N-Neurophys & Neuroanatomy 2

Front 1

Axons that arise from cell bodies located in one brain region that synapse on neurons in another region are called

Back 1

Axons that arise from cell bodies located in one brain region that synapse on neurons in another region are called projection fibers.

Front 2

_____ ions enter a neuron when it reaches the threshold of excitation.

Back 2

Sodium channels open permitting sodium ion entry when a neuron reaches the threshold of excitation. This allows a neuron's membrane potential to briefly become positive and produces the action potential.

Front 3

Neuron terminal buttons

Back 3

Neuron terminal buttons release neurotransmitters across synaptic clefts and into the extracellular fluid.

Front 4

When a neuron is at rest, the inside of an axon

Back 4

When a neuron is at rest, the inside of an axon is negatively charged with respect to the outside. A nominal value is –70 mV.

Front 5

While neurons cannot fire during _____, intense stimuli can trigger an action potential during _____.

Back 5

the absolute refractory period; the relative refractory period. While neurons cannot fire during the absolute refractory period, intense stimuli can trigger an action potential during the relative refractory period. The relative refractory period allows neurons to represent stimulus intensity by their firing rate."

Front 6

The difference in electrical potential inside and outside the cell at any point in time is the

Back 6

The difference in electrical potential inside and outside the cell at any point in time is the membrane potential.

Front 7

Presynaptic facilitation and presynaptic inhibition both take place at the

Back 7

Presynaptic facilitation and presynaptic inhibition both take place at the terminal button and are produced by axoaxonic synapses. Presynaptic facilitation increases neurotransmitter release while presynaptic inhibition decreases it.

Front 8

The process by which ions of a similar charge repel each other and thus evenly distribute themselves is called

Back 8

The process by which ions of a similar charge repel each other and thus evenly distribute themselves is called electrostatic pressure. Electrostatic pressure is one of two processes (the other is diffusion) that determine the distribution of ions inside and outside of a neuron's membrane.

Front 9

The specialized proteins located in neuronal membranes that have passages that can open or close are called

Back 9

The specialized proteins located in neuronal membranes that have passages that can open or close are called ion channels.

Front 10

The mechanism that causes an action potential involves a brief

Back 10

The mechanism that causes an action potential involves a brief drop in membrane resistance to sodium ions. The entry of positive sodium ions depolarizes the neuron.

Front 11

The part of the neuron that carries information to its own cell body is called the

Back 11

A dendrite carries information to the cell body (soma).

Front 12

Which of these detect and generally reduce transmitter synthesis and release?

Back 12

Autoreceptors are metabotropic receptors that detect and generally reduce neurotransmitter synthesis and release. Autoreceptors are presynaptic neuron receptors that are linked to a G–protein. Autoreceptors bind circulating drugs, neurochemicals released extracellularly by the neuron itself, or neurochemicals released by other neurons. Autoreceptors help neurons adjust the synthesis and release of neurochemicals through the second–messenger system.

Front 13

The _______ interacts with the cortex to produce cortical EEG rhythms.

Back 13

Thalamus. Thalamic–cortical circuits generate cortical EEG rhythms in the upper cortical layers. Thousands of synapses are synchronized together, due to their shared input signals, so they simultaneously depolarize (become more positive) or hyperpolarize (become more negative).

Front 14

To which of these would a neurotransmitter attach to produce long–lasting changes in neurons like an increase in vigilance?

Back 14

A neurotransmitter would attach to a metabotropic receptor to produce long–lasting neuronal changes like vigilance. Neurotransmitter binding activates G proteins which can produce changes in a neuron's membrane potential and performance.

Front 15

The postsynaptic potential produced by an ionotropic receptor is

Back 15

The postsynaptic potential produced by an ionotropic receptor is rapid and short–lived.

Front 16

The brain and spinal cord comprise the

Back 16

The brain and spinal cord comprise the central nervous system.

Front 17

What do Axoaxonic synapses do?

Back 17

Alter the amount of neurotransmitter released by the postsynaptic neuron. Axoaxonic synapses involve chemical communication between two terminal buttons. They can increase or decrease the amount of neurotransmitter released by the postsynaptic neuron."

Front 18

The voltage level that triggers an action potential is called

Back 18

The voltage level that triggers an action potential is called the threshold of excitation. This threshold is approximately 20 mV more positive than a neuron's resting potential.

Front 19

Which structure is involved in aggression, defense, fear, and reproduction?

Back 19

The amygdala, a limbic structure, is involved in aggression, defense, fear, and reproduction.

Front 20

Which would produce an inhibitory postsynaptic potential (IPSP)?

Back 20

An IPSP is a negative change in a neuron's membrane potential that makes it less likely to initiate an action potential. Both positive potassium ions leaving a neuron and negative chloride ions entering a neuron can produce IPSPs.