the nervous system

• what does the nervous systems mean?

  it means humans can react to their surroundings and coordinate their behaviour
• what does the nervous system do?

  detects and reacts to stimuli
• why do organisms need to respond to stimuli?

  they need to in order to survive
• single celled organisms


  can just respond to its environment
• multicellular organisms 


  need to communicate in order to respond to its environment
• what is the nervous system made up of?

  central nervous system

  sensory neurones

  motor neurones

  effectors
• central nervous system (CNS)

  in vertebrates (animals with backbones) consists of the brain and spinal cord only. in mammals the CNS is connected to the body by sensory neurones and motor neurones
• sensory neurones


  neurones that carry information as electrical impulses from the receptors to the CNS
• motor neurones


  the neurones that carry electrical impulses from the CNS to the effectors
• effectors


  all your muscles and glands which respond to nervous impluses
• receptors 


  detect stimuli, can form larger complex organs
• true or false. muscles and glands are examples of receptors

  false. they are effectors
• in humans what does the CNS consist of?

  brain and spinal cord
• which type of neurone carries impulses from the CNS to effectors?

  Motor neurons
• why is the nervous system important in humans?

  the nervous system means that humans can react to their surroundings and coordinate their behaviour
• how does the CNS coordinate a response?

  receive information from receptors and then coordinates a response. the response is carried out by effectors
• synapses


  connect neurones, nerve signals are transferred by chemicals which diffuse across the gap. the chemical signal is set of in the next neurone
• how are nerve signals transferred across a synapse?

  chemicals diffuse across the synapse and set off a new electrical impulse in the next neurone