Ch. 16 Nervous System Senses Flashcards
Convert stimulus energy into electrical energy
Transducers
The distribution area of the endings of a sensory neuron
Receptive Field
Smaller receptive fields allow for more ________ stimulus localization.
Precise
Type of energy transmitted by the stimulus
Modality (ex. Touch)
__________ of stimulus determined by which receptive field is active.
Location
_____________ of stimulus determined by how many nerve signals reach CNS.
Intensity
__________ - time from start to end of a response in the receptor
Duration
Receptor adaptation helps determine stimulus ________.
Duration
Adaptation is _____________ sensitivity to continuous stimulus
Decreased
_______ receptors show limited adaptation; respond continuously
Tonic (ex. Pain receptors)
__________ receptors adapt rapidly, only respond to new stimuli.
Phasic (ex. pressure receptors)
Sensory receptors can be classified by their receptor distribution, ___________ vs. __________
General vs. Special
____________ sense receptors: simple structures distributed throughout the body.
General
Somatic sensory receptors are a type of ________ sense receptor.
general
Visceral sense receptors are a type of __________ sense receptor.
General
__________ Sensory receptors: Tactile receptors of skin and mucous membranes; proprioceptors of joints, muscles, and tendons.
Somatic
__________ Sensory Receptors: Found in walls of internal organs, they monitor stretch, chemical environment, temperature, and pain.
Visceral
___________ Sense receptors - Receptors in complex sense organs of the head.
Special
5 Special Senses:
Olfaction
Gustation
Vision
Audition
_____________
Equilibrium
Sensory receptors can be classified by their stimulus origin:
__________ detect stimuli from external environment.
Exteroceptors
Sensory receptors can be classified by their stimulus origin:
__________ detect stimuli from internal organs
Interoceptors
Sensory receptors can be classified by their stimulus origin:
____________ detect body and limb movements.
Proprioceptors
Sensory receptors can be classified by their modality of stimulus:
_____________ detect chemicals dissolved in fluid.
Chemoreceptors
Sensory receptors can be classified by their modality of stimulus:
________________ detect changes in temperature
Thermoreceptors
Sensory receptors can be classified by their modality of stimulus:
_______________ detect changes in light intensity, color, movement.
Photoreceptors
Sensory receptors can be classified by their modality of stimulus:
__________ detect distortion of cell membrane
Mechanoreceptors
Sensory receptors can be classified by their modality of stimulus:
____________ detect painful stimuli
Nociceptors
__________ Nociceptors detect chemical, heat, or mechanical damage to the body surface or skeletal muscles.
Somatic
_____________ Nociceptors detect internal organ damage.
Visceral
_____________ Receptors - abundant mechanoreceptors of skin and mucus membranes
Tactile
____________ tactile receptors - Dendritic ends of sensory neurons with no protective cover.
Unencapsulated
Simplest tactile receptors
Terminal ends of sensory neuron dendrites
Located close to skin surface
Phasic or Tonic
Free Nerve Endings
Unencapsulated tactile receptor
Wrap around hair follicle
Located in deeper layer of dermis
Detect hair displacement
Phasic receptors
Root Hair Plexuses
Flattened endings of sensory neurons extending to tactile (merkel) cells.
Tactile disks
Tactile cells are specialized epithelial cells in __________ layer of epidermis.
Basal
Tactile discs are (phasic or tonic) receptors.
Tonic
___________ tactile receptors: Neuron endings wrapped by connective tissue to covered by connective tissue and glial cells
Encapsulated
Encapsulated Tactile Recpetor
Located in dermis and mucus membranes
Detect pressure and low-frequency vibrations
Tonic Receptors
End (Krause) bulbs
Encapsulated Tactile Receptors
Located deep in dermis, hypodermis, some organ walls
Detect deep pressure, coarse touch, high frequency vibration
Phasic receptors
Lamellated Corpuscles
Encapsulated Tactile Receptors
Located in dermis and subcutaneous layer
Detect deep pressure and skin distortion
Tonic receptors
Bulbous Corpuscles
Encapsulated tactile receptor
In Dermal papillae
Allow for recognition of texture, shape
Phasic Receptors
Tactile corpuscles
The inaccurate localization of pain signals from viscera, perceived as originating from skin, muscle.
Referred pain
While experiencing referred pain, the ______________ cortex is unable to determine true source of signal.
Somatosensory
Phantom pain occurs when ____________ is still alive.
Cell body
Accessory structures are ___________ of the eyeball.
Outside
Aid in nonverbal communication, prevent sweat from dripping into eye
Eyebrows
Extend of margins of eyelids, prevent objects from coming into contact with eye
Eyelashes
Palpebrae are also known as
Eyelids
Transparent lining of eye and lid surfaces, made of stratified columnar epithelium.
Conjunctiva
_____________ conjunctiva covers anterior sclera (white of eye)
Ocular
____________ Conjunctiva covers internal surface of eyelid
Palpebral
Pink Eye
Conjunctivitis
Produces tears
Lacrimal Apparatus
____________ drains into lacrimal canaliculus, to lacrimal sac, to nasolacrimal duct, to nasal cavity
Lacrimal Fluid
_________ cavity of eye, contains permanent vitreous humor
Posterior
___________ cavity of the eye, contains circulating aqueous humor
Anterior
Wall of eye is formed by ___ tunics.
three
________ Tunic - tough outer layer, composed of posterior sclera and cornea
Fibrous
White of the eye
Sclera
Sclera is composed of dense ____________ CT, provides eye shape, protection, and attachment site for muscles
irregular
Fibrous Tunic is made up of ______________ & ____________
Sclera & Cornea
Convex transparent structure at front of eye
Cornea
Cornea:
Inner layer - Simple _______ epithelium
Middle Later - Collagen
Outer layer - Stratified squamous epithelium
Squamous
Cornea:
Inner layer - Simple squamous epithelium
Middle Later - Collagen
Outer layer - Stratified ________ epithelium
Squamous
Cornea:
Inner layer - Simple squamous epithelium
Middle Later -____________-
Outer layer - Stratified squamous epithelium
Collagen
There are no blood vessels in this part of the fibrous tunic.
Cornea
This part of the fibrous tunic refracts light
Cornea
__________ Tunic: Composed of Choroid, Ciliary body, Iris
Vascular
This tunic houses blood vessels, lymph vessels and intrinsic muscles
Vascular
___________ : Part of the vascular tunic, with many capillaries and melanocytes
Choroid
Part of vascular tunics, houses ciliary muscles and processes
Ciliary Body
Ciliary ___________: Contain capillaries secreting aqueous humor
Processes
Gives eye color
Iris
Divides the anterior segment into the anterior chamber and posterior chamber
Iris
Opening in the center of iris connecting the two chambers
Pupil
(Volatile molecules) that are dissolved into nasal mucus and detected by chemoreceptors
Odorants
Olfactory Epithelium has 3 types of cells:
1. Olfactory __________ cells - Detects odors
Receptor
Olfactory Epithelium has 3 types of cells:
2. ____________ cells - sustain receptors
Supporting
Olfactory Epithelium has 3 types of cells:
3. _____________ cells - replace olfactory receptor cells every 40-60 days
Basal
Olfactory receptor cells have a __________ structure.
Bipolar
Cilia projecting from olfactory receptor cell dendrite, house chemoreceptors for a specific odorant
Olfactory Hairs
Mucus contains ________-binding proteins
Odorant
How do you detect smells?
- Odorant binds to ________ in mucus
- Protein stimulates receptor cell
- Action potential is triggered on axon, conducted to olfactory bulbs
- Conducted to olfactory tracts
- Conducts signal to various CNS areas
Protein
How do you detect smells?
- Odorant binds to protein in mucus
- Protein stimulates receptor cell
- Action potential is triggered on axon, conducted to olfactory ______
- Conducted to olfactory _____
- Conducts signal to various CNS areas
- Bulbs
- Tracts
Olfaction DOES NOT project to _________
thalamus
_____________ cells - chemoreceptors within taste buds
Gustatory
__________ Papillae - Short and spiked, with no taste buds, help to manipulate food, front of tongue
Filiform
___________ papillae - Mushroom shaped, contains a few tastebuds, tip and sides of tongues
Fungiform
_______________ Papillae - Largest, least numerous, contains the most tastebuds
Vallate
_________ Papillae - leaf like ridges, not well developed, house a few taste buds in early childhood, posterior-lateral tongue
Foliate (Foliage like leaves)
onion shaped organs housing taste-receptors
Taste buds
Within taste buds, basal cells are neural stem cells that _______ gustatory cells.
replace
Gustatory cells live for approx.
7-9 days
__________ Nerve is responsible for anterior parts of the tongue
Facial (CN VII)
____________ Nerve is responsible for posterior parts of the tongue
Glossopharyngeal (CN IX)
____________ Nerve is responsible for Pharynx
Vagus (X)
Primary gustatory complex is located in the _________
Insula
Are taste sensations localized?
No - spread over broad regions of the tongue
For sweet, bitter, and umami the tastants are…
Molecules
For salt and sour the tastants are…
Ions
Generating AP for tastants that are __________…
- The tastant binds to specific cell membrane receptor
- G-protein is activated causing formation of second messenger
- Results in cell depolarization
Molecules (Sweet, Bitter, Umami
Generating AP for tastants that are _________—
Tastant depolarizes the cell directly
ions (Salt and sour)
Processing of Gustatory Information
- Primary neuron in cranial nerve brings signal to nucleus __________ within medulla
- Medullary activity triggers salivation and stomach secretions ( or Nauseating stimuli trigger gagging)
- Signal is relayed to thalamus
- The relayed to primary gustatory cortex
Solitarius
Processing of Gustatory Information
- Primary neuron in cranial nerve brings signal to nucleus solitarius within medulla
- Medullary activity triggers salivation and stomach secretions ( or Nauseating stimuli trigger gagging)
- Signal is relayed to _________
- The relayed to primary gustatory cortex
Thalamus
__________ Pupillae muscles: concentrically circular fibers constrict pupil with parasympathetic nervous system acivity
Sphincter
______________ Pupillae muscle: Radially organized smooth muscle dilates pupil with sympathetic nervous system activity
Dilator
___________ Reflex: Alters pupil size in response to light
Pupillary
________ controls pupil diameter
Iris
The neural tunic is also known as the ________
Retina
____________ Layer of Retina: Attached to choroid, provides Vit. A, absorbs stray light
Pigmented
__________ Layer of Retina: Houses photoreceptors and associated neurons, converts light to nerve signals
Neural
________________ of Retina: boundary between photosensitive and non-photosensitive parts of retina
Ora Serrata
Cells of neural layer form 3 sublayers:
____________ Cell layer: contains rods and cones, and pigments
Photoreceptor
Cells of neural layer form 3 sublayers:
__________ Cell Layer: Their dendrites receive synaptic input from rods and cones
Bipolar
Cells of neural layer form 3 sublayers:
__________ Cell layer: Their axons gather at optic disk and form optic nerve
Ganglion
These interneurons are found where? Horizontal cells and Amacrine cells
Retina
This part of the Retina contains no photoreceptors - is a blind spot. And is where ganglion axons exit toward the brain.
Optic Disc
This structure of the retina contain fovea centralis, has the highest proportions of cones, and is the area of sharpest vision
Macula Lutea
_________ Retina contains primarily rods and functions most effectively in low light.
Peripheral
______: Changes shape to focus light on retina
Lens
Shape of lens is determined by ciliary muscle and __________ ligaments
Suspensory
____________ Humor helps to maintain eye shape, is permanent, and supports retina
vitreous
____________ Humor is continuously produced, nourishes and oxygenates lens and inner cornea
Aqueous
Drainage failure of Aqueous humor can lead to…
Glaucoma
Emmetropia
Normal Vision
Hyperopia
Far-sighted
Myopia
Near-Sighted
Hyperopia is corrected with a ________ lens
Convex
Myopia is corrected with ________ lens
Concave
The unequal focusing, or unequal curvatures in one or more refractive surfaces
Astigamtism
Age related change in vision
Presbyopia
How is light focused for vision? Objects closer than 20 feet:
Eyes _______, lens accommodates, pupil constricts
converge
How is light focused for vision? Objects closer than 20 feet:
Eyes converge, lens ___________, pupil constricts
Accommodates
How is light focused for vision? Objects closer than 20 feet:
Eyes converge, lens accommodates, pupil ________
Constricts
How is light focused for vision? Objects farther than 20 feet:
Eyes face forward, lens ________, pupil dilated
flattens
How is light focused for vision? Objects farther than 20 feet:
Eyes face forward, lens flattens, pupil ______
Dilated
Converting light to electrical signals
Phototransduction
Synaptic terminals of photoreceptors contain what neurotransmitter?
Glutamate
Rods or cones are more numerous?
Rods
Cones have a __________ relationship with bipolar cells and ganglion cells
1 to 1
Light absorbing molecules found within membranes of rods and cones. Made of opsin and retinal
Photopigments
Each photoreceptor has only one _________ type
photopigments
Rods contain the photopigment…
Rhodopsin
There are ____ types of cones, each w/ a type of photopsin with a different sensitivy
3
Cones contain the photopigment
Photopsin
(3 types - Blue, Green, Red)
In the dark, rhodopsin (Rods) contains cis-retinal.
Light causes reconfiguration to trans-retinal, which dissociates from opsin.
This is known as…
Bleaching
After bleaching, Rhodopsin must be rebuilt for rod to function…
Is this process slower or faster than rebuilding cone photopsins.
Rhodopsin rebuilds more slowly
Return of sensitivity to low light levels after exposure to bright light. May take 20-30 minutes.
Dark Adaptation
Process of adjusting from low light to bright conditions, pupils constrict but cones are initially overstimulated. takes about 5-10 minutes
Light Adaptation
Events of Phototransduction
- In the dark, rods are __________ and glutamate is continuously released by the rod.
- Glutamate hyper polarizes bipolar cells, preventing them from exciting ganglion cells
- Light Hyper-polarizes rods causing them to stop releasing glutamate
- Bipolar cells are no longer inhibited, and release glutamate to ganglion cell
- Ganglion cell excitation leads to impulses being sent along axon to the brain
Depolarized
Events of Phototransduction
- In the dark, rods are depolarized and _________ is continuously released by the rod.
- Glutamate hyper polarizes bipolar cells, preventing them from exciting ganglion cells
- Light Hyper-polarizes rods causing them to stop releasing glutamate
- Bipolar cells are no longer inhibited, and release glutamate to ganglion cell
- Ganglion cell excitation leads to impulses being sent along axon to the brain
Glutamate
Events of Phototransduction
- In the dark, rods are depolarized and glutamate is continuously released by the rod.
- Glutamate hyper polarizes bipolar cells, preventing them from exciting ganglion cells
- Light __________ rods causing them to stop releasing glutamate
- Bipolar cells are no longer inhibited, and release glutamate to ganglion cell
- Ganglion cell excitation leads to impulses being sent along axon to the brain
Hyperpolarizes
Events of Phototransduction
- In the dark, rods are depolarized and glutamate is continuously released by the rod.
- Glutamate hyper polarizes bipolar cells, preventing them from exciting ganglion cells
- Light Hyper-polarizes rods causing them to ______ releasing glutamate
- Bipolar cells are no longer inhibited, and release glutamate to ganglion cell
- Ganglion cell excitation leads to impulses being sent along axon to the brain
STOP
Events of Phototransduction
- In the dark, rods are depolarized and glutamate is continuously released by the rod.
- Glutamate hyper polarizes bipolar cells, preventing them from exciting ganglion cells
- Light Hyper-polarizes rods causing them to stop releasing glutamate
- Bipolar cells are no longer inhibited, and release glutamate to ____________ cells
- Ganglion cell excitation leads to impulses being sent along axon to the brain
Ganglion cells
Visual Pathway in the Retina:
Photoreceptors to bipolar cells to ________ cells
Ganglion
_____________ cell axons bundle at disc to form optic nerve
Ganglion
Visual pathway optic nerves:
Exits back of eye and converges at optic _________
Chiasm
____________ Optic nerves cross to opposite side of the brain at the optic chiasm
Medial
Visual pathways of optic tracts:
Most axons go to lateral ____________ nucleus of thalamus
Thalamic neurons’ axons project to visual cortex in occipital lobe
Geniculate
The overlapping visual fields of the L and R eye allows for stereoscopic vision, also known as,
Depth Perception
________________ Colliculi (in the midbrain) coordinate reflexive eye movements
Superior
_______________ Nuclei, in the midbrain, coordinate pupillary reflex and lens accommodation reflex
Pretectal
Tunnel shaped, visible part of the ear. Protects entryway and direct sound inward
Auricle
Tympanic Membrane is also know as
Eardrum
Tympanic membrane transmits sounds waves to _________ ear
Middle
Passage extending from middle ear to nasopharynx, opens with yawning and chewing
Auditory tube (Eustachian Tube)
Name the Auditory Ossicles
Malleus, Incus, Stapes
Auditory ossicles amplify sound waves and transmit them to _______ window
Oval
Oval window initiates pressure waves in inner ear _______
Fluid
What three main regions compose the inner ear?
Cochlea, Vestibule, Semicircular canals
What structure houses the membranous cochlear duct?
Cochlea
What structure contains the utricle and saccule
Vestibule
Equilibrium is monitored by what structure of the ear
Vestibule/Semicircular Canals
_____________ detect static equilibrium and linear acceleration
Utricle/Saccule
________________ detect angular acceleration
Semicircular ducts
Sensory structure for hearing located within cochlear duct
Spiral Organ (of Corti)
Spiral Organ (of corti) consists of ______ cells and supporting cells on basilar membrane
Hair
Hair cells within ear have many ___________ and one __________ at their apex
Many Stereocilia
One Kinocilium
Transducing Sound Waves to AP
- When the _________ membrane moves up, hair cells are pushed into tectorial membrane and their tips are tilted, pulling tip links
- Tip links pull open ion channels, allowing K+ to diffuse into the hair cell and depolarize it
- Hair cell releases more neurotransmitter from its base, exciting the sensory neuron, which can fire AP
- When the basilar membrane moves down, the process quickly reverses.
basilar
Transducing Sound Waves to AP
- When the basilar membrane moves up, hair cells are pushed into tectorial membrane and their tips are tilted, pulling tip links
- Tip links pull open ion channels, allowing ______ to diffuse into the hair cell and depolarize it
- Hair cell releases more neurotransmitter from its base, exciting the sensory neuron, which can fire AP
- When the basilar membrane moves down, the process quickly reverses.
K+
Transducing Sound Waves to AP
- When the basilar membrane moves up, hair cells are pushed into tectorial membrane and their tips are tilted, pulling tip links
- Tip links pull open ion channels, allowing K+ to diffuse into the hair cell and __________ it
- Hair cell releases more neurotransmitter from its base, exciting the sensory neuron, which can fire AP
- When the basilar membrane moves down, the process quickly reverses.
Depolarizee
Transducing Sound Waves to AP
- When the basilar membrane moves up, hair cells are pushed into tectorial membrane and their tips are tilted, pulling tip links
- Tip links pull open ion channels, allowing K+ to diffuse into the hair cell and depolarize it
- Hair cell releases more neurotransmitter from its base, exciting the sensory neuron, which can fire AP
- When the basilar membrane moves _______, the process quickly reverses.
Down
How do sound waves become nerve signals?
Sound waves enter ear…
- Vibrate ______ membrane
- Ossicles vibrate and transmit waves to _______window
- Fluid pressure waves in scala vestibuli push vestibular membrane
- Pressure waves form in endolymph of cochlear duct
- Specific regions of basilar membrane move depending on frequency of sound
- Hair cells distort, and cause changes in neurotransmitter release
- Sensory neurons with axons in CN VIII fire
- Pressure is transmitted to scala tympani and absorbed by round window
Tympanic membrane
Oval Window
How do sound waves become nerve signals?
Sound waves enter ear…
- Vibrate tympanic membrane
- Ossicles vibrate and transmit waves to oval window
- Fluid pressure waves in scala _________ push vestibular membrane
- Pressure waves form in _________ of cochlear duct
- Specific regions of basilar membrane move depending on frequency of sound
- Hair cells distort, and cause changes in neurotransmitter release
- Sensory neurons with axons in CN VIII fire
- Pressure is transmitted to scala tympani and absorbed by round window
Vestibuli
Endoplymph
How do sound waves become nerve signals?
Sound waves enter ear…
- Vibrate tympanic membrane
- Ossicles vibrate and transmit waves to oval window
- Fluid pressure waves in scala vestibuli push vestibular membrane
- Pressure waves form in endolymph of cochlear duct
- Specific regions of basilar membrane move depending on frequency of sound
- Hair cells distort, and cause changes in neurotransmitter release
- Sensory neurons with axons in CN _____ fire
- Pressure is transmitted to scala tympani and absorbed by round window
VIII
How do sound waves become nerve signals?
Sound waves enter ear…
- Vibrate tympanic membrane
- Ossicles vibrate and transmit waves to oval window
- Fluid pressure waves in scala vestibuli push vestibular membrane
- Pressure waves form in endolymph of cochlear duct
- Specific regions of basilar membrane move depending on frequency of sound
- Hair cells distort, and cause changes in neurotransmitter release
- Sensory neurons with axons in CN VIII fire
- Pressure is transmitted to scala ________ and absorbed by ______ window
Tympani
Round
The rate of vibration in hertz
Frequency
Humans can hear 20 to ____________ Hz
20,000
______________ depends on wave amplitude
Loudness
Auditory Pathways
- Movement of basilar membrane produces nerve signals that are propagated to cochlear nucleus within the _______________
- Some secondary neurons relay signals directly to inferior colliculus of midbrain, while other relay signals to superior olivary nucleus within the pons first then continue on the inferior colliculus
- Nerve signals are then relayed to thalamus (Medial geniculate nucleus)
- Then relayed to primary auditory cortex of the temporal lobe
Medulla Oblongata
Auditory Pathways
- Movement of basilar membrane produces nerve signals that are propagated to cochlear nucleus within the medulla oblongata
- Some secondary neurons relay signals directly to _______ colliculus of midbrain, while other relay signals to superior olivary nucleus within the pons first then continue on the _______ colliculus
- Nerve signals are then relayed to thalamus (Medial geniculate nucleus)
- Then relayed to primary auditory cortex of the temporal lobe
Inferior
Auditory Pathways
- Movement of basilar membrane produces nerve signals that are propagated to cochlear nucleus within the medulla oblongata
- Some secondary neurons relay signals directly to inferior colliculus of midbrain, while other relay signals to superior _______ nucleus within the pons first then continue on the inferior colliculus
- Nerve signals are then relayed to thalamus (Medial geniculate nucleus)
- Then relayed to primary auditory cortex of the temporal lobe
Olivary
Auditory Pathways
- Movement of basilar membrane produces nerve signals that are propagated to cochlear nucleus within the medulla oblongata
- Some secondary neurons relay signals directly to inferior colliculus of midbrain, while other relay signals to superior olivary nucleus within the pons first then continue on the inferior colliculus
- Nerve signals are then relayed to ________ (Medial geniculate nucleus)
- Then relayed to primary auditory cortex of the temporal lobe
Thalamus
Auditory Pathways
- Movement of basilar membrane produces nerve signals that are propagated to cochlear nucleus within the medulla oblongata
- Some secondary neurons relay signals directly to inferior colliculus of midbrain, while other relay signals to superior olivary nucleus within the pons first then continue on the inferior colliculus
- Nerve signals are then relayed to thalamus (Medial geniculate nucleus)
- Then relayed to primary auditory cortex of the ________ lobe
Temporal
________ Deafness: interference of wave transmission in external or middle ear
Conductive
____________ Deafness: Malfunction in inner ear or cochlear nerve
Sensorineural deafness
Receptor for static equilibrium and linear acceleration
Macula
Hair cells of Macula project into gelatinous __________ membrane
Otolithic
Tilting your head shifts otolithic membrane and bends __________
Stereocilia
Base of each semicircular canal has swollen _________
Ampulla
Ampulla contains Crista ampullaris with hair cells and supporting cells, hair cells are embedded within gelatinous _________
Cupula
