nervous system Flashcards
what does the central nervous system consist of?
- brain
- spinal cord
what is stimulus?
change in environment requiring a response
what do receptors do?
sensitive to stimulus and convert stimulus energy into electrical impulses
what are the five sense organs?
eyes ears nose tongue skin
what receptors do eyes contain?
light
what receptors do ears contain?
- sound
- balance (sensitive to changes in position
what receptors does the nose contain?
smell receptors sensitive to chemical stimuli
what receptors does the tongue contain?
taste receptors sensitive to sweet, sour, salt, bitter and other chemical stimuli
what receptors does the skin contain?
receptors sensitive to temperature, touch, pain and pressure
what are neurons and what do they do?
nerve cells - transmit electrical impulses around the body
name three types of neurons
sensory
relay
motor
what are dendrites/ dendrons?
branched nerve endings that connect with other neurons
what are axons made from?
cytoplasm stretched out into long fibre surrounded by membrane
sometimes have myeli sheath as electrical insulator
where does sensory neuron carry impulses from and to?
receptor to CNS
- 1 long dendrite picks up impulses
- 1 short axon carries it to CNS
where does relay neuron carry impulses from and to?
sensory neuron to motor neuron
- many short dendrites picks up impulses from sensory neurons
- many short axons carries it to motor neurons
