The Human Senses Flashcards
What does sensation refer to?
The passive prices of detecting environmental stimuli through our various senses
What does perception refer to?
The active process of receiving, re-organising, and interpreting raw sensory information
When does sensation occur?
Occurs when a sensory receptor become stimulating, absorbs energy from the stimulus itself, and converts it into neural impulses that the brain can interpret
When are we able to sense a stimulus?
When it reaches an absolute threshold
What is an absolute threshold?
The point at which energy from a serious becomes detectable
When can we detect ranges in the strength of a stimulus?
If the strength of the stimulus exceeds our difference threshold
What is the difference threshold?
The minimum change in stimulus intensity need for us to notice at least 50% of the time that a changes occurred
What does Weber’s Law state?
The magnitude of the just noticeable difference is proportional to the intensity of the original stimulus
What is background sensory information?
Noise
Define criterion
The level of confidence in filtering noise and judging its importance
What does the signal detection theory explain?
The detection of the stimulus depends not only on the intensity of that stimulus, but also the physical and psychological state of the individual
What is sensory adaptation?
The decrease in sensitivity to and and changing stimulus
What is psychophysics?
The quantified study of such sensations in the stimuli that produce them
What initiates the process of sensation?
Sensory receptors
And in telling stimulus alters the membrane permeability of the sensory receptors nerve ending stimulating a?
Receptor potential
What does the receptor potential generate? Where does this lead?
An action potential; it really is the information to the CNS
What is sensory transduction?
The transformation of physical energy from the stimulus into an electrical message
What are the two types of nerve endings?
Encapsulated and free nerve ending
What is an encapsulated sensory receptor nerve ending?
It is enclosed by a structure
What type of nerve ending is nonencapsulated?
A free nerve ending
What three traits classify sensory nerve receptors?
Conduction speed, location, and modality
What are the two types of conduction speeds for sensory receptor cells?
Phasic receptors and tonic receptors
What are phasic receptors?
Rapidly adapting receptors that respond quickly and entirely to a stimulus, but stop responding even at the stimulus remains constant
What are tonic receptors?
Slowly adapting receptors that respondent gradually to a stimulus and provide a continuous signal for the entire duration of the stimulus
What are the three types of sensory receptors based on location?
Exteroceptors, interoceptors, and proprioceptors
What are exteroceptors?
They are located close to the body surface and are specialised to detect external stimuli such as tactile, gustatorily, visual, olfactory, and auditory stimuli
What are interceptors?
Receptors located within internal organs and are specialised to detect sensory information concerning the bodies internal environment such as blood pressure, pH levels, dissolved gas concentrations
What are proprioceptors?
Receptors located in joints, muscles, tendons, and the stimulus structures of the inner ear. They detect specific movement and positioning required for spatial reasoning and balance
What are the five types of receptors according to stimulus modality?
Chemoreceptors, mechanoreceptors, nocireceptors, photoreceptors, and Thermoreceptors
What do chemoreceptors do?
They detect chemical stimuli and playing important role in olfaction and gustation
What do mechanoreceptors do?
They detect stimuli
That physically deformed the tissue in which resides such as pressure or vibration
What do nocireceptors do?
There are sensitive to damaging and painful stimuli and are almost always tonic
What do photoreceptors do?
They respond to electromagnetic radiation and are essential for sight
What do thermoreceptors do?
They detect warmth and cold and almost always phasic
What is a sensory pathway?
It describes the stimulus induced relaying of information to the central nervous system for complex integration and perception
What three types of neurons are involved in the sensory pathway?
Primary, secondary, and tertiary neurons
What are primary neurons? Where are they located? Where do they take their information?
Afferent or sensory neurons; they are located in the peripheral nervous system; they received the news information and relay it to either the spinal cord on the brainstem
What takes our information received by the primary neurons? Where did these neurons send the information?
Secondary neurons;that information is relayed to the thalamus for processing and redirected to the correct sensory area of the cerebral cortex
What type of neuron redirects information from the thalamus to the cerebral cortex?
Tertiary neuron
Why are sensory pathways able to inform the the cerebral cortex about exactly what type of stimulus is been experience and where?
Because the brain maps the location of each receptor, and because each receptor is activated only by a particular stimulus
What is perception?
Organisation and interpretation of sensory information that allows us to make sense of our surrounding environment
What is top-down processing?
Describes the use of previous knowledge and contextual information in pattern recognition
What type of processing explains why it is much easier to understand messy handwriting when reading a sentence rather than an isolated word?
Top down processing
What does bottom up processing suggest?
Postulates that the perception begins with the stimulus itself, using bits and pieces of sensory information to generate a larger picture
Because bottom up processing requires the interpretation of incoming stimuli, what is it often referred to?
Data driven processing
What type of processing do we use to perceive our environment accurately?
Both bottom up and top down processing
What for characteristics does perceptual organisation rely on?
Depth, motion, constancy, and form
What does depth perception enable one to estimate?
An object’s distance
From what two types of cues is depth perception determined?
Monocular cues and binocular cues
What type of cues are two-dimensional cues that one eye can detect?
Monocular cues
What are examples of monocular cues?
Perception is based on relative size, interposition, texture, shading, and height
What is relative size?
Compares objects assumed to be similar in size in order to discern distance
Relative size indicates that larger objects are perceived to be…… Than smaller objects
Closer
What is interposition?
Overlap
In what monocular cue does one person with a partially blocked object to be further away than the blocking object?
Interposition
How does texture act as a monocular cue?
As the texture of an object becomes more detailed, one perceives it to be closer than a smoother object.
Differences in……… Produce depth perceptions based on our assumption that light comes from above, resulting in images that either protrude toward or away from us.
Shading
Finally based on our perception of the horizon, objects located………… In our visual fields are perceived to be………… than objects located closer to the bottom of our visual field.
Closer; further away
How many eyes are needed for monocular cues which allow one to perceive three-dimensional information from two-dimensional images?
One eye
How many eyes do binocular cues depend on?
Both eyes
Because our eyes are about 2 1/2 inches apart, each eye receives slightly different information resulting in a difference in retinal images, what are the two terms for this difference?
Retinal disparity or binocular disparity
How many images do we sense with their eyes? How many images do we perceive?
2; 1
What major binocular cue shapes our perception of depth based on muscular feedback involved with eye rotation?
Convergence
To learn whether depth perception in infants is innate or learned, what object did researchers develop?
Visual cliff
What is the visual cliff?
A structure with the shallow end covered in a certain pattern connected it to the deep end of the same pattern with Plexiglas on top
Because in the Visual cliff experiment, infants of all ages would not go over the deep end, what does this suggest about the development of the depth perception?
Infants develop the depth perception as soon as they begin to crawl
The perception of…… Is based on visual, vestibular, and proprioceptive inputs to characterise the whether and object is moving.
Motion
What does motion parallax explain?
It explains why we perceive fast moving objects to be closer than slow moving objects
What is the apparent motion caused by the rapid succession of stationery stimuli? (Movies)
Phi phenomenon
What is The tendency to recognise familiar objects as having the same properties despite the changes and lighting, distance, or angle of perspective?
Perceptual constancy
What are the three main categories of perceptual constancy?
Colour constancy, size constancy, and shape constancy
What does colour constancy allow us to do?
Allows us to recognise and perceive the colour of an object as remaining relatively unchanged under different viewing or illumination conditions
What does size constancy allow us to do?
Allows us to perceive in objects true size despite appearing to be larger or smaller, depending on changes in proximity
What does shape constancy allow us to do?
Perceive an object is true shape despite being distorted by differences in our viewing angle
Perception is largely organised by………… And begins by distinguishing an object, or figure, from its surroundings, or ground.
Full stop
What is it called when the figure and ground have been identified, sensory information is further organised into groups
Figure ground relationship
What are the rules for grouping?
Gestalt principles
What are the four gestalt principles?
Similarity, proximity, continuity, and closure
What gestalt principle is similarity?
Our tendency to perceive similar stimuli to be part of the same object, and to group them accordingly
What gestalt principle is proximately?
The tendency to perceive stimuli that are close to one another to be part of the same object, and to group them accordingly
What is the gestalt principle of continuity?
Refers to our affinity for spotting patterns and our ability to differentiate between overlapping stimuli
What is the gestalt principle of closure?
Address is the minds inclination to recognise complete figures and fill in gaps, even if a picture is incomplete
What is the most thoroughly studied and heavily relied upon human sense?
Vision
What is the sensory organ responsible for vision?
The eye
For any sensation to occur, there must always be what to universal criteria?
1) A stimulus
2) A specialised receptor to receive the stimulus and convert it into neural impulse
In the case of vision, what is the stimulus?
Electromagnetic energy
What portion of the electromagnetic spectrum is the human eye capable of interpreting?
Visible light
What two physical characteristics of light play a role in vision?
Wavelength and intensity
What is the wavelength of visible light?
The distance between adjacent crests of EM radiation
What physical characteristic of light determines the colour we perceive?
Wavelength
What is the lights intensity?
The energy it contains
What is the term for intensity on the EM spectrum?
Amplitude
What does intensity determined in vision?
The brightness of the colour we perceive
What is the order from longest wavelength to shortest wavelength of the EM spectrum?
radio waves, microwaves, infrared, visible (colours ROYGBIV), ultraviolet, X-rays, and gamma-rays.
What is the wavelength in nanometres on the visible light spectrum of the colour red?
700 to 630 nm
What is the wavelength in nanometres on the visible light spectrum of the colour orange ?
630 to 590 nm
What is the wavelength in nanometres on the visible light spectrum of the colour yellow?
590 to 560 nm
What is the wavelength in nanometres on the visible light spectrum of the colour green?
560 to 480 nm
What is the wavelength in nanometres on the visible light spectrum of the colour blue?
480 to 440 nm
What is the wavelength in nanometres on the visible light spectrum of the colour violet?
440 to 400 nm
Where does light into the eye through?
The cornea
What is a transparent and protective membrane that functions as an outer lens, bending light to provide roughly 70% of the eyes total focusing power?
Cornea
Why does the cornea not have blood vessels? How does it get its nutrients?
It is clear; it’s nutrients are acquired instead from the diffusion of tear fluid
Once light enters the cornea, where does it travel to?
The pupil
What is an opening of adjustable diameter that is regulated by surrounding contractile tissues?
Pupil
What are the surrounding contractile tissues of the pupil?
Iris
That Iris muscle contracts or dilates to maintain a balance between what two things depending on changes in illumination ?
Visual acuity and visual sensitivity
What is visual acuity?
The ability to see sharply
What is visual sensitivity?
The ability to see under dimly lit conditions
What is immediately behind the pupil?
The lens
What does the lens do?
Focuses incoming light onto the retina
What is the Multi layered, light sensitive tissue that lines the inner surface of the eye?
Retina
Similar to a biconvex lens, the eyes lens focuses an image onto the render that is _____, _____, and _____ compared to the viewed object
Smaller, inverted, and right left reversed
What acts as the suspensory ligament holding the lens in place to apply adjustable increments attention necessary for focus?
Ciliary muscles
When we focus on distant objects, the ciliary muscles _____, causing the suspensory ligament is to become _____, which in turn ______ the lens, effectively _______ its focal distance.
Relax, taut, flattens, increasing
When we focus on close up objects, the ciliary muscles _____, causing the suspensory ligaments to _____. As tension _______, the lens becomes more spherical and gains increased ability to _____ light.
Contract, relax, decrease, refract
What is the prices of lens curvature adjustment necessary for focus called?
Accommodation
What are five other important structures that do not alter lights path to the retina, but act as an essential part to maintain the eye?
Sclera, aqueous humor, vitreous humor, choroid, and extraocular muscles
What is the visible, white portion of the eye called?
Sclera
What is a fibrous, protective layer that covers the eye and provides rigidity?
Sclera
What structure of the eye is located in the anterior chamber?
Aqueous humor
What is the anterior chamber of the eye?
The space between the cornea and lens
What is the gelatinous fluid that maintains the intraocular pressure of the eye, supplies nutrients, and removes debris?
Aqueous humor
In what chamber is the vitreous humor found?
Vitreous chamber
What is the gelatinous fluid found behind the lens, in the vitreous chamber?
Vitreous humor
What is the structure of the eye that maintains the eyes shape while also firmly keeping the retina in place?
Vitreous humor
What does the vitreous humor press the retina against?
The choroid
What is a layer of connective-tissue and blood vessels that nourish the posterior structures of the eye?
Choroid
What structures control gross eye movement and eyelid elevation?
Extraocular muscles
What is the conversion of light stimuli into neural impulses?
Phototransduction
Where does photo-transduction occur?
The photoreceptor cells of the retina
Before a light reaches the phone receptor cells it must travel through for other types of neurons that form ________ ______.
Retinal layers
Progressing from the inner, vitreous humour side of the right now to the outer, choroid side, what are the five types of neural cells that line the retinal layers?
1) retinal ganglion cells
2) amacrine cells
3) bipolar cells
4) horizontal cells
5) photoreceptor cells
What two types of photoreceptor cells synapse across the other neurons to communicate laterally and coordinate sensory input?
Amacrine cells and horizontal cells
When light activates _______ cells, a biochemical cascade results in decreased _______ release, which affects the activity of ______ cells, which in turn relays this _____ or ____ response to ______ ______ _______. The axons of the ______ ______ ______ exit the retina via the ______ ______ and carry _____ ______ _______ to the ______.
Photoreceptor, glutamate, bipolar, excitatory, inhibitory, retinal ganglion cells, retinal ganglion cells, optic nerve, visual sensory information, brain
Light must pass through ____ ____ layers before Activating the _______ to generate a neural message.
Four neuronal; photoreceptors
Describe the path of light in the retinal neurons.
Light hits the outer of the neurons in the vitreous humor. It then travels through these neural cells to reach the rods/cones and back through with an activated neural message to the optic nerve
Because the axon of each retinal ganglion cell exits through the same point, _____ ______ ______, there is no room for photoreceptors in this region creating a ______ ______.
The optic nerve, blind spot
Because the four neuronal layers distort light on their way to the photoreceptors, what is in place to reduce distortion?
Fovea
What is the indentation at the centre of the retina that helps to minimise distortion of light called?
Fovea
What is the central focal point on the retina? What does this point allow for?
Fovea; highest visual acuity
What are the two types of photoreceptor cells?
Cones and rods
Which photoreceptor cells are responsible for colour vision?
Cones
Which photoreceptor cells are responsible for peripheral vision, contrast and edge perception, and nighttime vision?
Rods
Both rods and cones contain what three components?
1) dendritic outer segment
2) dendritic inner segment
3) synaptic terminal
The outer segment of the rods and cones contain ______ ______ stacked on top of one another?
Photosensitive discs
What did the photosensitive discs stacked on top of one another in rods and cones do?
Specialise the cell to receive and transduced light
What is the difference in between the rods and cones in appearance?
Size and shape; cones have short, tapering segments that give them their conical shape; rods have a long, cylindrical outer segments that give them their rod shape
Do cones have fewer or more discs than rods? How does this influence their sensitivity to light?
Cones have less disks than rods, cones are less sensitive to light than rods
What type of vision is facilitated by cones?
Photopic vision
What type of vision occurs under conditions of high illumination and generates coloured perceptions with high acuity?
Photopic vision
According to the ______ _______ __ ________ ________, there are three different types of cones
Trichromatic theory of colour vision
How did the cones differ in the trichromatic theory of colour vision?
Spectral sensitivity; 60% of cones are red wavelengths, 30% of cones are green wavelengths, 10% of cones are blue wavelengths
Combinations of the red, blue, and green colours of light can produce……..
Any colour within the visible spectrum
Under conditions of low illumination ______ do not activate reliably, so ______ facilitate a more sensitive, yet less finely detailed, ______ _______.
Cones, rods, scotopic vision
What type of vision is facilitated by rods?
Scotopic vision
Where are cones located in the retina? Where are rods located in the retina?
Cones= centre Rods= periphery
Do cones or rods have a higher sensitivity to colour?
Cones have a high sensitivity to colour; rods have a low sensitivity to colour
Do cones or rods have a high sensitivity to detail?
Cones have a high sensitivity to detail
Do cones or rods have a dim light sensitivity?
Rods have a high dim light sensitivity
How many cells do cones have? How many cells to rods have?
Cones= 6 million cells Rods= 120 million cells
What is the visual system of cones? What is the visual system of rods?
Photopic; scotopic
Once light reaches the photoreceptor layer, it strikes either a ______ or a ______ to initiate phototransduction
Rod or a cone
What is the specific biochemical cascade that converts incoming light energy into neural signals? How does this differ for rods and cones?
Signal transduction pathway; same for both rods and cones
Within the disks of the outer segment, what pigment absorbs incoming light?
Rhodopsin
What is rhodopsin composed of? What does it do?
A pigment composed of opsin and retinal; absorbs incoming light, causing the chromophore for retinal to change from the 11 cis form for the 11 trans form
the confirmational change of 11-cis and 11-trans cause the alpha unit of ____ to bind and activate a cyclic GMP-specific _________.
Transducin; phosphodiesterase
What is a three subunit molecule bound to rhodopsin that binds to activate phosphodiesterase?
Transducin
Because one activated rhodopsin mobilises about 100 transducins this is considered to be an _____ _____.
Amplification step
Each retinal ganglion cell has a complex _____ _____
Receptive field
What is the receptive field of each retinal ganglion cells?
The particular area in which a stimulus triggers that neuron to fire
The three semicircular canals, along with otolith organs that are the receptive organs of the ________ system
Vestibular
What is the sensory system responsible for providing one’s awareness of head rotation, gravitation and movement
Vestibular system
The vestibular system relies on the movement of_________on hair cells to generate neural signals.
Endolymph
The three _______ ______ specialise in detecting head rotation.
Semicircular canals
When head British and speed changes, the semicircular canal is move, but the endolymph lags behind due to inertia. What does this cause the sterocilia on hair cells to do?
1) deflect toward the kinocilium– resulting in a depolarisation
2) Deflect away from the kinocilium– resulting in hyperpolarisation
Why are the three semicircular canals particularly sensitive to a specific type of movement?
They are oriented perpendicular to one another
Which semicircular canal detects rotation along the transverse plane?
Horizontal semicirclular canal
Which semicircular canal detects rotation along the coronal plane?
Superior semicircular canal
Which semicircular canal detects rotation along the sagittal plane?
Posterior semicirclular canal
Information from each canal is paired with information from its correspondingly oriented canal located in the other ear, what does this allow for in the degrees of stimulation?
When the left superior semicircular canal is maximally stimulated, the right superior semicircular canal is maximally inhibited
What system between semicircular canal is allows the brain to detect all possible directions of rotation?
Push-pull system
Where are the otolith organs located?
Between the semicircular canals and the cochlea
What are the two otolith structures?
Utricule and saccule
What do the otolith organs specialise in doing?
Detecting horizontal and vertical acceleration
What is each otolith organ filled with?
Gelatinous mixture of endolymph and calcium carbonate crystals
What is the gelatinous mixture of endolymph and calcium carbonate crystals called?
Otoliths
What is the function of otoliths?
To increase the inertial mass of the fluid acting on hair cells
In what direction are the kinocilium of hair cells oriented on otolith structures?
Every direction; The hair cells most band toured the kinocilium reveal the direction of gravitational or linear acceleration
What otolith organ is located in the horizontal plane and is sensitive to horizontal movement?
Utricle
What otolith organ is located in the vertical plane and is sensitive to vertical movement?
Saccule
What is the primary visual pathway?
Retina-geniculate striate pathway
Where does the retina geniculate striate pathway conduct its signals through?
Lateral geniculate nuclei to primary visual cortex
Where is the lateral geniculate nuclei located?
Thalamus
Where is the primary visual cortex located?
Posterior occipital lobe
All information acquired from the left visual field reaches the ____ primary visual cortex and all information required from the right visual field reaches the ______ primary visual cortex.
Right; left
What is the outer portion of the retina called?
Temporal hemiretina
What does ipsilaterally mean?
Along the same side
What does the temporal hemiretina do?
Receives visual signals from the opposite visual field and sends them ipsilaterally to the primary visual cortex
Where does the temporal hemiretina send visual signals?
Primary visual cortex
What is the inner portion of the retina called?
Nasal hemiretina
What does the nasal hemiretina do?
Receives visual signals from the like sided visual field and sends them contra-laterally to the opposite primary visual cortex
Where does the nasal hemiretina send visual signals?
Primary visual cortex
From what side of the visual field does the temporal hemiretina receive visual signals?
Opposite visual field
From what side of the visual field does the nasal hemiretina receive visual signals?
Like sided visual field
Which portion of the retina sends visual signals ipsilaterally?
Temporal hemiretina
Which portion of the retina sends visual signals contralaterally?
Nasal hemiretina
Via what structure does the nasal hemiretina send visual signals to the primary visual cortex?
Optic chiasm
What is considered to be the point of visual decussation?
Optic chiasm
Information is said to ______ when it crosses from one side of the brain to the other.
Decussate (form an X and cross)
What are the two subdivisions of the retina geniculate striate pathway?
1) parvocellular pathway
2) magnocellular pathway
Roughly one million _____ ______ ______ form the optic nerve and travel through the six layers of the ______ ______ _______.
Retinal ganglion cells; Lateral geniculate nucleus;
What are the four top layers of lateral geniculate nucleus collectively called?
Parvocellular pathway
What are the two bottom layers of lateral geniculate nucleus collectively called?
Magnocellular pathway
Parvocellular neurons specialise in what type of resolution of an object?
Spatial resolution
What LGN pathway primarily receives input from cones and are sensitive to colour, stationary objects, and fine pattern details?
Parvocellular pathway
Magnocellular neurons specialise in what type of resolution of an object?
Temporal resolution
What type of LGN pathway receives input from the rods and is particularly sensitive to movement?
Magnocellular pathway
Together, the parvocellular in magnocellular pathways are essential to ______ _______.
Feature detection
What is feature detection?
The ability to identify the colour, form, depth, and movement of an object
The brains ability to process different components of incoming stimuli simultaneously is called _____ ______.
Parallel processing
What is parallel processing?
The brains ability to process different components of incoming stimuli simultaneously
What is triggered by either a chemical structure passage through an ion channel or interaction with a G – protein – linked receptor?
Gustatory transduction
In gustatory transduction, what do ion channels do?
Mediate salty and sour tastes
In gustatory transduction, what do you G – protein – linked receptors do?
Mediate sweet, bitter, and umami tastes
What are the simplest gustatory receptors?
Salt receptors
What are embedded in the salt receptors membrane to allow direct flow of sodium ions into the cell?
Ion channels
In salt receptors, The influx of sodium ions ______ the cell, which causes ____ _____ _____ ______ to open.
Depolarises; voltage gated calcium channels
In salt receptors, the influx of sodium ions (from the channels) and calcium ions (from voltage gated calcium channels) an _____ _______.
Action potential
What three different receptor proteins are necessary for gustatory transduction?
1) Simple ion channel that allows hydrogen ions to flow directly into the cell
2) proton gated ion channel that binds hydrogen ions and closes to prevent potassium ions from leaving the cell
3) proton gated ion channel that binds hydrogen ions and opens to allow sodium ions to flow into the cell
Sweet receptors do not have ion channels but instead have what in their membranes?
G – protein – linked receptors
In sweet receptors, natural sugars and related chemicals will bind to the G – protein – linked receptors, which causes a _____ _____ that releases ______.
Conformational change; gustducin
What cascade do bitter receptors follow?
G protein linked receptor cascade
Umami receptors primarily respond to what neurotransmitter?
Glutamate
What receptor path follows the same pathway as bitter receptors?
Umami receptor
Neural information from each taste receptor is transmitted (ipsilaterally/contra-laterally) via the ____ and _____ nerve.
Facial and glossopharyngeal nerve
Where do the facial and glossopharyngeal nerve transmit neural information from each receptor to?
Solitary nucleus
Where is the solitary nucleus located?
Medulla
What is our sense of smell called?
Olfaction
What is our sense of taste called?
Gustation
Food molecules simultaneously stimulate both smell and taste receptors, resulting in an integrated sensation we recognise as ____.
Flavour
Together, olfaction in gustation are known as?
The chemical senses
Why are gustation and olfaction known as the chemical senses?
Because both systems respond to chemical substances of the external environment
What are oderants?
Volatile molecules suspended in the air
How does olfaction begin?
When oderants bind to specific sites on olfactory receptors and initiate transduction
Where are olfactory receptors enbedded?
Olfactory mucosa
What is mucus covered tissue located in the upper portion of the nasal cavity that allows oderants to dissolve and become more readily detected by olfactory receptors dendrites?
Olfactory mucosa
Where do the axons of the olfactory receptors travel through?
Cribiform plate
What is unique about the olfactory system of all the senses because of its relay of information?
Information about smell is not relayed through the thalamus before reaching the cortex
What are the main structures of the limbic system?
Hypothalamus, amygdala, and hippocampus
Where is the orbitofrontal cortex located?
Anterior portion of the frontal lobes
When does olfactory transduction occur?
Occurs when an oderant binds to specific membrane receptor proteins located on the outside of the olfactory receptor
There are hundreds of different smell receptor proteins, each with their own affinity for …………
A wide range of oderants
What does the accessory olfactory system in most animals detect?
Pheromones
What are pheromones?
Excreted or secreted chemicals capable of triggering social or physiological responses in members of the same species
In most animals, pheromones are received and transduced by olfactory receptors in the ______ organ.
Vomeronasal
Similar to the olfactory system, the gustatory system depends on _______ to detect chemical compounds and convert them into neural signals that the brain can process.
Chemoreceptors
What is the specific name for taste receptors?
Gustatory receptors
What are gustatory receptors sensitive to?
Chemicals the brain interprets as taste
Although gustatory receptors are dispersed throughout the world cavity, there are primarily located on the tongue in clusters of about 50 to 100 called ____ _____.
Taste buds
Typically, taste buds line small protuberances called _____ that give the tongue its rough, sensored surface
Palillae
In order to reach the gustatory receptors necessary for sensory transduction, food dissolved by saliva must pass through ______.
Taste pores
What are minute openings between supporting epithelial cells that cover taste buds?
Taste pores
Once at the taste buds, chemicals become transduced into ___ ____ that encode taste.
Neural messages
Our gustatory receptors are sensitive to what five different tastes?
Salty, sour, bitter, sweet, umami
What are the accessory tastes?
Alkaline or fatty
Where does the perception of spicy come from?
Heat and pain receptors
Each tastebuds contains how many types of specialised gustatory receptors?
All five
Is each taste bud able to detect any taste or are specific areas able to detect specific tastes?
Each taste bud is able to detect any taste
Together, many photoreceptors the information to a _____ ______ _____ _____ for organisation and transmission to the brain.
Single retinal ganglion cell
Each retinal ganglion cell has a complex ____ ____
Receptive field
What is the particular area in which a stimulus triggers that neuron to fire?
Receptive field
When a photoreceptor is directly connected to a retinal ganglion cell, via a bipolar cell only, it is a part of the _____ of that retinal ganglion cells receptive field.
Centre
When a photoreceptor is indirectly connected to a retinal ganglion cells, via a horizontal cell via a bipolar cell, it is a part of the _____ of that retinal ganglion cells receptive field.
Surround
What are the two types of retinal ganglion cells that respond differently to stimulus activation of either the centre or the surround?
1) on centre, off surround
2) off centre, on surround
What are on-centre, off surround cells?
Ganglion cells that preferentially fire more strongly when light strikes the centre of their receptive fields, but not their surrounds.
What are off centre, on surround cells?
Ganglion cells preferentially fire more strongly when light strikes the surround of their receptive fields, but not their centre
The compartmentalised integration of receptive field information allows us to perceive contrast between objects and identify their ____.
Edges
What is the term for the sense of hearing?
Audition
What is the sensory organ responsible for audition?
Ear
What are the specialised receptors for audition?
Hair cells
Our perception of sound arises from _____ changes generated by ____ ____ _____.
Pressure; vibrating air molecules
Is the movement of air molecules longitudinal are latitudinal?
Longitudinal
What are regions where air pressure is compressed under high-pressure called?
Compression
What are the regions called where air pressure is spread apart under low pressure?
Rarefactions
Compressions and rarefactions cycle together to form _____ ______.
Sound waves
What is another term for sound waves?
Pressure waves
What does amplitude determine in sound?
Loudness
What is the maximum displacement measured from equilibrium called?
Amplitude
What does frequency determine in sound?
Pitch
What is the number of completed cycles per unit time?
Frequency
What is the intensity (amplitude) of sound measured in?
Decibels (dB)
The structure of the year is organised into what three sections?
Outer, middle, and inner ear
Sound waves enter through the _____ ear through the _____
Outer; pinna
What is the visible, curved piece of cartilage that ‘catches’ sound?
Pinna
What structure attenuates and reflects soundwaves differently depending on their specific angle of entry, which helps inform the brain of the sounds direction and location?
Pinna
In what structure after the pinna, do sound waves become amplified?
Auditory canal
What is another name for the tympanic membrane?
Eardrum
What are the three ossicles?
Malleus, incus, stapes
Which ossicle first detects vibrations from the tympanic membrane?
Malleus
What is the function of the ossicles?
Amplify sound vibrations and protect the inner ear from loud, damaging noises
What structure of the ear protects it from loud and damaging noises?
Ossicles
What is the thin membrane from the ear to the inner ear?
Oval window
Prolonged exposure to loud sound triggers the ___ ____
Stapedius muscle
When the oval window begins to vibrate, what structure on th other side of the cochlea begins to move in the opposite direction to reduce pressure?
Round window
The cochlea is a long, snail shaped tube that contains an inner membrane called ………
The organ of Corti
The organ of corti partitions the cochlea into a longer, narrower tube composed of two membranes called:
Basilar and tectorial membrane
What type of receptors are hair cells? On what membrane of the organ of Corti are they located?
Mechanoreceptors; basilar membrane
What do hair cells do?
Convert pressure differences into neural signals that are sent to the brain via the auditory nerve
Via what nerve are pressure signals in the ear converted into neural signals sent to the brain?
Auditory nerve
What is the process of converting the mechanical sound vibrations into neural signals, occurring in the hair cells of the inner ear?
Auditory transduction
Protruding from the basilar membrane, the exposed portion of the hair cell is called?
Hair bundle
What is a hair bundle composed of?
Stereocilia
The stereocilia on a hair bundle progressively _____ in length toward one end
Increase
What is the tallest stereocilia called?
Kinocilium
What connects the tips of the stereocilia together?
Tip links
The tip links of stereocilia are also attached to the ……….
Gates of potassium channels
Auditory transduction occurs when ……..
Potassium gates are pulled open
What does it mean for information to dessucate?
Cross from one side of the brain to the other
What is tonotopic organisation of the auditory system?
Neurons are spatially arranged according to which frequencies they respond to best
The auditory system is organised in this fashion to combine neural signals from each ear and at an early, low level (in the superior olivary complex) while allowing information to be precisely organised before being relayed to the brain. What type of organisation is this?
Tonotopic
Where does tonotopic organisation begin in the auditory system?
Cochlea
When classifying the sensations that come from my body, what term are they usually lumped under?
Touch
Our perception of touch is derived from many sensory modalities, including pressure, stretch, vibration, temperature, pain, and body positioning. Therefore touch is more accurately described as…..
Somatosensation
What are the five predominant cutaneous receptors?
1) Meissner’s corpuscle
2) Merkel disks
3) Free nerve endings
4) Ruffinian corpuscle
5) Pacinian corpuscle
What is the general structure of the cutaneous receptor?
Dorsal root ganglia and of the spinal-cord and dendrites that are sensitive to specific stimuli
What is the main differences between cutaneous receptors?
Differences in dendrites
What types of cutaneous receptors possess dendrites encapsulated by coverings of connective tissue?
Meissner’s corpuscles, Pacinian corpuscles, Merkel’s discs, and Ruffini endings
The _____ properties of the cutaneous receptors covered by connective-tissue determine what type of stimulus they respond to and how fast.
Mechanical
Went to cutaneous receptors are considered fast adapting receptors?
Meissner’s corpuscles and Pacinian corpuscles
What types of cutaneous receptors are considered slow adapting receptors?
Merkel’s discs
Ruffini endings
When dropping a pencil in your hand, what receptors fire as the pencil hits your hand, and stop as soon as the pencil stops moving in your hand?
Meissner’s corpuscles and Pacinian corpuscles
When something is in your hand what cutaneous receptors fire to let you know something is in your hand?
Merkel’s disks and Ruffini endings
What happens to slow adapting receptors under prolonged exposure to a constant stimulus?
Desensitised (adapt)
What are cutaneous receptors that are simply exposed dendrites?
Free nerve endings
What cutaneous receptors are particularly sensitive to temperature and pain?
Free nerve endings
Meissner’s corpuscles, Merkel’s disks, Ruffini corpuscles and Pacinian corpuscles are all cutaneous receptors identified as?
Mechanoreceptors
What is something that transducers mechanical stimuli into neural impulses?
Mechanoreceptors
Meissner’s corpuscles are mechanoreceptors specialised to detect? In what size of receptor field?
Pressure; small receptive field
Merkel’s disks are mechanoreceptors specialised to detect? In what size of receptor field?
Pressure; small receptive field
Ruffini’s endings are mechanoreceptors specialised to detect? In what size of receptor field?
Stretch ; large receptive field
Pacinian corpuscles are mechanoreceptors specialised to detect? In what size of receptor field?
Vibration; large receptive field
What type of nerve fiber are all encapsulated cutaneous nerve receptors covered with?
A beta fibers (AB)
What are A beta fibers characterised by?
Large diameters and thickly myelinated axons
The temperature in pain systems are largely intertwined and rely on ___ ____ ____.
Free nerve endings
What type of receptor detects pain?
Nociceptors
What type of receptor detects temperature?
Thermoreceptors
The transduction a temperature occurs when either heat or cold reaches ____ ___ ____.
Transient receptor potential
Where are transient receptor potentials located?
Membrane of thermoreceptors
When the temperature of an object reaches a certain extreme and becomes harmful to touch, we no longer perceive temperature and instead perceive ____.
Pain
Why do we no longer perceive temperature when the temperature is so extreme and instead perceive pain?
Thermoreceptors possess TRPV1 receptors have the dual ability to respond to extreme temperature and to pain.
Temperature and pain are carried along what two different nerve fibers?
A delta fibers and C fibers
What nerve fibers for pain and temperature possess myelinated axons of medium diameter and conduct neural signals at a moderate rate?
A delta fibers
What nerve fibers for pain and temperature possess unmyelinated axons of a small diameter and conduct nerve signals relatively slowly?
C fibers
When burning your hand on a hot stove, what type of nerve fibers make you recoil your hand? What type give you the persistent burning sensation afterward?
A delta fibers; C fibers
What are the two major pathways that carry somatosensory information from both sides of the body to the brain?
The dorsal column medial lemniscus system and the anterolateral system
What type of somatosensory information does the dorsal column medial lemniscus system carry?
Generally carries information regarding pressure, stretch, vibration, and proprioception
What information does the anterolateral somatosensory pathway carry?
Information regarding temperature and pain
What are the three separate nerve tracts of the anterolateral system?
1) spinoreticular tract
2) spinotectal tract
3) spinothalamic tract
Where does the spinoreticular tract terminate?
Reticular formation
Where does the spinotectal tract terminate?
Tectum of the midbrain
Where does the spinothalamic tract terminate?
Ventral posterolateral nucleus
Where is information from the spinothalamic tract relayed?
Somatosensory cortex
How is somatosensory information organised?
By location
What are distinct areas of the skin called?
Dermatomes
What are innervated by individual peripheral nerve fibers then enter the spinal-cord a different points?
Dermatomes
What is the locational organisation of the various pathways to the somatosensory cortex called?
Somatotopic organisation
What type of organisation allows the brain to create a special map of the body represented in the somatosensory cortex?
Somatotopic organisation
What is the map created by the locational dermatome pathways to the somatosensory cortex?
Somatosensory homunculus
The somatosensory cortex is proportionally devoted to different body regions based on the _____ of their innervation, not their _____.
Density; size
What is our sense of the location of our body parts relative to one another called?
Proprioception
Where are proprioceptors primarily located?
Within joints, tendons, and muscles
What provides information about muscle stretch, muscle tension, and joint angle to help inform the brain of a body parts position in space?
Proprioceptors
What type of proprioceptor provides information concerning muscle stretch and length?
Muscle spindle
What type of proprioceptor provides information about muscle tension? Where is this proprioceptor found?
Golgi tendon; tendon
Proprioceptors are located (perpendicular/parallel) to muscle fibres and are encapsulated with ____ ______ at either end.
Parallel; contractile protein
What sense allows us to perceive body motion and coordinate body movements in space and time?
Kinesthetic sense
What is the difference between proprioception and kinesthetic sense?
Proprioception involves information about body position, whereas kinaesthesia provides information about body movement
What sense is the major component of muscle memory and hand eye coordination?
Kinesthetia
Can proprioception be improved with training? Can kinesthetia be improved with training?
Proprioception cannot be improved but kinesthetia can be improved with training
Is proprioception more of a behavioural trait or a cognitive trait? Is kinesthetia more of a behavioural trait or a cognitive trait?
Proprioception is cognitive; kinesthetia is behavioural
