B1 Nerves and Hormones

The Nervous System
1. Parts of the Nervous System
  1. Spinal Chords
  2. Brain
  3. Neurons
  4. Receptors
2. Allows organisms to react to their surroundings and co-ordinate their behavior
3. Information gets passed along neurons to the brain
  1. The brain co-ordinates the response, which is then carried out by an effector
    1. The effector may be a muscle, which responds by contracting, or a gland which responds by releasing chemicals
4. Receptors..
  1. Sensory Neurone
    1. Relay Neurones
      1. Spinal Chord or Brain
        Motor Neurones
        Effector
5. Types of Neurons
  1. Motor Neurone
    1. Impulse travels away from cell body
  2. Sensory Neurone
    1. Impulse travels towards cell body
  3. Relay Neurone
    1. Impulse travels first towards, then away from cell body
  4. Neurones are specially adapted cells that can carry an electrical signal, e.g. a nerve impulse
    1. Neurones are elongated to make connections between parts of the body
    2. Branched endings to allow a single neurone to act on many muscle fibres
    3. Cell body has many connections to allow communication with other neurones
      1. Connections between Neurones
        Neurones don't touch each other, there's a small gap between them called a synapse
        When an electrical impulse reaches the gap, a chemical transmitter is released which activates receptors on neurone B and causes an electrical impulse to be generated in neurone B. The chemical transmitter is then destroyed.
6. Types of Receptor (receptors detect stimuli)
  1. Light
  2. Sound
  3. Change of position
  4. Taste
  5. Smell
  6. Temperature
  7. Pain
  8. Touch
  9. Pressure
Reflex Action
1. Sometimes conscious action is too slow to prevent harm to the body, e.g. removing your hand from a hot plate
  1. Reflex action speeds up the response time by missing out the brain entirely

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B1 Nerves and Hormones

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	Creado por Louisa Wania hace casi 11 años