1. Functions of the nervous system The nervous system is responsible for: - sensory perception - cognitive functions - motor functions - regulatory functions

2. Functions of the nervous system Collectively, these diverse activities can be grouped into three basic functions: - sensory input - integration of information - motor output

3. Organisation of the nervous system Central nervous system (CNS), brain and spinal cord Peripheral nervous system (PNS), all nervous tissue outside the CNS

4. The brain

7. Cells of the nervous system Neuron. Principal cell of the nervous system Neuronal structure includes: cell body dendrites axon synaptic terminals myelin sheath

8. Cells of the nervous system Neuroglia. Support neuronal function There are various types of neuroglia that differ in their location, morphology and specific functions within the nervous system Astrocytes Oligodendrocytes Microglia

9. Neurotransmission Neurons are electrically excitable. Able to produce actions potential (impulses) in response to stimuli This neuronal excitability depends on two basic features of the plasma membrane: The resting membrane potential The presence of specific types of ion channels

10. Neurotransmission

11. Myelination Most axons are surrounded by a lipid covering called myelin sheath This electrically insulates the axon and increases the speed of neuronal conduction

13. Neurotransmission 1.Impulse reaches end of axon. 2.Neurotransmitter is released from presynaptic terminal. 3.Neurotransmitter diffuses across synaptic cleft. 4.Neurotransmitter attaches to receptors on postsynaptic neuron. 5.Action potential is triggered in postsynaptic neuron.

14. Neurotransmitters Neurotransmitters can be: Stimulatory: initiate action potential e.g. Acetylcholine Inhibitory: prevent action potential e.g. GABA, dopamine

15. Synapses

18. Sensory systems - pain