Sensory and Motor Systems: Hearing, Touch, Smell, and Taste Flashcards
The sense of hearing.
audition
Sound Reflection Is Used in ______
Echolocation
We use the sense of audition, or hearing, to _____
to identify objects in the environment and to determine where objects are in relation to our bodies.
The height of a periodic curve measured on its vertical axis.
Amplitude
The number of cycles of a periodic wave per unit of time.
Frequency
A unit used to express a difference in intensity between two sounds.
Decibel (dB)
A unit of sound frequency equal to one cycle per second.
Hertz (Hz)
The quality of a sound that distinguishes it from other sounds of the same pitch and volume.
Timbre
Sound at frequencies above the range of human hearing, or higher than about 20,000 Hz.
Ultrasound
Sound at frequencies below the range of human hearing, or lower than about 20 Hz.
Infrasound
The components that make up the ear are generally divided into three parts:
The Outer, Middle, and Inner Ear.
The visible part of the outer ear.
Pinna
A tube-shaped structure in the outer ear that leads to the tympanic membrane.
Auditory canal
forms the boundary between the outer ear and middle ear.
Tympanic membrane, or eardrum
A membrane that forms the boundary between the middle and inner ears.
Oval window
The bones of the middle ear.
Ossicles
3 parts of ossicles
Malleus
Incus
Stapes
The purpose of these bones in the middle ear is to ______
transfer sound energy from the outside air to the fluid in the inner ear without losing too much of it.
The protective restriction of the movement of the tympanic membrane and the ossicles, resulting in a reduction of sound to the inner ear by a factor of 30 dB.
Acoustic reflex
two muscles in the middle ear
1.Tensor tympani
2.Stapedius
The _____ contains two sets of fluid-filled cavities embedded in the temporal bone of the skull.
inner ear
The fluid-filled _____ contains specialized receptor cells that respond to the vibrations transmitted to the inner ear.
cochlea
The cochlea is about ____ long and ____ in diameter. When rolled up like a _____, the human cochlea is about the size of a ____. (“____” in Greek)
32 mm, 2 mm, snail shell, pea, snail
Cochlea’s three parallel chambers:
Vestibular canal
Tympanic canal
Apex
The part of the cochlea most distant from the oval window.
Apex
Fluid found in the vestibular and tympanic canals of the inner ear.
Perilymph
One of three chambers found in the cochlea.
Cochlear duct
The fluid found in the cochlear duct.
Endolymph
A membrane that separates the vestibular canal and the cochlear duct in the inner ear.
Reissner’s membrane
A structure in the cochlea that separates the tympanic canal and the cochlear duct.
Basilar membrane
A membrane covering the end of the tympanic canal.
Round window
A structure within the cochlear duct responsible for translating vibrations in the inner ear into neural messages.
Organ of Corti
The movement of the basilar membrane is sensed by the _____ attached to the organ of Corti.
hair cells
Out of the approximately _____ hair cells in each human inner ear, about _____ of them are known as _______, which are the actual _____. The remaining ____ hair cells are known as , which appear to ____.
15,500, 3,500, inner hair cells, auditory receptors, 12,000, outer hair cells, amplify sound
Movement of the cilia back and forth within the endolymph alternately hyperpolarizes and depolarizes the hair cells away from their resting potential of _____.
−70mV
The amount of movement needed to produce a response in the hair cells is _____.
quite small
Cortex located just below the lateral fissure in the temporal lobe that provides the initial cortical processing of auditory information.
primary auditory cortex
Structure found in the inner ear whose axons form the auditory nerve.
spiral ganglion
Primary auditory cortex.
Heschl’s gyrus
Areas surrounding Heschl’s gyrus in the temporal lobe that process more complex types of stimuli.
secondary auditory cortex
The part of the human secondary auditory cortex that specifically decodes speech.
Wernicke’s area
A person is considered legally deaf when speech sounds of _____ cannot be heard.
82 dB or less
Typical speech occurs at about _____.
60 dB
Hearing loss resulting from problems in the outer or middle ear is referred to as _____.
conduction loss
After the age of 30, most people cannot hear frequencies above ___. After the age of 50, most people can’t hear sounds above ___, and people over 70 have difficulty with sounds over __. Because speech normally ranges up to ___, many elderly people begin to have difficulty understanding the speech of others.
15,000 Hz, 12,000 Hz, 6,000 Hz, 8,000 Hz
Conduction loss can result from a buildup of ___ in the _____, _____ of the ____, and a disease known as _____.
wax, ear canal, infections, middle ear, otosclerosis
The system that provides information about the body senses, including touch, movement, pain, and temperature.
somatosensory system
The sensory system that provides information about the position and movement of the head.
vestibular system
Two Types of Vestibular Structures
Otolith organ, Semicircular canal
A structure in the inner ear vestibular system that provides information about the angle of the head relative to the ground and about linear acceleration.
Otolith organ
One of three looping chambers found in the inner ear that provide information regarding the rotation of the head.
Semicircular canal
the largest and heaviest organ of the human body and provides a boundary separating what is inside from what is outside. It prevents dehydration and protects the body from dirt and bacteria.
Skin
two basic varieties, of skin:
1.hairy skin
2.glabrous, or hairless skin (ex. lips, palms of the hands, and soles of the feet)
Outer layers of the skin:
1.Epidermis (outer)
2.Dermis (inner)
The outermost layer of the epidermis is actually constructed of ______.
dead cells
Below the dermis, we find ______, which contains connective tissues and fat.
subcutaneous tissue
Human skin varies dramatically in thickness across different areas of the body, from about ____ on your face to ______ on the bottom of your foot.
half a millimeter, twenty times that thickness
A skin receptor that senses touch, pressure, or vibration.
Mechanoreceptor
A mechanoreceptor in which the axon fibers are surrounded by a fluid-filled capsule formed of connective tissue.
Encapsulated receptor
responds primarily to pressure.
Meissner’s corpuscle
provides information about pressure and vibration.
Pacinian corpuscle
provides information primarily about pressure.
Merkel’s disk
provides information regarding stretch.
Ruffini’s ending
The sensory fibers of the peripheral nervous system are classified into four categories based on diameter and speed.
Aδ (alpha-delta) fiber
C fiber
Aα (alpha-alpha)
The Aβ (alpha-beta) class
A myelinated fiber that carries information about cold and sharp pain to the central nervous system.
Aδ (alpha-delta) fiber
A small, unmyelinated fiber that carries information about temperature, itch, and dull, aching pain to the central nervous system.
C fiber
the largest fibers; carry information from the muscles.
Aα (alpha-alpha)
carries information from the Meissner’s corpuscles, Merkel’s disks, Pacinian corpuscles, and Ruffini’s endings toward the central nervous system.
Aβ (alpha-beta) class
The spinal pathway that carries information about touch and position to the medulla.
Dorsal column
The pathway originating in the dorsal column nuclei and synapsing in the ventral posterior (VP) nucleus of the thalamus that is responsible for carrying information about touch and position.
Medial lemniscus
A nerve that carries sensation from mechanoreceptors, temperature receptors, and pain receptors in the skin of the face, mouth, tongue, and the dura mater of the brain.
Trigeminal nerve (cranial nerve V)
occurs in the human somatosensory cortex as a result of both loss and enhancement of input.
Plasticity
are free nerve endings in the skin that respond to surface temperature and are distributed in irregular patterns across the surface of the skin.
Thermoreceptors
Spots that are approximately ___ in diameter respond to either hot or cold, but not to both. The skin between the spots is relatively ____ to temperature.
1 mm, insensitive
The surface of your skin is typically about ____. ____ begin to fire at about 30°C and increase their firing rates as temperature increases to about 45°C. At this point, thermoreceptors begin to respond ____, and pain receptors begin to ____.
33°C, warm fibers, less, respond
_____ begin to respond at skin temperatures of about 35°C and increase their response rate until the skin temperature decreases to about ____.
Cold fibers, 10°C
Below 10°C, ____ generally stops, leading to the _____ that occurs at cold temperatures.
firing, numbing loss of sensation
No other sensory modality is as dramatically affected by culture, emotion, context, and experience as our sense of ___
pain
Pain is not a perfect _____ system.
warning
We need ____ to remind us to stop when we are injured, to assess a situation before proceeding, and to allow the body time to heal.
pain
Free nerve endings that respond to pain are called _____.
nociceptors
A variety of _____ can also activate nociceptors.
chemicals
An interesting class of nociceptors responds to chemicals known as ____, a group that includes _____.
vanilloids, capsaicin
fibers are responsible for that quick,sharp “ouch.”
Alpha delta
The slower, unmyelinated ____ are responsible for dull, aching types of pain sensation.
C fibers
Both types of ascending pain fibers appear to use ___ as their primary neurotransmitter.
glutamate
A group of cells in the outer gray matter of the dorsal horn that receive synapses from pain fibers.
Substantia gelatinosa
A neurotransmitter substance associated with the sense of pain that also serves as a stimulus at some nociceptors.
Substance P
The sense of smell, begins with the detection of molecules suspended in the air.
Olfaction
Individuals vary in their sensitivity to smell. As we age, our sensitivity to smell ____.
decreases
Females are generally ____ sensitive to smell than males
more
The layer in the nasal cavity containing olfactory receptors.
Olfactory epithelium
Axons from the olfactory bulbs form the
olfactory tracts
As these olfactory tracts proceed toward the brain, they are quite _____ to damage, particularly from traffic accidents.
vulnerable
People typically respond to the resulting loss of their sense of ____ by developing symptoms of _____ (Deems et al., 1991) and often resort to flavoring their food with pepper sauce to give it some noticeable flavor
smell, depression
The most likely original purpose of our sense of taste was to protect us from _______
eating poisonous or spoiled food.
Four major categories of taste:
1.Sweet
2.Sour
3.Salty
4.Bitter
5.Umami
One of the five basic taste groups, characteristic of tastes found in seaweed and other “meaty orsavory” elements of Asian cuisine.
Umami
Receptors for taste are found not only on the tongue but also in other parts of the mouth.
Taste Receptors
Bumps on the tongue containing taste buds and taste receptors.
Papillae
Small fibers extending from taste receptors.
Microvilli
The tongue also contains _____ that are sensitive to capsaicin, the main “hot” ingredient in peppers.
pain receptors
