2. By Po-Han Chen

3.  Creatures on the world can feel the surrounding in order to adapt the environment for survival. Animals relies on Endocrine system and Nervous system to adjust itself. Nervous system controls muscle contraction and coordinate the organs within a short time in order to protect itself. 3% of overall mass, but it is the most complicated system in body

4.  The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body

5. Your Nervous system is mainly made up of

6. The nervous system is made up of Neurones. Each neurone consists of a cell body and extending nerve fibre

7. Neurons can be divided into 3 types Sensory Motor Interneurons

8. INPUT From sensory organs to the brain and spinal cord. I.e., from Nose, eyes to brain

9. OUTPUT From the brain and spinal cord To the muscles and glands.

10. Interneurons carry information between other neurons only found in the brain and spinal cord.

11. The Neuron can be separated into 4 parts : The cell body Dendrites Axon Myelin sheath

12. The cell body Contains the Cell’s Nucleus Round structure Contains DNA Dose Protein manufacturing Directs metabolism No role in neural signaling

13. Dendrites Information collectors Receive inputs from neighboring neurons If enough inputs the cell’s AXON may generate an output

14. Axon Output structure One axon per cell, 2 distinct parts The tube branches at the end and attaches to other cells.

15.  http://www.youtube.com/watch?v=i- NgGKSNiNw http://www.youtube.com/watch?v=i- NgGKSNiNw

16.  Neurons communicate by electrical signal called the Action Potential.  it is based on movements of ions between cells.  When an Action Potential occurs a molecular message is sent to neighboring neurons

18. The nervous system is divided into two sections: Central Nervous System + Outer Nervous System

19. The Central Nervous System is made up of Brain and Spinal cord Electrical Signals are carried from the Brain to the receptors through Spinal cord

20.  Between the receptors and the effectors, the Central Nervous system coordinates the action potentials passing through the nervous system.

21. The Outer Nervous System is made of the nerves and the sense organs Sense Organs includes Skin - Touch Nose - Smell Tongue - Taste

24.  Resting neurons have Potential Difference Outer surface-> Positively charged Inner surface -> Negatively charged  Resting potential (-65mV), therefore said Polarised

25.  Resting potential is generated by Sodium-potassium pump and a potassium channel  The pump moves three sodium ions out by active transport for every two potassium ions brings in.  The facilitated diffusion allowed to let potassium ions back out.  More positive ions move out than move in.

26.  Sodium potassium pumps work all the time, but Channel protein can be opened or closed.  Depolarisation requires another protein channel, which is Sodium Channel. When Stimulated, sodium channel opens and then ions diffuses in. This increases the positive charge inside the cell. Charge is now Reversed. With a potential difference of +40mV, This is Action Potential and membrane is depolarised.

27.  http://www.youtube.com/watch?v=SCasruJT- DU http://www.youtube.com/watch?v=SCasruJT- DU

28.  Q: What do sensory, relay and motor neurons do in the nervous system?  Answer: Sensory – INPUT From sensory organs to the brain and spinal cord. Relay – Interneurons carry information between other neurons only found in the brain and spinal cord. Motor – OUTPUT From the brain and spinal cord To the muscles and glands.

29.  Q: Give two factors that increases the speed of conduction of action potentials  Answer: Bigger axon diameters Increase in temperature

30.  Notes from Richard  www.deafed.net/PublishedDocs/ www.deafed.net/PublishedDocs/  www.psych.wright.edu/Wayne/ www.psych.wright.edu/Wayne/  http://academic.luzerne.edu/ http://academic.luzerne.edu/  http://en.wikipedia.org/wiki/Neuron http://en.wikipedia.org/wiki/Neuron  http://en.wikipedia.org/wiki/Action_potential http://en.wikipedia.org/wiki/Action_potential  http://faculty.clintoncc.suny.edu/faculty/micha el.gregory/files/bio%20102/bio%20102%20lect ures/nervous%20system/neurons.htm http://faculty.clintoncc.suny.edu/faculty/micha el.gregory/files/bio%20102/bio%20102%20lect ures/nervous%20system/neurons.htm

31. Thank you for your attention