Chapter 36: Sensory System Flashcards
Audition
Sense of hearing
Auricle
cartilaginous outer ear
Basilar membrane
stiff structure in the cochlea that indirectly anchors auditory receptors
Bipolar neuron
neuron with two processes from the cell body, typically in opposite directions
Candela
(cd) unit of measurement of luminous intensity (brightness)
Cochlea
whorled structure that contains receptors for transduction of the mechanical wave into an electrical signal
Cones
weakly photosensitive In center of retina Detects bright light Primary role is color vision Contains photopigments
Cornea
transparent layer over the front of the eye that helps focus light waves
Forea
region in the center of the retina with a high density of photoreceptors and which is responsible for acute vision
Free nerve ending
ending of an afferent neuron that lacks a specialized structure for detection of sensory stimuli; some respond to touch, pain, or temperature
Glabrous
describes the non-hairy skin found on palms and fingers, soles of feet, and lips of humans and other primates
Gustation
Sense of taste
Incus
(also, anvil) second of the three bones of the middle ear
Inner ear
innermost part of the ear; consists of the cochlea and the vestibular system
Iris
pigmented, circular muscle at the front of the eye that regulates the amount of light entering the eye
Kinesthesia
Sense of body movement
Labyrinth
bony, hollow structure that is the most internal part of the ear; contains the sites of transduction of auditory and vestibular information
Lens
transparent, convex structure behind the cornea that helps focus light waves on the retina
Malleus
(also, hammer) first of the three bones of the middle ear
Mechanorecepter
sensory receptor modified to respond to mechanical disturbance such as being bent, touch, pressure, motion, and sound
Middle ear
part of the hearing apparatus that functions to transfer energy from the tympanum to the oval window of the inner ear
Nociception
neural processing of noxious (such as damaging) stimuli
Odorant
airborne molecule that stimulates an olfactory receptor and binds to them
Olfaction
sense of smell
Olfactory bulb
neural structure in the vertebrate brain that receives signals from olfactory receptors
Olfactory epithelium
specialized tissue in the nasal cavity where olfactory receptors are located
Olfactory receptor
Dendrite of a specialized neuron
Organ of corti
Inside cochlea
Organ for transduction of sound, a mechanical wave, to a neural signal
Ossicle
one of the three bones of the middle ear
Outer ear
part of the ear that consists of the auricle, ear canal, and tympanum and which conducts sound waves into the middle ear
Oval window
thin diaphragm between the middle and inner ears that receives sound waves from contact with the stapes bone of the middle ear
Papilla
one of the small bump-like projections from the tongue
Perception
individual interpretation of a sensation; a brain function
Proprioception
sense of limb position; used to track kinesthesia
Pupil
Small opening through which light enters
Reception
receipt of a signal (such as light or sound) by sensory receptors
Receptive field
region in space in which a stimulus can activate a given sensory receptor
Receptor potential
membrane potential in a sensory receptor in response to detection of a stimulus
Retina
layer of photoreceptive and supporting cells on the inner surface of the back of the eye
Rhodopsin
main photoreceptor in vertebrates
2 parts:
transmembrane protein opsin
Retinal
Rod
strongly photosensitive (response to light) In outer edges of the retina Detects dim light Used in peripheral and nighttime vision Contains rhodopsin
Semicircular canal
one of three half-circular, fluid-filled tubes in the vestibular labyrinth that monitors angular acceleration and deceleration
Sensory receptor
specialized neuron or other cells associated with a neuron that is modified to receive specific sensory input
Sensory transduction
conversion of a sensory stimulus into electrical energy in the nervous system by a change in the membrane potential
Stapes
(also, stirrup) third of the three bones of the middle ear
Stereocilia
Hair-like projections from hair cells that help detect sound waves
Brought together by proteins
Tastant
food molecule that stimulates gustatory receptors
Taste bud
Clusters of taste cells
Tectorial membrane
cochlear structure that lies above the hair cells and participates in the transduction of sound at the hair cells
Tonic activity
in a neuron, slight continuous activity while at rest
Tympanum
(also, tympanic membrane or ear drum) thin diaphragm between the outer and middle ears
Ultrasound
sound frequencies above the human detectable ceiling of approximately 20,000 Hz
Umami
one of the five basic tastes, which is described as “savory” and which may be largely the taste of L-glutamate
Vestibular sense
sense of spatial orientation and balance
Vision
Sense of sight
Types of sensation
Olfaction (smell) Gustation (taste) Equilibrium (balance and body position) Vision Hearing Electroreception Magnetoreception
Somatosensation types
Vestibular: spatial orientation/balance
Proprioception: bone,joint,muscle position
Kinesthesia: limb mvmt and tracking
General senses receptors
Tactile sensations
Temperature
Pain
Muscle sensing
Special senses receptors
Vision Hearing Equilibrium Smell Taste
Sensory Transduction Order
Stimulus
Reception
Ion channels being affected
Neuron could fire Action Potential
Receptor types in skin
Merkles disks: not encapsulated, touch
Meissners corpuscles: touch & LF vibration
Ruffini endings: stretch/ joint deformation
Pacian corpuscles: pressure & HF vibration
Krause end bulbs: detect cold
Primary tastes
Salty, sweet, sour, bitter, umami
Wavelength
Corresponds to pitch
Amplitude corresponds to volume
Smaller amplitude means softer sound
Stereocilia ion channels
Open: when array is bent towards tallest member
Closed: when array is bent towards shortest member
Vestibular receptor organs (Inner Ear)
Utricle
Saccule
3 semicircular canals
What happens when hair cells are bent in the ear?
Action potentials are sent to the brain
Photoreceptors
Located in the retina
Inner surface of the back of the eye
When LIGHT strikes a retinal…
- It changes from cis to a trans form
- Signal is passed to G-protein called transducin (involved in signal transduction)
- Transducin activates phosphodiesterase
- Phosphodiesterase converts cGMP to GMP which closes sodium channels
- Membranes become hyperpolarized, meaning no AP
- Hyperpolarized membrane does not release glutamate to bipolar cell
Transduction of light: dark vs light
Dark: depolarized (positive value) AP sent
Light: hyperpolarized (negative value), no AP
Route of sensory signals
EXCEPT OLFACTION
From the thalamus to cortex of brain
Intensity understanding
Rate of APs (frequency)
Number of receptors activated
Receptor types (general)
Thermoreceptors Pain receptors Chemoreceptors Mechanoreceptors (all skin types) Proprioreceptors (position) Baroreceptors (pressure)
Bipolar olfactory neurons
Extend from olfactory epithelium to olfactory bulb
When smell enters nose
- Signal transduction
- APs to olfactory bulb
- To the brain via olfactory nerve
- Finally perception of smell
Regions of tongue
Foliate
Fungiform
Circumvallate
Hearing sensation location
Cohchlea
Balance sensation location
Vestibule
