Action Potentials, Synapses And Neurotransmitters

Question 1

What is a cell membrane potential

Answer 1

• resting potential 0.07v
• cells communicate through membranes
• membrane potential changes are fast electrical events
• cell membrane of undisturbed has excess of + on outside and - on inside
• uneven distribution = pot dif (v)

Potential difference is membrane potential

Question 2

What are the two types of channel on the membrane

Answer 2

Leak channels = always open

Gated = open or close due to circumstances

Question 3

Explain changes in membrane potential

Answer 3

• Stimulus opens gated channels that are usually gated at resting potential
• accelerates movement of ions across membrane
• changes membrane potential

Question 4

Explain depolarisation and repolarisation

Answer 4

• increase number of + ions on cell membrane = potential increases towards 0v
• when stimulus restored = repolarisation to resting potential

Question 5

What is an action potential

Answer 5

• change’s permeability of membrane
• skeletal muscle fibres and axons have excitable membranes so will conduct action potentials

Question 6

Explain excitatory and inhibitory neurotransmitters

Answer 6

Excitatory- cause depolarisation of postsynaptic, promote action potentials

Inhibitory- cause hyper polarisation of postsynaptic and suppress action potentials