W8 - Neural System Flashcards
(95 cards)
1
Q
What comes under the CNS
A
Brain
Spinal cord
2
Q
What comes under the PNS
A
Cranial nerves (12 pairs)
Spinal nerves (31 pairs)
3
Q
Parts of the brain
A
Cerebrum
Cerebellum
Diencephalon
Brain stem
4
Q
What are the 4 lobes of the cerebrum?
A
Frontal
Parietal
Temporal
Occipital
5
Q
What is the cerebellum responsible for?
A
Coordinating voluntary movements, including motor skills like:
Balance
Coordination
Posture
6
Q
What is the Diencephalon responsible for?
A
Processes sensory info + has autonomic control
7
Q
What does the Diencephalon contain?
A
Epithalamus
Thalamus
Hypothalamus
Ventral thalamus
8
Q
What is the brainstem responsible for?
A
Involuntary actions of the body
i.e heat beat + breathing
9
Q
What does the brain stem connect what to what?
A
Brain to spinal cord
10
Q
What are the 2 main parts of the brain?
A
Left = Motor area
Right = Sensory area
11
Q
What does TMS stand for?
A
Transcranial magnetic stimulation
12
Q
CRANIAL NERVES
Which is a sensory nerve involved with the nose for smell?
A
Cranial nerve 1
13
Q
CRANIAL NERVES
Which is a sensory nerve involved with the eye for vision?
A
Cranial nerve 2
14
Q
CRANIAL NERVES
Which is a motor nerve involved with the upper eyelid + eyeball?
A
Cranial nerve 3
15
Q
CRANIAL NERVES
Which is a motor nerve involved with the movement of the eyeball?
A
CN 4
16
Q
CRANIAL NERVES
Which is a sensory/motor nerve involved with touching, pain + chewing ?
A
CN 5
17
Q
In what 2 ways are nerves grouped?
A
Afferent
Efferent
18
Q
What do afferent nerves do?
A
Carry signals FROM receptors in the periphery TO the CNS.
19
Q
What type of neurones are afferent neurones?
A
Sensory
20
Q
What do efferent nerves do?
A
Carry impulses away from the CNS to effectors i.e muscles.
21
Q
What type of neurones are efferent neurones?
A
Motor
22
Q
Examples of sensory neurones
A
Baroreceptors
Chemoreceptors
Mechano/proprioreceptors
Metaboreceptors
Thermoreceptors
Nociceptors
23
Q
What are baroreceptors sensitive to changes in?
A
bp
24
Q
What do nociceptors detect?
A
Pain
25
What is an association neurone also known as?
An interneurone
26
What do interneurones do?
Connect spinal motor + sensory neurones by passing the afferent transmission to the efferent response w/out need to involve the brain.
However they can also communicate with each other to form circuits of various complexity.
27
What is a myotatic stretch reflex?
Contraction of a muscle in response to its passive stretching.
28
What does the stretch reflex do when a muscle is stretched?
Regulates the length of the muscle by ⬆️ its contractility as long as the stretch is w/in the physiological limits.
29
What does the brainstem consist of?
Medulla
Pons
Midbrain regions
30
Which division comes off the CNS?
Afferent or Efferent?
Afferent
31
Which division comes off the PNS?
Afferent or Efferent?
Efferent
32
What are the 3 main components of the stretch reflex?
Muscle spindle responding to stretch
Afferent nerve fibre carrying sensory impulse from spindle --> spinal cord
Efferent spinal cord motor neurone activating the stretched muscle fibres
33
Efferent division in the autonomic nervous system
Includes involuntary processes by involving the SNS + PNS
34
Efferent division in the somatic nervous system
Includes motor neurones to initiate skeletal muscle function
35
What senses change in the internal + external env through sensory receptors
Afferent neurons
36
What analyses the sensory info, stores some aspects + makes decisions
Interneurons
37
What neurone responds to stimuli by initiation of action?
Efferent
38
What is nervous tissue composed of?
Neurones
Neuroglia (supporting cells)
39
Where can the 6 types of neuroglia be found?
4 in the CNS
2 in the PNS
40
What are the 4 neuroglia/glial cells in the CNS?
Astrocytes
Microglial cells
Epndymal cells
Oligodendrocytes
41
What are the 2 neuroglia in the PNS?
Satellite cells
Schwann Cells
42
What are dendrites?
Motor neurones
43
How long are dendrites?
Short
BUT have a large surface area for receiving signals from other neurones.
44
What do dendrites do?
Convey incoming messages towards the cell body
45
What is the dendrite region also known as?
Receptive input region
46
What do astrocytes do?
Regulate electrical transmission in the brain
47
Do neuroglia generate or conduct nerve impulses?
No
48
What are the 2 components of a motor unit?
Alpha-motor neuron (AMN)
Muscle fibres innervated by the AMN
49
What are the 3 types of motor unit?
Slow / type 1
Fatigue resistant / type IIa
Fast fatiguing / type IIx
50
What does the axon hillock do?
Acts like a manager:
Summing the total inhibitory + excitatory signals.
- If the sum of these signals exceeds a certain threshold, the AP will be triggered + an electrical signal will be transmitted down the axon AWAY from the cell body.
51
What on the neuron services as a contact point?
Synapse
52
What do Schwann Cells play an essential role in?
Development, maintenance, function + regeneration of peripheral nerves.
53
In the mature nervous system, what are the 2 classes that Schwann Cells can be categorised into?
Myelinating cells
Nonmyelinating cells
54
What is the node of Ranvier?
1-2 micrometer gap between the glial cells of the myelin sheath.
55
When is the node of Ranvier ONLY ever present?
When the axon of a neuron is myelinated.
56
What is the importance of the myelin sheath?
For the speed of the impulses
57
What are the 3 nerve fibre groups?
A - Alpha, beta, gamma
B - Nerve fibres
C - Nerve fibres
58
Are A - Alpha, beta, gamma fibres myelinated?
YES
59
Are B - Nerve fibres myelinated?
Moderately
60
Are C - Nerve fibres myelinated?
NO
61
What happens to the velocity of the AP when there's more myelination?
Faster
62
What happens to the velocity of the AP when there's a bigger axon diameter?
Faster
63
What happens to the velocity of the AP when temp increases?
Faster
64
What are the structural classifications of neurones?
Multipolar
Bipolar
Unipolar
65
Where is the cell body in a multipolar neurone?
In the dendrites
66
Where is the cell body in a bipolar neurone?
Middle
67
Out of the 3 classifications of neurones, which has the shortest axon?
Bipolar neurone
68
Where is the cell body in a unipolar neuron?
Middle but to the side
69
What do APs do?
Reverse the membrane potential + then restore it to a resting state
70
What are the excitable cells?
Neurons
Muscle
Endocrine
71
Define a membrane potential
Difference in the amount of electrical charge inside + outside of cell
72
Define a physics potential
Separation of charge
73
What charge does a neurone have at rest?
- ive
| - 70mV
74
What are the main ions inside + outside neurones?
Na+
K+
Cl-
Organic anions
75
What causes there resting membrane potential?
No. of +ively K+ inside + outside the cell
76
What channels are CLOSED at the resting potential?
All voltage-gated Na+
Most voltage-gated K+
77
What does the Na+/K+ transporter do at resting potential of the membrane?
Pumps K+ INTO cell
Na+ OUT
78
What happens to the resting membrane potential in response to depolarisation?
Some Na+ channels open = Na+ INTO cell
Membrane starts to depolarise so charge across membrane decreases.
IF threshold of excitation is reached = ALL Na+ channels open
79
What happens at the peak AP?
Na+ channels close
K+ channels open
= K+ leave cell = membrane eventually becomes hyperpolarized.
80
What causes a neurone at rest to be slightly negative compared to the surrounding fluid?
The movement of K+ ions OUT of cell
81
What is it called when the membrane is hyperpolarized and can't fire impulses?
In the refractory period
82
What must happen within a neuron for it to reach its threshold in order to carry out an action potential?
Na+ enter cell via open channels to make inside of cell increasingly less -ive
83
What are the types of membrane ion channels?
Leakage channels
Voltage gated channels
Ligand-gated ion channels
84
What are the types of synapse?
Chemical
Electrical
85
How do synaptic vesicles release neurotransmitters?
By exocytosis
86
Name an excitatory NT
Glutamate
87
Name an inhibitory NT
Gamma aminobutyric acid
88
Name the NT that function as excitatory + inhibitory NTs
Acetylcholine
Noradrenaline
89
What is the excitatory postsynaptic potential (EPSP) responsible for?
Depolarisation via the ligand-gated Na+ channels
90
What is the inhibitory postsynaptic potential (IPSP) responsible for?
"More" -ive or hyper polarised via ligand-gated Cl- or K+ channels
91
What are the types of signal summation?
Spatial summation
Temporal summation
92
What is Spatial summation?
When more primary afferent (presynaptic) neurones are activated simultaneously until enough NT is released to activate an AP in the spinal cord (postsynaptic) neuron.
93
What is temporal summation?
Happens when 1 presynaptic neurone releases NT many times over a period of time
94
Which part of the brain coordinates movement?
Cerebellum
95
Which are the functional divisions of the PNS?
Somatic nervous system
Autonomic nervous system
