Biology and Neuroscience Flashcards
1
Q
What are the two main divisions of the nervous system
A
CNS and PNS
2
Q
What does the CNS consist of
A
Brain and spinal cord
3
Q
What does the PNS consist of
A
All the nerves in the body that are not the brain/spinal cord
4
Q
What are the 3 roles of your nervous system:
A
- Receives information from world and our own body
- Analyze and interprets the information
- Uses the information to send out messages
5
Q
What are the two important cells of the nervous system
A
Neurons and Glia Cells
6
Q
What are neurons
A
the basic unit of communication in the nervous
7
Q
What is the communication process between neurons called
A
Its an electrochemical process.
8
Q
Describe the 3 steps a neuron takes to communicate
A
- When it wants to communicate, it fires by sending an electrical impulse (aka action potential)
- The action potential causes the release of neurotransmitters
- The release of neurotransmitters deliver the message from one neuron to another
9
Q
What are the 8 important structures of the neuron
A
- Soma
- Dendrites
- Axon
- Axon terminals
- Terminal buttons
- Myelin Sheath
- Synapse
- Synaptic Cleft
9
Q
What is the soma and what is its role
A
The cell body of a neuron. It contains the nucleus and DNA. It manufactures everything the neuron needs to survive
10
Q
What are the 2 roles of dendrites
A
- they increase the surface area of the soma without taking up too much space
- Receive messages from other neurons
11
Q
What is an axon and what is its role
A
Its a thin tube in the neuron. It carries the electrical impulse
12
Q
What is an axon terminal and what is its role
A
Its a part of the axon in the neuron. It carries the action potential (electrical impulse) until it reaches the terminal buttons
13
Q
What are the terminal buttons and what are their roles
A
little nobs at the end of axon branches in a neuron. They release neurotransmitters when the action potential reaches them
14
Q
What is a myelin sheath and what is its role
A
a white fatty-like substance on the axon of a neuron. It speeds up the transmission of the information.
15
Q
What is a synapse
A
the place where neurons need to communicate
16
Q
What is a synaptic cleft
A
a little gap at the synapse between two neurons. It is where the communication happens.
17
Q
What is a presynaptic neuron
A
the neuron that sends out messages
18
Q
What is a post synaptic neuron
A
a neuron that receives messages
19
Q
Why are Glial Cells called ‘Nannies of the neurons’
A
They provide neurons with everything they need to survive: protection, insulation, nutrition, clean after them
20
Q
What are the 4 types of glial cells
A
- Oligodendrocytes 2. Schwann Cells 3. Astrocytes 4. Microglia
21
Q
What are Oligodendrocytes and Schwann Cells both involved in
A
the production, laying down, and repair of the myelin sheath
22
Q
What is the difference between Oligodendrocytes and Schwann Cells
A
Oligodendrocytes repair the myelin sheath in the central nervous system and Schwann Cells repair the myelin sheath outside the brain and spinal cord
23
Q
What is the function of microglia and astrocytes?
A
They both form the immune system of the brain
24
What percent of a neuron is water?
80%
25
What is intracellular fluid?
fluid dissolved inside neuron
26
What is extracellular fluid?
fluid outside the neuron
27
What are the 3 dissolved chemicals in neurons?
Na+ (sodium), Cl- (chloride), K+ (potassium)
28
What is happening with the dissolved chemicals inside a neuron when the neuron is AT REST?
When neuron is at rest, there is a higher concentration of negative neurons on the inside. There is a higher concentration of positively charged ions on the outside.
29
What does a inhibitory message mean to the neuron?
Not to fire. Not to produce an active potential
30
How will an inhibitory message keep the neuron from not firing?
message will change the concentration of ions to make it MORE negative inside the neuron. As a result, neuron is less likely to fire
31
What does it mean when a neuron is hyperpolarized?
the inside is made MORE negative than normal. it will be less likely to fire.
32
What does an excitatory message mean to the neuron?
Instructs the neuron to fire. To produce an action-potential
33
How will an excitatory message get the neuron to fire?
It will change the concentrations of the inside of the neuron to be LESS negative. As a result, it is more likely to fire
34
What does it mean when a neuron is depolarized?
When the inside is LESS negative than normal. More likely to fire.
35
At what charge will a neuron most likely to fire at?
About -50 mv
36
What are the nodes of Ranvier in a neuron and why are they there?
they are gaps in the myelin sheath that covers the axons. Ions use them to get in and out of the neuron
37
Explain the movement of ions in the neurons during an inhibitory response
Chloride (Cl-) channels open which causes an influx of chloride ions in the neuron. When this happens, there is an excess of negative ions inside the neuron, making the neuron more negative (hyperpolarized)
38
Explain the movement of ions in the neurons during an excitatory response
Sodium (Na+) channels open, causing sodium channels to rush into the cell. This increase the amount of positive ions in the neuron, causing it to be less negative (depolarization)
39
What is the threshold of excitation and how is it reached?
Its about -50mv. Its the electrical charge that the neuron must get to for it to fire. It is achieved through depolarization.
40
What is resting potential?
Around -70mv. Its the electrical charge that a neuron rests at.
41
After a neuron is fired, it has to go back to resting membrane potential. How does it return?
AFTER sodium channels open and sodium has rushed inside cell, potassium channels open. Potassium (K+) ions start leaving the neuron. Potassium ions leaving = less positive ions inside cell = less positive charge = back to resting potential
42
What is a refractory period?
During this period, the neuron will not fire when stimulated. The membrane is hyperpolarized.
43
What are the 7 steps of a presynaptic neuron firing?
1. Presynaptic neuron decides to send a message to another neuron. It fires, producing an action potential.
2. Action potential travels down the axon until it reaches the terminal buttons
3. It goes inside the terminal buttons, where it reaches the terminal neurons.
4. When it arrives at the terminal neurons, the synaptic vesicles attach the the membrane of the neuron.
5. Synaptic vesicles burst open and release neurotransmitters into synaptic gap.
6. Neurotransmitters cross the gap and attach to receptor sites of the synaptic neurons
7. Once they attach to receptor sites, they send the message to the postsynaptic neurons.
43
The neurotransmitters MUST attach to ________ otherside it cannot deliver the message.
Receptive sites
44
What are two ways that we get rid of the neurotransmitters once the message has been delivered?
1. Reuptake
2. Degradation
45
What is the reuptake of neurotransmitters?
the neurotransmitter is reabsorbed into the neuron that released it
46
What is the degradation of neurotransmitters?
Once message is delivered, an enzyme comes and breaks down the neurotransmitters.
47
Why do neurotransmitters have to be removed once they have delivered the message?
If they are not removed, it is going to remain active, delivering the same message over and over again. This can overexcite the nervous system or over-inhibit it.
48
What are neurotransmitters?
Chemicals the neurons use to send messages to other neurons. They deliver the messages from one neuron to the other.
49
What is an example of a neurotransmitter that delivers only excitatory messages
Acetylcholine
50
What is an example of a neurotransmitter that delivers only inhibitory messages
GABA
51
What is an example of a neurotransmitter that delivers both excitatory and inhibitory messages
Dopamine, Serotonin
52
How do drugs affect the synapse
All molecules from drug go to synapse. They interfere with the communication between neurons by interfering with the activity of the neurotransmitters.
53
What is an agonist
Drugs that enhance and increase the activity of the neurotransmitters
54
List 2 ways that agonists can affect neurotransmitters
1. increase the release of the neurotransmitter so that there is more of it
2. Mimic the neurotransmitter by attaching to the receptor sites, delivering same message.
55
What is an antagonist
they weaken the activity of the neurotransmitter or completely block it
56
List 2 ways that antagonists can affect neurotransmitters
1. block the release of the neurotransmitter so that there is less of it
2. attaching to the receptor site and blocking it so that the neurotransmitter cant bind. (doesnt release signals)
57
Define Competitive-Direct drugs
they compete with the neurotransmitter for the same parking spot. Once they attach, they will either mimic the neurotransmitter or block its activity
58
Define non-competitive drugs (indirect)
They do not attach to the same receptor site as the transmitter. Rather, they attach to a different receptor site and affect activity of neurotransmitter by either enhancing or decreasing it.
59
What does a CT Scan do and how does it do it?
Detects changes in structure due to disease. uses X-rays that pass through the body and can generate images of "slices" of body.
60
What does MRI do and how does it do it?
Detect changes in structure due to disease. Uses magnetic fields to image alignment of hydrogen ions (different tissues have different amounts of water)
61
what does fMRI do and how does it do it
Measures brain activation during a task or following stimulation. Tracks oxygenated blood that are more consumed by active areas in brain
62
What does DTI do and how does it do it
Study white matter degeneration in disease. Tracks water movement along neutral pathways. Tracks nerves and connections in brains.
63
What does a PET/SPECT do and how does it do it
visualize the activity of the specific neurotransmitters. uses a radioactive compound to track molecular changes.
64
where does the brainstem start
starts where the spinal cord ends
65
Why is the brainstem a relay station
all the info coming to the brain will have to go through it and all the
information leaving the brain will have to go through it
66
Why is the brainstem called the crossover point
The information coming from the left side of the body will cross over to the right side of
the brain and vice versa.
The information coming from the right side of the body will cross over to the left side of
the brain and vice versa
67
Why is the brainstem the life center of the brain
it contains structures that control vital functions that are
essential for survival. These structures include the medulla, the pons and the RAS
68
What does the cerebellum control
Controls voluntary movements. Regulates balance and muscle tone
69
What is the cerebellum involved in
with motor movements that become automatic (typing, writing)
70
Where are half of the neurons in the brain located?
cerebellum
71
What are the 2 functions of the thalamus
1. Relay: all of our senses (except smell) send information to the thalamus and thalamus released information to other brain areas
2. Filter: filters information and highlights what is important
72
What is the limbic system linked to
a variety of functions. ex// emotion, memory, learning, motivation
73
What 2 things are the hippocampus linked to
1. formation of new memories
2. formation and maintenance of cognitive maps
74
How many amygdala do we have
2, one of left and one on right
75
What is the amygdala associated with
1. aggresion 2. emotion 3. fear 4. perception of emotion 5. emotional memories
76
Why is the amygdala the alarm system of the body?
it activates and informs us when there is a threat, real or imaginative
77
Why is the hypothalumus called the "The brain within the brain"
controls and regulates a variety of functions essential for survival
78
What are the 3 main functions of the hypothalamus
1. Drives (hunger, sex, thirst)
2. Homeostasis (balance)
3. Social bonds (produces oxytocin)
79
What is the cerebral cortex
the outer layer of the brain
80
What is the corpus callusom
A bundle of nerve fibers in between the two hemispheres of the cortex. It is what the two hemispheres use to communicate with one another
81
Where does the left hemisphere receive info from + control?
Receives info from and controls the right side of the body
82
Where does the right hemisphere receive info from + control?
Receives info from and controls the left side of the body
83
What are the 4 lobes of the brain
Frontal, Parietal, Temporal, Occipital
84
Each lobe consists of two areas: _________
Primary and Association areas
85
What are primary areas in a lobe
They are linked and associated with the processing of either motor or sensory information.
86
What primary area is found in the occipital lobe and what does it do
P. visual cortex. Processes visual information
87
What primary area is found in the temporal lobes and what does it do
P. auditory cortex: processes auditory information
88
What primary area is found in the parietal lobe and what does it do
P. sensory cortex. . It receives information from the skin, muscles and joints. Processes information pertaining to touch, pain, temperature etc..
The right part of the parietal cortex receives info from the left side of the body. The left part of the parietal cortex receives information from the right side of the body.
89
What primary area is found in the frontal lobe and what does it do
P. motor cortex. controls voluntary movements. The right part of the motor cortex services the left side of
the body and the left part services the right part of the body.
90
What is an association area
linked and associated with higher and more
complex mental functioning (e.g., reasoning). The association areas are also involved in the
processing of complex motor or sensory information
91
What is the main job of the PNS
carry information between body to CNS and vise-versa
92
What are the two main divisions of the PNS
Somatic and Automatic
93
what are the 2 main functions of the somatic system
1. Sensory
2. Motor function
94
What are the axons of the sensory neurons called and why
afferent axons because they carry information from
the body/the external world to the CNS
95
What are the axons of the motor neurons called and why
efferent axons because they carry information from
the CNS to the body
96
What does the autonomic NS consist of
glands, organs, and involuntary muscles
97
What are the 2 divisions of the ANS
Sympathetic and Parasympathetic
98
What is the function of the Sympathetic system
Fight or Flight system
99
What is the function of the Parasympathetic system
Rest and Digest
100
What is the endocrine system and what does it consist of
a major communication network. consists of gland and hormones
101
what are hormones
Hormones are chemicals and they carry messages from the endocrine system to the
body system, as well as to the brain. Hormones influence both physical processes, as well as mental processes.
102
What are the 3 types of hormones:
1. homeostasis. ex// insulin
2. reproductive. ex// testosterone
3. Stress. ex// epinephrine
103
what is the pituitary gland?
It is the master gland of the endocrine system. It is the master gland because it
is the boss of almost all the other glands of the endocrine system
104
how does the nervous system and endocrine system affect each other
The nervous system controls the endocrine system via the hypothalamus. The hormones of the ES (endocrine system) influence and affect the NS (nervous
system), including the brain.
105
what is the function of the frontal lobe
tasked with decision making (anterior, frontal portion) and movement (posterior, back regions). The prefrontal cortex (most anterior portion) receives input from across the cerebral cortex and helps us decide when, why and how we do things.
106
what is the function of the parietal lobe
It houses the primary sensory processing area for touch but receives information about what we are seeing from the visual cortex. This helps us orient ourselves in our environment. Damage to this region interferes with our ability to pay attention to objects and locations in space.
107
what is function of temporal lobe
The temporal lobes assist with the task of forming memories and processing sound. It houses the primary auditory cortex, which is the primary sensory processing area for hearing or object idenitifcation
108
what is function of occipital lobe
house the visual cortex, which is the primary sensory processing area for visual information, or light.
109
what are the major divisons of cerebellum
1. spinocerebellar (fine tunes motor patterns)
2. vestibulocerebellar (adjusts posture and balance)
3. cerebrocerebellar (adjusts timing and planning of movements).
