Nervous Flashcards
0
Q
What is the name of the star shaped glial cells which supply nutrients to neurons, ensheath blood capillaries and transmit information?
A
Astrocytes
1
Q
What does integrating and coordinating mean?
A
Senses environment and produces an appropriate response.
2
Q
Astrocytes - shape and function?
A
Are star shaped cells which supply nutrients to neurons, ensheath blood capillaries and transmit information.
3
Q
What glial cells perform immune system functions and engulf debris/micro organisms?
A
Microglia
4
Q
Microglia function?
A
Perform immune system functions and engulf debris/micro organisms.
5
Q
What are the glial cells which line fluid filled spaces of the brain and spinal cord and circulate the CSF using cilia?
A
Ependymal cells
6
Q
Ependymal cells function?
A
The glial cells which line fluid filled spaces of the brain and spinal cord and circulate the CSF using cilia.
7
Q
What are the glial cells which support nerve fibres and ensheath them in myelin in the CNS?
A
Oligodendrocytes
8
Q
Function of oligodendrocytes?
A
The glial cells which support nerve fibres and ensheath them in myelin in the CNS.
9
Q
What is the function of a Schwann cell?
A
Support nerve fibres
Ensheath them in myelin
Similar to Oligodendrocytes
10
Q
What is the structure and function of the myelin sheath?
A
Lipid wrapped around an axon.
Increases conduction velocity.
11
Q
What happens if cells are not myelinated?
A
Weakness, un-coordination, visual and speech impairment caused by an auto immunity or infection.
12
Q
What are the four neural zones?
A
Input zone, summation zone, conduction zone, output zone.
13
Q
What is in the input zone? What is the function of the input zone?
A
Comprises of the dendrites and cell body.
Receives chemical signals from other neurones.
14
Q
What is the structure and function of the summation zone?
A
Axon hillock
Decides whether to transmit signal or not.
15
Q
What is the structure and function of the conduction zone?
A
An axon
Carries the electrical signal between brain areas, to and from the spinal cord, or to and from peripheral sensory receptors.
16
Q
What is the structure and function of the output zone?
A
The axon terminals
Contact with other neuronal input cells
Release neurotransmitter
17
Q
What are the three morphological types of neurones? Cve an example for each.
A
Multipolar - CNS
Bipolar - Eye
Pseudo unipolar - Sensory Cell
18
Q
What are the three types of synapses?
A
Axodendritic, axosomatic, axoaxonic
19
Q
Afferent vs efferent?
A
Afferent is toward CNS
Efferent is toward effectors
20
Q
What is a nucleus and what type of matter is this?
A
Collection of cell bodies in the CNS, grey
21
Q
What is a tract and what type of matter is this?
A
Axons in the CNS, white.
22
Q
What are ganglia and nerves?
A
Ganglia - cell bodies
Nerves - axons
Both in the PNS
23
Q
Autonomic subdivisions based off information flow?
A
Afferent and efferent.
24
Information flow based on control?
Somatic and autonomic.
25
Information flow based on anatomy?
Central and peripheral
26
Describe the somatic efferent pathway in the PNS
One neuron, myelinated. Uses ACH and ends at skeletal muscle at a NMJ.
27
Define a reflex.
A predictable, reproducible, automatic response to a sensory stimulus.
28
Which reflex is mono synaptic? Where is the cell body?
Stretch reflex. Cell body in dorsal root ganglion.
29
What do ipsilateral and contra lateral refer to?
Ipsilateral is the withdrawal muscle action.
Contralateral is the stabilisation of the other muscle groups.
30
Which reflex has an inter neuron?
Withdrawal reflex.
31
Describe the function of the prefrontal, pre motor and primary motor (pre central gyrus).
Prefrontal is the desired goal, pre motor is the motor program, pre central is the execution of the desired movement.
32
Where in the pre central gyrus is the head controlled?
Lateral
33
How many neurons does the corticospinal pathway have?
Two
34
Where does the primary neuron of the corticospinal pathway synapse?
At the spinal cord
35
Where does the secondary neuron of the corticospinal pathway synapse?
At the effector
36
Where does the primary neuron of the corticospinal pathway have its cell body?
In the motor cortex.
37
Describe the path of the corticospinal pathway.
Primary neuron has it's cell body in the motor cortex, crosses over in the medulla. It synapses in the spinal cord. The secondary neuron synapses on the effector.
38
What are the two extra pyramidal tracts, and what types of movements do they take care of.
Reticulo and Rubro spinal. (Bros flex)
| Performs automatic movements such as walking chewing and smiling.
39
What modalities does the medial lemniscal pathway take?
Touch and proprioception
40
Where does the medial lemniscal pathway cross over?
In the medulla.
41
What type of neurons does the proprioception pathway have?
1a, the fastest.
42
What happens when there is a contraction of the muscle in terms of proprioception?
The Golgi tendon causes relaxation, which protects from tearing. Located at the ends of muscles.
43
What happens when there is a lengthening of muscles in terms of proprioception?
Muscle spindles located in the middle of muscles activate the stretch reflex shortening the muscles, retaining posture.
44
Where is the cell body of the primary neuron of the lemniscal pathway?
Dorsal root ganglion.
45
Where is the cell body of the secondary neuron in the lemniscal pathway.
In the medulla prior to crossing over.
46
Where is the cell body of the tertiary cell neuron in the lemniscal pathway?
Thalamus.
47
Describe the lemniscal pathway.
Sensory information creates an AP, travels up primary neuron, cell body in DR ganglion. Synapses in the medulla.
The secondary neuron crosses in the medulla, and then travels up the medial lemniscal pathway, and synapses in the thalamus.
The tertiary neuron travels to the post central gyrus , where it synapses.
48
What modalities travel in the spinothalamic pathway?
Pain and temperature.
49
Where does the spinothalamic pathway cross over?
Spinal cord.
50
Out of acute and chronic pain, which axons are myelinated?
Acute
51
Where does the primary neuron in the spinothalamic pathway send an offshoot?
Reticular formation - arousal
52
Where does the secondary neuron of the spinothalamic pathway send an offshoot to?
Limbic system - emotion.
53
Where does the primary neuron in the spinothalamic pathway synapse?
In the spinal cord.
54
Where does the secondary neuron in the spinothalamic pathway synapse?
Thalamus.
55
Where does the tertiary neuron in the spinothalamic pathway synapse?
In the somatosensory sensory area (post central gyrus).
56
Describe the spinothalamic neuronal pathway.
Sensory information produces AP, which travels up primary neuron, which has its cell body in the DR ganglion and synapses in the spinal cord.
The secondary neuron has its cell body in the spinal cord, where it crosses over and travels up the spinothalamic pathway to the medulla where it synapses.
The tertiary neuron has its cell body in the thalamus and synapses in the somatosensory area (post central gyrus).
57
Where would feeling in the legs synapse in the post central gyrus?
Medially.
58
What is the role of the parietal lobe in terms of sensory information?
Association and perception.
59
What levels does the sympathetic system exit the vertebrae?
T1 to L1 (thoraculmbar).
60
How many chain ganglia are there?
21-23
61
How many collateral ganglia are there?
Three.
62
What is the pre ganglionic neuron for both autonomic nervous systems?
Cholinergic nicotinic.
63
What is the postganglionic neuron for both autonomic nervous systems?
Cholinergic muscarinic for para and occasionally sympa.
Adrenergic for most sympathetic neurons.
64
What effectors are not under dual innervation, and only sympathetic?
Sweat, adrenal medulla, pilo erectors, blood vessels (lots is vasoconstriction).
65
What levels does the parasympathetic nervous system exit from?
Craniosacral.
66
What autonomic nervous system has long preganglionic neurons?
Parasympathetic.
67
What autonomic neuron is myelinated?
Pre ganglionic.
68
What is ions tropic activation?
Nicotinic, depolarising, between neurons.
69
What is metabotropic activation?
Muscarinic, adrenergic alpha or beta, de/hyperpolarisation
70
Describe dual innervation.
Para and sympa both inhibit each other and both activate an effector.
71
What are the sympathetic effects?
```
Higher HR
More blood to muscles
Less GI motility
Less salivation
Increase in pupil size
Increase in sweating
```
72
What are some effects of the parasympathetic?
Less HR
More GI motility
Smaller pupil size
More salivation
73
Where does afferent information enter the spinal cord?
Posterior
74
Where are somatic motor neurons found in the spinal cord?
Anterior
75
Where are autonomic motor neurons found in the spinal cord?
Lateral/anteriolateral
76
What levels of vertebra is the spinal cord found at?
C1 to L1
77
When a dorsal nerve root and a ventral nerve root come together, they form a what?
Spinal nerve
78
What does a spinal nerve split up into?
Dorsal and ventral rami
79
How does the ventral rami communicate with the sympathetic chain?
Via sympathetic rami
80
What are the bones of the skull?
```
One frontal
Two parietal
One occipital
Two temporal
One sphenoid
One ethmoid
```
81
What is a Fontanelle?
The gaps between sutures in babies and children
82
What bones is the frontal suture between?
Frontal
83
What bones is the Sagittal suture between?
Parietal
84
Where is the coronal suture?
Frontal and parietal
85
Where is the lambdoidal suture?
Occipital and parietal.
86
Where is the squamous suture?
Temporal and parietal.
87
What are the bones of the face?
Zygomatic 2 cheek
Maxillary 2 upper jaw
Mandible 1 lower jaw
Nasal 2 top of nose.
88
What are the three main dural reflection and in what plane are these?
Falx cerebri median
Falx cerebelli median
Tentorium cerebelli horizontal
89
Describe the venous sinuses
Drainage from the brain
| Arrachnioid villi perforate into them
90
Where is CSF foun in the meninges?
Sub arachnoid layer
91
What is a gyrus and a sulcus?
Gyrus is a hill sulcus is a valley
92
What is the flow of CSF like?
Produced by choroid plexi, travels through the lateral, third, cerebral aqueduct, fourth and central canal.
Enters the sub arachnoid space and provides nourishment and cushioning for the brain.
Exits through the arachnoid villi to the venous sinuses.
93
What is hydrocephalus?
A blockage in the ventricles causes accumulation if CSF. Ventricles expand, head grows in children, in adults it puts pressure on the brain, can cause brain damage.
94
What is the role of the frontal lobe?
Movement, planning, decision making, emotions etc
95
What is the role of the parietal lobe?
Sensory information.
96
What is the role of the occipital lobe?
Vision
97
What is the role of the temporal lobe?
Hearing and memory.
98
What are the main sulci?
Central, parieto-occipital, lateral (frontal and temporal)
99
Where is the main brain fissure?
Transverse, between cerebellum and cerebrum.
100
What are association tracts?
In the same hemisphere
101
What are commissural tracts and where do they pass through?
Corpus callosum, go from one hemisphere to the other.
102
What are projection tracts?
They go down the spinal cord.
103
What makes up the diencephalon?
Thalamus
| Hypothalamus
104
What makes up the brainstem?
Midbrain
Pons (HINDBRAIN)
Medulla Oblongata (HINDBRAIN)
105
What is he role of the basal nuclei?
Selects appropriate movements for situations. Initiation and termination.
106
What is the role of the cerebellum?
Coordinates movements
107
What happens in Parkinson's disease?
No dopamine, which means basal nuclei don't work, so trouble controlling movements.
108
At rest, what channels are open?
Some potassium
109
What does the sodium potassium pump control?
Maintains RMP, three Na+ out for two K+ in.
110
What is RMP?
-70mV
111
What is a local potential?
Fluctuation in a local region of a membrane
112
What is threshold?
The minimum voltage needed to pass an AP down an axon, usually -59mV
113
What is an action potential?
Depolarisation to a maximum value of +30mV, AP propagates.
114
What is the process of an AP?
Stimulus gated Na+ open
Voltage gated Na+ open
Voltage gated Na+ close
Voltage gated K+ open and then close
115
Speed improved by myelination called what?
Saltatory Conduction
116
What is the absolute refractory period?
From threshold till Na voltage gated channels close
117
What is the relative refractory period?
When the axon is heading toward RMP
118
What is an electrical synapse?
Linked via gap junction
| Very fast
119
What is a chemical synapse?
Linked by chemical transmitters
| Slower than electrical but still fast
120
What are some features found in the axon terminal?
Vesicles
Cytoskeleton
Mitochondria
Voltage gated Ca2+ channels
121
What are two things found in the post synaptic membrane?
Post synaptic density
| Receptors
122
How is neurotransmitter in the cleft removed?
Re-uptake into glia or bouton
| Degradation via enzymes
123
GO THROUGH THE STEPS OF AP IN SYNAPSE!!
Okay!!!
124
GO THROUGH THE STEPS OF MUSCLE ACTIVATION!!
Okay!!!
125
What are some EPSP neurotransmitters?
ACH
| GLUTAMATE
126
What is the IPSP neurotransmitter?
GABA
127
What are the three types of summation?
Temporal
Spatial
Inhibition vs excitation
128
What is a feature if a divergent network?
Amplification.
129
What is a feature if a convergent network?
Redundancy
130
What makes actin molecules and strands?
G actin molecules join to make F actin strands
131
What is troponin?
The binding site for Ca2+
132
What is tropomyosin?
The long strand which moves to reveal the active site.
133
Where does ACH bind to receptors at the NMJ?
The motor end plate
134
Where does the AP travel in the muscle?
Along Sarcolemma and t-tubules.
135
Where is there a high concentration of calcium in muscle at rest?
Sarcoplasmic reticulum
136
How many seconds of contraction does creating phosphate give?
20
137
What is anaerobic contraction good for?
Short term, high energy movements
| No O2 needed.
138
What is aerobic contraction good for?
Longer term, steady movements.
| Needs O2
139
How many seconds of contraction does ATP give?
2-4
140
Describe fast muscle fibres
White
Fast myosin type
Rapid fatigue
141
What is intermediate muscle fibre type good for?
Posture
142
Describe slow muscle fibre.
Red
Slow myosin type
Myoglobulin high
Low fatigue
143
Phases of a twitch?
Latent period (occurs because Ca2+ occurs quicker than muscle activation).
Contraction
Relaxation
144
What are multiple successive twitches called?
Treppe
145
What is the peak value of multiple twitches called?
Tetanus, complete if smooth, incomplete If bumpy.
146
What effects does exercise and lack thereof have?
Increases strength through contractile filaments
Increases aerobic fitness through more blood supply and myoglobulin.
Disuse causes less contractile filaments.
147
Features of skeletal muscle?
Multinucleate
Striated
Each cell has a discrete synapse
148
Features of cardiac muscle?
```
Mononucleate branching
Striated
Lots of gap junctions
Pacemaker initiates movements
Scattered neural varicosities.
```
149
Features of smooth muscle?
Mononucleate spindle shaped cells
No striations
EITHER lots of gap junctions and bulk movement
OR fewer gap junctions and more refined movement
150
What are the four types of stimulus information?
```
(MILD)
Modality- type
Intensity- AP firing rate
Location- receptive fields
Duration- adaptation to a stimulus.
```
151
Describe the myosin and actin interaction cycle
ATP binds to myosin head, moves to rest position
Myosin head moves to attach to active site on actin
Myosin head flexes, remains attached until another ATP arrives
