neurons, synaptic transition and more

• What is the primary function of the sympathetic nervous system (SNS)?

  Responses to emergencies
• How does the SNS prepare the body for emergencies?

  By increasing heart rate and blood pressure
• What happens to blood vessels in muscles during SNS activation?

  They dilate
• What does the SNS cause the body to release during emergencies?

  Stored energy
• What bodily processes does the SNS slow down during emergencies?

  Digestion and urination
• What is the primary function of the parasympathetic nervous system (PNS)?

  Relaxation after emergencies
• How does the PNS affect heart rate and blood pressure?

  It slows the heartbeat and reduces blood pressure
• What does the PNS promote in the body?

  Digestion and energy conservation
• What are the key differences between the SNS and PNS?

  • SNS: "Fight or Flight"
  • Increases heart rate and blood pressure
  • Dilates blood vessels in muscles
  • Slows digestion and urination

  
  

  • PNS: "Rest and Digest"
  • Slows heartbeat and reduces blood pressure
  • Promotes digestion and energy conservation
• How many neurons does the average human brain contain?

  100 billion neurons
• What is the role of neurons in the nervous system?

  To move electrical impulses

  
• What are the three types of neurons?

  Sensory, relay, and motor neurons

  
• What are the main components of a neuron?

  Cell body, dendrites, and axon

  
• What is the function of dendrites in a neuron?

  To receive signals from other neurons

  
• What does the axon do in a neuron?

  Transmits impulses away from the cell body

  
• What is the myelin sheath's role in neurons?

  To insulate the axon for faster transmission
• What happens if the myelin sheath is damaged?

  Impulses slow down
• What is the action potential?

  An electrical signal in neurons

  
• How do sensory neurons function?

  They carry impulses from sensory receptors

  
• What do sensory neurons convert information into?

  Neural impulses

  
• What is the role of relay neurons?

  To connect sensory and motor neurons

  
• What do motor neurons control?

  Muscle contractions
• What happens when a motor neuron is stimulated?

  It releases neurotransmitters to muscles

  
• What is a reflex arc?

  A neural pathway controlling reflexes
• How does a reflex arc enable quick responses?

  By synapsing in the spinal cord
• What is the pathway of a reflex arc?

  1. Somatic receptors in skin
  2. Sensory neurons to spinal cord
  3. Relay neuron in spinal cord
  4. Motor neuron to muscle
  5. Muscle contracts (effector)

  
• What is the synapse?

  The gap between two neurons
• How are signals transmitted between neurons?

  Chemically across the synapse

  
• What are synaptic vesicles?

  Sacs containing neurotransmitters

  
• What happens when an action potential reaches synaptic vesicles?

  They release neurotransmitters

  
• How do neurotransmitters interact with receptors?

  Like a lock and key
• What is the effect of excitatory neurotransmitters?

  They increase the likelihood of firing
• What is the effect of inhibitory neurotransmitters?

  They decrease the likelihood of firing
• What is summation in neurotransmission?

  Adding excitatory and inhibitory influences
• If there are 300 excitatory impulses and 50 inhibitory impulses, what happens?

  The postsynaptic membrane will fire