Nuerons

Question 1

what is the cell membrane?

Answer 1

the semipermeable membrane surrounding the cytoplasm of a cell.
(double layer)

Question 2

what is polarization of a cell?

Answer 2

difference in electrical charge between the inside and outside of a cell

Question 3

what is voltage?

Answer 3

the difference in electrical charge between two points

Question 4

what is resting potential?

Answer 4

A resting (non-signaling) neuron has a voltage across its membrane

Question 5

what does resting potential charge come from?

Answer 5

ions

Question 6

what are ions?

Answer 6

any atom or group of atoms that bears one or more positive or negative electrical charges.
- Positively charged ions are called cations; negatively charged ions, anions.

Question 7

what is negatively charged?

Answer 7

chloride, proteins & amino acids

Question 8

what is positively charged?

Answer 8

Na+ and K + (sodium and potassium)

Question 9

why does resting potential occur?

Answer 9

because of the unequal distribution of +/- ions across membrane

Question 10

what happens to Na+ and K+ during resting potential?

Answer 10

at rest, Na+ is outside the cell and K+ is inside, when nueron fires an abrupt reversal of electrical charge occurs (Na+ and K+ switch)

Question 11

what is action potential?

Answer 11

A large, sudden and brief reversal in the polarity of a membrane. (an abrupt depolarization (becomes less negative) inside the cell membrane)

Question 12

why does action potential occur?

Answer 12

when different ions cross the neuron membrane. A stimulus first causes sodium channels to open (Na+). Because there are many more sodium ions on the outside, and the inside of the neuron is negative relative to the outside, sodium ions rush into the neuron.

Question 13

what are postsynaptic potentials?

Answer 13

a temporary change in the electric polarization of the membrane of a nerve cell (neuron).

Question 14

what happens during postsynaptic potentials?

Answer 14

chemical transmission of a nerve impulse at the synapse, the postsynaptic potential can lead to the firing of a new impulse.

Question 15

what do postsynaptic potentials look like?

Answer 15

they are graded (waves)

Question 16

what are excitatory postsynaptic potentials?

Answer 16

small local depolarization (inside becomes more positive)

Question 17

what are inhibitory postsynaptic potentials?

Answer 17

small local hyperpolarization (inside becomes more negative)

Question 18

where do postsynaptic potentials take place?

Answer 18

axon hillock

Question 19

what is the threshold of excitation?

Answer 19

a level above which any simulation produces a massive depolarization

Question 20

what is a synapse?

Answer 20

The junction between the most distal (farthest from soma) part of an axon terminal and the membrane of a second neuron.

Question 21

what are the postsynaptic receptors?

Answer 21

The particular effect of a neurotransmitter on the postsynaptic membrane depends on these
(ionotropic and metatropic)

Question 22

what is a ionotropic receptor?

Answer 22

open channels directly produce fast action
- opens directly and rapidly when the
correct neurotransmitter molecule binds with it.

Question 23

what is a metabotropic receptor?

Answer 23

open channels indirectly and slowly to produce longer lasting effects
- This type of receptor opens more slowly, and has longer lasting and more diffuse effects.

Question 24

what are glial cells?

Answer 24

Cells in the CNS that can become malignant.

Question 25

what is an axoaxonic synapses?

Answer 25

formed by one neuron projecting its axon terminals onto another neuron’s axon

Question 26

The part of the neuron that brings information to the soma?

Answer 26

dendrite

Question 27

what does an axon do?

Answer 27

takes information away from the soma.

Question 28

This property of the neuron cell membrane creates polarization and the resulting resting potential voltage?

Answer 28

selective permeability

Question 29

what does depolarization mean?

Answer 29

inside of cell becomes more positive

Question 30

what does hyper-polarization mean?

Answer 30

inside of cell becomes more negative

Question 31

what is the name of area in the soma where an action potential is generated?

Answer 31

axon hillock

Question 32

what is glutamate?

Answer 32

The main “excitatory” neurotransmitter in the brain.

Question 33

what is spatial summation?

Answer 33

The combination of post synaptic potentials occurring simultaneously at different locations on the dendrite and soma.
(a mechanism of eliciting an action potential in a neuron with input from multiple presynaptic cells)

Question 34

what are three of the ways that synaptic activity is regulated?

Answer 34

axoaxonic synapses, autoreceptors on presynaptic terminals, and glial cells

Question 35

What is the resting membrane potential voltage?

Answer 35

-70 millivolts

Question 36

what are three ways that synaptic activity may be terminated?

Answer 36

reuptake, enzymatic degradation, absorption by glial cells

Question 37

what is reuptake inhibition?

Answer 37

The pharmacological mechanism by which SSRI’s/SNRI’s work

Question 38

what is summation?

Answer 38

The combination of potentials in a postsynaptic neuron.

Question 39

what are microtubules?

Answer 39

This structure of the neuron is involved in transporting molecules and helps the axon maintain its shape

Question 40

what are autoreceptors?

Answer 40

Receptors found in the presynaptic axon membrane.