The Nervous System Flashcards
What is homoestasis?
The maintenance of a constant internal environment at optimal conditions
What is a receptor?
Cells which detects stimuli/change in the environment e.g temperature, light levels etc.
Where does the signal that is sent by the receptor go and where after that?
Coordination center, which will pass the signal on to an effector
What happens to the stimulus after being detected by a receptor cell?
The stimulus is changed into an electrical signal by the receptor cell
Where does the signal go after being transformed from stimulus to signal?
The Nervous System sends this signal along neurons
How are neurons specialised?
to be conductive of electrical charges and to branch and form numerous connections within the body
Whatt type of neurons found between receptors and coordination center?
Sensory neurons
How do sensory neurons respond to in the skin and eyes?
Eyes=light
Skin=pressure, temperature changes
What type of neurons is found between coordination centre and effector?
Motor neurons
What is the coordination centre made up of and what do they form?
Brain and spinal cord, which form the central nervous system?
What happens once the effector receives the signal?
A response will be generated
What is the spine divided in?
Vertebraes
Where does the signal go in sensory neurons in a reflex?
To the spinal cord (in a vertabrae)
What connects the sensory and motor neurons in the spine and what does it do?
Relay neuron, ensure the message passes onto the correct motor neuron
What is a motor neuron connceted to in a reflex?
To the effector, either:
Gland that will release a chemical e.g hormone
Muscle, which will contract or relax, in this case contract to get smaller to pull the hand from in this case the heat source
Why are reflexes important?
The communication loops around the spine rather than travelling all the way up to the brain to be consciuosly processed
This process is quick and automatic, reducing damage
What are some other reflexes?
Blinking
Breathing
Sneezing
What is triggered in by the nerve impulse in the synapse?
The release of chemical, neutransmitter molecules that are packaged in circle like-shapes
These are sitting waiting to receive that nerve impulse
What do packages of neutransmitter do?
They move towards the membrane of the end of that neuron and they actually fuse with it
This causes them to open up to allow neutransmitter chemicals inside them to be released
These diffuse across the synapse
What happens to neurotransmitter molecules when diffused in synapse?
They dock into receptor molecules located at the start of the next neuron
Another electrical impulse will be generated
What is the electrical signal converted in across a synapse?
Chemical signal
What is time equal to in the required practical?
Square root of 2xdistance (m)
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Acceleration 9.81m/s*2
What is another way to investigate reaction time?
Computer simulation
