neurones

• Neuron


  Basic building block of the nervous system, processes and transmits messages through electrical and chemical signals.
• Sensory neurons


  Carry messages from the peripheral nervous system to the central nervous system.
• Relay neurons


  Connect sensory neurons to motor or other relay neurons.
• Motor neurons


  Connect the central nervous system to effectors such as muscles and glands.
• Central nervous system (CNS)


  Part of the nervous system consisting of the brain and spinal cord.
• Peripheral nervous system (PNS)


  Neurons outside the CNS that transmit information.
• Cell body (soma)


  Includes a nucleus and carries nerve impulses from neighboring neurons towards the cell body.
• Dendrites


  Branch-like structures that carry nerve impulses towards the cell body.
• Axon


  Carries nerve impulses away from the cell body down the length of the neuron.
• Myelin sheath


  Fatty layer that protects the axon and speeds up electrical transmission.
• Nodes of Ranvier


  Gaps in the myelin sheath that speed up the transmission of the impulse.
• Terminal buttons


  Located at the end of the axon, they communicate with the next neuron in the chain across a synapse.
• motor neurons function


  Carry messages away from the brain and spinal cord to organs and muscles in the body.
• Sensory Neurons Function


  Carry messages from receptors in the body towards the brain and spinal cord.
• Relay Neurons (Function)


  Connect sensory neurons to motor neurons or other relay neurons.
• What is the functional difference between motor neurons and sensory neurons?

  Motor neurons carry messages away from the brain and spinal cord to the organs and muscles in the body while, Sensory neurons carry messages from the receptors in the body towards the brain and spinal cord.
• Electric Transmission


  The firing of a neuron that happens within neurons.
• Chemical Transmission


  The process by which neighboring neurons communicate with each other by sending chemical messages across the synapse.
• When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing .............................

  an action potential to occur.
• Synaptic Transmission


  The process by which neighboring neurons communicate with each other by sending chemical messages across the synapse.
• Neurotransmitter


  Brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another.
• synaptic transmission process


  *Once the neurotransmitter crosses the gap, it is taken up by the next postsynaptic receptor site - in other words, the dendrites of the next neuron.

  *Here, the chemical message is converted back into an electrical impulse and the process of transmission begins again in this other neuron.

  *Several dozen types of neurotransmitters have been identified in the brain (as well as in the spinal cord and some glands).

  *Each neurotransmitter has its own specific molecular structure that fits perfectly into a postsynaptic receptor site, similar to a lock and key.

  *Neurotransmitters also have specialist functions - for instance, acetylcholine (ACh) is found at each point where a motor neuron meets a muscle, and upon its release, it will cause the muscle to contract.
• Excitation


  When a neurotransmitter increases the positive charge of the postsynaptic neuron, increasing the likelihood of firing.
• Inhibition


  When a neurotransmitter increases the negative charge of the postsynaptic neuron, decreasing the likelihood of firing.
• Neural Networks


  Groups of neurons that communicate with each other.
• synapse


  Gap separating each neuron from the next
• Presynaptic Terminal


  The end of the neuron where neurotransmitters are released.
• Postsynaptic Receptor Site


  The dendrites of the next neuron where neurotransmitters are taken up and converted back into an electrical impulse.
• Excitatory Effect


  Neurotransmitters that increase the positive charge of the neighboring neuron, making it more likely to fire.
• Inhibitory Effect


  Neurotransmitters that increase the negative charge of the neighboring neuron, making it less likely to fire.
• Biological Approach


  Approach that studies the neurochemical processes occurring in the brain and their real-life applications.
• Antidepressants


  Medication used to increase levels of serotonin in the synapses to treat clinical depression.
• Serotonin


  A neurotransmitter that causes inhibition in the receiving neuron, making it less likely to fire.
• Adrenaline


  A neurotransmitter that causes excitation in the postsynaptic neuron, making it more likely to fire.
• Label a synapse diagram

  
• evaluation


  Point: One strength of the biological approach is that it has real life application. Our understanding of the neurochemical processes occurring in the brain has helped to develop psychotic drugs to treat some mental disorders.

  Example: For example, the biological approach has promoted the treatment of antidepressants for individuals diagnosed with clinical depression to increase levels of serotonin in the synapses in the brain.

  Explain: Such drugs have reduced a number of symptoms for people living with depression and have allowed them to manage their condition. Therefore, the biological approach is beneficial to understanding brain processes and in turn developing medication to reduce symptoms.

  CA: However, antidepressants don't work for all patients. Researchers have found that medication is sometimes more effective when used in combination with cognitive therapy. This challenges the value of the biological approach as it may not account for all cases.