NS pt 7 Flashcards
what are the general senses?
- pain
- touch
- pressure
- vibration
- proprioception
what are the 3 receptor types?
1) interoceptor (visceral)
- detect internal changes in environment
2) exteroceptor (somatic)
- changes in external environment
3) proprioceptor (somatic)
- also an interoceptor
- detect change in position
what are the 4 types of receptors based on the stimulus they detect?
1) nociceptor
- extreme temp, physical damage, chemicals
- results in pain once stim reaches certain threshold
2) thermoreceptors
- cold, warm
- mostly located on external regions of body (integumentary system)
3) mechanoreceptors (tactile, baroreceptor, proprioceptor)
- respond to pressure
4) chemoreceptor
- respond to chemicals (specific)
where are thermoreceptors located?
- hypothalamus
- liver
- integumentary system (dermis)
which are more common? cold or warm thermoreceptors?
way more cold
what are the special senses?
- smell
- taste
- equilibrium
- hearing
- vision
what are the olfactory organs?
- cerebrum
- olfactory nerve
- olfactory bulb
- olfactory tract
- olfactory epithelium
what type of neuron is the olfactory nerve?
-bipolar
where is the cell body of the olfactory nerve located?
-mostly found in olfactory epithelium - axon extends through cribriform plate where it’ll synapse with second neuron (olfactory bulb)
the olfactory nerve synapses in the thalamus
true or false?
false
-synapses directly into olfactory cortex
where is the olfactory cortex?
inferior portion of insula
describe the olfactory pathway
1) olfactory epithelium
2) olfactory nerve (I)
3) olfactory bulb
4) olfactory tract
5) CNS
what cells are responsible for gustation?
gustatory epithelial cells - found inside taste buds
what are the 4 types of lingual papillae?
- filiform
- fungiform
- vallate
- foliate
where is the gustatory cortex?
-superior insula
describe the gustatory pathway
3-neuron system
- gustatory epithelium
- sensory afferent fibres carried by CNs (VII, IX, X) synapse in medulla (1st to 2nd order neuron)
- axons of postsynaptic neurons enter thalamus (2nd to 3rd order)
- gustatory cortex
what are the 3 regions of the ear?
1) external
- tympanic membrane separates from middle
2) middle
- auditory tube connects to inner ear
3) inner
- cochlea and vestibular system
what are the 2 portions of the vestibulocochlear nerve?
1) cochlear nerve (attached to cochlea)
- hearing
2) vestibular (on vestibule)
- balance
what are the 3 ossicles?
- malleus
- incus
- stapes
the stapes covers which window?
-oval window
what are the 3 ducts in the cochlea?
- vestibular
- cochlear (endolymph)
- tympanic
membranous labyrinth
- inside body labyrinth
- contains endolymph
what is found between the membranous labyrinth and the bony labyrinth?
perilymph
contrast semicircular canals with semicircular ducts
canals
-bony
ducts
-within body parts
what are the 3 semicircular ducts? what head movements do they detect?
1) anterior
- detects anterior/posterior motion (e.g. nodding yes)
2) lateral
- detect shaking head “no”
3) posterior
- side to side movement (coronal plane)
which structure of the inner ear makes up the vestibular nerve?
-axons from hair cells
what structures make up the otolithic membrane?
-otoliths and gelatinous membrane
otoliths detect _____
movement because they are weighted
what’s the difference between the utricle and the saccule?
- utricle: detects horizontal displacement
- saccule: detects vertical displacement
the basilar membrane gets deformed when fluid comes through the ______. What is the result of this?
Scala vestibuli
-causes apical surface of cells to come in contact with tectorial membrane above
describe the auditory pathway
1) sound waves arrive at tympanic membrane
2) movement of tympanic membrane = movement of ossicles
3) movement of stapes at oval window = pressure waves in perilymph of Scala vestibule
4) pressure waves distort basilar membrane on way to round window of Scala tympani
5) vibration of basilar membrane causes hair cells to vibrate against tectorial membrane = hair stimulation and neurotransmitter release
6) info about frequency and intensity = relayed to CNS via cochlear nerve
describe the visual pathway
1) photoreceptors in retina
2) optic nerve (II)
3) optic chiasm
4) optic tract
5) lateral geniculate nucleus
6) projection fibres
7) visual cortex
know main anatomical components of eye
textbook
