Communication in our nervous system

Question 1

Ion -

Answer 1

An electrically charged molecule

Question 2

Anion -

Answer 2

Negatively charged ion

Question 3

Cation -

Answer 3

Positively charged ion

Question 4

The electric signalling:

Answer 4

conducting information within a neuron

Question 5

ANIONS and CATIONS inside the neuron are within…

Answer 5

INTRACELLULAR FLUID

Question 6

Outside neuron (through the CELL MEMBRANE) are other ions in the…

Answer 6

EXTRACELLULAR FLUID

Question 7

Inside a neuron there are more ANIONS than cations - so it is …… charged

Answer 7

negatively

Question 8

The electrical charge across a cell membrane;

Answer 8

the difference in electrical potential inside and outside the cell.

Question 9

2 membrane potentials of interest…

Answer 9

Resting potential - balance of ions at rest (generally about -70 milivolts (mV))

Action potential - brief electrical impulse (big changes in cell membrane potential) that provides the basis for conduction of information along an axon

Question 10

ionic forces –forces that control the ions…

Answer 10

Diffusion through semi-permeable membrane - Molecules move from areas of HIGH concentration to areas of LOW
concentration

Electrostatic Pressure - Opposite charges ATTRACT one another
Like charges REPEL one another

Question 11

Sodium-Potassium Pump, what does it do/main points…

Answer 11

Pushes Na+ out
Exchanges Na+ for K+
Pushes 2 Na+ out for each 1 K+ allowed in
MAINTAINS RESTING POTENTIAL

Question 12

Sodium Channels?2 more important terms …

Answer 12

Ion Channel – A channel in the cell membrane that permits specific ions to enter or leave the cell

Voltage-gated ion channel - An ion channel that opens or closes according to the value of the membrane potential

Question 13

Opening of Sodium channels starts the…

Answer 13

action potential

Question 14

RATE LAW -

Answer 14

the rate of firing of the neuron determines the response of our system

Question 15

A strong muscular contraction =

Answer 15

fast rate firing (quick succession of action potentials)

Question 16

A very low light =

Answer 16

causes slower rate of firing of neurons serving the eyes (slower series of action potentials)

Question 17

The chemical signalling:

Answer 17

information transmission between neurons

Question 18

Postsynaptic Receptors, what does it do/main points…

Answer 18

Specialised to fit particular neurotransmitters

Like a particular key opening a particular lock

A molecule of the correct size and shape to fit the receptor is a LIGAND

Question 19

Ligands can be:

Answer 19

Endogenous ligand – neurotransmitters and hormones occurring naturally in the body
Exogenous ligand – drugs and toxins from outside the body

Question 20

Neurotransmitters

Answer 20

Dopamine – general arousal - movement
Serotonin – related to mood
Acetylcholine – learning, memory, 
attention
Noradrenaline – mental arousal
Glutamate – formation of long-term 
memories
Endorphins/ Enkephalins – opioids  
modulate pain, reduce stress