TOPIC 6B Flashcards
Describe the resting potential of a neurone.
(see page 136 in the revision guide)
Make more detailed flash cards in this if needed
Describe the action potential of a neurone.
(see page 136 in the revision guide)
Make more detailed flash cards in this if needed
What is hyper polarisation of a neurone?
Potassium ion channels are slow to close so there’s. a slight ‘overshoot’ where too many potassium ions diffuse out of the neurone.
The potential difference becomes more negative than the resting potential (e.g. less than -70mV)
What is the resting potential of a neurone?
The ion channels are reset. The sodium-potassium pump return the membrane into its resting potential and maintains it until the membrane is excited by another stimulus.
What is the refractory period?
After an action potential, the neurone cell membrane can’t be excited again straight away. This is because the ion channels are recovering and they can’t be made to open - sodium ion channels are closed during depolarisation and potassium ion channels are closed during hyper polarisation.
How does a wave of depolarisation occur in a neurone?
(see page 137 in the revision guide)
What 3 things does a refractory period do to an action potential in a neurone?
(see page 137 in the revision guide)
Read the purple box on page 137 in the revision guide.
understand?
What 3 factors affect the speed of conduction of action potentials across a neurone?
- Myelination
- Axon diameter
- Temperature
Why does myelination affect the speed of conduction of action potentials across a neurone?
(see page 138 in the revision guide)
Why does the axon diameter affect the speed of conduction of action potentials across a neurone?
(see page 138 in the revision guide)
Why does temperature affect the speed of conduction of action potentials across a neurone?
(see page 138 in the revision guide)
What is a synapse?
A synapse is the junction between a neurone and another neurone or between a neurone and an effector cell, e.g. a muscle or gland cell.
Draw the structure of a motor neurone.
(see page 138 in the revision guide)
Describe how one neurone can trigger an action potential in another neurone.
(see page 139 in the revision guide)
Describe how a nerve impulse is transmitted across a cholinergic synapse.
(see page 139 in the revision guide)
What do excitatory neurotransmitters do?
(see top of page 140 in the revision guide)
What do inhibitory neurotransmitters do?
(see top of page 140 in the revision guide)
What is summation?
Name the two types of summation.
Summation is where the effect of neurotransmitter released from many neurones (or one neurone that’s stimulated a lot in a short period of time) is added together.
- spatial summation
- temporal summation
Describe spatial summation.
(see page 140 in the revision guide)
Describe temporal summation.
(see page 140 in the revision guide)