Exam 1 Flashcards
Explain why sensory receptors are called transducers.
They convert light, sound, heat energy, pressure, and vibration into nerve impulses
List the modalities that are trans do used by sensory receptors
light sound heat vibration pressure
List the four broad categories of information that are transmitted by sensory receptors
modality
location
intensity
duration
If a cutaneous sensory receptor has a small receptor field, is the skin more sensitive or less sensitive?
More sensitive
List two types of adaptation to the duration of a sensory stimulus.
Phasic & Tonic
How is the response to the duration of a stimulus different in phasic receptors compared to tonic receptors?
Phasic - rapid impulses, sharply reduced firing
Tonic - slowly begin impulse transmission, steadily transmits
List the types of sensory neurons that are categorized as having phasic receptors.
Tactical corpuscles
End bulbs
Lamellar corpuscles
Type of sensory relay neuron categorized as having tonic receptors
Bulbous corpuscles
Which type of receptor classified by modality transmits the sensation of pain?
Nociceptors
The sensory receptors triggered by a full bladder are classified as which type when using the modality classification? 
Origin of stimulus classification?
Distribution classification?
Mechanoreceptors
Interoreceptors
General
The sensory receptors trasmitting the sensation of taste are classified as which type when using the modality classification?
Origin of stimulus classification?
Distrobustion classification?
Chemoreceptors
Exteroreceptors
Special
What is the stuctural difference between encapsulated and unencapsulated receptors?
Encapsulated - no wrapping
Unencapsulated - wrapped w/ glial cells, connective tissue
Types of receptors that are structurally encapsulated
Tactile corpuscles
End bulbs
Bulbous corpuscles
Lamellar corpuscles
Types of receptors mentioned in class that are structurally unencapsulated. 
Free nerve endings
tactile discs
hair receptors
How is sensation transmission different when comparing phasic receptors to tonic receptors?
Phasic – fast
tonic – slow
Where are tactile corpuscles located?
Dermal papillae
Where are end bulbs located?
Mucous membranes
Where a bulbous corpuscles located?
Dermis and subcutaneous layers
Where are lamellar corpuscles located?
Periosteum, joint capsules, deep dermis
In a somatosensory pathway which order neuron includes the sensory receptor?
1st
Which modalities transmitted by first order neurons are transmitted fast? Which is transmitted slowly?
Fast - temperature
Slow - touch, pressure, proprioception
Are the neurons in the reticular formation first second or third order sensory neurons?
3rd
To which part of the brain to third order neurons transmit sensory impulses?
Cerebral cortex
Second order fibers in the spinalchord transmitting the sense of proprioception are a part of which tract?
Spinocerebellar tract
What is different about the projection pathway associated with proprioception compared to other sensations?
Projects to cerebellum
What is the function of the cerebellum in proprioception?
Controlled and accurate movements
What is the difference between visceral pain, deep somatic pain, superficial pain, and neuropathic pain?
Vp - organs
Dsp - bones & muscle
Sp - skin
Np - nervous tissue
How are A delta nociceptive fibers different from type C nociceptive fibers?
A - fast; myelinated, easy to locate
C - slow; unmyelinated, hard to locate
What is the abnormality in nociception in the disorder fibromyalgia and phantom limb pain?
Fibro - Heightened response in cerebrum
Phantom - cerebrum initiates pain independently
What are endogenous opioids?
Oligopeptides chemically similar to morphine
List 3 endogenous opiods
Enkephalins
Endorphans
Dynorphins
Which opioid compound capable of acting on the body is produced by plants but not humans?
Morphine
What is gustation?
Sense of taste
List the four types of lingual papillae
Filiform
Foliate
Fungiform
Vallate
If filiform papillae don’t have taste buds, what is their function?
Provide information about food texture
Which type of papillae is lost in early childhood?
Foliate
Which two types of papillae have taste buds in their structure?
Fungiform and vallate
Why do vallate papillae have more taste sensation the fungiform papillae?
250 vs 3 tastebuds per papillae
Where are fungi form papillae located on the tongue?
Tongues Apex
Where are vallate papillae located on the tongue?
Rear of tongue
What taste cell structure has chemical receptors?
Microvilli
How is the first order sensory neuron associated with a taste cell?
Taste cells contain neurotransmitter that depolarizes first order neuron
In a taste bud, what is the function of basal cells?
Replace taste cells
What chemical triggers each of the primary taste sensations?
Salty: Metal ions
sweet: Carbohydrates
umami: Amino acids
sour: Acids
bitter: Alkaloid compounds
Which two cranial nerves transmit to sensation from the tongue?
VII - 7
IX - 9
First order neurons transmitting taste sensation communicate with second order neurons in which part of the brain?
Medulla
Second order neurons transmitting taste sensation communicate with third order neurons in which two parts of the brain?
Hypothalamus & Amygdala
Third order neurons transmit taste sensation to which part of the cerebrum for awareness of taste?
Insula
What is olfaction?
Sense of smell
Where is olfactory mucosa located?
5 cm area where superior nasal conchae, nasal septum, and ethmoid bone meet at the roof of the nasal cavity
Which part of the cerebral cortex is responsible for awareness of smell sensation?
Insula
Which pathways are responsible for memory of smells and emotional responses to smells?
Insula, hypothalamus, amygdala, and hippocampus
Explain what sound is
Vibration of molecules
What is the unit of measurement for frequency?
Hertz - Hz
What increases when frequency increases?
Number of vibrations per second
What is the range of frequencies over which sensitive ears are able to perceive sound?
20 - 20,000 Hz
What is the unit of measurement for loudness
Decibels - dB
In decibels, what is the threshold of human hearing?
0 dB
List two terms for the fleshy, external part of the ear
Auricle & pinna
What type of Cartlidge gives the external part of the ear its shape?
Elastic Cartlidge
What type of tissue makes up most of the ear lobe?
Adipose
What is the external acoustic meatus?
Opening into the auditory canal
What bone surrounds the outer ear canal?
Temporal bone
List two types of glands found in the epithelium of the outer ear canal
Cereminous & sebaceous
What is cerumen?
Earwax that protects epithelial layer
Where are structures of the middle ear located?
Tympanic cavity of the temporal bone
Which article is attached to the stapedius muscle?
Neck of stapes
What is the function of the stapedius muscle?
Reduce motion of the stapes
Which article is attached to the tensor tympani muscle?
Malleus
Is the tympanic membrane a structure of the outer, middle, or inner ear?
Middle
How does the tympanic membrane contribute to hearing?
Transduce vibrations 
Which cranial nerves supply the tympanic membrane?
X - 10
V - 5
Where does the air in the tympanic cavity come from?
Pharynx 
Where is the auditory tube located?
Between nasopharynx & middle ear
List the auditory ossicles in order starting with the one attached to the tympanic membrane
1 - malleus
2 - incus
3 - stapes
What window is the stapes attached to?
Oval
What is the name of the bony space surrounding the inner ear structures?
Bony labyrinth
What is the relationship between the membranous labyrinth and the cochlear duct?
Cochlear duct is within the membranous labyrinth
The cochlear duct another name for:
Scala media
What fluid fills the cochlear duct?
Endolymph
What fluid surrounds the cochlear duct?
Perilymph
What structure is made up of the scala vestibuli and the scala tymphani filled with perilymph and the scala media filled with endolymph?
Cochlea – organ of hearing 
What scala begins near the oval window?
Vestibuli
What scala ends at the round window?
Tymphani
The vestibular membrane is the floor of which scala?
Vestibuli
The basilar membrane is the roof of which scala?
Tympani
Where is the spiral organ located?
On the basilar membrane
How does perilymph move in relation to the scala vestibuli and tympani?
Perilymph is moved forward up the scala vestibuli and down the scala tympani
What function does the round window serve?
Relieve perilymph pressure
Where is the tectorial membrane located?
Floor of scala media
What tiny structures are embedded in the tectorial membrane?
Inner hair cells
When do the stereocilia of inner hair cells and outer hair cells get bent?
When head moves, membrane moves, cilia are bent
What causes depolarization of hair cells located in the spiral organ?
K+ rushing into cells
Explain differentiation between soft and loud sounds
Intensity of basilar membrane vibration – release of neurotransmitter, triggered by hair cell movement
What is the orientation of hair cells in the macula saccule?
Lies vertical on walls of saccule
What is the orientation of hair cells in the macula utriculi
Lies horizontal
What is the difference between stereocilia and kinocilia?
Stereocilia – most of the cilia on a hair cell
Kinocilia – main cilia on hair cell
List the three semicircular ducts
Anterior, posterior, & lateral
Describe the orientation of the semicircular ducts
Anterior & posterior - right angle
Lateral - 30° from horizontal 
What is the composition of otoliths?
Calcium carbonate granules
What is the function of otoliths in the otolithic membrane?
Give extra weight to membrane and increase inertia
Where are impulses for equilibrium taken in order to control eye-movement reflexes?
Cerebellum
Where impulses for the sensation of equilibrium taken in order to control postural reflexes?
Cerebellum
Where are impulses for the sensation of equilibrium taken for conscious awareness?
Cerebral cortex
