The Nervous System Flashcards
nervous system function
allows us to respond to changes in our environment
stimulus
detectable change in the internal or external environment
specialised receptor cells
act as transducers as they detect energy in one form and convert it to electrical energy which travels along neurons as a nerve impulse
effector
nerve impulses initiate a response here which is always a muscle or gland
central nervous system (CNS) and its 2 parts
made up of neurons
somatic nervous system - made of pairs of nerves, branching from brain to spinal cord, carry impulses from receptor cells to cns and from cns to effector cells
autonomic nervous system - provides unconscious control of internal organs e.g. heart beat and breathing
neurons
highly specialised cells which carry nerve impulses in one direction
sensory neuron
carries nerve impulses from receptor cells in the sense organ to the cns
relay neurons
found in cns and connects sensory and motor neurons
motor neurons
transports nerve impulse from cns to effectors
dendrite
carries impulses towards cell body
axon
carries impulses away from cell body
node of ranvier
speed up nerve transmission and can be depolarised
synapse
produce neurotransmitters
spinal cord
flattened cylinder of nervous tissue running from the base of the brain to the lumbar region protected by vertebrae
structures in spinal cord
grey matter
white matter
dorsal root
dorsal root ganglion
ventral root
sensory, relay, and motor neurons
