Synapses

• What is the main function of the cell body in a neuron?

  Contains nucleus
• What is the role of the nucleus in the cell body of a neuron?

  Contains genetic material
• What is the function of dendrites in a neuron?

  Receive signals
• How do dendrites receive signals from nearby nerve cells?

  Through nerve impulses
• What is the function of the axon in a neuron?

  Carries impulses away
• What is the role of the myelin sheath in a neuron?

  Insulates and speeds up transmission
• What are the gaps in the myelin sheath called?

  Nodes of Ranvier

  
• How do nodes of Ranvier speed up the transmission of the impulse?

  By forcing it to jump across gaps
• What is the function of terminal buttons in a neuron?

  Communicate with next nerve cell
• What is the state of the neuron when it is not activated by a stimulus?

  Resting state
• What happens to the inside of the cell when a neuron is activated by a stimulus?

  Becomes positively charged
• What is the result of the inside of the cell becoming positively charged?

  Action potential occurs
• What is the role of the electrical impulse in synaptic transmission?

  Travels down the axon
• How do neurotransmitters communicate with the next neuron in the chain?

  Diffuse across the synapse

  
• What is released by the neuron when an electrical impulse reaches the end of the axon?

  Neurotransmitters

  
• What is the role of the post-synaptic receptor site in synaptic transmission?

  Absorbs neurotransmitters
• What is the effect of the neurotransmitter serotonin on the receiving neuron?

  Inhibition
• How does serotonin cause inhibition in the receiving neuron?

  Makes it more negatively charged
• How does adrenaline cause excitation in the receiving neuron?

  Makes it more positively charged
• What is the effect of the neurotransmitter adrenaline on the receiving neuron?

  Excitation
• What is the effect of psychoactive drugs on mental illnesses?

  Alter levels of neurotransmitters
• How do SSRIs (e.g. Prozac) increase levels of serotonin in the brain?

  Lengthen its effects at the synapse
• What is the role of an antagonist in the context of psychoactive drugs?

  Blocks action of neurotransmitter
• What is the role of an agonist in the context of psychoactive drugs?

  Copies action of neurotransmitter
• What are the three types of neurons found in the nervous system?

  Sensory, relay, motor

  
• What is the function of a sensory neuron?

  Carries messages from sensory receptors to brain and spinal cord
• What is the structure of a sensory neuron?

  Long dendrites and short axons

  
• What is the function of a relay neuron?

  Transfers messages from sensory neurons to other interconnecting neurons or motor neurons

  
• What is the structure of a relay neuron?

  Short dendrites and short axons

  
• What is the function of a motor neuron?

  Carries messages from central nervous system to effectors such as muscles and glands
• What is the structure of a motor neuron?

  Short dendrites and long axons

  
• How do the different types of neurons work together to transmit information in the nervous system?

  Sensory neurons transmit information to relay neurons, which then transmit information to motor neurons

  
• What would happen if a sensory neuron was damaged and could no longer transmit information to the brain and spinal cord?

  The brain and spinal cord would not receive the information, and the person might not be able to respond to the stimulus