Taxes and kinesis Flashcards
what is taxes?
a simple response where an organism will move its entire body towards a favourable stimulus or away from an unfavourable stimulus
what is a positive taxis?
moving towards
what is a negative taxis?
moving away
what is kinesis?
when an organism changes speed of movement and the rate it changes direction
what happens when moving from an area of beneficial stimuli to an area of harmful stimuli?
the kinesis response will be to increase the rate it changes direction to return to a favourable environment
what happens when surrounded by negative stimuli?
the rate of turning decreases to keep it moving in a straight line to increase chances of finding favourable conditions
what is a stimulus?
a detectable change in environment
what is a receptor?
a cell that detects stimuli
what are effectors?
cells that bring about a response to a stimulus to produce an effect
what do effectors include?
muscle cells and glands
what do sensory neurones do?
transmit electrical impulses from receptors to the CNS
what do motor neurones do?
transmit electrical impulses from the CNS to effectors
what do relay neurones do?
transmit electrical impulses between sensory neurones and motor neurones
describe the process of nervous communication
-a stimulus is detected by receptor cells and an electrical impulse is sent along a sensory neurone
-when the impulse reaches a synapse, another impulse is generated
-the CNS processes the information and sends impulses along motor neurones to an effector
what is a simple reflex and where does the communication pathway go?
a rapid, involuntary response to a stimulus
goes through only the spinal cord, NOT conscious part of brain (so is automatic)
