The Nervous System Flashcards
define coordination
systems that allow communication between receptors and effectors of the body to maintain homoestasis
What are the two coordinating systems?
endocrine system and nervous system
what is the difference between th etwo coordinating systems?
nervous > fast> impulses in nerves
endocrine > slow > hormones in blood
describe the structure of the nervous system
CNS - brain and spinal cord
PNS - neurons
define homeostasis
a self-regulating process to maintain stability while adjusting to changing external conditions
define neuron
a modified cell that transmits electrical impulses.
structural unit of the Nervous system
define neurotransmitter
A chemical that carries an impulse across the synapse
define negative feedback
processes in the body that responds to changes from the norm in an opposite manner to return conditions back to normal, thus establishing homeostasis
what are synapses
the microscopic gap between neurons
why are synapses important
- flow of impulses in one direction only
- dispersal of impulses to many other neurons
neurotransmitter can stimulate several post synaptic membranes - filtering out of unimportant stimuli
synapse not able to renew supply of neurotransmitter fast enough
what is a reflex arc
the functional unit of the nervous system
pathway followed by impulses
receptor > effector
bring about a reflex action
what are reflex actions
fast automatic response
by effector organ
significance of a reflex action
responds quickly without involving CNS
safety mechanisms
