Noxious stimuli to the brain
come into dorsal horn ad immediately synapses, then secondary axon crosses the synapse and ascends through brain stem to the thalamus and then to the cortex.
Neruotransmitters: Glutamate and substance
PAG and pain
PAG -> pons -> dorsal horn (enough infor can block ascending message so that you dont receive pain)
Touch info to the brain
Ipsalateral until the spinal cord
up the spinal cord
brainstem
thamalums
cortex
Gate Theory of Pain Pathway
small nerve fibers (pain receptors) and large nerve fibers (normal receptors) synapse on projection cells (P), which go up the spinothalamic tract to the brain and inhibitory internerurons (I) within the dorsal horn
Vagus Nerve (CN X)
smallest contribution only gets the very back of the throat (used to perceive fats)
Glossopharyngeal Nerve (CN IX)
back 1/3 of the tongue
Chorda Tymapni Nerve (CN VII)
front 2/3 of the tongue
Trigeminal nerve
carries somatosensory information to the brain (whole fat molecules activate the nerve in the mouth)
Olfactory nerve (CN I)
carries smell to the brain
Pathway of the Olfactory receptor cells
axons go thru the cribiform place and end in olfactory bulb
ipsilateral projection all the way to the cortex
all of these axons together create the olfactory nerve
Cingulate cortex
focuses on the emotional aspects of pain
sits right on top of the corpus collosum
prefrontal cortex
important in memory and understanding the consequences of our actions, executive functioning, and working memory
insular cortex
primary taste cortex
orbitofrontal cortex
part of the prefrontal cortex, association cortex; cells are multimodal
taste information gets together with temp, touch, smell, taste,
good for flavor