co ordination and response Flashcards
what is a stimulus
A change in an animals surroundings
what is a response
a reaction to the change
what links the receptor and effcetor
coordination system
what is the order of a response
Stimulus
Receptor
coordination
effector
response
describe the effects of a ball being thrown towards you
Receptor organ- eyes
effector organ muscles in your hands
What does the human nervous system consist of
CNS- Central nervous system
Peripheral nervous system (PNS)
what makes up the CNS
and PNS( Peripheral nervous sytstem)
CNS- brain and spinal
PNS- all of the nerves in the body
Where do impulses from receptors pass along
sensory neurones until they reach the brain and spinal
How is information sent through the nervous system
Electrical impulses
what is a bundle of neourones called
Nerves
what are electrical impulses
Electrical signals that pass along the nerve cells known as neurones
What are the three types of neurones
sensory
motor neurones
relay neurones
what causes electrical impulses
movement of charged ions
the flow of positively charged ions across the neuronal membrane
what is the job of the CNS
to coordinate responses after receiving a response from a receptor
what is a synaptic cleft
Connection between two neurones
what does the synapses do
Transfer nerve signals by chemicals called neurotransmitters which diffuse across the gap
What is the process of the synapse
- electrical impulse moves along axon
- vesicles (containing neurotransmitters) are converted to chemical signals
- neurotransmitters chemical diffuse across synaptic cleft
- neurotransmitters bind to receptors on the next neuron
- convert chemical neurotransmitters back to electrical impulses
which move down the 2nd neurone
- enzymes in neurone 2 break down neurotransmitters to stop repeated impulses being sent
how do you prevent repeated signals being sent
enzymes break down neurotransmitters
what are the adaptations for neurone
long-travel over long distances ( allows quick accurate communication + responses)
myelin sheath – acts as electrical insulator increases speed of transmission
dendrites- projections and division increased surface area
gaps- moves faster
lots of mitochondria in nerve cells provide energy for synthesis of neurotransmitters
what does a general neurone consist of and what are it’s functions
Cell body- where nucleus and main organelles found
Axon- Main long fibre of the neurone that carries impulses
Dendrites- These extend out of the cell body of the neurone, carry impulses
How do reflexes help prevent injury
example
reflexes are an automatic response to certain stimuli
e.g bright light shines in your eyes, your pupils automatically get smaller so that less light gets into your eyes this prevents your eye from getting damaged
e.g when you get a shock your body releases the hormone adrenaline automatically
what is the route taken by the information in a reflex called
reflex arc
explain the process of a reflex arc after touching something hot
- a cupcake candle burns finger
- Stimulation of the pain receptor
- impulses travel along the sensory neurone to CNS
- impulses are passed from CNS to a relay neurone , via synapse
- Impulses travel along a motor neurone via synapse
- impulse travels along the motor neurone to the effector
- when impulse reaches muscles it contracts
What is the difference between motor, relay and sensory neuorne
Sensory Neurone
- sensory neurone- Carries electrical impulses form receptor to relay
- receptor cells react to direct stimulus
- cell bod is in the middle branching off axon
- Longer axon
longer dendrites
allowing greater connection
Relay neurone
- Carries electrical impulses form sensory neurone to motor neuorne
- Part of CNS
- coordinate response
- Shorter small cell body
- with dendrites branching off
Motor neuorne
- carries impulses from relay to effector
- Cell body is at one end
- long axon
-dendrites branch of cell body - bod can connect to many relay neurones
