Nervous System Flashcards
1
Q
what is the central nervous system comprised of (CND)
A
Brain and spinal cord
2
Q
Purpose of the nervous system
A
Gather information, process it and determine a appropriate response
3
Q
Sensory input
A
Sensory receptors detect stimuli
4
Q
Integration
A
How the nervous system processes information
5
Q
Motor output
A
Activated muscles and glands
6
Q
What is the PNS for
A
Sensory input: motor output
7
Q
What is the PNS
A
Cranial nerves and spinal nerves
8
Q
How is the PNS and CNS connected
A
The PNS is the communication lines between the CNS and the rest of the body
9
Q
Motor division
A
Conducts impulses from CNS to effectors
10
Q
What are effectors
A
Muscles and glands
11
Q
What is sensory division
A
Conducts impulse from receptors to CNS
12
Q
Somatic nervous system
A
Conducts impulses from CNS to skeletal muscles
13
Q
Do you have control over the SNS
A
Yes you have control (voluntary) over the somatic nervous system
14
Q
Autonomic nervous system
A
Conducts impulses from CNS to cardiac muscles and glands
15
Q
Do you have control over the autonomic nervous system
A
No control (involuntary)
16
Q
Sympathetic division
A
Fight or flight
17
Q
Parasympathetic division
A
Conserves energy, rest and digest
18
Q
Nervous tissue
A
2 types of cells, neurons, and Schwann cells
19
Q
Neurons
A
They are cells that conduct impulses
20
Q
Schwann cells
A
Support cells and nourish them, wrap around neurons, impulses can’t pass through
21
Q
Cell body
A
Contain nucleus, biggest part of neuron, if damaged the whole neuron dies
22
Q
Dendrites
A
Branch from cell body, Carey a nerve impulse TO CELL BODY
23
Q
Axon
A
Long branch from cell body, Carry’s impulses AWAY FROM CELL BODY
24
Q
Myelin sheath
A
Made of Schwann cells wrapped around the axon
25
Node of ranvier
Gaps of exposed axon between Schwann cells
26
Axon terminal
Ends of axon, does not touch other cells, the impulse jumps the gap to continue
27
3 types of neurons
Sensory, relay, and motor
28
Sensory neurons
Detects stimulus and take impulse to CNS
29
What do sensory neurons look like
The have long dendrites and short axons
30
Inter-neuron/ relay neuron
They interpret sensory information and transmit impulses within the CNS
31
What do really neurons look like
They have long of axons and dendrites
32
Where are relay neurons
Only in the CNS (brain and spinal cord
33
Motor neuron
They transmit impulses FROM THE CNS
34
What do motor neurons do
They send impulses from the CNS to effectors (glands/ muscles)
35
Where is the cell body of motor neurons located
Mostly in the spinal cord
36
What do motor neurons look like
Long axons and short dendrites
37
What is the order of the 3 neurons
1 sensory neurons get stimuli and send the message which is eventually picked up by 2 relay neurons which send the message within the CNS which eventually reach 3 motor neurons which then figure out a response and send it back out
38
Where are sensory receptors
All over but you have many in the skin
39
What are sensory receptors
Dendrites
40
What is the CNS physically made of
Internurons (relay) no sensory or motor
41
What is afferent
Sensory neurons in the PNS
42
What is efferent
Motor neurons in the PNS
43
What is a nerve
They are a BUNDLE OF NURON PROCESSES ( axons and dendrites)
44
What kind of neurons do nerves have
Sensory or motor NO RELAY
45
Where are nerves found and what are they
The are ONLY found in the PNS and are a cable bundle of axons and nerve fibres
46
What is a reflex arc
It is an involuntary reflex which makes it so you can respond to stimuli quickly without your brain
47
How many step in the reflex arc
6
48
What is the first step in the reflex arc
Receptor sense high pain and that starts and impulse (affecter)
49
Step 2 in the reflex arc
Sensory neurons in PNS send the impulse along the dendrite to the cell body and then along the axon and eventually to the spinal cord
50
Step 3 reflex arc
The interneurons within the spinal cord pass the message to motor neurons
51
Step 4 reflex arc
The motor neurons pass the impulse the short dendrite to the cell body then along the axon which leads the muscle
52
Step 5 reflex arc
The effectors revive the message and reacts to pull away from stimuli
53
Is the reflex arc a conscious arc
No
54
Step 6 reflex arc
Step 1-5 happen before the brain had a chance to “think” but pain is not felt until brain receives the impulse
55
What is an action potential
It is the conduction of an impulse across a neuron
56
Characteristics of impulses
Temporary, quick and repeatable
57
Steps of action potential (1)
The cell body becomes depolarized due to a signal
58
How does the axon get depolarized
First a threshold is reached (-55mv), the Na + gates open and flud in
59
Resting action potential pumps
Na+/k+ pump is on so it pumps Na+ out and k+ in (3 Na out 2 K in)
60
Resting potential gates
Na+ gate is closed and K + gate closed
61
Where are Na+ and K+ during resting potential
Na + outside K+ inside (there are leak channels and that’s why you need the pump)
62
Pumps during depolarization
The pump turns off
63
Repolarization pumps
The pump is off
64
Repolarization gates
Na+ gates are closed and K+ gates are open
65
Why are K+ gates open during Repolarization
To help shift the charge
66
Can the neuron conduct and impulse when Repolarization
No, necessary the ions are not restored (Na+ and K+)
67
Recovery/ Refactory pumps
The pump is on to get the Na + out and K + in
68
Refractory/ recovery gates
All gates closed
69
Where are the gates on a neuron
All over cell membrane
70
What is salty banana
K+ inside and 2x Na+ outside when in resting potential
71
Order of action potential
1-resting-2 depolarized-3 repolorize-4 refractory/recovery ( happens all the way down )
72
Saltatory conduction =
Impulses are faster in myelinated neuron because they jump from node to node
73
Characteristics of action potential
Stimulus must exceed threshold, all are none response
74
What is an all or none response
The stimuli must reach a threshold, so all impulses are the same (do different things)
75
How many impulses can happen at once
Neurons can have many or one at the same time in different locations
76
What do stronger stimuli do
They send repeated impulses
77
Can you stop an impulse
No you can’t stop it or send a new one till it’s done sending
78
What is an action potential
When a stimulated neuron sends an impulse
79
How do impulses get from one neuron to another
Neurotransmitters are sent from one neuron and they lock into receptors on the dendrites of the next neuron
80
How are impulse conducted within the neuron
Electrically
81
How are impulses conducted between neurons
Chemically
82
Where are neurotransmitters stored
In vesicals at the end of axon terminals (axon bulbs)
83
What is the somatic cleft
The gap between neurons
84
How are excess neurotransmitters removed from the somatic cleft
With enzymatic breakdown by reabsorption so the stimulus stops
85
What is a presynaptic neuron
Is is the neuron the impulse is coming from
86
What is the postsynaptif neuron
It is the neuron receiving the nerve impulse via neurotransmitters
87
How does the next neuron chemically get the impulse
Neurotransmitter receptors take neurotransmitters in
88
How many steps of the transmission across the synapse
8
89
Step 1 across the synapse
The impulse reaches the end of the axon and is at axon bulb
90
Step 2 across the synapse
The depolarization causes the calcium ions to flood into the axon bulb which pull the vesicles to the presynaptic membrane
91
Step 3 across the synapse
Neurotransmitters go across the synaptic cleft and activate sodium gates
92
Step 4 across the synapse
Sodium floods into the POSTSYNAPTIC membrane and causing the next neuron to depolarize
93
6-7 steps of across the synapse
Action potential continues down the postsynaptic neuron
94
Step 8 of across the synapse
Enzymes are released to neutralize neurotransmitters in the sympathetic cleft or the neurotransmitters are reabsorbed into axon bulb
