nervous system Flashcards
define stimuli
changes in the environment that can be detected by organisms
define receptors
cells or groups of cells that can detect stimuli
define effectors
parts of the body that respond to stimuli
define coordination
the way that receptors detect stimuli and pass information to effectors
two different forms of coordination
nerves + hormones
differences between nervous system and endocrine system
nervous: faster, nerves, electrical impulse caused by receptors
endocrine: slower, blood, hormones produced by gland
define myelin sheath
layer of fat and protein insulating nerve fibers so they can carry signals faster
what are dendrites
projections of the cell membrane of a motor neuron
what does a motor neuron do
carrys electrical impulses from the CNS to the effector
what is the axon
long projection of the cell membrane of a motor neuron which carries electrical impulses
what do dendrites do
pick up nerve impulses from nearby neurons
what makes up the central nervous system? (CNS)
brain and spinal cord
purpose of the central nervous system
coordinates all electrical impulses travelling through nervous system
what makes up the peripheral nervous system (PNS)
all the nerves that spread out from CNS (neurons, receptors)
what is the purpose of the PNS
regulates involuntary functions like breathing and heartbeat
describe a reflex arc
- a receptor detects a stimulus
- electrical impulse is sent along a sensory neuron to a relay neuron
- relay neuron is connected to the CNS somehow
- electrical impulse is sent along a motor neuron to the effector
