Nervous system (II) Flashcards
what is stimuli dectected by?
receptors
what can a receptor be?
dendrites on a unipolar neuron or an individual cell that synapses to a neuron e.g. hair cell (internal ear)
what happens when a receptor is stimulated?
stimulus causes opening of gated channels (usually Na+) on receptor membrane
what is a generator potential
it is when a dendrite of a unipolar neuron gets stimulated and a GP (depol) DIRECTLY generates an AP
How does a receptor potential occur?
nt goes onto associated neuron which triggers an EPSP on neuron which generates an AP
What is a phasic receptor?
it is a receptor that responds to a stimulus CHANGE and in the presence of a constant stimulus ADAPTATION OCCURS and sensitivity is decreased
What is a tonic receptor?
frequency of APs remains constant, NO adaptation. this receptor gives us constant info regarding posture, condition, pain etc
How does the brain mostly perceive different types of stimuli?
manily by the type of receptors stimulated. axons are activated by receptor and a synaptic connection goes to the brain (the brain always know which nerve is associated with whaterver is being stimulated)
how does thee brain perceive different stregths of stimuli?
Not by the stregth of the AP (because it is always the same strength) but by the frequency of that AP. stronger stimulus also activates more receptors.
