Final Exam Flashcards
from previous exams (147 cards)
1
Q
Neuroglia
A
Non-neuronal cells that are not electrically excitable.
2
Q
Which structure is specialized to send electrical signals over varying distances?
A
Nodes of Ranvier
3
Q
Which type of glial cell makes cerebral spinal fluid?
A
Ependymal cells
4
Q
Which cell types are found in the central nervous system?
A
Oligodendrocytes
Ependymal cells
Astrocytes
Microglia
5
Q
Which two cell types are responsible for making the myelin sheath?
A
Schwann cells
Oligodendrocytes
6
Q
Which cell type would respond following an injury to the central nervous system?
A
Microglia
7
Q
Astrocytes
A
maintain the blood-brain barrier
closely associated with synapses.
Nutrition and support
8
Q
Oligodendrocytes
A
add a layer of myelin
only in CNS
9
Q
Schwann Cells
A
Only PNS
provide a section of myelin sheath for peripheral nervous system neurons, and in this way, they function similarly to the oligodendrocytes.
regeneration of injured axons.
Repair injury
10
Q
Microglia
A
via phagostytosisAs immune cells, microglia identify and destroy clumps of proteins, dead/dying cells, or foreign pathogens that enter into the brain. After an injury to the central nervous system, like a traumatic blow to the head, microglia rapidly react to the area of the insult.
“PRUNING” allow to form new connections
11
Q
Ependymal Cells
A
Along the inside of the ventricles
Produce CSF
Part of choroid plexus- network of blood vessels and cells that form a boundary between the blood and the CSF.
12
Q
The inside of the neuron has a more ______ charge than the outside of the neuron.
A
negative
13
Q
Which particular ions are concentrated inside and outside membrane
A
sodium, calcium, and chloride are concentrated outside
potassium and negatively-charged molecules like amino acids and proteins are concentrated inside
14
Q
equilibrium potential
A
CHEMICAL AND EECTRICAL FORCES ARE BALANCED
The neuron’s membrane potential at which the electrical and concentration gradients for a given ion balance out is called the ion’s
15
Q
resting potential
A
-65 to -70mv
16
Q
A cell is at rest at -65 mV, and chloride channels open. In which direction does chloride flow and how does this affect the membrane potential?
A
Since chloride’s equilibrium potential is -65 mV, chloride is already at equilibrium, so there will be no net movement of the ions in either direction, and the membrane potential will not change.
17
Q
Sodium Potassium Pump
A
It uses energy (ATP) to move:
3 sodium ions (Na⁺) out of the cell 2 potassium ions (K⁺) into the cell maintaining the presence of electrochemical gradients
18
Q
The activity of the sodium-potassium pump can be evaluated by measuring how much sodium leaves the cell. If a cell was treated with a drug that prevented the synthesis of ATP, how would efflux of sodium change compared to baseline?
A
The sodium-potassium pump requires ATP to move sodium out of the cell. If ATP synthesis was blocked, the pump would not be able to function.
19
Q
In a typical neuron, at rest, which ion channel has the most open non-gated (leak) channels?
A
Potassium
20
Q
Potassium is concentrated…
A
inside
21
Q
The Absolute Refractory Period
A
occurs during the rising and falling phase of the action potential. Another action potential cannot be fired under any circumstance during this time.
22
Q
The Relative Refractory Period
A
Occurs during the undershoot. Another action potential can be fired, but a stronger stimulus is needed than when the cell is at rest
23
Q
Retrograde is only possible during
A
depolarization
24
Q
Which ion is responsible for the falling phase of the action potential?
A
Potassium
25
describe the relationship between the external sodium concentration and the shape of the action potential?
If the external sodium concentration were increased, the amplitude of the action potential would also increase.
26
Where are the voltage-gated ion channels located in the cell?
axon hillock and axon
27
Which ion is responsible for the rising phase of the action potential?
Sodium
28
If you wanted to measure action potentials, where would you place your recording electrode? (Select all that apply)
axon and axon hillock
29
Which factor is responsible for preventing the action potential from going backward down the axon?
Inactivated sodium channels
30
When a depolarizing stimulus arrives at the axon terminal, what type of channels are opened that allow for neurotransmitter release?
voltage-gated calcium channel
31
Small molecule vesicles
Dock at active zones
smaller vesicle size
32
Neuropeptide vesicles
must travel from cell body to terminal
Slower release of NT
33
ways that neurotransmitter signaling is terminated?
chemical degradation
Diffusion away from the synapse
Reuptake
34
Ionotropic receptors
Postsynaptic receptors in which neurotransmitters bind and cause the opening of an ion channel. The ion channel and receptor are the same transmembrane protein.
35
Metabotropic receptors (G-protein coupled receptors).
Postsynaptic receptors in which neurotransmitters bind and cause the activation of an associated G-protein and cell signaling cascades. The affected ion channel and receptor are found on different transmembrane proteins..
36
When an ionotropic receptor is opened, what flows through the pore of the channel protein?
ions
37
Which is direct mechanism and which is indirect
direct: ionotrphic
Indirect: metabotropic
38
The Requirements for Evolution
variation within a population
some variation must be heritable
Some individuals produce more offspring that survive to reproduce than others do.
Survival and reproductive success are not random!
39
4 major themes of evolution
Nervous systems rely on one major cell type for communication (neuron)
With bilateral symmetry came centralization and cephalization
Brain function is localized, relative size of brain regions are important
Brain is not static (not changing)
40
Brain Nuclei:
clusters of cells
41
Neuron Doctorine
Nerve cells communicate via contact (point to point) not continuity. Neuron = functional unit of nervous system.
42
what cellul;ar structure regulates concentration of different ions
cell membrane
43
In the neuronal membrane, phospholipids, each of which has a polar _____ region and a non polar ______ region
polar hydrophophilic and nonpolar hydrophobic region
44
axons in the PNS can regenrate thanks to...
Schwann cells
45
which glial cell is associated with alzheimers dz?
microglia
46
axoplasmic transport
a process that utilizes motor proteins to move materials both towards and away from the cell body of a neuron along microtubules.
47
true or false:
the value of the permeability of resting membrane potential is dependant upon the realative permeability of membrane to both Na+ and K+
True
48
CSF is circulated by
epedyml cells
49
electrical differences that exactly balances an ionic concentration gradient across membrane
Equilibrium potential
50
the cerebellum in squirells is larger than it was 50 years ago. How can this occur? include the specific requirements of evolution
natural selection. overtime, a POPULATION can adapt to their enviroment for survival , as INDIVIDUALS reproduce, they can accumulate new developments to help them thrive. However, there are 4 requiremtns for evolution:
1. Must be VARIATION in a population
2. must be HEIRITABLE
3. produce VIABLE offspring
4. survival and reproduction is NOT RANDOM!
51
similarity between glial and neuronal communication
both chemical communication (althoough neurons can also use electrical communication)
52
Difference in communication glial and neurons
Glial: broadcast signals widely
Neurons: Point to point
53
Cl- ions make inside more (-) and lead to...
IPSP
54
sodium channels opened, allowinf sodium to enter cell will result in... IPSP or EPSP
EPSP
55
Volatage gated _____ Channels are concentrated at the Nodes of Ranvier, with few to none located under the myelinated sheath
Na+ channels
56
what does it mean to say that a NT exerts mainly ionotrophic effects
it opens ion channels for particular ions
57
changes that occur in cells as a result of metabotropic receptor activation are (faster/slower) than channges at occur in cell as a result of ionotrphic receptor activatioon.
SLOWER
58
which NT is principally removed from the synapse by enzymatic degradation
acetocholine
59
a mouse is extremely deficient in tryptophan. what NT is it deficient in?
seretonin
60
IPSP always make it
harder to generate action potential in post synaptic cell
61
In the mammalian brain, _______is the major inhibitory neurotransmitter, and ________is the major excitatory neurotransmitter.
GABA = inhibitory
Glutamate = excitatory
62
______ are NT that are small lipid molecules released by postsynaptic neurons and act on presynaptic terminals
endocannabinoids
63
NT that is released along other NT and known as "cotransmitter". Functions in cellular storage and transfer, "energy currency of cells"
ATP
64
general name for process by which multipule excitatory and inhibitory signals can add together to affect membrane potential of a postsynaptic neuron
summation
65
Proteins called connexins form channels known as _____ that allow ions to pass directly from the cytoplasm of one neuron to the cytoplasm of another neuron
gap junctions
66
serotenergic neuron secretes seretonin, which is synthesized in the ________ and stored in synaptic vesicles
synthesized: axon terminals
Stored: synaptic vesicles
67
When a neuron is stimulated and a nerve impulse reaches the axon terminals, voltage-gated _______channels open in the membrane, which results in exocytosis of serotonin into the synaptic cleft.
Ca2+
Na⁺ is responsible for depolarizing the membrane during action potentials.
K⁺ helps repolarize the membrane after an action potential.
They're critical for electrical signaling, but not for triggering neurotransmitter release like calcium!
68
the protiens that are in presynaptic cleft that play a role in allowing exocytosis of NT is
SNARE protiens
69
seretonin diffuses across membrane and binds to _____ and eventually cleared by _______
binds to metabotropic receptors
cleared via reuptake transporters
70
distinguish neuropeptides from monoamines 2 ways
Neuropeptides are large
monoamines = reuptake, neuropeptides = no reuptake
71
state of ion channels during each phase:
rising
falling
resting
absolute refractory period
rising OPEN
falling INACTIVE
resting REST
absolute refractory period OPEN & INCATIVE
72
absolute refractory period
Na+ channels are closed, cannot open again- impossible to fire AP. K+ slow to close.
73
Stimulating the axon in the middle creates two action potentials — one traveling toward the axon terminal, and one traveling back toward the soma — because WHY?
When a neuron is stimulated to threshold in the middle of the axon (rather than at the axon hillock), you create a local depolarization that can spread in both directions.Both sides of the membrane adjacent to the stimulated site are at rest, so both are excitable.
74
What would happen if, before a neurotransmitter binds to its receptor, the concentration of chloride ions inside and outside the postsynaptic neuron is experimentally made the same?
No net movement of Cl⁻ ions across the membrane
As a result, no hyperpolarization would occur, because Cl⁻ influx is what normally makes the membrane potential more negative (inhibitory postsynaptic potential, or IPSP).
75
Contain mechanically gated ion channels that open when cell is under mechanical stretch
Merkels discs
76
dermatome
area of the skin innervated by the right and left dorsal roots of a single spinal segment
77
Receptors that continually send info to the brain as long as a continuous stimulus is applied are considered to be (slow/rapidly adapting)
SLOWLY
78
white matter:
Gray matter:
consist of
White: myelinated axons
Gray: cell bodies
79
axonal transport is important for neuron function because
transports proteins from one side of axon to the other. Disruption would ihibit nutrients from getting to other side.
80
natural selection results in change at...
population level
81
Microglia
found in CNS
defense, "pruning, allow new cinnections to form, waste removal (phagocytosis)
82
Schwann cells
found in PNS
facilitate repair of axon, wrap around axon for myelinsheath
83
conswequences of astrocytes not forming
1. neurons would not get as much ATP, not enough glucose/lactose form
2. weakened structural support,
84
IPSP and what ion:
inhibitory hyperpolarizing release of K+ and cl-, approaches more (-) threshold
85
EPSP:
excitatory, depolarizing intake of Na+, approaches more (+)
86
relative refractory period:
K+ channels slow to close, action potential can be fired only from stronger than normal stimulli
87
how refractory period prevents retrograde transmission
cannot trigger/go backwards
can only be in antergrade because as the next spot is triggered, the spot before cannot due to being in refractory period
88
there are 2 driving forces that act on ions and determine their movement across the neuronal membrane. what are these forces?
concentration and electrical gradient
89
what determines strength of concentration and electrical forces
chemical=concentration
charge difference = electrical
90
3 major players in Resting Membrane Potential
1. Saltly fluids on either side of membrane (salts dissociate, charged differences)
2. Membrane Phospholipid bilayer, selective barrier, doesnt pass charged ions.
3. proteins span membrane function as channels for ions
91
Graded vs action potential
Graded: Before axon hillock, input signal from dendrites and cell body. NOT all-or-none.
92
what triggers action potential
G-raded potential summatim
D-epolarizing Stimuli
o-pening Na+ channels
M-moving closer to 0
93
Breaking (+) feedback loop:
inactivation of Na+ channels
94
What would make AP more liekly to fire at axon hillock?
Increased density of voltage gated Na+ channels @ axon hillock- more depolarization
95
K+ open slower than Na+, what would happen if they opened even slower?
PROLONGED DEPOLARIZING PHASE AND DELAYED FALLING PHASE
96
(+) FEEDBACK
During rising phase, membrane potential becomes more (+), more Na+ enter the cell. This creates a (+) feedback loop, which amplifies initial depolarization, causing membrane potential to rise rapidly.
often referred to as "all-or-nothing" where AP either fires or not due to rapid amplification
97
electrical synapse
electrical current flows directly from one cell to the next, built for SPEED!
98
chemical synapse:
Slow, unidirectional
99
what accounts for antergrade in nerve impulses? (Nerve impulses can only be antergrade!)
Anterograde conduction of action potentials is driven by the sequential opening of voltage-gated sodium channels along the axon.
100
3 main receptors found at chemical synapse
ionotropic, metabotropic, autoreceptors ( Inhibit neurotransmitter release, causes negative feeback loop)
101
Explain how a single neurotransmitter can have different effects
in different tissues
Can bind to different receptor types (ionotropic or metabotropic) can trigger different effects
102
how are amino acids synthesized stored and secreted
Amino acid are synthesized in the cytoplasm, stored in small synaptic vesicles, and released via Ca²⁺-dependent exocytosis, affecting rapid and specific synaptic transmission.
103
Peptide stored and synthesized
synthesized in cell body, stored in large vesicles.
104
SNARE Protein docking process is mediated by V-Snares on the ____ and T-Snares on the ______.
V-Snares: vesicle
T-Snares: presynaptic membrane
105
The entry of Ca2+ is crucial for triggering ...
SNARE proteins snap together to create a fusion pore, exocytosis
106
Understand what characterizes an endogenous rhythm.
endogenous rhythm refers to internal biological rhythms.
period, frequency and amplitude
107
Provide evidence demonstrating that the suprachiasmatic
nucleus is the “master clock” in mammals.
1. Ablation of SCN abolishes rhythmicity
2. SCN neurons show rhythmic activity in lab
3. transplanting SCN from one animal to another transplants certain rhythms
108
Describe the input pathway and clock mechanism for
circadian rhythms in mammals;
Input: photoreceptors in retina detect light -> send signal to hypothalamus -> info entrains the rhythm
Clock/Pacemaker: SCN (maintains biological timing)
109
w how rhythmic
activity of the master clock is communicated to the rest of
the body.
SCN- neural connections to the pineal gland/ secretes melatonin into blood
110
effects of exposure to light at night on melatonin,
sleep, weight gain, and glucose regulation
- disruption of sleep/wake patterns
- dysregulation of circadian gene expression
- disruption of predictable patterns
111
EEG
Electroencephlogram
records brain rhythms
-Synchronousactivity=largeslow EEG signals
-
112
two main ways in which synchronous rhythms can
be generated.
1. led by pacemaker (SCN)
2. arise from collective behavior of all participants (people clapping in audience randomly - unsynchronized- then all uniform rhythm)
113
how REM and non-REM sleep states differ with regard
to brain function, nervous system activation, and physiology
NONREM: large slow,
not moving, low body temp, metabolic rate low (oxygen consumption), PNS dominates, about 75% time asleep
REM:faster, smaller, dreams, increase metabolic and body temp, muscle paralysis (atonia), SNS dominates, 25% time asleep
114
functions of sleep
restorative, adaptive, memory consolidation, waste removal
115
glymphatic system and how it relates to sleep and cognitive function
waste clearance system, works mainly during sleep. Made up of astrocytes, CSF, interstitial fluid (fluid between cells)
116
lymphatic system
immune and circulating systems that help protect body from illness and maintain fluid.
117
why can you predict the equilibrium potential of k+ to be (-)?
K⁺ tends to diffuse out of the cell, and this outward flow creates an inside-negative voltage that opposes further outflow.
118
at rest, k+ are highly permeable. neuronal membrane at rest has a membrane potential that is different than k+ Equilibrium potential what explains this
there are other ions flowing too, contributes to overall potential
119
signal amplification is possible in postsynaptic neuron
chemical synapse
120
characterized by calcium triggered neurotransmitter release
chemical synapse
121
this protein is a receptor and an ion channel
ionotropic
122
this receptor type can cause inhibitory response in post synaptic cell
ionotropic and metabotropic
123
during repolarization, na+ channels are______.
INACTIVE
124
what causes undershoot
The undershoot happens because voltage-gated K⁺ channels remain open briefly after repolarization, allowing excess K⁺ to exit the neuron and making the inside more negative than the resting potential.
125
how does capsaicin affect trpv1 channels
depolarizes membrane, ap fires, send signals to brain from nociceptors
126
In response to Noepinephrene, the contractile activity in some organs is increased, whereas the contractile activity in other organs is decreased. How is this poossible for the same NT to have such varied effects?
Different receptor types, has different effects on different organs depending on what receptor is doing.
127
Why lower metabolic rate
Conserve energy
128
Deep sleep
Stage 4
129
Memory consolidation hypothesis
Transfers memory to long term memory
130
Atonia
Tots loss of muscle movement
131
Cerebral cortex
Involved in memory consolidation during sleep
132
Retinohypothalamic tract
Pathways for light info to SCN
133
Zeitgerbers
Environmental time cues
134
Free running rhythm
Unregulated circadian rhythm in absence of cues
135
Circadian rhythm regulates…
Not just sleep- body temp, reflex, hunger and attention
136
Ultradian
<24 hours (eg REM cycles)
137
Infradian
>24 hours (eg menstrual cycle)
138
Blue light
Most effectively inhibits melatonin and delays sleep
139
Entrainment
Circadian rhythms can adjust to environment using zeitbergers
140
SCN
Regulates circadian rhythm
141
Thalamus
Sensory perception
142
Optic chiasm
Point where optic nerves cross
143
Intrinsic photosensitivity
Ability of retinal cells to detect light
144
Retinal ganglion cells
Neurons that transmit visual information to brain
145
Endogenous rhythm
Rhythm generated internally, independent of external cues
146
Light inhibition
Suppression of melatonin by light exposure
147
Circadian gene expression
Genes regulated by body’s internal clock
