Chapter Quiz 2 Flashcards
Inside the neuron there is a high concentration of _______ ions, while outside the cell there is a high concentration of _______ ions
potassium; sodium
Transporter molecules are involved in the _______ of neurotransmitter at the synapse
reuptake
The resting membrane potential is maintained by electrostatic pressure and _______ acting on the cation ________
diffusion; potassium
In general, the action potential is initiated at the
axon hillock
Hyperpolarizing stimuli ________
decreases the likelihood the neuron will fire an action potential
Action potentials are all-or-none phenomena. This means that _______
the amplitude of the action potential is independent of the size of the stimulus
The peak of the action potential is caused by the ________ of ___________ channels
opening; sodium
During the relative refractory phase,
the neuron is briefly hyperpolarized
Action potentials generally are not propagated along dendrites because dendrites usually have few __________
voltage-gated ion channels
Myelin increases the speed of conduction because it _________
offers considerable resistance to the flow of ionic current
________ seizures are most often accompanied by an unusual sensation called an aura and my not necessarily involve the entire brain
Complex partial
A neuron can be pushed to threshold if many EPSPs arrive at the axon hillock at the same time, but from different locations across the cell body. This process is referred to as __________
Spatial Summation
Ions are molecules that carry an electric charge due to the gain or loss of __________
electrons
A key causal event in the release of neurotransmitter molecules from vesicles into the synaptic cleft is the __________
influx of calcium ions in response to the arrival of an action potential at the terminal
Whether a synapse is excitatory or inhibitory is determined by the _________
type of transmitter receptor in the postsynaptic neuron
A ligand is a _________
substance that binds to receptor molecules
Which statement about multiple sclerosis is false?
It causes complex partial seizures
True Facts about MS:
1. it interferes with saltatory conduction
2. currently there is no cure
3. it damages myelin
After release, neurotransmitters are deactivated in the synapse by
the process of enzymatic degradation
The “lock and key” analogy relates to the ________
action of transmitter molecules on receptor proteins
Desynchronized electrical activity is seen _________
in a normal active brain
