Sensory Physiology Flashcards
What are the 5 special senses?
- Vision
- Gustation
- Hearing
- Olfaction
- Equilibrium
What are the 5 somatic senses?
- Touch
- Temperature
- Pain
- Itch
- Proprioception
Proprioception
- The ability to sense stimuli arising w/ the body reguarding position, motion, and equilibrium
Sensory receptor cells are distinct cells, mostly found in the ________ of the body.
- Head region
sensory receptor cells are housed in ___________.
- Sensory organs
- ex. Eyes and ears
- Or epithelial structures (taste buds and nose)
sensory receptor cells respond to ________.
- Respond to a stimulus
- sends messages to the brain
What are the types of sensory receptors?
- Mechanoreceptors
- Thermoreceptors
- Photoreceptors
- Chemoreceptors
- Nociceptors
Mechanoreceptors
- respond to mechanical force, such as touch
Thermoreceptors
- Respond to temperature changes
Photoreceptors
- respond to light
Chemoreceptors
- respond to chemicals
Nociceptors
- respond to damaging stimuli such as pain
Stimulus excites a ________.
- receptor (touch excites mechanoreceptors)
the stimulus much be within the receptors ______________.
- Receptive feild (area the receptor monitors)
Stimulus energy gets converted into a graded potential, this is called _________.
- Transduction
- initiates an AP on sensory nerve to CNS
- or causes receptor cell to secrete NT
The sensory cortex is where ___________.
- Where stimuli are counciously interpreted
describe how stimulus of touch is preceived and interpreted.
- Stimulus excites a receptor (touch excites mechano receptor)
- Stimulus must be within the receptors receptive feild
- Stimulus energy gets converted into a graded potential (transduction); an APis initiated on a sensory nerve to the CNS or Causes the receptor cell to secrete NT
- AP is sent to the brain where the stimuli is conciously interpreted in the sensoty cortex
how much of the body’s sensory receptors are found in the eye?
- 70%
the ___________ protects the eye.
- Skull
___________ eye muscles control eye movement. Cranial nerves ___ ___ and ___ control movement. The eye functions similar to a ________.
- 6 extrinsic eye muscles
- cranial nerves 3,4 and 6
- a camera
A) Cornea
B) Pupil
C) Aqueous humor
D) Iris
E) Lens
F) Vitreous humor
G) Sclera
H) Retina
I) Fovea Centralis
J) Optic nerve
K) Optic disc (blind spot)
How does the parasympathetic nervous system effect the eye?
- Pupils become constricted
- Sphincter pupillae muscle contracts
- Pupil size decreases
How does the sympathetic nervous system effect the eye?
- Dilated pupils
- Dilator pupillae muscle contracts
- Pupil size increases
The iris has how many muscles? What are their names?
- The iris has 2 muscles
- Sphincter pupillae
- Dilator pupillae
The retina contains _______.
- photoreceptor cells
- rods and cones
Rod cells
- more numerous
- function in low light
- help see black and white
Cone cells
- Provides high resolution for color vision
- responsible for high acuity (sharpness of vision)
The fovea contains more of what type of cell?
- cones
both rods and cones contain ________.
- Pigments
- Light excites the pigments and we see color
Pathway of information through the eye
- Light in atmosphere
- light hits cornea first
- light travels through aqueous humor where it is refracted
- light then enters pupil
- Light then hits lense and is refracted again
- Light enters vitreous humor in posterior chamber of the eye and is refracted
- Light then hits photoreceptors in the retina
- cones and rods send AP back out towards the optic nerve
- AP reaches the CNS
- information is sent to visual cortex and is processed by the brain
where is the visual cortex located?
- in the posterior portion of the brain
How does the eye work?
- Eye receives light and focuses it on the retina
- Light bends (refracts) when it travels through different mediums
- Air — cornea
- Cornea —- lens
- Lens —- vitreous humor
Glaucoma
- Aqueous humor not draining properly; pressure builds up in the eye
Cataract
- Coulding on the lense (hardening)
Astigmatism
- Abnormally shaped cornea
Color Blindness
- Congenital lack of cone pigments
Gustation and Olfaction sense __________.
- Chemicals
Olfaction
- Smell
Gustation
- Taste
Olfaction anf gustation are both very __________ senses, what does this mean?
- Primative senses
- strong direct connection to most basic needs
- Thirst, hunger, emotion, sex, some forms of memory
The cells that are responsible for picking up information during olfaction and gustation are called _________________.
- Chemo receptors
- These receptors are excited by chemicals in the air and dissolved in siliva
A) Olfactory Tract
B) Mitral cell
C) Glomeruli
D) Olfactory bulb
E) Cribriform plate
F) Filaments of olfactory nerve
G) Lamina Propria (CT)
H) Olfactory Axon
I) Olfactory stem cell
J) Olfactory sensory neuron
K) Support cell
L) Dendrite
M) Olfactory Cilia
N) Mucus
O) Olfactory epithelium
Focal length
- Point where light goes through lense and hits the fovea
lenses can change shape according to _________.
- Distance
Accommodation
- When the lens adjusts its shape to keep focus
Near point accommodation
- Closest distance at which an object is focused
Emmetropic eye
- Normal eye
- the focal point is right on the retina
Myopic eye
- Nearsighted
- eyeball is too long
- in uncorrected eye focal point s infront of the retina
- in a corrected eye a concave lens moves the focal pointback further
Hyperopic eye
- Far sighted
- Eye ball is too short
- in an uncorrected eye the focal point is behind the retina
- in a corrected eye a convex lens moves the focal point forward
What happens when you are exposed to a smell for too long? Why does this happen?
- Olfactory fatigue/ adaptation
- Less APs are sent to the brain the longer one is exposed to the odorant
A) Vestibular cortex
B) Somatosensory Cortex
C) Gustatory cortex
D) Visual cortex
E) Auditory cortex
F) Olfactory cortex
Taste buds
- Sensory organ for taste
Taste buds are found on _______.
- Papilla
What are the 3 types of papillae found on the tongue?
- Foliate Papillae
- Fungiform papillae
- Vallate papillae
Each taste bud contains ______________.
- 50-100 epithelial cells
Gustatory (taste) cells contain __________.
- Neurotransmitters
Basal epithelial cells in tongue
- they regenerate damaged ET in tongue
Where is olfactory epithelium located?
- In the roof of the nasal cavity
What substance “traps” and dissolves odorants?
- Mucus
Odorants (chemicals) bind to ___________.
- Olfactory cilia
- Olfactory cilia are the chemorecptors responsible for olfaction
Once odorants bind to olfactory cilia an ____ is sent to the ______, then to the __________.
- Action potential
- Olfactory bulb
- Olfactory cortex
Pathway of information; Olfaction
- Odorants are breathed in and trapped in mucus
- Mucus dissolves odorants
- odorants bind to olfactory cilia
- GP is sent up through dendrites and cell body to axon
- at the olfactory neuron’s axon it becomes a AP
- AP is sent to mitral cells in olfactory bulb
- Mitral cells refine, amplify and relay signals to the olfactory tract
- AP is sent to Olfactory cortex
- Signals are also sent to the frontal lobe/ hypothalmus-amygdala for processing
Mitral cells
- Refine, amplify and relay signals
Olfactory stem cells
- Stem cells are undifferentiated cells that can be molded into whatever type of cell
How many pathways can an AP from the olfactory tract travel?
- 2
- Frontal lobe or
- Hypothalamus/amygdala; emotional response to smell
A) Taste fibers of cranial nerve
B) Basal epithelial cells
C) Gustatory epithelial cells
D) Taste pore
E) Gustatory hairs
F) Stratified squamous epithelium of tongue
G) Support cell
Signals aare sent from taste cells via cranial nerves ___, ____ and ___ to the __________.
- 9
- 7
- 10
- gustatory cortex
signals are also sent to the ______, _______ and the ________ when we taste something.
- Hypothalamus/ limbic system; this tastes good
- stomach and salivary glands
Pathway of gustation
- Chemical enters mouth
- chemical is dissolved in saliva
- chemical diffuses through taste pore
- chemical binds to gustatory hair
- Gustatory cell releases NTs
- NTs bind to neurons
- AP travels up cranial nerves to gustation cortex
- Impulses also sent to hypothalamus (limbic system), stomach and salivary glands
What are the 5 basic taste sensations?
- Sweet
- Sour
- Salty
- Bitter
- Umami
Taste likes and dislikes have homeostatic value why?
- Sweet = glucose; needed for ATP production
- Sour = protection from spoiled food
- Salty = needed for many functions in the body; water balance, muscle contractions, and APs
- Bitter = protective
- Umami = we need protein
- Taste likes and dislikes have homeostatic value because it helps us eat all the things we need to maintain healthy bodily function and avoid substances that are harmful
Each taste cell is sensitive to only one taste, why?
- This allows us to taste more than one taste at a time
what percent of taste is smell?
- 80%
Spicy foods excite __________ and ____________ in the mouth.
- Nociceptors
- Thermoreceptors
Disruptions to taste and smell usually result from brain injury. Why?
- Because all the information for taste and smell is processed in the brain
Swollen taste buds
cause is unknown
The inner ear contains fluids that must be moved to stimulate ______________ to _______ and ________________.
- Mechanorecptors
- Hear
- Maintain balance
Hearing and balance are interconnected but the receptors for hearing and equilibrium are ________________.
- different
Hearing is our perception of the energy carried by ___________.
- sound waves
Sound transduction
- air waves —->fluid wave ——->chemical signals ——-> AP
Auditory ossicles
- Malleus
- Incus
- Stapes
A) External ear
B) External acoustic meatus
C) Tempanic membrane
D) Malleus
E) Incus
F) Stapes
G) Semicircular canals
H) Cochlea
I) Vestibule
J) Oval window
K) vestibular nerve
L) Cochlear nerve
M) Eustacian tube (pharyngotympanic tube)
N) External ear
O) Middle ear
P) Inner ear
Cochlea
- Involved in hearing
Vestibule
- Involved in equilibrium
Semi-circular canals
- involved in rotational acceleration
The structures of the inner ear; vestibule, semi-circular canals, cochlea have __________ because they each do ______________things.
- Different
- Different
Pathway of info: hearing
- Sound waves enter external ear
- sound waves hit the tympanic membrane
- Tympanic membrane viberates and hits the auditory ossicles
- Malleus hits the incus, incus hits the stapes
- Stapes vibrates the oval window
- vibrations creates waves in the fluid of the cochlea (organ of corti)
- Waves in fluid cause hair cells to bend
- Hair cell bending causes electrical signal that causes release of NTs onto cochlear nerve
- cochlear nerve sends AP to brain (auditory cortex)
Sound transduction
- air waves (sound) —-> fluid waves —–> chemical signals ——-> AP!
Sound is the brain’s interpretation of __________, _____________, and _____________ of sound waves that reach the ear!
- Frequency
- Amplitude
- Duration
- processed in cochlea
sound waves are measured in ___________.
- Hertz (Hz)
“loudness” is measured in ____________.
- decibles (dB)
what is the range of hertz that the average human ear can hear.
- 20-20,000 Hz
A normal conversation is ________.
- 60 dB
- above 80 dB can result in hearing loss
- average concert 120 dB
Frequency
- is percieved as pitch
- how often something happens (more frequent waves)
Amplitude
- amplitude (size or intensity) is perceived as loudness
- How high the wave is
What are the 3 forms of hearing loss?
- Conductive
- Central
- Sensorineural
Conductive hearing loss
- Sound doesn’t travel well
- can be due to wax build up
- External and some what middle ear problem
Central hearing loss
- Problem lies in the CNS
- stroke or damage to neural pathways
Sensorineural hearing loss
- Damage to the structure of the inner ear
- includes death of hair cells in the cochlea
