12.3 The Function of Nervous Tissue

what are the major functions of the NS

sensation, integration, response

what does sensation do

detects changes in the environment

sensation has specialized receptors in

the skin, eyes, ears, and other organs to sense different types of stimuli

different type of stimuli examples

light, sound touch, temperature

what is integration

the brain and spinal cord process sensory input and compare it with memories, emotional state, and determine an appropriate response

what is response

the NS sends signals to muscles or glands to cause an action

what is 1st step for the motor response pathway

sensory detection

what is 2nd step for the motor response pathway

signal transmission to CNS

what is 3rd step for the motor response pathway

processing in the brain

what is 4th step for the motor response pathway

motor command formation

what is 5th step for the motor response pathway

motor response execution

what is a thermoreceptor

type of sensory receptor that is sensitive to temperature

where can thermoreceptors be found in our body

skin of fingers or toes

what is the graded potential

the amount of change that is dependent on the strength of the stimulus

what is the threshold

the point at which an effect begins to be produced

what happens if the graded potential is strong enough

reaches the threshold

what is the action potential

electrical signal that travels down the axon

what happens when the graded potential reaches the threshold

action potential is triggered

what happens when the action potential is triggered

it propagates

what does propagates mean

movement of action potential traveling along the axon hillock, terminals, and synaptic end bulbs

what are neurotransmitters

chemical signal that is released from the synaptic end bulb of a neuron

what do neurotransmitters do

cause a change in target cell

what happens when action potential propagates to end bulbs

neurotransmitters are released

what is the thalamus

brain structure that acts as a relay station for sensory information (CNS)

after a neurotransmitter is released, where does it go

to the thalamus

after the neurotransmitter reaches the thalamus, where does that signal go

to the cerebral cortex

what is the cerebral cortex

outer most layer of gray matter in the brain

what does the gray matter in the brain responsible for

conscious perception and decision making

what is the precentral gyrus of the frontal cortex

part of brain that controls voluntary movements

what are upper motor neurons

neurons in the brain that sends movement commands to the spinal cord

what are lower motor neurons

neurons in spinal cord that directly controls muscle movements