?
- Electrical
| - Chemical
124
What is an electrical synapse?
Located at specialised membrane sites called gap junctions
125
What is gap junction made out of?
- 2 connexons
| - 6 connexins
126
What is a electrical synapse a direct transfer of?
Ionic currents between cells
127
Which synapse is bidirectional?
Electrical synapse
128
Which is the faster synapse?
Electrical synapse
129
What is a chemical synapse?
Chemical messenger via neurotransmitters
130
Which synapse is unidirectional?
Chemical synapse
131
Which is the slower synapse?
Electrical synapse
132
What is the structure of a chemical synapse?
- Presynaptic terminal
- Synaptic cleft
- Postsynaptic terminal
133
What is the presynaptic terminal?
- Contains synaptic vesicles
| - Active zone
134
What is the synaptic cleft?
- Made of matrix of proteins
| - Adhesion
135
What is the postsynaptic terminal?
- Postsynaptic density
| - Receptors
136
What is a neurotransmitter?
A chemical messenger meeting four criteria
137
What are the four criteria that must be meant to be a neurotransmitter?
- Synthesised in presynaptic neurone
- Exert an action on postsynaptic cell
- Exogenous administration mimics the endogenous effects
- Specific mechanism to remove it from the synaptic cleft
138
What are the three types of neurotransmitters?
- Amino acids
- Amines
- Peptides
139
How are peptide neurotransmitters synthesised?
- Rough ER to Golgi apparatus which activated peptide transmitter
- Producing secretary granules
140
Where are all neurotransmitters stored?
The presynaptic terminal
141
How are the amines and amino acids synthesised?
Precursor molecule synthesis by synthetic enzyme forming a neurotransmitter molecule.
Then transport protein forms a synaptic vesicle around neurotransmitter
142
What is a neurotransmitter released?
- Import of neurotransmitter = presynaptic terminal is polarised causing voltage-gated ions to open
- Movement to active site = synaptic vesicles move
- Docking at plasm zone = vesicles join presynaptic membrane
- Ca^2+ triggers exocytosis = fusing membrane of vesicle and presynaptic membrane
- Neurotransmitters are realised in to synaptic cleft
- Endocytosis via Cathrin-coated vesicles = close membrane and reload with neurotransmitters by fluctuation of H^+
143
How do neurotransmitter effect postsynaptic terminal?
Bind to specific receptors which are transmembrane proteins embedded in postsynaptic density where a conformation change occurs when activated by neurotransmitters
144
What are the two types of receptors at the postsynaptic terminal?
- Ligand-gated ion channels
| - G protein-coupled receptors
145
What is the structure of a ligand-gated ion channel?
- Membrane-spanning proteins
- 4/5 subunits = pore
- Ion selective
146
What happens to a ligand-gated ion channel when activated?
- ligand bind to active site
- Conformational cang
- Pore open
147
What does ligand-gated channels effect?
Excitatory/inhibitory (depending on ion)
| Fast
148
What are the components of s GPCR?
- Receptor (transmembrane protein)
- G-protein (intracellular)
- Effector (ion channel or enzyme)
149
What happens when GPCRs are activated?
Ligand bind to active site
Conformational change of G-protein
Activation of effector
150
What are the effects of GPCRs?
Slower but lasts longer
151
What must happen to a neurotransmitter to allow another run of synaptic neurotransmission?
Removal of neurotransmitter from synaptic cleft
152
What are two examples of amino acid neurotransmitters?
- Glutamate
| - GABA
153
What are the receptors for glutamate?
AMPA, Kainate and NMDA
154
What are the receptors for GABA?
GABAa and GABAb
155
Is the glutamate neurotransmitter must abundant for excitatory or inhibitory?
Excitatory
156
How is glutamate synthesised?
From glutamine by the enzyme glutaminase
157
What is the action of glutamate terminated?
- Reuptake by excitatory amino acid transporters (EAAT)
| - Loaded into synaptic vesicles (antiproton transporters)
158
What are the two ionotropic glutamate receptors?
AMPA
| NMDA
159
Describe the AMPA receptor to glutamate:
- Ligand-gated
- Permeable to Na+ and K+
- Fast excitatory synaptic transmission
160
Describe the NMDA receptor to glutamate:
- Ligand-gated and voltage-gated
- Permeable to Na+, K+ and Ca2+
- Slow excitatory synaptic potential
161
What are the three metabotropic glutamate receptors?
- Group I
- Group II
- Group III
162
What metabotropic glutamate receptor increase synaptic transmission and excitability?
Group I
163
What metabotropic glutamate receptor decreases synaptic transmission and excitability?
Group II and group III
164
What does GABA stand for?
γ-Aminobutyric Acid
165
Is the GABA neurotransmitter the main neurotransmitter for for excitatory or inhibitory?
Inhibitory
166
How is GABA synthesised?
From glutamate by glutamic acid descarboxylase (GAD)
167
How is GABA terminated of action?
- Reuptake by Na+ - dependent transporters
| - Metabolised by the enzyme GABA transaminase in astrocytes
168
Which GABA receptor is ionotropic?
GABAa
169
Which GABA receptor is metabotropic?
GABAb
170
Describe GABAa receptors:
- GABA-gated Cl- channels
- α-β-α-β-γ subunits
- Binding sites between α-β subunits
- Located at postsynaptic
- Mediate fast and tonic inhibition
171
Describe GABAb receptors:
- GPCR
- Inhibit violate-gated Ca2+ channels
- Opens K+ channels
- Inhibit the adenylyl cyclase pathway
- Dimer: two seven transmembrane subunits
172
What are the two dimes of GABAb?
- B1: binding site for GABA
| - B2: interacts with the G protein
173
Give 3 examples of amine neurotransmitters:
- Acetylcholine
- Serotonin
- Catecholamines
174
What are the three catecholamines?
- Dopamine
- Norepinephrine
- Epinephrine
175
What is the receptor for acetylcholine?
Muscarinic and Nicotinic
176
What is the receptor for serotonin?
5TH 1-7
177
What is the receptor for dopamine?
D1 and D2
178
What are the receptors for norepinephrine?
α & β
179
What are the receptors for epinephrine?
α & β
180
How is acetylcholine synthesised?
By chlorine acetyltransferase (ChAT) from choline and acetyl CoA
181
How is acetylcholine degraded?
By acetylcholinesterase (AChe) in the synaptic cleft to choline and acetic acid
182
How is choline taken up in the presynaptic cell?
By choline co-transporters with Na+
183
Which acetylcholine receptor is ionotropic?
Nicotinic
184
What acetylcholine receptor is metabotropic?
Muscarinic
185
Describe nicotinic receptors:
Ligand-gated ionotropic receptors
Permeable to Na+, K+ and Ca2+
Excitatory effect
186
Describe muscarinic receptors:
GPCRS
Five types: M1-M5
Nervous system: M1, M4 and M5
187
What does M1 and M5 couple to?
Gq
188
Is the coupling of M1/M5 to Gq excitatory or inhibitory?
Excitatory
189
What does M4 couple to?
Gi
190
Is the coupling of M4 to Gi excitatory or inhibitory?
Inhibitory
191
What does acetylcholine act on?
- Basal forebrain
| - Brainstem
192
What is acetylcholine involved in?
- Attention
- Arousal
- Reward
- Learning and memory
193
What is the actual name of serotonin?
5-hydroxytryptamine (5-HT)
194
How is serotonin synthesised?
From amino acid tryptophan by a sequence of enzymatic reactions
195
What enzyme synthesised 5 HTP from tryptophan?
Tryptophan hydroxylase
196
What enzyme synthesised serotonin from 5 HTP?
5 HTP decarboxylase
197
How is serotonin terminated?
- Reuptake from synaptic led by membrane transporters
| - Reloaded in to synaptic vesicle or degraded by MAO
198
What type of receptor is 5TH3?
Ionotropic - ligand gated Ca2+ channel
199
What type of receptors are 5TH 1-7 excluding 5TH 3?
Metabotropic
200
Is the receptor 5-TH cause an inhibitory or excitatory effect on presynaptic/postsynaptic neurones?
Both
201
Where are serotonergic neurons located?
Raphe Nucleus of the brainstem
202
Where does serotonin effect?
Cortex
Hypothalamus
Spinal cord
203
What is serotonin included in?
- Sleep/wake cycles
- Mood/emotion
- Feeding behaviour
- Thermoregulation
- Pain
204
Where are catecholamines neurotransmitters derived from?
Amino acid tryosine
205
How are catecholamines terminated?
- Reuptake from synaptic cleft by membrane transporters
| - Reloaded into synaptic vesicles or degraded by MAO
206
What is catecholamines involved in?
- Motor control
- Mood
- Attention
- Arousal
207
How do the D1 family receptors of dopamine act?
Gs (excitatory)
| Activate ionic channels (Na+, K+ and Ca2+)
208
What are the receptors in the D1 family?
D1, D5
209
How do the D2 family receptors of dopamine act?
Gi (Inhibitory)
Activate K+ channels
Inhibit Ca+2 channels
210
What are are the receptors in the D2 family?
D2, D3 and D4
211
What are the functions of dopamine?
- Motor (nigrostriatal pathway)
- Behaviour: mesocortical and mesolimbicpathway
- Endocrine: tuberohpophyseal pathway
212
What are the other names for norepinephrine and epinephrine?
Noradrenaline and adrenaline
213
How are the action of norepinephrine and epinephrine mediated?
By GPCRs = α1, α2, β1 and β2
214
How are norepinephrine and epinephrine synthesised?
By neurons of brainstem
215
What are norepinephrine and epinephrine important in?
- Control of wakefulness and alertness
- Control of mood
- Stress reaction
216
Give 2 examples of peptide neurotransmitter:
- Insulin
| - Somatostatins
217
What do peptide neurotransmitter activity depend on?
Amino acid sequence and length
218
How are peptide neurotransmitters synthesised?
Pre-propeptide to propeptide to peptide by proteases
219
How are peptide neurotransmitters degraded?
By peptidase into inactive amino acids
220
What can peptide neurotransmitters be released with?
Smaller neurotransmitter
221
What are the differences between peptide and smaller neurotransmitter?
- Synthesised in the cell body
- Stored in dense-core vesicles (Golgi)
- Exocytosis not limited to active zone and requires non-localised increase of Ca2+ concentration
222
What are the actions of peptide neurotransmitters?
- Sensory perception
- Emotion
- Pain
- Stress
- Reproduction
- Reward
- Analgesia
- Food intake
223
What type of receptors are involved in with peptide neurotransmitter?
GPCRs
224
What are the characteristics of a neuromodulator?
- Mediators
- Produced by neuronal or non-neuronal cells
- Cannot be stored
- Released as convectional neurotransmitter
- Regulate the release of the neurotransmitter release/post
- GPCRs
- Slower response
225
What are the different types of neuromodulator ?
- Conventional neurotransmitters acting on autoreceptors
- Lipid mediators
- Gaseous mediators
226
Where can you find auto receptors?
Presynaptic membrane
227
What are auto receptors sensitive to?
Own neurotransmitters
228
What type of receptors are auto receptors?
Mainly GPCRs
229
What type of mechanism are auto receptors?
Self-regulating
230
What is the endocannabiniod system relating to neuromodulators?
Feedback system to regulate conventional synaptic transmission
231
Where is the endocannabinoid system synthesised?
By post synaptic cell when every active
232
What does endocannabinoid system do?
Reduces the opening of presynaptic calcium channels inhibiting neurotransmitter release
233
What are the two main GPCRs of the endocannabinoid system?
CB1
| CB2
234
What are the two main ligands of the endocannabinoid system?
- Anandamide (AEA)
| - 2-Arachydonil glycerol (2-AG)
235
What type of neuromodulator is the endocannabinoid system?
Lipid mediator
