Chapter 16 Sense Organs Flashcards
Transduce energy sensed in to electrical signal (3 names)
transducer, sense receptor, first order afferent neuron
where in the CNS are excess sensations filtered to keep them from our conscious mind?
brainstem
4 kinds of info about sensation
modality, location, intensity, duration
how does the receptive field affect sensing location?
number of sensory neurons in an area determines how accurately we can determine the location of a stimulus
what are the 3 ways our brains interpret intensity?
which fibers, how many, how fast
difference between Phasic and Tonic receptors
Phasic will adapt rapidly and reduce sensitivity ie Smell of a candle - Tonic will adapt slowly and stimulate more steadily throughout sensation
General Senses’ traits
all over body, simple structures
somatic pain
more precise, from skin muscles and joints
visceral pain
internal, poorly localized, more like stretch, chemo, or ischemia (lack of blood)
pain in viscera often mistakenly ‘felt’ on superficial site
referred pain
analgesic
pain relieving
name the 3 endogenous opioids
Enkephalins, Endorphins, and Dynorphins
how do our endogenous opioids work
neuromodulators that block pain and give pleasure
define spinal gating
not opening the ‘gate’ at the spinal cord for pain signals - rubbing or applying pressure to change the signal being sent
gustation
sensation of taste
transducer of taste
taste buds
5 sensations of taste are
sweet, salty, bitter, sour, umami
3 main nerves involved in transducing taste
lingual (into Facial), gossalpharngeal, vagus
Facial nerve gets sensation from…
taste buds on anterior 2/3 of tongue
Glossalpharyngeal nerve collects sensation from…
taste buds on posterior 1/3 of tongue
Vagus nerve collects sensation from…
palate, pharynx, and epiglottis
olfaction
small
transducer for smell is
olfactory bulb
nerve calls are only mitotic in…
olfactory bulb exposed to external environment
lifespan of olfactory fibers is
60 days
transducer for hearing is
cochlea
transducer for equilibrium is
semicircular ducts of vestibule
ear and ear canal (outer ear) used for
directing sound vibrations toward middle and inner ear
middle ear has these structures…
ossicles - 3 middle ear bones
what is the primary function of the ossicles?
to dampen sound vibrations to help not overwhelm choclea
tympanic membrane
ear drum
Otitus Media
)middle ear infection (technically swelling of middle ear
how do we get our sense of equilibrium
with 3 semicircular ducts that are in each of the 3 planes
what are and define the 2 main types of hearing loss
conductive - damage of blockage of the structures that move sound through the ear
Sensorineural - death of hair cells (or other nervous component) usually from long exposure to loud noises
what if the transducer for vision?
retina
membranes that make up the visible white part of the eye - does not go all the way around
Conjunctiva
lacrimal apparatus
makes, distributes, and drains tears
Transparent anterior cover
Cornea
Fluid in anterior cavity of eye - secreted by ciliary body and tea sorbet by sclera venous sinus
Aqueous Humor
This structure changes shape to focus
Lense
Eyeball jelly
Vitreous body (humor)
What are the 2 neural components of vision?
Retina (transducer)
Optic nerve
Cloudiness of lense
Cataract
Elevated pressure in eye from poor drainage of aqueous humor - can not be reversed
Glaucoma
What are the 2 types of photoreceptor cells - only ones that produce visual images
Rods and cones
Duplicity theory of vision
A single type of receptor can not produce both high resolution and and high sensitivity
