nervous system Flashcards
what is homoesitis
its the balance of the internal conditions of an orgnaism to keep the optimal conditions for it to function
what do inernal conditiions include
body temp
ph
glucose concentration in blood
water content in body
what are automic control systems
thinsg that react to changes in the body, externally like heat and sunbut also internally like blood sugar and water loss, this includes the nervous system and chemical responses
what are receptors
cells that detect the changes/ sttimuli
what is stimuli
the changes internally or externally
what are coordination centers
areas that hear about changes from the receotors and send out singals alerting the system, this includes the brain which sends out singals
what are effectors
the muscle/ gland that responds to the stimuli by restorin the conditions
how does the nervous system work
so once the receptors have picked up on the stimuli they send electrical signals that pass along cells called neurons to the coordination cneters which send the responses back down through motor neurons to the receptors
what are sensroy and motor neurons
motor neurones carry info from the coordination centers to the effectors whilst neurons, ususally in giant bundles of nerves, just carry it to the CC
WHAT ARE SENSPRY NEurones
carry imulses from sense organs to the CC- like the nose sends imulses to make the salivary gland produce moer when it smells food
independant variables of reaction prpactical
you could change hands, drink something in between, change background noise etc
explain required practical reaction time
so one person sits on a stool and stretches their hand across the table with their hand over it, person two places a ruler in their hand so the thumb is at 0 and drops it randomly. the faster the person can snap their hand shut the faster the reaction time
what are reflexes
automic responses, like breathing, that dont resquire the concious part of the brain
what neurpnes to reflexes involve
sensory
motor
relay
what are relay neurones
found in the CC it links the other two
what are synaposes
junctions between neurones that they have to diffuse across by a diffused chemical
how does the reflex arc work if you touch something hot
when we come across a stimuli so a sudden burn an electrical impulse goes along the sensory neurone to the CNS
AWHEN WE ARRIVE AT THE SYNAPSE between the sensory and relay neurone a chemical is released that diffuses from the relay to the motor, then at that synapse another chemical is released travelling to the effector
an impulse also goes from the CNS to the brain to let us know its happened
where are central communication centers
brain
spinal chord
pancreas
