Nerve Impulse (Leaving Cert Biology): Quizzes
📚Quizzes
Practise the questions
12 questions from this quiz
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Practise the questions
12 questions from this quiz
What causes a nerve impulse?
What causes a nerve impulse?
Movement of ions across neuron membrane
When a neuron is not carrying an impulse, what is the charge inside the axon?
When a neuron is not carrying an impulse, what is the charge inside the axon?
Negatively charged
What is the threshold in relation to nerve impulses?
What is the threshold in relation to nerve impulses?
Minimum stimulus to start an impulse
According to the All or Nothing Law, what affects the size of the nerve impulse?
According to the All or Nothing Law, what affects the size of the nerve impulse?
Nothing, if stimulus is above threshold
What determines the amount of pain felt?
What determines the amount of pain felt?
Number of neurons & impulse frequency
What happens to the charge inside the axon during an impulse?
What happens to the charge inside the axon during an impulse?
It becomes positive
What is needed for ionic changes during a nerve impulse?
What is needed for ionic changes during a nerve impulse?
ATP
What is the refractory period?
What is the refractory period?
Time to recover before next impulse
How does myelin affect the speed of a nerve impulse?
How does myelin affect the speed of a nerve impulse?
Increases speed by jumping at nodes
How does neuron diameter affect impulse speed?
How does neuron diameter affect impulse speed?
Greater diameter = faster impulse
What is the synaptic cleft?
What is the synaptic cleft?
Tiny gap between two neurons
What happens to neurotransmitters after transmission across the synaptic cleft?
What happens to neurotransmitters after transmission across the synaptic cleft?
Broken down by enzymes or reabsorbed