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