Topic 2) Co-ordination and response Flashcards
what is the nervous system used for?
to enable humans to react and control coordination behaviour in response
what are the changes in your internal and external surroundings?
stimuli
what do stimuli detect?
receptors
what do receptor cells do?
detect a change in the environment and start electrical signals along neutrons
where are receptor cells located?
usually clustered together in sense organs
what are receptor cells made of?
nucleus
cytoplasm
cell membrane
how is information carried around the nervous system?
electrical signals (impulses)
what is the central nervous system made of?
brain
spinal chord
nerve cells
what are the main three neurones?
sensory
motor
relay
features of a neurone
long fibre, which is insulated, tiny branches
what makes a nerve cell?
a bundle of neurones
what are neurones made of?
dendrite
nucleus
axon
nerve ending
cytoplasm
cell membrane
dendrite
receives nerve impulses from other neurones or receptors
cell body
contains the nucleus
axon
carries nerve impulses away from cell body, very long, can transmit impulses quickly
dendrons
carry nerve impulses towards the cell body
myelin sheath
surrounds some axons speeds up the electrical impulses as it insulates the axon
axon terminal
end of a nerve, from here the signal is transmitted to another neuron or an effector
examples of effectors
muscles
glands
reflex
automatic responses are known as reflexes
what are reflexes for?
to avoid danger or harm
to take care of basic body functions
examples of reflexes
breathing
moving food through the digestive system
reflex arc
the sequence through the nervous system
what is the reflex arc sequence?
stimulus
receptor
sensory neurone
relay neurone
motor neurone
effector
response
