5.3 Flashcards
what is a pacinian corpuscle
a pressure sensor found in the skin
what is a sensory receptor
cells/sensory nerve endings that respond to a stimulus in the internal or external environment of an organism and can create action potentials
what is a transducer
a cell that converts one form of energy to another- in this case to an electrical impulse
what are motor neurones
neurones that carry an action potential from the CNS to the effector
what are sensory neurones
neurones that carry an action potential from the sensory receptor to the CNS
what do relay neurones do
join sensory neurones to motor neurones
what does a myelinated neurone have
has an individual layer of myelin around it
what does a non-myelinated neurone not have
has no individual layer of myelin
what is the resting potential
-60mV
the interior of the cell is maintained at a negative potential compared with the outside. the cell membrane is said to be polarised
how is generating an action potential an example of positive feedback
a small depolarisation of the membrane causes a change that increases the depolarisation further
what is saltatory conduction
when the action potential appears to jump from one node of Ranvier to the next because sodium and potassium ions cannot diffuse through the myelin sheath so sodium ions diffuse along the neurone from one node of Ranvier to the next
what is the significance of the frequency of transmission of action potentials
our brains determine the intensity of a stimulus and if there is a more intense stimulus there will be higher frequency of action potentials
(all action potentials are the same size they can only be more/less frequent not bigger or smaller depending on the stimulus)
what is a colinergic synapse
a synapse that sues acteylcholine as its neurotransmitter
