nervous system; CNS Flashcards
what are the three overlapping functions of the nervous system
- sensory receptors monitor changes inside and outside the body
- change= stimulus
-gathered info= sensory output - processes and interprets sensory info
-integration=subconscious - dictates a response by adding activating effector regions
-response motor output
axon
impulse generator ad conductor away from the cell body
-each neuron has a single axon
dendrites
extensive branches from the cell body
transmit chemical or electrical signals toward the body
synapses
sites at which neurons communicate
presynaptic neuron
conducts the signal towards a synapse
postsynaptic neuron
transmits activity away from a synapse
sensory neuron
(afferent) make up the sensory division of the PNS, transmit impulse towards the CNS from sensory receptors in the PNS
motor neuron
(efferent) make up the motor division of the PNS, they carry impulses away from the CNS effector organs (muscle and glands)
interneurons
located between the motor and sensory neurons
-synapse with sensory neurons
-confined entirely to the CNS
-integration site
reflex arc
simple chain of neurons
-explain reflex behaviors
-reflect the structural plan of neurons (in to away)
-mostly involuntary
what are the two basic divisions of the nervous system
-CNS: brain and spinal cord
-PNS: nerves and ganglia
what is a nucleus in the CNS
a collection of nerve cell bodies within the CNS- neurons
tract
bundle of axons within the CNS connecting neighboring or distant nuclei of the cerebral cortex
the brain and spinal cord are composed of what type of matter
gray and white
gray matter
nerve cell bodies lie within; appears as in cross section
-the struts of the H are horns. there are left, right, posterior and anterior horns
