Sensory Pathways Flashcards
what are the categories of sensory receptors?
mechanoreceptors
thermoreceptors
photoreceptors
chemoreceptors
nociceptors
where do Aalpha afferent fibers conduct signals from?
proprioceptors in muscle spindles and golgi tendon organs
where do Abeta afferent fibers conduct signals from?
non-noxious mechanoreceptors
what are the three major somatosensory tracts?
dorsal column medial lemniscal pathway
spinothalamic tracts
spinocerebellar tracts
what does a first-order neuron in a conscious pathway do?
delivers sensations to the CNS
where does the paleospinothalamic tract project to?
higher cortical areas (amygdala) to coordinate emotional aspect of pain
where does the spinomesencephalic tract project to?
periaqueductal gray
where does the spinoreticular tract project to?
reticular formation
what provides sensory innervation of the head?
all three branches of the trigeminal nerve (CN V)
external ear: CN VII, IX, X, spinal nerves C1 and C2
what controls the muscles of mastication?
proprioceptive afferents and motor efferents of the trigeminal
when does the vestibular system maintain balance?
forward movement
head rotation
tilting of the head or trunk
what are the compartments of the membranous labyrinth?
semicircular canals (3)
macula: utricle and saccule
firing is _____________ in the direction of the head movement
increased
where are cell bodies of bipolar vestibular neurons found?
within vestibular ganglion
where do some fibers from the optic nerve cross?
optic chiasm
where are olfactory receptors?
olfactory epithelium in upper nasal cavity
where do axons from the vomeronasal organ project to?
accessory olfactory bulb
what is the only sensory input with direct cortical innervation?
olfaction