1. The Structure of Neurones Aims 1.To describe the structure of sensory and motor neurones 2.To relate the structure of sensory and motor neurones to their function

2. NeuronesNeurones

3. Click button to reveal type of neurone and direction of impulse. Neurone 1

4. Click any label to reveal name of structure. AAAA BBBB CCCC DDDD EEEE FFFF GGGGImpulse Sensory Neurone

5. AAAA Click button to reveal further information. Schwann Cell BBBB CCCC DDDD EEEE FFFF GGGGImpulse Sensory Neurone

6. AAAA Found in mammals. Cell wraps itself around axon, enclosing it in many layers of plasma membrane. This creates a myelin sheath (largely lipids with some proteins) which speeds up conduction by offering electrical insulation. They can carry out phagocytosis to remove cell debris. Schwann Cell BBBB CCCC DDDD EEEE FFFF GGGGImpulse Sensory Neurone

7. Click button to reveal further information. AAAA BBBB CCCC DDDD EEEE FFFF GGGG Cell Body Impulse Sensory Neurone

8. Cell body contains neurone’s nucleus and cytoplasm with many mitochondria and ER. Groups of ribosomes are often visible as dark specs. Neurotransmitter (e.g. Serotonin) are produced here. AAAA BBBB CCCC DDDD EEEE FFFF GGGG Cell Body Impulse Sensory Neurone

9. Click button to reveal further information. AAAA BBBB CCCC DDDD EEEE FFFF GGGGReceptor Impulse Sensory Neurone

10. Receptor cells are transducers – convert one form of energy e.g. light or heat into electrical energy. Often found in sense organs. Initiate the action potential in the sensory neurone in response to a stimuli. AAAA BBBB CCCC DDDD EEEE FFFF GGGGReceptor Impulse Sensory Neurone

11. DDDD Click button to reveal further information. Synaptic knob AAAA BBBB CCCC EEEE FFFF GGGGImpulse Sensory Neurone

12. DDDD Axon terminates in a junction with next neurone. A gap of 20nm between them. The knob is packed with mitochondria and vesicles with neurotransmitter. This will diffuse across gap and excite/inhibit signal in next neurone. Synaptic knob AAAA BBBB CCCC EEEE FFFF GGGGImpulse Sensory Neurone

13. EEEE Click button to reveal further information. Axon AAAA BBBB CCCC DDDD FFFF GGGGImpulse Sensory Neurone

14. Extension of cytoplasm from the cell body. Carries electrical signal (action potential) from the cell body to the synaptic knobs in the central nervous system (CNS). AAAA BBBB CCCC DDDD EEEE FFFF GGGGAxon Impulse Sensory Neurone

15. Click button to reveal further information. AAAA BBBB CCCC DDDD EEEE FFFF GGGG Node of Ranvier Impulse Sensory Neurone

16. 2-3μm gaps in the myelination of the axon. Occur between Schwann cells every 2-3mm. Help speed of transmission by enabling action potential to jump from one node to next. AAAA BBBB CCCC DDDD EEEE FFFF GGGG Node of Ranvier Impulse Sensory Neurone

17. Click button to reveal further information. AAAA BBBB CCCC DDDD EEEE FFFF GGGGDendrites Impulse Sensory Neurone

18. Many thin extensions of cytoplasm from the cell body. Carry the electrical signal (action potential) from the receptor to the cell body. AAAA BBBB CCCC DDDD EEEE FFFF GGGGDendrites Impulse Sensory Neurone

19. Click button to reveal type of neurone and direction of impulse. Neurone 2

20. BBBB DDDD EEEE FFFF Many thin extensions of cytoplasm from the cell body. Carry the electrical signal (action potential) from synapse with previous neurone to the cell body. GGGGF Impulse Motor Neurone Dendrites AAAA CCCC

21. Click any label to reveal name of structure. BBBB CCCC AAAA DDDD EEEE FFFFImpulse Motor Neurone

22. BBBB DDDD EEEE FFFF Click button to reveal further information. GGGGF Impulse Motor Neurone Dendrites AAAA CCCC

23. BBBB DDDD EEEE FFFF Click button to reveal further information. Impulse Motor Neurone Node of Ranvier AAAA CCCC

24. BBBB DDDD EEEE FFFF 2-3μm gaps in the myelination of the axon. Occur between Schwann cells every 2-3mm. Help speed of transmission by enabling action potential to jump from one node to next. Impulse Motor Neurone Node of Ranvier AAAA CCCC

25. BBBB DDDD EEEE FFFF Click button to reveal further information. DDDDImpulse Motor Neurone Axon AAAA CCCC

26. BBBB DDDD EEEE FFFF Extension of cytoplasm from the cell body. Carries electrical signal (action potential) from the cell body in the CNS to the synaptic knobs at neuromuscular junctions. An axon in a motor neurone can be over a metre long! DDDDImpulse Motor Neurone Axon AAAA CCCC

27. BBBB CCCC DDDD EEEE FFFF Click button to reveal further information. CCCCImpulse Motor Neurone Cell body AAAA

28. BBBB CCCC DDDD EEEE FFFF Cell body contains neurone’s nucleus and cytoplasm with many mitochondria and ER. Groups of ribosomes are often visible as dark specs. CCCCImpulse Motor Neurone Cell body AAAA

29. BBBB DDDD EEEE FFFF Click button to reveal further information. BBBBImpulse Motor Neurone Schwann cell AAAA CCCC

30. BBBB DDDD EEEE FFFF Found in mammals. Cell wraps itself around axon, enclosing it in many layers of plasma membrane. This creates a myelin sheath (largely lipids with some proteins) which speeds up conduction. BBBBImpulse Motor Neurone Schwann cell AAAA CCCC

31. BBBB AAAA DDDD EEEE FFFF Click button to reveal further information. AAAAImpulse Motor Neurone Synaptic knob CCCC

32. BBBB AAAA DDDD EEEE FFFF Axon terminates with a neuromuscular junction. The knob is packed with mitochondria and vesicles with neurotransmitter. This will diffuse across junction and lead to contraction of muscle. AAAAImpulse Motor Neurone Synaptic knob CCCC