Neurons Flashcards
1
Q
Gyrus
A
The ridge
2
Q
Dorsal horn
A
in posterior side of spinal cord, receives input from afferent (sensory nerves)
3
Q
Sucus
A
The wrinkle
4
Q
Ventral horn
A
in anterior side of spinal cord, receives input from efferent (motor nerves)
5
Q
Grey matter
A
contains neuronal cell bodies
6
Q
White matter
A
contains myelinated axons
7
Q
Is autonomic nervous system automatic or voluntary functions
A
automatic
8
Q
Sympathetic nervous system
A
fight or flight
9
Q
fight or flight
A
sympathetic nervous system
10
Q
parasympathetic nervous system
A
rest and digest
11
Q
rest and digest
A
parasympathetic nervous system
12
Q
role of astrocytes
A
maintain external environment, form BBB
13
Q
role of ependymal cells
A
make CSF
14
Q
role of microglia
A
macrophages of CNS
15
Q
role of oligodendrites
A
form myelin in CNS
16
Q
role of schwann cells
A
form myelin in PNS
17
Q
role of satellite cells
A
support cell bodies in PNS
18
Q
what are graded potentials
A
decide when an action potential should be fired
19
Q
Why is there a resting membrane potential
A
keeps cells ready to fire
20
Q
role of dendrites
A
recieve info
21
Q
role the axon hillock
A
triggers action potential
22
Q
another name of the axon hillock
A
Initial segment
23
Q
How many cervical nerves are there
A
8
24
Q
What do the cervical nerves innervate
A
Neck, shoulders and arms
25
How many thoracic nerves are there
12
26
What does the thoracic nerves innervate
Chest and abdomen
27
How many lumbar nerves are there
5
28
What do the lumbar nerves innervate
Hips and legs
29
How many sacral nerves are there
5
30
What does the sacral nerves innervate
Genitalia and GI tract
31
What is the pathway for sensory info to get to spinal cord
Afferent (sensory) nerves → dorsal root ganglion → interneurons
32
What is the pathway for motor info to get from spinal cord to muscle
Interneurons → ventral root ganglion → efferent nerve
33
What are the 4 neuron morphologies
1. Bipolar
2. Pseudounipolar
3. Multipolar
4. Anaxonic
34
What morphologies do afferent neurons have
Bipolar + pseudounipolar
35
What morphologies to interneurons have
multipolar + anaxonic
36
What morphologies do motor neurons have
Multipolar
37
What is hyperpolarisation?
When the membrane becomes more negative, brings voltage further away from firing threshold
38
What is depolarisation
When the membranes becomes more positive bringing it close or to the threshold firing voltage
39
What is a nerve
A bundle of neuron axons
40
What are the 4 types of graded potentials
1. generator potentials
2. postsynaptic potentials
3. end plate potentials
4. pacemaker potentials
41
Where are generator graded potentials
In sensory receptors
42
Where are end plate graded potentials
The neuromuscular junction
43
Where are pacemaker graded potentials
Pacemaker tissues
44
What are the 4 characteristics of graded potentials
1. graded (duh)
2. decremental
3. hyper or depolarising
4. summative
45
What does a decremental graded potential mean
charge decreases as it is going through the membrane
46
Why are graded potentials also called local potentials
Because due to decremental charcteristic they can only travel short distances
47
What are the 2 types of hyperpolarising potentials
Fast and slow IPSPs
48
What are the 2 types of depolarising potentials
Fast and slow EPSPs
49
What ions are involved in fast IPSPs
Fast Cars go in, Slow biKes go out
Cl- ions moving into the cell
50
What ions are involved in slow IPSPs
Fast Cars go in, Slow biKes go out
K+ moving out of the cell
51
What receptor type is responsible for fast IPSPs and EPSPs
ionotropic
52
What receptor type is responsible for slow IPSPs and EPSPs
Metabotropic
53
What ions are involved in fast EPSPs
Fast Excitement Needs Kicks, Slow Excitement Keeps Out
Na+ ions moving into the cell and K+ moving out
54
What ions are involved in slow EPSPs
Fast Excitement Needs Kicks, Slow Excitement Keeps Out
K+ ions moving out the cell
55
What is temporal summation
back to back signals from the same presynaptic neuron will summate
56
What is spatial summation
similar signals from different PSNs will summate
57
What are the 3 types of synapses in the CNS
1. axo-dendritic
2. axo-somatic
3. axo-axonic
58
Where do axo-dendritic synapses synapse onto
a dendrite
59
Where do axo-somatic synapses synapse onto
onto the soma
60
Where do axo-axonic synapses synapse onto
synapses onto another axo-dendritic or axo-somatic synapse
61
What are the 3 ionic stages of an action potential
1. Leaky K+ channels move K+ out of cell
2. Na+ channels open and move Na+ into cell → depolaisation
3. Voltage gated K+ channels open and move K+ out of cell → repolarisation and hyperpolarisation
62
What are the 5 properties of action potentials
1. all or nothing firing
2. threshold for firing
3. self propagating
4. have a refractory period
5. travel slowly
63
What is saltatory conduction
Myelination
64
How does myelination affect action potential conduction
increases speed
increases membrane resistance = less leakage
decreases membrane capacitance = less currant wasted
65
What changes in action potentials due to demyelination diseases
decreased membrane resistance
increased membrane capacitance
66
What are the 5 nerve fibre types
A alpha
A beta
A gamma
A delta
C
67
What is the only nerve fibre type that isnt myelinated
C
68
What is the conduction velocity of A alpha nerves
70-120m/s
69
What is the conduction velocity of A beta nerves
30-70m/s
70
What is the conduction velocity of A gamma nerves
15-30m/s
71
What is the conduction velocity of A delta nerves
12-30m/s
72
What is the conduction velocity of C nerves
0.5-2m/s
73
What is the functions of Aa fibres
Proprioception and motor neurons
74
What is the functions of Ab fibres
Touch and pressure
75
What is the functions of Ay fibres
Motor neurons of muscle spindles
76
What is the functions of Ad fibres
Touch, cold and fast pain
77
What is the functions of C fibres
Warmth and slow pain
78
What are the 6 neurotransmitter types
1. acetylcholine
2. amines
3. amino acids
4. peptides
5. purines
6. gases
79
What neurotransmitters are amines
adrenalin
dopamine
serotonin
histamine
80
What neurotransmitters are amino acids
glutamate
GABA
81
what neurotransmitters are peptides
endorphines
82
what neurotransmitters are purines
ATP
adenosine
83
What gas acts as a neurotransmitter
nitric oxide
84
What are the 2 types of synaptic connectivity
divergence (1 to many)
convergence (many to 1)
85
Characteristics of the NMJ
large graded potential
no synaptic integration
post junctional folds increase no of channels
86
What are the 4 reasons that CNS synapses are more complicated then NMJ
1. more neurotransmitters
2. range of postsynaptic potentials
3. arrangement of synapses
4. arrangement of wiring (fire together, wire together)
87
What is feedback inhibition in neurons
action potential firing triggers inhibitory interneuron
prevents repeated firings
88
What is a monosynaptic reflex
A spinal cord reflex that involves 1 synapse
89
Is the muscle spindle (stretch) reflex mono or polysynaptic
Mono
90
What type of motor neuron innervates extrafusual muscle fibres
alpha
91
What type of motor neuron innervate intrafusual muscle fibres
gamma
92
What does alpha and gamma coactivation do in the muscle spindle reflex
allows muscle spindle to respond to stretch, whatever the muscle length is
93
What is an example of the muscle spindle reflex
Doctors knee hammer test
94
Is the golgi tendon reflex mono or polysynaptic
poly
95
How does the golgi tendon reflex work
excessive tension sends a signal to inhibitory interneurons in spinal cord to inhibit motor neuron
96
Is the flexion and crossed extensor reflex mono or polysynaptic
poly
97
Whats an example of the flexion and crossed extensor reflex
stepping on a lego brick
98
what is the role of the primary motor cortex
controls individual motor neurons during movement
99
what is a motor homunculus
a respresentation of the human body based on what area of the body that area controls
100
what connects the motor cortex to motor neurons in the spinal cord
corticospinal tract
101
what is the role of the premotor cortex
decides if a movement should be made
102
what is the role of the basal ganglia
plans the details of how to make a specific movement
103
what structures make up the basal gangia
striatum
→ caudate
→ putamen
globus pallidus
substantia nigra
104
what dopaminergic pathways connect the striatum and substantia nigra
nigrostriatal and straitonigral pathways
105
what is the role of the cerebellum
coordinated timing and force of movements (fine tunes)
106
what structures does the cerebellum get inputs from
proprioceptors and vestibular apparatus (sensory info)
motor cortex (via thalamus)
107
where does the cerebellum send info to
spinal cord (via rubrospinal tract)
motor cortex (via thalamus)
108
what is the role of the brainstem and spinal cord in movement
brainstem integrates postural reflexes
spinal cord contains central pattern generators
109
What are the differences in innervation between the autonomic and somatic nervous systems
A - pre and postganglion fibres
S - single neuron
110
What type of receptor is in the ANS
ionotropic
111
what type of receptor is in the SNS
metabotropic
112
Is the ANS exitatory or inhibitory
exitatory
113
Is the SNS exitatory or inhibitory
both
114
where do the sympathetic nerves branch from
T1-12 and L1-2
115
where do the parasynpathetic nerves branch from
Cranial III, VI, IX and X, and S2-4
116
Where are the sympathetic ganglia located
in spinal cord - prevertebral
or near spinal cord - paravertebral
117
where are the parasympathetic ganglia located
near the target
118
what neurotransmitter does the sympathetic nervous system release
Noradrenalin
119
What neurotransmitter does the parasympathetic system release
Acetylcholine
120
What adrenalin receptor dilates the eyes
A1
121
How does the sympathetic system dilate the eyes
activated a1 adrenergic receptors on radial muscle of iris, muscle contracts and pupils expand
122
How does the parasympathetic branch constrict the eyes
actiavtes muscarinic receptors on sphinctor muscle in iris, muscle contracts and pupils contract
123
How does the sympathetic branch affect vision
activated b2 receptors on ciliary muscle around lens, muscle relaxes and eye can focus on distant objects
124
How does the parasympathetic system affect vision
activates muscarinic receptors in ciliary muscle, contracts and eye focuses on close objects
125
How does the sympathetic branch affect heart rate
activates B1 receptors in pacemaker cells and myocytes, increase heart rate and contraction strength
126
How does the parasympathetic branch affect heart rate
activates muscarinic receptors in pacemaker cells to decrease heart rate
127
How does the sympathetic branch affect lung function
activates b2 receptors on smooth muscles in airways → dilates = more airflow
128
How does the parasympathetic branch affect lung function
activates muscarinic receptors to constrict smooth muscle in airways
129
How does the sympathetic branch affect blood vessels
activates a1 receptors in smooth muscle → contraction, activates b2 receptors in smooth muscle → dilation (in different tissues)
130
how does the parasym branch affect blood vessels
no effect
131
how does the symp branch affect saliva production
activates b receptors to secrete a thick saliva high in enzymes
132
how does the parasymp branch affect saliva production
activates muscarinic receptors to secrete a thin water saliva
133
how does the symp branch affect bladder function
activates b2 receptors in smooth muscle in bladder wall → relaxes to reduce pressure and activates a1 receptors in smooth muscle of sphincter → contracts to stop a weewee
134
how does the parasymp branch affect bladder function
activates muscarinic receptors in bladder wall to contract, activates in sphincter to cause a weewee
135
How does the symp branch affect the male reproductive tract
activates a1 receptors in urethra to cause ejaculation
136
How does the parasymp branch affect male reproductive tract
activates muscarinic receptors in corpus cavernosum to cause erection
137
How are B2 agonists used as medication
B2 agonists dilate airways and have a limited affect on heart → asthma treatment
138
How are B1 antagonists used as medications
B1 antagonist decreases heart rate and has a limited affect on airways → beta blockers
139
what receptors does acetylcholine act on
nicotinic and muscarinic receptors
140
What is the ratio of release of adrenalin and noradrenalin by sympathetic postganglion cells
80:20
141
What are some of the rule breakers in ANS neurotransmitters
some sympathetic cholinergic fibres innervate sweat glands
some post ganglion fibres use other transmitters
sometimes coreleased with the orthodox transmitter
142
What is an example of dual innervation with non-antagonistic actions in ANS
salviary glands
143
what is an example of dual innervation with complementary effects in ANS
male reporduction tract
144
What are the 2 types of autonomic acetylcholine receptors
Muscarinic
Nicotinic
145
What adrenalin receptors contracts blood vessels
A1
146
What adrenalin receptors contract the bladder sphincter
A1
147
What adrenalin receptor causes male ejaculation
A1
148
What do A2 adrenalin receptors regulate
Trick question - nothing
149
What do A1 adrenalin receptors regulate
1. eye dilation
2. contract blood vessels
3. contract bladder sphincter
4. male ejaculation
150
What adrenalin receptor increases heart rate
B1
151
What adrenalin receptor thickens saliva
Bs
152
What functions do B1 receptors regulate
heart rate and saliva viscosity
153
What adrenalin receptor relaxes the lens
B2
154
What adrenalin receptor dilates airways
B2
155
What adrenalin receptor dilates blood vessels
B2
156
What adrenalin receptors relax the bladder wall
B2
157
What 5 functions do the B2 adrenalin receptors regulate
1. relaxes lens
2. dilates airways
3. dillates blood vessels
4. thickens saliva
5. relaxes bladder walls
158
What 2 adrenalin receptors work together to contract and dilate blood vessels
A1 and B2
159
What acetylcholine receptor regulates the parasympathetic functions
muscarinic
160
Is an end plate potential an action or graded potential
graded
161
How many nerves extend from the cervical, thoratic, lumbar and sacral vertebrae
C8
T12
L5
S5
