BioKnowledgy DP notes 6.5 Neurons and synapses notes - bottom line
6 Human Physiology – 6.5 Neurons and synapses
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6.5 Neurons and synapses - the bottom line
The learning Statements
The can you statements tell you what you notes should enable you to do. They are guidance to a minimum
expectation. The deeper your understanding the easier you will find it to respond to questions and
communicate your understanding.
6.5.U1 Neurons transmit electrical impulses.
Can you state the function of the nervous system and it’s functional units, neurons?
Can you annotate a diagram of a neuron cell with the name and function of the dendrites, axon and cell
body? (Optional extra: can you draw a diagram of a neuron?)
6.5U5 Nerve impulses are action potentials propagated along the axons of neurons.
Can you define a nerve impulse?
Can you distinguish between the resting and action potential?
Can you state the two phases that the action potential consists of?
6.5.U3 Neurons pump sodium and potassium ions across their membranes to generate a resting potential.
Can you define resting potential?
Can you explain what is meant by the term antiport?
Can you describe how the movement of ions maintains the resting potential?
Can you explain why the resting potential is negative?
6.5.U4 An action potential consists of depolarization and repolarization of the neuron.
Can you state what causes the depolarisation of a region of an axon?
Can you outline depolarization of the neuron?
Can you outline repolarization of the neuron?
Can you suggest why a refactory period must follow repolarization, why a second impulse cannot
immediately follow the first?
6.3.S1 Analysis of oscilloscope traces showing resting potentials and action potentials.
Can you draw and annotate a diagram of an oscilloscope trace to show the resting potential, action potential
(depolarization and repolarization), threshold and refractory period/undershoot?
Can you outline how oscilloscopes can be used to measure membrane potentials?
6.5.U6 Propagation of nerve impulses is the result of local currents that cause each successive part of the
axon to reach the threshold potential.
Can you explain how the movement of sodium ions propagates an action potential along an axon?
Can you explain why the action potential can only move in a single direction?
6.5.U2 The myelination of nerve fibres allows for saltatory conduction.
Can you describe how Schwann cells myelinate the axon.
Can you state what the myelin consists of?
Can you explain how saltatory conduction increases the rate at which a nerve impulse can be propagated?
Can you explain why energy expenditure in myelinated neurons is less than in unmyelinated neurons?
6.5.U7 Synapses are junctions between neurons and between neurons and receptors or effector cells.
Can you define the terms synapse, synaptic cleft and effector?
Can you outline the role of neurotransmitters in nervous communication?
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6.5.U8 When presynaptic neurons are depolarized they release a neurotransmitter into the synapse. AND
6.5.U9 A nerve impulse is only initiated if the threshold potential is reached.
Can you outline the process of synaptic transmission, including the role of depolarization, calcium ions,
diffusion, vesicles, exocytosis, neurotransmitters, receptors, sodium ions, sodium channels and action
Can you explain, with reference to the threshold potential, why not all releases of neurotransmitters into the
synapse lead to an action potential in the post synaptic neuron?
6.5.A1 Secretion and reabsorption of acetylcholine by neurons at synapses.
Can you outline the formation, secretion and action of acetylcholine?
Can you outline how acetylcholine is broken down and it’s products reabsorbed?
Can you suggest the consequences of not breaking down acetylcholine?
6.5.A2 Blocking of synaptic transmission at cholinergic synapses in insects by binding of neonicotinoid
pesticides to acetylcholine receptors.
Can you outline the action of neonicotinoids on insects and hence why they are used as insecticides?
Can you define the cholinergic synapse in insects?
Can you explain why neonicotinoids are less toxic to humans than to insects?
Nature of science: Cooperation and collaboration between groups of scientists - biologists are contributing
to research into memory and learning. (4.3)
Can you give an example of scientists from multiple scientific disciplines collaborating to understand
learning and/or memory?
Allott, Andrew. Biology: Course Companion. S.l.: Oxford UP, 2014. Print.