1/31
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
Physical Senses
Audition, vision, touch
Chemical Senses
Taste (gustation), smell (olfaction), and the Trigemenial System
Senses and the Outside World
The outside world interacts with sensory organs via physical contact, and we perceive our environment via physical and chemical interactions (physical interactions happen outside, chemical interactions happen internally)
Taste (Gustation)
Perceived via the interaction between soluble solutions and gustatory receptors located in the taste buds on our tongue
The Five Detectable Tastes
Sweet, sour, salty, bitter, umami (savory)
Smell (Olfaction)
Perceived via olfactory receptors located in the olfactory mucosa in the upper naval cavity, which we can use to distinguish between millions of odors
Trigeminal System Function
Provides motor (movement) and sensory information for different aspects of your head and face using processes like chemesthesis
Chemesthesis
A third chemosensory system, next to smell and taste, used to evaluate pain or thermal sensations such as tingling, itchiness, or irritation and is located on trigeminal fibers in the nasal/oral mucosa
Taste Bud Location
Found on the papillae on the mucosa of the tongue and along the oral cavity
Types of Papillae
Filiform, fungiform, foliate, circumvallate
Taste Bud Pathway
They use different cranial nerves to get to the solitary nucleus of the brainstem
Taste Map
A debunked urban myth, we can taste all qualities of flavor everywhere on the tongue
Taste Processing
From the solitary nucleus to the VPM of the thalamus, to the insula and parietal cortex, which is the critical spot for gustatory processing
Nostril Anatomy
Relatively narrow at first and goes far up, with the septum completely separating both nasal cavities until reaching the pharynx in the throat. At the back of the nose lies the vermonosal organ.
Nostril Symmetry
Highly asymmetrical
Olfactory Receptor Neurons (ORNs)
Neurons situated in the roof portion of the nasal cavity located in cilia hair cells, with one ORN per receptor, which can be activated by all sorts of substances as per it's olfactory code
Olfactory Code
A hypothesis that odor is stimulated by a distinct set of receptor cells and its associated receptor proteins which can be mixed in a near infinite number of combinations
Neural Olfaction I
ORN axons pass through the cribriform plate of the ethmoid bone and reach the olfactory bulb, to which they snyapse.
Neural Olfaction II
All ORNS converge onto one glomerulum within the olfactory bulb
Olfactory Processing Areas (In order)
Olfactory Bulb + Tract, primary olfactory cortex, pirifirm cortex, amygdala, endoterminal cortex, secondary olfactory cortex: ACC + Insula
Olfactory Processing Direction
Ipsilateral processing (e.g left nostril, left hemisphere) with no relay in the thalamus
Olfactory Processing Response
Will stimulate areas of emotion, learning, memory, and perception of reward
Proust Phenomenon
The power of odors to elicit memories that are especially old and vivid caused by hippocampal processing)
Orthonasal vs retronasal olfaction
The first involves smelling outside scents that go through the nose to he olfactory epithelium, the latter involves the scent entering through the mouth and throat to the epithelium
Olfaction Functions
Warning, nutrition, and social communication
Olfactory Dysfunction
Hyposmia
Anosmia
Phantosmia
Parosmia
Ansomia
The complete loss of smell (5%)
Hyposmia
An impaired sense of smell (15%)
Parosmia
An abnormal or perverted sense of smell (30% of hyposmiacs)
Phantosmia
The sensation of an odor that isn't there
Olfaction & Gustation Confusion
Most people with olfaction issues confuse it for gustation issues
Causes of Olfactory Dysfunction
Disease, neurodegenration, traumatic brain injury, Alzheimer's, chronic sinuitis (spinonasal disease)