Chapter 7- The Other Sensory Systems Flashcards
What are sound waves?
periodic compressions of air, water or other media. Varies in amplitude and frequency
True or false. We are able to detect all sensory information?
False. Some sensory information lies beyond our ability to detect it.
True or False. Audition depends upon our ability to detect sound waves?
True.
What is Amplitude?
The intensity of a sound wave, measured in decibels. Related to loudness, the psychological experience of amplitude ( perception)
What is Frequency?
The number of compressions per second, measured in hertz. Related to pitch, the psychological experience of frequency ( perception)
What is the range of frequencies that adults can hear?
15hz to about 20,000 hz
Name the three tiny bones of the Tympanic Membrane.
Malleus ( hammer), Incus ( Anvil) and Stapes (Stirrup)
What does the Pinna do?
helps us locate the source of the sound. It is the funnel, structure of flesh and cartilage attached to each side of the head
What is the net effect of the audition system?
sound waves are converted into waves of greater pressure on small oval window
What is the Cochlea?
snail- shaped structure in inner ear containing three long fluid filled tunnels.
Scala Vestibula
Scala Media
Scala Tympani
what is the correct order of the structures that sound waves travel through as they pass from the outer ear to the inner ear?
Pinna, tympanic membrane, oval window, cochlea
What are the two main ways of coding sensory information?
Which cells are active and how frequently they fire
What is Place Theory?
Basilar Membrane resembles strings of a piano, each area along membrane is tuned to a specific frquency
What is wrong with the Place Theory?
Various parts of the Basilar Membrane are bound to tightly together for this to work
What is the Frequency Theory?
Basilar membrane vibrates in synchrony with a sound, causing auditory nerve axons to produce action potentials at the same frequency
What is wrong with the Frequency Theory?
The refractory period of a neuron is .001 or 1/1000 of a second. this means that the max firing rate would be 1000 hz, which in actuality its 20,000 hz
What is the Current Theory of sound?
a combination of place and frequency theory.
for low frequency sounds ( up to about 100 hz) basilar membrane vibrate in synchrony with sound waves, like the frequency theory says.
At higher frequencies, neuron’s action potentials are phase- locked to peaks of the sound waves ( they occur at the same phase of the sound waves) like the place theory says
What is the Volley Principle?
Auditory nerve as a whole produces volleys of impulses for sounds up to about 4,000 per sec, even though no individual axon approaches that frequency.
auditory cells must time their responses precisely
True or False. Most human hearing takes place below 4000 Hz?
True.
What is Amusia?
impaired detection of frequency associated with thicker than average auditory cortex in right hemisphere ( tone deafness)
What is Absolute Pitch?
the ability to hear a note and identify it. Genetic predisposition, but main determinant is early and extensive musical training. More common among people who speak tonal languages.
True or False. Axons cross over midbrain to enable each hemisphere to get most of its input from opposite ear?
True.
Where does sound information ultimately reach?
The Primary Auditory Cortex AKA Area A1 in the the Superior Temporal Cortex
Where is Area A1 ( Primary Auditory Cortex) located?
Superior Temporal Cortex
What is the Superior Temporal Cortex?
the area important for detecting visual motion and motion of sounds. contains area MT.
True or False. Auditory system requires experience for full development?
True
What is the difference between damage to area V1 and damage to area A1?
Damage to A1 does not necessarily cause deafness unless it extends to the subcortical areas
True or False. Auditory Cortex is necessary for all hearing?
False. It’s only necessary for advanced processing of hearing.
What does the auditory cortex provide ?
a tontopic map in which cells in the primary auditory cortex are more responsive to preferred tones
True or False. Each cell in A1 gives prolonged response to its preferred sound and little or no response to other sounds?
True. Most cells respond best to a complex sound
Cells outside of A1 respond best to…
Auditory objects ( animal sounds, music, machinery noise) . Involved in interpreting meaning of sounds
What are the two categories of hearing impairment?
Conductive deafness ( middle-ear deafness) and Nerve Deafness( inner-ear deafness)
What is Conductive deafness?
deafness that results from disease, infection, or tumorous bone growth which prevent middle ear from transmitting sound waves properly to the cochlea.
Can be corrected by surgery or hearing aids to amplify the stimulus. Normal Cochlea and normal auditory nerve allows people to hear their own voices clearly
What is Nerve deafness?
deafness that results from damage to the cochlea, hair cells, or auditory nerve. Can occur in any degree and may be confined to one part of the cochlea. People can only hear certain frequencies and this can be inherited or can develop from a variety of problems or disorders
What is Tinnitus?
ringing in the ears often produced by nerve deafness. sometime this is due to a phenomenon like the phantom limb
What are the three cues to sound localization?
Sound Shadow- for high frequency sounds with wave lengths shorter that the width of the head, makes the sound louder for the closer ear
Time of arrival- most useful for localizing sounds with a sudden onset
Phase difference between the ears- difference is a signal to the sounds direction depending on what ear it hits first . Provides cues to sound localization with frequencies up to 15,000 Hz
What do your Mechanical sense respond to?
Pressure, bending, or other distortions of the receptor. Also touch, pain and other body sensation including vestibular sensation
When you move your head, the vestibular organ adjacent to the cochlea monitors movements and..
directs compensatory movements of your eyes. Helps maintain balance
The Vestibular organ consists of…
Saccule, Utricle and three semicircular canals filled with a jell-like substance that are activated when the head moves
What are Otoliths?
Calcium Carbonate particles that lie next to the hair cells
Action potential initiated by hair cells travel…
through part of the eighth cranial nerve to brainstem and cerebellum
What is the Somatosensory system?
The sensation of the body and its movements . located in the parietal lobe
What are Merkl disks?
receptors that respond to light tough. women and men have same number of disks, but women have small fingers to they are compacted into a smaller area
True or False. most skin receptors respond to more than one kind of stimulus
True.
What are touch receptors?
they might be a simple bare neuron ending, an elaborated neuron ending or bare ending surrounded by other cells that modify its function. A modified dendrite ( merkl disk)
What does the stimulation of a touch receptor do?
opens sodium channels in the axon and starts an action potential
A heat receptor responds to______ and a coolness receptor responds to _____
Capsaicin and Menthol ( sometimes mint)
Where does information from touch receptors in the head enter the Central Nervous System ( CNS)?
Cranial nerves
Information below the head enters the spinal cord and passes toward the brain through the…
31 spinal nerves
What is a dermatome?
Skin area connected to a single sensory spinal nerve
True or False? Each spinal nerve innervates a limited area of the the body called a dermatome?
True.
True or False. The touch pathway and the pain pathway are the same?
False
Damage to the somatosensory cortex impairs..
Body perceptions
True or False. Different sub areas of somatosensory cortex responds to different areas of the body?
True.
What does the somatosensory thalamus sends its impulses?
To different areas of primary somatosensory cortex( parietal lobe)
The somatosensory cortex acts as a ____ of body location
map
Pain sensation beings with…
a bare nerve ending, least specialized of all receptors
Pain axons release which neurotransmitter for mild pain?
Glutamate
Pain axons release which neurotransmitters for stronger pain?
Glutamate and Substance P
Axons carrying pain information have little or no myelin sheath. What us the implication of this?
Impulses travel more slowly.
Thicker and faster axons equal what kind of pain?
Sharp Pain
Thinner and slower axons equal what kind of pain?
Dull pain
The brain processes pain information…
rapidly and motor responses are fast
Pain pathways cross to a tract ascending the contralateral side…
of the spinal cord
Which brain areas are associated with emotional associations of pain?
Central Nuclei of the Thalamus, Amygdala, Hippocampus, Prefrontal Cortex, and Cingulate Cortex
What does hypnotic suggestion do to pain?
Decreases it
What are Opiod Mechanisms?
Systems that respond to opiate drugs and similar chemicals
Pert and Snyder discovered that opiates…
bind to receptors found mostly in spinal cord and the periaqueductal gray area of the midbrain
How do opiate receptors act?
by blocking release of substance P in the spinal cord and grey area of the midbrain
What is the brain’s natural pain killer?
Endorphins, a group of chemicals that attach to the same brain receptors as morphine
What are other situations in which endorphins are released?
Exercise, Sex, Thrilling music. Endorphins are decreased by brooding about past experiences
The female hormone estradiol facilities …
opiate activity
What is the Gate Theory of Pain?
Spinal cord neurons that receive messages from pain receptors also receive messages from touch receptors and from axons descending from the brain.
Other inputs “ close” the gates to pain messages and decrease pain perception
True or False? Placebos decrease brain’s emotional response to pain perception?
True.
Cannabinoids act mainly in the…
Periphery of the body, not the Central Nervous System.
Blocks certain kinds of pain
Capsaicin …
produces a painful burning sensation by releasing substance P. High doses of it can damage pain receptors
However, it releases substance P faster than neurons can resynthesize it so cells are less able to send pain messages
Most theorists believe that the first sensory system of the earliest animals was a…
Chemical sensitivity
What is the Label-line principle?
each receptor responds to a limited range of stimuli and the meaning depends entirely upon which neurons are active
What is the Across-Fibers pattern?
each receptor responds to a wider range of stimuli and a given response by a given axon means little except in comparison to what other axons are doing
What is an across-fibers example of color perception?
the way we perceive green across the short, medium and long length cones
True or False. All or nearly all perceptions depend on the pattern across an array of axons?
True.
Flavor is a combination of taste and..
smell
Taste and smell axons converge onto many of the same cells in the…
endopiriform cortex which enables taste and smell to combine their influences on food selection
True or False. Receptors for taste are neurons?
False. They are modified skin cells.
How often are taste receptors replaced?
about 10-14 days
Receptors are in taste buds located in…
papillae. A given papilla may contain up to 10 or more taste bud, with each bud containing about 50 receptor cells.
Where are human adult taste buds located?
along the outside edge of the tongue
How do taste receptors transmit information to the brain?
they have excitable membranes and release neurotransmitters to excite neighboring neurons
What is Adaptation concerning taste?
The fatigue of receptors sensitive to sour tastes
What is Cross- Adaptation concerning taste?
Reduced response to one taste after exposure to another
Saltiness receptor…
detects presence of sodium and permits sodium ions to cross its membrane
Sour receptors detect presence of…
acids. Closes potassium channels when acid binds to the receptor, causing a depolarization of the membrane
Sweetness, bitterness and umami receptors resemble what kind of synapses?
Metabotropic
Different chemicals result in different…
temporal patterns
Does taste depend on a pattern of responses across fibers, or a system of pure labeled lines?
Across fibers
How many bitter receptors do we have?
25 types, sensitive to varying degrees of toxicity.
We taste a great variety of dangerous chemicals, but can’t detect very low concentrations of bitter substances because of the low number of receptors in these receptors
Bitter Taste…
bitter substances include a long list of dissimilar chemicals
Information from receptors in anterior part of tongue is carried to the brain along the..
Chorda Tympani ( branch of the 7th cranial nerve)
- different nerves carry taste information to the brain from the anterior 2/3’s of the tongue, then from the posterior tongue to the throat.
Taste nerves project to the nucleus of the…
Tractus solitaries ( NTS) in the medulla. and then branches out to reach a number of structures in including:
Somatosensory Cortex- responds to touch stimulation on tongue
Insula- the primary taste cortex, also responsible for disgust
Information is ipsilateral
What is Olfaction?
Response to chemicals that contact the membranes inside the nose
What are olfactory cells?
neurons responsible for smell. They line the olfactory epithelium in rear of nasal air passages. Each cells has cilia ( threadlike dendrites) that extend from cell body into mucous surface of nasal passage. Olfactory receptors are located on cilia
How many olfactory receptors do we have?
hundreds
What is localization of smell?
we arrange our olfactory receptors over the entire surface of the nasal passages
True or False. Smell does not go through the thalamus?
True.
Is Sight, Hearing or Olfaction subject to more rapid adaptation ?
Olfaction
When an olfactory receptor is stimulated, where does its axon carry the impulse?
To the olfactory bulb , then sends axons to olfactory area of cerebral cortex , where messages are coded by location
What is the Vomeronasal Organ(VNO) ?
set of receptors located near olfactory receptors, specialized to respond only to pheromones. VNO is tiny in humans and has no receptors
Behavioral effects of response to VNO occur unconsciously and include…
people responding to certain chemicals in skin even though they describe them as odorless, exposure alters skin temperature and other autonomic responses
What is Synesthesia?
The experience of one sense in response to stimulation of a different sense.
Caused by some axons from one cortical area branching into another area
