Exam #4 BIO 232 Flashcards
What type of sense is touch?
Mechanoreceptive sense
What type of sense is taste?
Chemoreceptive sense; liquids
What type of sense is smell?
Chemoreceptors sense; gaseous chemicals
What type of sense is hearing?
Hearing and balance
Free Nerve Endings Characteristics
- pain reception that goes to spinal cord and brain
- damaged when skin or nails are cut
Tactile disc (merkel cell and merkel disc)
- Merkel Cell is located in the Epidermis
- Merkel Disc is located in the Dermis, detects papercut
Tactile (Meissner’s) Corpuscle Characteristics
- light touch
End Bulb Characteristics
- associated with temperature perception
Lamellar (Pacinian) Corpuscle Characteristics
- deep pressures
Krause End Bulb Characteristics
Named after the German anatomist Wihelm Krause and are typically though of as thermoreceptors, sensing cold temperatures although there are questions about this.
Ruffini Corpuscle Characteristics
Named after Angelo Ruffini, these receptors are sensitive to skin stretch and contributed to the kinesthetic sense of and control of finger position/movement.
Do fingertips have a high or low density of neurons?
High density: therefore can discern different points of stimuli more finely.
Does our shoulder have high or low density of neurons compared to our fingertips?
Few neurons, but each with larger neuronal fields. The distance between stimuli needs to be greater in this region for us to be able to discern the stimuli as two distinct points.
What solutions are used for tongue mapping?
- sugar
- salt
- weak vinegar
- tonic water
The 4 Taste Modalities are?
Sweet receptors
Salty receptors
Sour receptors
Bitter receptors
Where are sweet receptors located on the longue?
Front
Where are salty receptors located?
Behind sweet
Where are sour receptors located?
Behind salty
Where are bitter receptors located?
Back of tongue
Why are salty and sweet receptors near the tip of the longue?
Allow for quick consumption of the minerals
Why are sour receptors towards the back of the tongue?
Allows us to recognize food that has gone bad before we consume it
Why is bitter towards the back of the tongue?
Allows us to realize food that is bitter/toxic before we swallow
Purpose of Circumvallate Papilla?
Bitter taste buds
Purpose of Fungiform Papilla?
Sweet, salty, and sour taste buds
Gustatory Hair Characteristics
Stimulated by chemicals that are drank
Characteristics of Umami Taste Receptors
The food additive MSG (monosodium glutamate) tastes very rich and is described as having an “earthy depth” that enhances flavor.
Don’t have the umami receptor= MSG tastes mildly salty
About 30% of humans have this taste receptor.
Characteristics of Fat/Savory Taste Receptor
Allows a more diverse flavor profile to higher fat foods like steak.
25% of people have this receptor
The 3 Cranial Nerves that are associated with the tongue are?
Cranial Nerve VII (facial)
Cranial Nerve IX (glossopharyngeal)
Cranial Nerve X (vagus)
Characteristics of Cranial Nerve VII (facial)
Responsible for taste in the anterior two-thirds of the tongue.
Characteristics of Cranial Nerve IX (glossopharyngeal)
Responsible for taste in the posterior one-third of the tongue and into the entry of the pharynx (which has a few taste buds as well).
Characteristics of Cranial Nerve X (vagus)
Responsible for taste in the posterior one-third of the tongue and into the entry of the pharynx (which has a few taste buds as well).
What is the Olfactory Epithelium responsible for?
The sense of smell
Characteristics of the Olfactory Epithelium
Odors waft into the nasal cavity and molecules of the odors will stimulate cells in the olfactory epithelium.
A very small, thin bony plate between the olfactory epithelial layer and the brain’s olfactory bulb known as the cribriform plate.
Characteristics of the Olfactory Gland
- produces a mucus that contains odorant binding proteins and the mucin protein
- secretions help flush out the olfactory epithelium layer mucous so that odorants do not linger for extended periods
We have all experienced a situation where we have an odor lingering because there is often a slowing of the function of the olfactory glands and the odorants that have dissolves in the mucous linger and continue to stimulate the olfactory receptor cells. - receptor cells go to the brain
In the small section of olfactory epithelium, there is an array of olfactory receptor cells present. Each receptor cells are capable of detecting a variety of odors. Some will be better at detecting some odorants than others.
Characteristics of Cilia
- embedded in a layer of mucous that lines the entirety of the nasal cavity
- when an odorant molecule of some sort comes into contact with mucous, it has potential to dissolve/migrate into the mucous later; this is the way that the odorant may be able to stimulate the cilia
- if enough stimulation occurs, the receptor cell will have an action potential generated which will travel upwards to the olfactory bulb and into the brain for sensory interpretation
How does meningitis reach the brain?
It goes through the cribriform plate, due to the holes/pores
6 Odorant Categories
- Spicy
- Flowery
- Camphoraceous; smell of camphor oil; vicks vaporub or muscle creams
- Musky; smell of ‘body odor’
- Putrid; smell of decay or combustion
- Ethereal; smell of volatile, gasoline
What odorants are in Tobacco?
- Flowery
- Ethereal
- Spicy
What odorants are in Tobacco when combusted?
- Ethereal
- Spicy
- Putrid
Important Details about the sense of Smell
When we smell an odor, it is going to be in the form of a gas that enters our nasal cavity through the nostrils.
Or it can be a gas that has been created from the volatilization of food in our oral cavity.
- this can occur easily due to the warmth of our oral cavity, the mechanical chewing and breakdown of food and its mixing with warm saliva.
Some food can turn gaseous and travel into the nasal cavity through our pharynx.
- this latter way of sensing the smell of food is calling retronasal aroma and is very important for the flavor of food.
Olfactory Receptor Details
Sense of smell
Chemoreceptor
Olfactory Cilia (receptor)
- stimulation
- odorant (smell) enters- cause
The receptor protein to release a second messenger compound
How is George Wald important to science?
Wald made discoveries in physiology visual processes of the eye.
Characteristics of Vision
- photons of light energy
- images enter the eye upside down
Characteristics of the Eyebrows
- ability to direct water flow
- keeps water/sweat out of the eyes
Characteristics of the Eyelashes
- “push broom”
- keeps dirt/dust/debris out of the eyes
Characteristics of the Conjunctiva
- protective structure
- blocks anything trying to reach the posterior side of the eye
Why do we have a runny nose when crying?
Lacrimal sac goes to nasal cavity for warmth
What is the term for a wandering eye?
Strabismus
Characteristics of Strabismus
Lazy eye
Progressive; neural blindness can develop
- brain turns off neural signal
Surgery is possible if caught early
Eye Layers from Outer to Inner
Sclera
Cornea
Retina
Two types of Sclera
Opaque (white portion)
Cornea (translucent)
Details of the eye
Sclera; fibrous connective tissue
- strong, durable, holds shape
What is the Carotide?
Layer of rich blood supply in the eye
Does the Retina have a direct blood supply?
No, it is the neural layer
Characteristics of the Ciliary Zonule
Suspensory ligament
humor=lens
cornea+lens–> aqueuous humor
lens+retina–> vitreous humor
What does the Parasympathetic system do?
Causes circular muscles to contract (pupil becomes smaller).
What does the Sympathetic system do?
Causes radial muscles to contract (pupil becomes bigger).
What is Albinism?
Pink/Red Iris
Purpose of the Iris
Light shield
- controls how much light enter the eye
- changes the size of the pupil
Normal Vision
Emmetropia
Farsightedness Vision
Hyperopia
- eye shape; thin front to back
Nearsightedness Vision
Myopia
- eye shape; larger front to back
Age related loss in Vision
Presbyopia
- eye shape; flex in the lens
Characteristics of the Rods
- “on/off switches” to define the visual field
- help with “black and white” vision but that is not a 100% accurate statement
Characteristics of the Cons
3 Types- detect color
red cones
; L-long wavelengths
green cones
; M-medium wavelengths
blue cones
; S-short wavelengths
All 3 cones will provide normal color vision
Characteristics of Opsin
Retinal- occurs in 2 forms
Cis-retinal
- see in low light environments (the dark)
- very light sensitive
Trans-retinal (bleached)
- see in high light environments (the light)
- less light sensitive
Can switch between the 2 forms based on the environment.
Eyes get used to dark areas and convert from trans to cis-retinal.
What is the most common color blindness to have?
Red/Green
What does Cataract surgery affect?
The suspensory ligaments; changes translucency of the eye lens
What system involves distant vision?
Sympathetic
What system involves close vision?
Parasympathetic
Why is Binocular Vision important?
For depth perception
- overlap of visual fields used in depth perception
Details of the Pinna
- outer ear
- funnel for sound
- bigger pinnas (ears)= hear better
The Auditory Tube consists off..
the Eustachian and Pharyngotympanic tubes
Characteristics of the Eustachian Tube
Changes towards adulthood; becomes more vertical
Young children get ear infections more because fluids can build up in the eustachian tube due to the angle; more horizontal compared to adults.
- tubes in ears allow for the fluid to drain from the ears to reduce ear infections
- scarring of the tube will make it more difficult to regulate pressures
Characteristics of the Pharyngotympanic Tube
Canal that spans from the middle ear to our pharynx.
Manges the pressure.
Chewing and swallowing massages the tissue of the pharynx to allow gasses to pass easily in the auditory tube.
- chewing and swallowing on airplanes when elevation change occurs is important
Three bones of the middle ear
- Malleus (hammer)
- Incus (anvil)
- Stapes (stirrup)`
What do sound waves vibrate?
The tympanic membrane; varies on the pitch.
- vibrations will cause the end of the malleus to vibrate which causes the head of the malleus to vibrate against the incus then transmits to the stapes
Importance of the ear muscles
Muscles allow for contraction and relaxation which impacts the way that the bones of the middle ear vibrate. Also, muscles restrict the movement of the bones which helps prevent hearing loss.
What does the Tensor Tympani Muscle do?
Regulates the malleus
What does the Stapedius Muscle do?
Regulates the stapes
Purpose of the Inner Ear
Converts signals along with balance and body position to the brain.
Characteristics of the Oval Window
Receives the vibrations of the stapes.
Characteristics of the Cochlea
- “snail shell”
- perceives the vibrations as different pitches of sound
- relays to the brain
- perilymph is one type of fluid found in this area
Characteristics of the Semicircular Canals
- mechanism for balance and body position
- semicircular canals are organized in each plane of space
- contain fluid called endolymph which moves movement of head that will push against the crista ampullaris then impacting the vestibular nerves
- crista ampullaris is upright when still; changes with movement
Characteristics of the Vestibulocochlear Nerve
Relays signals to the brain
- vestibular nerve
- cochlear nerve
Characteristics of the Round Window
- “pressure relief valve”
- dissipates the sound waves; makes sound quieter
Details of High Pitch
High pitch sound waves will travel shorter in the basilar membrane before going into the scala tympani
Details of Low Pitch
Low pitch sound waves will travel farther in the basilar membrane before going into the scala tympani
What is Amplitude?
Strength of the sound.
What is Wavelength?
Pitch of the sound.
Characteristics of the Macula
Contain hair cells that contain structural elements
2 types
- kinocillia
- stereocillia
Contains the Otolithic Membrane
Details of Kinocillia
Spoon like ending
Detials of Stereocillia
Tube-like
Characteristics of the Otolithic Membrane
Sheet-like membrane that rests on top of the hair cells (like a blanket)
Otoliths (otolithic crystals) on top of the “blanket”
- pressures down on hair cells (even pressure) so remain upright
- titling head forward (otolithic membrane is on angle) weighs down on the cilia causing them to bend
