Neurophysiology

Question 1

Information is transmitted from the axon terminals of one neuron

Answer 1

the presynaptic neuron

Question 2

to the dendrites and cell body of the next neuron across synapses

Answer 2

the postsynaptic neuron

Question 3

Presynaptic Membrane: on the axon terminal of the presynaptic neuron

Postsynaptic Membrane: on the dendrite or cell body of the postsynaptic neuron

Synaptic Cleft: the gap that separates the membrane

Answer 3

synapses have three components

Question 4

small spheres in presynaptic axon terminals that contain a neurotransmitter, a specialized chemical

• Neurotransmitters are released in response to electrical activity in the axon (when the cell “fire”)

Answer 4

Synaptic Vesicles

Question 5

in the postsynaptic membrane are specialized proteins that react to neurotransmitter molecules

Answer 5

Neurotransmitters Receptors

Question 6

refers to the continual remodeling of neuronal connections

Answer 6

Neural Plasticity (or neuroplasticity)

Question 7

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

Answer 7

A resting neuron is polarized

Question 8

electrically charged molecules
-are dissolved in fluid

Answer 8

Ions

Question 9

negatively charged (e.g., Cl-)

Answer 9

Anions

Question 10

positively charged (K+)

Answer 10

Cations

Question 11

Fluid inside the cell

Answer 11

intracellular fluid

Question 12

fluid outside the cell
- separated lipid bilayer cell membrane

Answer 12

extracellular fluid

Question 13

inserted into a neuron will show that the interior is more negative than the exterior (this means there are more negative ions inside the cell than outside)

Answer 13

microelectrode

Question 14

about -65 millivolts (mV)- the negative sign indicates that the cells interior is more negative than the outside

Answer 14

resting membrane potential

Question 15

• Selectively Permeable Ion Channels
• Diffusion
• Electrostatic pressure
• Sodium-Potassium Pump

Answer 15

things that work together to contribute to this membrane potential

Question 16

• Large proteins that span the membrane of the cell and allow some ions to pass in and out
• Some are semi-permeable and open all the time (e.g., K+)

→ this is called selective permeability, as some ions are allowed to move in and out, but not others

• Some are gated and open in response to something

Answer 16

Ion Channels

Question 17

opens when a specific molecule binds to the receptor

Answer 17

Ligand-Gated

Question 18

1. Diffusion
2. Electrostatic Pressure

Answer 18

Two Opposing Forces Drive Ion Movement

Question 19

causes ions to spread towards a uniform concentration, along a concentration gradient

Answer 19

diffusion