synaptic signalling

Question 1

The cell membrane is impermeable to ____.

Answer 1

charged ions

Question 2

Synaptic signalling is mediated by the

Answer 2

regulated movement of ions across the membrane

Question 3

Cells utilize active transport to

Answer 3

maintain ion gradients

Question 4

In a resting neuron there is higher___inside the cell than outside, while there is higher____and____outside the cell than inside

Answer 4

K+
Na+ and Cl-

Question 5

Since K+ concentrations are higher in the cell then out it is____to leave the cell. This is done by____

Answer 5

favourable. This is done by K+ leak channels

Question 6

At equilibrium K+ moving out of the cell is___as that moving in. This is a balance between chemical and eletrical properties thus called____.

Answer 6

the same
electrochemical gradient. Since this will result in a change of charge across the membrane the membrane now has potential

Question 7

For a single ion we can calculate membrane potential by using__

Answer 7

Nernst equation

Question 8

In the neuron K+ is not the only thing contributing to the potential so we can use____to calculate Na+ and Cl- also.

Answer 8

Goldman equation

Question 9

If one ion has a much higher permeability than the other two we can us ___to calculate the membrane potential

Answer 9

Nernst equation
Goldman?

When the relative permeability of one of the ions is very high, the Goldman equation reduced to the nernst equation for that ion.

Question 10

Myelination of axons

Answer 10

causes the wave of depolarization/repolarization to jump between nodes, increasing the speed and efficiency of the action potential. Loss of myelination is associated with neurodegenerative diseases such as multiple sclerosis

produced by Schwann cells and olgiodendrytes

Question 11

Changes in the membrane potential during action potential are mediated by

Answer 11

initial opening and closing of the Na+ channel depolarizing the membrane with ve+ charge flooding in and K+ flooding out repolarizing the membrane

Question 12

When the positive charge reaches the ___ it causes opening of ion gated Ca+ channels. Ca+ then floods into the cell, causing___

Answer 12

synaptic bouton
the secretory vesicles containing neurotransmitter to fuse with the plasma membrane and release their contents into the synapse

Question 13

H20 urea and glycerol are ___

Answer 13

small uncharged polar molecules

Question 14

Channel proteins form__

Answer 14

hydrophilic channels
-passive

Question 15

The dendrites in a neuron____. And axons ___

Answer 15

receives signals
transmits signals which is terminated in synaptic boutons

Question 16

Cytosol contains anions and cations but only the __ get to the extra cellular fluid

Answer 16

cations

Question 17

When membranes depolarize, they become more positively charged on the ____side

Answer 17

cytoplasmic

When Na comes in it causes helix S4 to move into the up position opening the channel