Zusammenfassung der Ressource
B1 Nerves and Hormones
- The Nervous System
- Parts of the Nervous System
- Spinal Chords
- Brain
- Neurons
- Receptors
- Allows organisms to react to their
surroundings and co-ordinate their
behavior
- Information gets passed
along neurons to the brain
- The brain co-ordinates the response, which
is then carried out by an effector
- The effector may be a muscle, which responds by
contracting, or a gland which responds by releasing
chemicals
- Receptors..
- Sensory Neurone
- Relay Neurones
- Spinal Chord or Brain
- Motor Neurones
- Effector
- Types of Neurons
- Motor Neurone
- Impulse travels away from cell body
- Sensory Neurone
- Impulse travels towards cell body
- Relay Neurone
- Impulse travels
first towards, then
away from cell
body
- Neurones are specially adapted cells that
can carry an electrical signal, e.g. a nerve
impulse
- Neurones are elongated to
make connections between
parts of the body
- Branched endings to
allow a single neurone to
act on many muscle
fibres
- Cell body has many connections
to allow communication with
other neurones
- 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.
- Types of Receptor (receptors
detect stimuli)
- Light
- Sound
- Change of position
- Taste
- Smell
- Temperature
- Pain
- Touch
- Pressure
- Reflex Action
- Sometimes conscious action is too slow to prevent harm to
the body, e.g. removing your hand from a hot plate
- Reflex action speeds up the response time by missing out the brain entirely