1. Nerves, Hormones & Homeostasis
Stephen Taylor
i-Biology.net

3. Schwan cell

4. The Motor Neuron nerve impulse
Diagram from:

6. -70mV
Membrane 50 times more permeable to K+ ions than Na+
Proteins inside the nerve fiber are negatively charged which increases the charge imbalance.

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

14. Acetylcholine Neurotransmitter in many synapses
Produced in pre-synaptic neuron, loaded into vesicles & released into synaptic cleft during synaptic transmission.
Receptors located in post-synaptic membrane
While bound, one action potential is initiated.
After transmission it breaks down.

15. Threshold potential
Action potentials only initiated if threshold potential is reached
At synapse, the amount of neurotransmitter secreted following depolarization of the pre-synaptic membrane may not be enough to cause t.p. to be reached in post-synaptic membrane.
Depolarization does not take place. Returns to resting potential
Neurons in brain & spinal cord have many pre-synaptic neurons. Often multiple must secrete neurotransmitters at same time.

16. neonicotinoids Synthetic compounds similar to nicotine
Bind to acetylcholine receptor in the central nervous system of insects.
Binding is irreversible, permanently blocking receptors resulting in paralysis and death
Advantage in pesticides: not toxic to humans or mammals.
Disadvantages: effects on honeybees and other beneficial insects.

25. @IBiologyStephen
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