ch 4 the human nervous system Flashcards
central nervous system
made up of the brain and spinal cord
acts as the body’s control center
the spinal cord runs from the base of the brain (brain stem), inside bones of the spine, to the lower mid-section of the spine
peripheral nervous system
made up of all the nerves (outside of the brain and spinal cord) that carry messages to and from the CNS
CNS and PNS work together to make rapid changes in your body in response to stimuli
autonomic nervous system
responsible for communication between the body’s non-skeletal muscles and the internal glands and organs that carry out bodily functions
somatic nervous system
consciously controlled - deciding to move muscles or not
reflexes
automatic response to stimulus
sympathetic nervous system:
branch of the autonomic nervous system that activates the fight-flight-freeze response
parasympathetic nervous system
responsible for maintaining day-to-day function of the body (eg. breathing and digesting)
flight, fright or freeze
the sympatheic nervous system serves an important adaptive function by helping prepare the body for the fight-flight-freeze responses to emergencies
It is part of the PNS
neurons
the basic unit of structure and function in the nervous system
cells that conduct impulses made up of dendrites, cell body and an axon
dendrites
the branch like extensions that receive impulses and carry them toward the cell body
dendrites receive impulses from many other axons
axon
single extension of the neuron that carries impulses away from the cell body
the axon branches out at ending to send impulses to many different neurons.
3 types of neurons
sensory neurons: carry impulses from inside and outside the body to the brain and spinal cord
interneurons: found within the brain and spinal cord, process incoming impulses and pass them on to motor neurons
motor neurons: carry impulses away from the brain and spinal cord
homeostasis
the state of balance in the body’s metabolism
