The nervous System

• What are the two main components of the nervous system?

  The central nervous system and the peripheral nervous system
• What is the role of the central nervous system (CNS)?

  It is the origin of all complex commands and decisions
• How does the peripheral nervous system (PNS) function?

  It sends information to the CNS from the outside world and transmits messages from the CNS to muscles and glands
• What does the somatic nervous system do?

  It transmits information from receptor cells in the sense organs to the CNS
• What is the autonomic nervous system (ANS) responsible for?

  It transmits information to and from internal bodily organs and operates involuntarily
• What are the two main divisions of the autonomic nervous system?

  The sympathetic and parasympathetic nervous systems
• What are neurons?

  Neurons are the basic building blocks of the nervous system
• How do neurons transmit nerve signals?

  They process and transmit messages through electrical and chemical signals
• What is the maximum speed at which neurons can transmit signals?

  Up to 200 mph
• What are the main components of a neuron?

  A cell body (soma), dendrites, and an axon
• Why do not all sensory neurons reach the brain?

  Some neurons stop at the spinal cord, allowing for quick reflex actions
• What happens when motor neurons are stimulated?

  They release neurotransmitters that bind to receptors on muscles to trigger a response
• What are the steps involved in synaptic transmission?

  1. Electrical impulses reach the presynaptic terminal
  2. Impulses trigger release of neurotransmitters
  3. Neurotransmitters diffuse across the synaptic cleft
  4. Neurotransmitters combine with receptors on the postsynaptic membrane
  5. Stimulation results in excitation or inhibition of the postsynaptic membrane
• What triggers the release of neurotransmitters during synaptic transmission?

  Electrical impulses (action potentials)
• What is the effect of neurotransmitters on the postsynaptic membrane?

  They can result in either excitation (depolarisation) or inhibition (hyperpolarisation)