Term
| What do sensory cells do? |
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Definition
| transduce physical or chemical stimuli into signals that are transmittable and interpretable |
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Term
| Do receptor cells look like neurons? |
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Definition
| no, but they behave like neurons |
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Term
| What are sensory cells (or receptor cells)? |
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Definition
| they are modified neurons, specialized for detecting different kinds of stimuli, such as pressure, heat, or light |
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Term
| What are photoreceptors and where are they found? |
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Definition
|
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Term
| What are mechanoreceptors and where are they found? |
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Definition
| respond to movement, in ears |
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Term
| What are chemoreceptors and where are they? |
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Definition
| receive chemicals, in body sense CO2, O2, found in nose |
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Term
| What are thermoreceptors and where are they found? |
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Definition
|
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Term
| What are nocireceptors and where are they found? |
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Definition
| pain receptors, all over body |
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Term
| What are electroreceptors and where are they found? |
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Definition
| sense electrical field, humans dont have them, ex: shark and blood |
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Term
| What are magnetoreceptors and who has them? |
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Definition
| sense magnetic field, bird |
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Term
| Where are mechanoreceptors found? |
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Definition
|
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Term
| What do mechanoreceptors respond to? |
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Definition
|
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Term
| What are pacinian corpuscles and what do they do? |
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Definition
| mechanoreceptors, provide information about vibrating stimuli of higher frequencies |
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Term
| Where are dendrites of sensory neurons found? |
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Definition
| wrapped around hair follicles which detect displacement of the hairs |
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Term
| What is lateral inhibition? |
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Definition
| the way to know exactly where was stimulated, called receptor acuity where you can localize exactly where stimulus came from |
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Term
|
Definition
| the vibration of air molecules |
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Term
| What can waves of vibrations have? |
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Definition
| 1. high amplitude (loudness) 2. frequency (pitch) |
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Term
|
Definition
| acts like a funnel to attract all vibrations |
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Term
| What is the external cannal? |
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Definition
|
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Term
| What is the tympanic membrane? |
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Definition
| eardrum, end of external canal, connected to small bones called ossicles |
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Term
| When the stepes pushes on the oval window what happens? |
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Definition
| causes shaking of cochlea fluid which causes vibration |
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Term
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Definition
| 1, malleus 2. stapes 3. incus |
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Term
| Where are mechanoreceptors in the ear? |
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Definition
|
|
Term
| What is the cochlea filled with? |
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Definition
|
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Term
| How is sound transmitted? |
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Definition
| 1. vibration of air molecules go through the pinna, passing through the external auditory canal 2. the air then vibrates the tympanic membrane which cause the three ossicles to vibrate 3. the ossicles cause the oval window to vibrate 4. this leads to stimulation of hair cells inside the cochlea |
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Term
| What is the cochlea divided into? |
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Definition
|
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Term
|
Definition
| mechanoreceptors that have hair like structures called stereocilia |
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Term
| What does a hair cell have? |
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Definition
| many stereocilia and one kinocilium |
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Term
| What are found between the hair like structures? |
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Definition
|
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Term
| What does any movement of hair toward the kinocilium cause and why? |
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Definition
| electrical activity to occur because there are stretch gated channels that are opened |
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Term
| When the stereocilia move towards the kinocilium what happens? |
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Definition
| stretch gated channels open |
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|
Term
| What happens when stereocilia move away from kinocilium? |
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Definition
| stretch gated channels close |
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Term
| What happens when hair cells are stimulated? |
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Definition
| 1. K+ influx occurs 2. this will cause the hair cell to depolarize which leads to the activation of the voltage gated Ca channels 3. Ca influx causes the release of glutamate which activates the afferent neurons |
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|
Term
| What happens when the hair cells are not stimulated? |
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Definition
| the afferent neurons are silent |
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Term
| What stimulates the hair cells? |
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Definition
| 1. movement of the stereocilia towards the kinocilium activates the stretch activated channels (depolarization) 2. movement of the stereocilia away from the kinocilium closes the stretch activated channels (hypopolarization) |
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|
Term
| What cause the hairs to move? |
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Definition
| the vibration of the fluid inside the inner ear |
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Term
| What is the neural pathway of hearing? |
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Definition
| 1. cochlear nerve fibers synapse on interneuron that send the signal to the thalamus 2. from the thalamus, the information go to the auditory cortex of the temporal lobe |
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|
Term
| What are the eyes composed of? |
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Definition
|
|
Term
| What is the function of the eyes? |
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Definition
| 1. focus the image on sensory cells (photoreceptors) 2. transform the image to the brain through series of action potential 3. have receptors that are sensitive to light 4. eyes are messenger to brain |
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Term
|
Definition
| 1. spectrum of electromagnetic radiation 2. described in terms of wavelengths frequencies |
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Term
|
Definition
| the distance between two successive wave peaks |
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Term
| What is the visible spectrum? |
|
Definition
| the wavelengths capable of stimulating the receptors of the eyes |
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Term
| What are the three layers of the eye? |
|
Definition
| 1. fibrous 2. vascular 3. neural |
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|
Term
| What is the purpose of the fibrous layer? |
|
Definition
| outer layer for protection |
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|
Term
| What is in the vascular layer? |
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Definition
|
|
Term
| What is found in the neural layer? |
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Definition
| inner layer, neurons are found |
|
|
Term
| What parts of the eye are for protection? |
|
Definition
| schelera (poterior) and cornea (anterior) |
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|
Term
|
Definition
| white part of the eye, protection, part of fibrous layer, posterior |
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Term
|
Definition
| anterior, first structure to receive light rays |
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|
Term
| What is the function of the choroid? |
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Definition
|
|
Term
| What is the purpose of the iris? |
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Definition
| contain smooth muscles to determine the size of the pupil, help guide the image to form neural layer, colored part of eye |
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|
Term
| What do smooth muscles determine? |
|
Definition
|
|
Term
| What are the 2 layers of the choroid? |
|
Definition
|
|
Term
| Where is the choroid and what does it contain? |
|
Definition
| back of eyes, contains light and does not let it escape |
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|
Term
| What does the retina have? |
|
Definition
| photoreceptors to receive the light and send it to the brain through the optic nerve. Contains the fovea centralis (high visual acuity-details) |
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|
Term
| What happens when light rays strike the cornea? |
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Definition
| the lens move inward and converge into a specific point on the retina |
|
|
Term
| where are objects in the center focused? |
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Definition
|
|
Term
| Does the retina invert the image? if so what is done to correct it? |
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Definition
| yes, the brain corrects for it so we see right side up |
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|
Term
| What is the order when light hits the eye? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| do all structures allow focus of image when on retina? |
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Definition
|
|
Term
| What are suspensory ligaments? |
|
Definition
| chords that connect ciliary body to lens |
|
|
Term
| What are the three parts of the middle vasculary layer? |
|
Definition
| 1.choroid coat 2. ciliary body 3. iris |
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|
Term
| What does the ciliary body do? |
|
Definition
| forms a ring around the front of the eye |
|
|
Term
| What do the suspensory ligaments do? |
|
Definition
|
|
Term
| What do the suspensory ligaments and ciliary muscles enable? |
|
Definition
| the lens to adjust shape to focus |
|
|
Term
| Where must objects that are at close distance be focused? |
|
Definition
|
|
Term
| Why does the lens change shape? |
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Definition
| to allow the image to be focused on the retina, so we can focus the image we see and see it clearly |
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|
Term
| Where are distant objects focused? |
|
Definition
|
|
Term
| What happens when suspensory ligaments contract? |
|
Definition
| cause the lens to flatten |
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|
Term
| What happens when suspensory ligaments relax? |
|
Definition
| cause the lens to thicken |
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|
Term
| What happens when the ciliary muscles are relaxed? |
|
Definition
| the suspensory ligaments contract and the lens becomes thin and flat in order to focus distant objects |
|
|
Term
| What happens when the ciliary muscles are contracted? |
|
Definition
| suspensory ligaments are relaxed and the lens becomes thick to focus close objects |
|
|
Term
| What changes the size of pupil? |
|
Definition
|
|
Term
| What happens in dim light? |
|
Definition
| radial smooth muscles contract, muscles of iris widen, pupil becomes larger and dilated |
|
|
Term
| What happens in bright light? |
|
Definition
| circular smooth muscles contract, constrict the size of pupil |
|
|
Term
| Where are radial smooth muscles? |
|
Definition
|
|
Term
| Are smooth muscles voluntary or involuntary? |
|
Definition
|
|
Term
| What type of muscles are in the eye? |
|
Definition
|
|
Term
| What types of cells are in the retina? |
|
Definition
| 1. ganglion cells 2. amacrine 3. bipolar 4. horizontal 5. photoreceptors (rods and cones) |
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|
Term
|
Definition
| special receptor cells, are excitable, dont have shape of neuron but are like neuron, form synapses with bipolar cells |
|
|
Term
| What is the function of horizontal cells? |
|
Definition
|
|
Term
| What is the function of ganglion cells? |
|
Definition
| receive synapses from bipolar cells |
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|
Term
| What is the function of amacrine cells? |
|
Definition
|
|
Term
| What does the axon of ganglion cells form? |
|
Definition
|
|
Term
|
Definition
| 1. photoreceptor 2. sensitive to light 3. respond to low illumination 4. contain pigments that absorb light |
|
|
Term
|
Definition
| 1. photoreceptors 2. less sensitive to light 3. respond to high illumination 4. contain pigments that absorb light |
|
|
Term
|
Definition
| any molecule that changes conformation once it is exposed to light |
|
|
Term
| What pigments do rods contain? |
|
Definition
|
|
Term
| What pigments do cones contain? |
|
Definition
| 3 types (blue, green and red) photopsin |
|
|
Term
| What protein do the pigments in rods and cones contain? |
|
Definition
|
|
Term
| Describe in detail the neural pathway of vision |
|
Definition
| photoreceptors form inhibitory synapses with bipolar cells. photoreceptors are hyperpolarized (make cell less excitable). they stop releasing the inhibitory neurotransmitter onto bipolar cells. Bipolar cells are not activated and they excite ganglion cells. Axons from the ganglion cells form the optic nerve. the 2 optic nerves meet to form the optic-chiasm. some axons cross to the opposite side of the brain forming optic tracts. fibers pass to the thalamus. signals are sent from the thalamus to the visual cortex |
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|
Term
| Where are the highest amount of photoreceptors? |
|
Definition
| central point of the retina |
|
|
Term
| What does the amount of photoreceptors determine? |
|
Definition
|
|
Term
|
Definition
| can see in front of you clearly with details |
|
|
Term
| What is peripheral vision? |
|
Definition
| when looking straight ahead and cannot see sides with detail |
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|
Term
| List the parts of the eye for the neural pathway of vision |
|
Definition
| eye-optic tract-optic nerve-optic chiasm-thalamus-visual cortex |
|
|
Term
| What is optical illusion? |
|
Definition
| background can confuse the brain to see something else |
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