exam 1 questions Flashcards
T or F: electrical synapses are present in non-neural cells
true
T or F: both pre and post-synaptic regions of synapses have structural specializations required for signaling
true
which of the following is false:
- plato believed the brain was involved in mental processes
- aristole thought the heart was the center of intelligence
- the egyptians believed memories were stored in the brain
- galen believed nerves were tubes
the egyptians believed memories were stored in the brain
what is the mind-brain problem?
individually human mental capacities exist outside the brain, that is in the mind
the combined work of bell and magnesia revealed what fundamental fact about the spinal nerve?
spinal nerves are bundles of sensory and motor nerves and in each sensory and motor nerve fiber
for what purpose did Franz Joseph Gall study the dimensions of the human head?
to understand the propensity for certain personality traits
**what experiment convinced scientists nerves acted as wires?
**two of the above
what is the rationale behind the use of animal models to understand the human brain?
the nervous systems of different species of animals and humans share many common mechanisms
paul broca’s contributions to the understanding of the nervous system function included?
providing strong evidence for localization of function in the human cerebral cortex
T or F: dendritic spines are sensitive to the quality of the environment experienced during early development
true
identify the protein that helps anterograde transport to move materials from soma to the terminal
kinesin
what is the role of astrocytes in the CNS?
regulate contents of the extracellular space
neurons compromise two types of processes: axons and dendrites. what is the major difference between the two?
dendrites receive incoming signals from other neurons while axons carry the output of the neurons
which of the following is FALSE regarding axons:
- no rough
- can form recurrent collaterals
- microtubules are present throughout the axon
- have variable diameters
microtubules are present throughout the axon
T or F: anterograde axonal, fast transport, and retrograde axonal transport move at the same speed
false
which of the following regarding projection neurons is FALSE:
- have long axons
- are also called golgi type 2 neurons
- include many pyramidal cells
- extend between brain regions
are also called golgi type 2 neurons
cerebral cortex contains some of the most beautiful cells in the brain, such as basket cells, bouquet cells, double-bouquet cells, and chandelier cell. these cells get their names from distinct patterns of their dendritic trees and axonal arbors. what stain would you use if you wanted to see all the cells in all of their glory?
golgi stain
which of the following cells would be likely to myelinate an axon in your spinal cord?
oligodendroglia
what does the neuron doctrine state?
individual cells communicate by contact and not continuity (cajal)
how does the sodium potassium pump help maintain the resting membrane potential?
pumps potassium in and sodium out
how do the lipids of the neuronal membrane contribute to the neuronal membrane potential?
forms a barrier to water-soluble ions and water
how do action potentials differ from passively conducted electrical signals?
action potentials are signals of fixed size and duration; passively conducted signals are conducted over long size and duration
which of the following ions is at a higher concentration inside than outside a neuron during the falling phase of an action potential?
K+
ion X is negatively charged and more concentrated inside than outside of the cell. therefore…
EX is postive
if Ik = 0, then
- gK is zero
- potassium is impermeable
- Vm = EK
when would the driving force for Na+ be largest?
-80 mV
which of the following statements is FALSE?
- equilibrium occur when diffusion and electrical forces are balanced in the cell
- large concentration of ions must move to change the membrane potential of the cell from negative to positive
- each ion has its own equilibrium potential
- cells without a resting potential can’t transmit an AP
large concentration of ions must move to change the membrane potential of the cell from negative to positive
assume the neuron has a resting membrane potential of -65 mV and ECl of -65 mV. if you could bring the membrane potential of this neuron up to +20 and open channels permeable to Cl-, which way would Cl- flow?
into the cell
using the Nernst equation, if the Cl- concentration outside of the cell was decreased by 5x, what would happen to the K equilibrium potential?
stay the same
in order for a neuron to generate an AP, it requires?
entry of cations which depolarizes the membrane
T or F: amount of depolarization controls firing frequency
true
which are characteristics of voltage gated sodium channels?
various types of exist and compromised of a single long protein
Hodgkin and Huxley used which technique to determine ion permeability changes that occur during an AP?
voltage clamp
excitatory postsynaptic potentials (EPSPs)
are usually due to opening of transmitter-gated channels
why don’t APs move toward the cell body from the axon (go backwards)?
absolute refractory period
if an axon at -50 mV were exposed to TTX the result would be
TTX will have little to no effect
if the sodium channel inactivation gate couldn’t open until the cell was at -85 mV what would happen to the cell signaling?
only one AP could be sent
if delayed rectifier K+ channels worked more efficiently, the membrane would?
repolarize at a faster rate after an AP
the movement of what ion is reflected in the rising phase of the action potential?
inward, Na+
which of the following is FALSE regarding electrical synapses?
- consist of unique connections called gap junctions
- common in glial cells
- considered evolutionarily older
- unidirectional
unidirectional
which of the following is most directly responsible for the release of NT from the presynaptic terminal?
concentration of calcium in the presynaptic terminal
which of the following is NOT true about NTs?
- different NTs can have different synthetic pathways
- a single neuron can only produce and release one NT type
- upon synthesis, NTs travel in vesicles until released at the synaptic cleft
- NTs can be peptides, amines or amino acids
a single neuron can only produce and release one NT type
T or F: symmetrical synapses in the CNS are usually excitatory
false
which of the following NTs are stored in large secretory granules (large dense core vesicles)?
peptides
a dendrite with which properties have the lowest length constant?
low membrane resistance and high internal resistance
quantal analysis shows that a single AP at the NMJ causes an EPSP of 40 mV or more as against only a few tenths of a mV at many CNS synapses. what accounts for this difference?
a larger number of synaptic vesicles releasing NT at the NMJ compared with CNS synapses
T or F: if SNARES on the synaptic vesicles were damages or removed vesicle release would increase
false
a presynaptic neuron fires at 10 APs per sec. and the postsynaptic cell does not fire an AP. when the same presynaptic neuron fires at 20 APs per sec. however, the postsynaptic cell fires. this is an example of?
temporal summation
