Term
|
Definition
| actual stimulus receive and detected by body, generates action potentials. |
|
|
Term
|
Definition
| The Brain's understanding of the stimulus. |
|
|
Term
|
Definition
| the catagory of the stimulus ie. proprioception, temperature, vision, hearing, taste, pressure, pain. |
|
|
Term
|
Definition
| preferred range within that modality. ie. cold vs warm, red vs blue, loud vs soft. |
|
|
Term
|
Definition
| strength of the stimulus. |
|
|
Term
|
Definition
| when is it, how long is it, is it changing? |
|
|
Term
|
Definition
|
|
Term
| Principle of Labeled Lines |
|
Definition
| each recpetor, when stimulated, gives rise to only one sensation. ie - visual receptors only caues you to see, you won't feel pain from those receptors when punched in the eye, you will "see stars". |
|
|
Term
| Stimulus Intensity is determined by what? |
|
Definition
| increasing number of action potentials = more intense. increased firing of a single neruon, or different neurons with different thresholds. As the stimulus gets more intense higher and higher threshold neruons are actiavted, signaling a more intense stimulus. Recruitment - low stimulus, 1 neuron. High stimulus, neuron "recruits" adjacens neurons of same modality to intensify signal given to brain. |
|
|
Term
| What are the four questions one asks when talking about receptor encoding / signals? |
|
Definition
| What is its modality / submodality? Its intensity, temporality, and location? |
|
|
Term
|
Definition
| slowly adapting receptors, continuously generating AP througout stimulus, ie. fan in room that you "tone out" because you're always hearing it but your mind ignores it because it doesn't matter as much. |
|
|
Term
|
Definition
| rapidly adapting, only generate AP @ onset (somtimes offset) of stimulus. Convent info about change in sitmulus intensity. |
|
|
Term
|
Definition
| focused on exteranl stimuli, the world around you, distance / contact receptors (ie. sight, touch) |
|
|
Term
|
Definition
| Focused on the thigns within me (ie. my body temeprature) |
|
|
Term
|
Definition
| Focused on my momement, balance, and position relative to things around me - coordination. |
|
|
Term
|
Definition
| ability to discriminate between location of simultaneous stimuli. High acuity = high ability to tell the difference between two stimuli adjacent to each other. For example, two pins touching your finger, at some point they will get close enough that it feels like one pin because you can't t tell the difference. You don't have the acuity to distinguish between the two different stimuli. |
|
|
Term
|
Definition
| region of receptor surface that corresponds to a single neuron. High receptive field = low acuitiy and vis versa. |
|
|
Term
|
Definition
| stretch activated ion channels - they detect forces. The channels are literally forced open. Send info to the primary somatic sensory cortex. There are four types. |
|
|
Term
| What are the four type sof touch receptors? Are they phasic or tonic? Where are they located? |
|
Definition
Meissner's corpuscle- phasic - superficial skin
Merkle's corpuscle - tonic- superficial skin
Pacinian's corpuscle - phasic - subcutaneous
Ruffini corpuscle - tonic - subcutaneous |
|
|
Term
| What is mechanism of pacinian corpuscle? |
|
Definition
| Large structure - neuron in center with layers and layers of membrane and fluid surrounding it. Put pressure it - stimulates neuron and fluids spreads out and settles. Once it settles no pressure / stimulation occurs on the neuron. When the pressure is no longer being put on the corpuscle, the fluid goes back to its original form and the neuron is sensing the change until it settles back to original form. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| A large bump on the surface of the tongue (not taste buds). |
|
|
Term
|
Definition
| not neurons - they stimulate neurons behind them. |
|
|
Term
|
Definition
| help give shape and structre to the taste bud in general. |
|
|
Term
|
Definition
| constantly replacing taste and support cells. |
|
|
Term
| What are the basic tastes? |
|
Definition
| salty, sour, sweet, bitter, umami (amino acids, meat) |
|
|
Term
| Describe how salt is tasted |
|
Definition
| sodium channels are always open. So when sodium is present, it rushes in and depolarizes, giving a signal, |
|
|
Term
| Describe how sour is tasted |
|
Definition
| potassium channels always open, protons block potassium channels - getting rid of potassium permeability, sodium still can travel, depolarization. |
|
|
Term
| describe how sweetness is tasted |
|
Definition
| uses second messenger systems. combination of different receptors |
|
|
Term
| how is bitterness tasted? |
|
Definition
| alkaloids - incomplete answer |
|
|
Term
|
Definition
| chemical in grapefruit that is extremely bitter to some people who have a receptor for it, some dont have the receptor so they don't taste the bitterness. |
|
|
Term
|
Definition
| the taste of amino acids, proteins, meat. |
|
|
Term
|
Definition
|
|
Term
| what are the two chemical senses? |
|
Definition
|
|
Term
|
Definition
| where olfactory receptors are located. |
|
|
Term
|
Definition
| neurons which we constantly replace (very interesting, rare that we can replace neurons) |
|
|
Term
| what are the 3 cell types in the olfactory sensing system |
|
Definition
support - structure
basal - reparation
olfactory receptors - neurons that get signal |
|
|
Term
|
Definition
loss of sense of smell
causes - injury to cribiform plate
exposure to toxic chemicals
zinc deficiency
aging |
|
|
Term
| What are the three sections of the ear? |
|
Definition
outer ear
middle ear - air filled cavity
intter ear - fluid filled, where organs involved with hearing and balance are located |
|
|
Term
|
Definition
| it is the area where hair cells are housed, to detect sound. it if fluid filled with 3 basic canals. sound waves come in through the scala vestibuli, go out through the scala tympani. |
|
|
Term
| what do the semicircular canals do? |
|
Definition
| they help detect angular acceleration |
|
|
Term
| what does the vestibule do? |
|
Definition
| helps detect the position of the head. has utriculus and sacculus in it. |
|
|
Term
| what is the organ of corti / what is its function? |
|
Definition
| This is where the hair cells are actually located. It is inside the choclea. Hair cells are connected to the bottom, basalar membrane and to the "ceiling" tectoral membrane. The basalar membrane is movable, tectoral is unmovable. So sound moves the bottom, pushing the hair cells into the tectoral membrane and bending them, opening up strech activated ion channels. |
|
|
Term
| Describe the two ends of the basalar membrane. |
|
Definition
basal end - compact, dense, difficult to vibrate - high frequency
Apical end - less dense, easier to vibrate, low frequency - further from where sound waves enter |
|
|
Term
| how do hair cells detect pitch? |
|
Definition
| based on location of where sound wave affects basalar membrane. basal end = high pitch apical end = low pitch. |
|
|
Term
|
Definition
| the sense of the body's position in space. important for posture, balance, and coordinated movement. |
|
|
Term
|
Definition
| gel that hair cells are in |
|
|
Term
| what do we use to detect proprioception |
|
Definition
| semicircular canals - begin movement to the left and fluid moves to the right, pushing the cupula which houses the hair cells, bending the hair cells. At end of movement fluid moves left, cupula moves left as well bending hair cells in other direction. Match these movemetns with visual information to accurately determine movement. |
|
|
Term
| What is rhodopsin made out of? |
|
Definition
Retinal - derivative of vitamin A, cis form fits into opsin, trans doesn't. Use ATP to retrun to cis form, goes to trans when absorbs light.
Opsin - transmembrane protein, g-protein linked |
|
|
Term
How does a photoreceptor act in the dark?
|
|
Definition
| Na channel open - cell depolarizes - release neuro transmitter |
|
|
Term
| How does a photoreceptor act in the light? |
|
Definition
1. light hits rhodopsin -> retinal goes to trans form
2. transucin (g protein) activates cGMP phosphodiesterase
3. cGMP phosphodiesterase takes cGMP away from Na channel, so Na channel closes.
4. Repolarization |
|
|
Term
| How many types of opsin are there and what are they? |
|
Definition
4 opsin
3 cone, R G B
1 rod |
|
|
Term
| what is the order of events, in broad terms, from signal to brain with vision? |
|
Definition
| light hits eye -> hits rod / cone (photoreceptors) -> signal goes to bipolar cells which send signal to ganlion which in turn brings to the brain |
|
|
Term
|
Definition
| the point of highest focus - packed with cones, doesn't function in low light. |
|
|
Term
|
Definition
| blind spot, it is where ganglion cells exit |
|
|
Term
| 3 reasons why our optic disk is unnoticable to us |
|
Definition
1. 2 eyes, overlapping sight
2. brain fills in image
3. eyes are always moving |
|
|
Term
| Difference between rods and cones |
|
Definition
| rods are 15-30 per bipolar cell, less acuity but greater receptive field. cones are 1 cone per bipolar, they then have much higher acuity but are less sensitive than rods. |
|
|
Term
| what is difference between lens and cornea with respect to the bending and focusing of light? |
|
Definition
| the cornea does the majority of the bending while the lens does the fine-tuning. Cornea is before the lens. |
|
|
Term
|
Definition
| surrounding the lens, suspensory ligaments connecting muscle to lens |
|
|
Term
| how does one focus on distant objects? |
|
Definition
| ciliary muscle relaxes, the suspensory ligaments are then pulled tighter because the muscle is further form the lens, causing the lens to be flatter so the distant parralel light is not bent. |
|
|
Term
| how does one focus on nearby objects? |
|
Definition
| ciliary muscle contracted, brining it closer to the lens so the suspensory ligaments are not taught, allowing the lens to assume its natural curved, convex shape, bending the light. the lens rounds. |
|
|
Term
|
Definition
| nearsightedness due to the eyeball being too long, the focal point the lens creates is in front of the photoreceptors. |
|
|
Term
|
Definition
| farsightedness, eyeball is too short, the focal point is behing the photoreceptors |
|
|
Term
|
Definition
| decreased lens elasticity, aging of the lens |
|
|
Term
| how is vision different in birds? |
|
Definition
| both lens and cornea can round / flatten, allowing for sight at greater distances as well as close up - larger range of focus. |
|
|
