1. Neurons transmit the message, synapses modulate the message
6.5 Neurons and synapses
Neurons transmit the message, synapses modulate the message

4. Neurons transmit electrical impulses
Q: Draw and label a neuron. Use arrows to show the direction an impulse travels and saltatory conduction. The myelination of nerve fibres allows for saltatory conduction.

6. Neurons pump Na+1 and K+1 ions across their membranes to generate a resting potential
Q: With respect to positive and negative charges, what is “potential”? Q: Describe the resting potential of a neuron.

9. From McGraw Hill: http://goo.gl/tI2MD

10. An action potential consists of depolarization and repolarization of the neuron
Q: Differentiate between depolarization and repolarization. Nerve impulses are action potentials propagated along the axons of neurons.

11. Q: Define propagation. Q: Define threshold potential.
Propagation of nerve impulses is the result of local currents that cause each successive part of the axon to reach the threshold potential
Q: Define propagation. Q: Define threshold potential.

12. Skill: Analysis of oscilloscope traces showing resting and action potentials

13. Synapses are junctions between neuron; between neurons and receptor or effector cells
Q: Differentiate between a receptor and an effector.

14. When presynaptic neurons are repolarized they release a neurotransmitter into the synapse
Q: What is the most common neurotransmitter? Q: What happens to this neurotransmitter in the synapse? A nerve impulse is only initiated if the threshold potential is reached. Application: Secretion and reabsorption of acetylcholine by neurons at synapses.

19. Application: Blocking of synaptic transmission at cholinergic synapses in insects by binding of neonicotinoid pesticides to acetylcholine receptors.

20. Application: The social effects of the abuse of psychoactive drugs could be considered, as could the use of the Botox for cosmetic treatments