Lecture 9: Hearing, Somatosenses (Tactile Perception, Proprioception & Pain) Chemosense (Taste & Smell) Flashcards
What is Audiology?
Hearing, testing, and optimization of acoustic stimulus using hearing aids
What is Otolaryngology?
A specialization in conductive and sensorineural hearing losses, cochlear implants
What is Speech Therapy?
Specialization in developmental aspects of hearing difficulties affecting speech
4 ways in which Hearing Loss Affects Children?
- Can delay the development of speech-related receptive and expressive communication problems
- Speech related language deficits can cause learning problems that result in reduced academic achievement
- Can lead to social isolation and poor self regard
- Impacts vocational choices
What are Outer Hair Cells?
Mechanical amplifiers that involve prestin “ a motor protein” that performs a direct voltage-to-displacement function that mechanically enhances the vibrations of the basilar membrane caused by acoustic stimulation
What are Inner Hair Cells?
Acoustic transducers effected by shearing
What happens when a hair cell depolarizes?
Voltage gated calcium channels at the base of the cell open, and the resulting influx of calcium causes synaptic vesicles to fuse to the cell membrane and release a neurotransmitter into the synaptic cleft between the hair cell and the cochlear nerve fibers.
What is Auditory-Evoked Potentials (AEPs)?
Electrical responses from different generators within the auditory system (electrical signal is very small)
What is the difference between longer latency and shorter latency in AEPs?
Shorter Latency: Components reflect peripheral visual processes - auditory nerve, cochlear nucleus, superior olive, and inferior colliculus of the brainstem
Longer Latency: Components reflect central processes (medial geniculate nucleus of the thalamus, A1, A2, and higher cortical areas
What is Conductive Hearing Loss?
Factors affecting the conduction of sound to the cochlea (serious otitis media)
What is Sensorineural Hearing Loss and what is it caused by?
Factors affecting transduction of acoustic energy to neural response in the cochlea
Caused By Potentially:
- Diseases (e.g mumps, measles)
- Ototoxic drugs (e.g quinine, solvents)
- Trauma
- Aging
- Etc…
What is Central Auditory Processing Disorder?
Problems with auditory localization (binaural fusion), auditory discrimination, pattern recognition, temporal ordering, temporal masking, etc…
What is Equilibrioception?
The capacity to sense the position of various parts of the body and use that information as feedback in motor control processes that dynamically modify the position of body parts to maintain posture and antigravity stance
Balance is generated and maintained in the Vestibular System!!
What are 3 Fluid-filled semicircular canals attached to each cochlea code rotational acceleration of the head?
- Anterior SCC
- Posterios SCC
- Lateral SCC
What is Anterior SCC?
Codes for nodding movements of the head, called “pitch”
What is Posterior SCC?
Codes for tilting yu head towards your shoulder, called “roll”
What is Lateral SCC?
Codes for head movements while looking from side to side, called “yaw”
What are the 2 Otolith Organs?
Utricle and Saccule
What are the 2 Otolith Organs most Sensitive to?
Utricle: Mosts sensitive to upright head tilt
Saccule: Most sensitive to horizontal head tilt
What are SA1 Mechanoreceptors?
Slowly adapting, small receptive fields and produce a sustained response to stimulation - Merkel Corpuscle end organ (mediate the perception of form and roughness)
What are SA2 Mechanoreceptors?
Slowly adapting, large receptive fields - Ruffini Corpuscle end organ (pressure, skin stretch)
What are RA1 Mechanoreceptors?
Rapidly adapting, small receptive fields, produce a transient response to stimulation - Meissner’s Corpuscles end organ (light touch, changes in texture, slow vibrations)
What are RA2 Mechanoreceptors?
Rapidly adapting, large receptive fields, produce transient response to stimulation - Pacinian Corpuscles (deep pressure, fast vibrations)
What are Thermoreceptors?
Free nerve endings in the dermis - detect heat and cold in the innocuous temperature range
What is the difference between Warm and Cold Receptors?
Warm Receptors: Increase AP rate when heated, decrease when cooled
Cold Receptors: Increase AP rate when cooled, decrease when heated
What are Nociceptors?
Free nerve endings in the epidermis - transmit pain signals via two different types of axons A fibers (Fast, unmyelinated) and C fibers (Slow, unmyelinated)
Whats the difference between Cold and Warm Receptors in Temperature?
Cold Receptors: Transduce by opening Na + channels in the cell membrane at temperatures between 10 degrees Celsius and 35 degrees Celsius
Warm Receptors: Warmed in the range of 38-50 degrees Celsius
What is Conscious Proprioception?
Mediated by the afferent dorsal column - medial lemniscus pathway of the spinal cord, protecting to the somatosensory cortex
What is Non-Conscious Proprioception?
Mediated by the afferent dorsal and ventral spinocerebellar tracts projecting to the cerebellum (e.g the righting reflex - a reflective head movement so the eyes are parallel to the horizon)
What is Sensory Discriminative?
Perception of pain intensity, location, quality and duration
What is Affective Motivational?
Unpleasantness and urge to escape the unpleasantness
What is Cognitive-Evaluative?
Appraisal, cultural values, distraction, and hypnotic suggestion
What is Pain?
An unpleasant sensory and emotional experience associated with or resembling that associated with actual, or potential tissue damage
What is Nociceptive Pain?
Pain caused by stimulation of nociceptors, classified according to the mode of noxious stimulation. The most common categories are thermal (e.g hot and cold), mechanical (e.g crushing, tearing, shearing, etc..), and chemical (e.g iodine in a cut or chemicals released during inflammation)
What is Neuropathic Pain?
Pain caused by damage or disease affecting any part of the somatosensory system
What is Nociplastic Pain?
Pain characterized by changed nociception but without evidence of real or threatened tissue damage, or without disease or damage in the somatosensory system
Psychogenic: Pain caused, increased or prolonged by mental, emotional or behavioral factors
What is Chronic Pain?
Pain that extends beyond the expected period of healing typically persists for 6 months
What is Acute Pain?
Usually transitory (acute) lasting until the cause (e.g noxious stimulus) is removed or the underlying damage or pathology has healed that typically persists for 30 days
What is Allodynia?
Pain experienced in response to a normally painless stimulus. Classified by the type of stimulus that elicits it:
- Dymaci
- Mechanical
- Punctate
- Static
What is the McGill Pain Index?
A measurement tool for multi-dimensional pain assessment of chronic pain
How do you rate Acute Pain?
A 10-point scale where 0 is no pain and 10 is the worst pain the patient has ever experienced
What is Cross Modality Matching?
Having the patient match the intensity of the pain they experience to the brightness of a light, the loudness of a tone, or the force of their grip
What taste do G-protein-coupled Chemoreceptors (GPCRs) give?
Transduce chemicals associated with sweet, bitter, and umami
What taste do Ion Channels give?
Mediate salty and sour tastes
