13.2 Neurones Flashcards
whats a stimulus
a change in the internal or external environment
whats a neurone
a specialised nerve cell
whats the role of a neurone
to transmit electrical impulses around the body to respond to stimuli
whats the cell body of a neurone like
it contains a nucleus and lots of RER and mitochondria to produce neurotransmitters
whats a neurotransmitter
a chemical used to transmit impulses from one neurone to the next
what are dendrons
extentions of the cell body which divide into dendrites that carry nerve impulses towards the body
what are axons
single elongated nerve cells which carry impulses away from the body
what are the three types of neurone
relay, motor and sensory
what are sensory neurones
they transmit impulses from sensory receptor cell to relay, motor or brain. they have 1 dendron and 1 axon
what are relay neurones
they transmit impulses between neurones they have many short axons and dendrons
what are motor neurones
they transmit impulses from relay or sensory neurone to an effector, they have1 long axon and many dendrites
whats the nervous response pathway
receptor, sensory, relay, motor, effector
whats a myelin sheath
many layers of plasma membrane that can be found covering the axons of neurones
whats the function of a myelin sheath
an insulating layer which can transmit impulses at much faster speeds than unmyelinated
whats a node of ranvier
a gap in myelin sheath of nerve, between adjacent Schwann cells
