Stimulus changed into electrical signal is
transduction
List some different types of stimuli
mechanical, chemical, temperature, and electromagnetic
What 4 attributes of sense are there?
Modality, location, intensity, and timing
What two sytems of nerve fiber classification are there?
Erlanger’s and LLoyd’s
Differentiate the two classification systems of nerve fibers
Erlanger’s is A, B, and C
LLoyd’s is I, II, II, IV
What are the parameters of speed of conduction?
fiber diameter and myelination
What type of nerves Erlanger’s system used for?
motor nerves and skin afferents
What type of nerves is LLoyd’s used for?
afferents from receptors in muscle and spinal joints
Describe slow adaptation
it provides continuous information
Describe fast adaptation
It reacts strongly when a change is taking place
What are the most heavily sensory innervated spinal joints?
the cervicals
Describe type I mechanorecptors
they are in the outer layers of the joint capsule
they have a low threshold
they are slow adapting
have tonic effects on lower motor neuron pools
fire at a degree proportional to joint movement
Describe type II mechanorecptors
they are in the deepest layer of the joint capsule
they have a low threshold
they rapidly adapt
not activity in immobilized joints
monitors joint movements
phasic effecys on lower motor neurons pools
Describe type III mechanoreceptor
found in spinal joints
slow adaptation
high threshold
joint version of a GTO
Describe type IV mechanoreceptors
theyre nociceptors
high threshold
inactive in normal joint
activates with joint narrowing, incresaed capsular pressure, and chemical irritation
What is tactile information?
the ability to recognize objects in the hand based on touch alone
What is stereognosis?
the ability to perceive through touch
What system does sterognosis test?
the dorsal column-medial leminiscal system
Besides the ability to perceive what else does sterognosis test?
the cognitive processes in the brain where integration occurs
What categories of sensory modalities are there?
pressure, cold, warm, and nociceptors
Wetness is the perception of
pressure and temperature receptors being stimulated
Ticklishness is the perception of
gentle stimulation of pressure receptors
Itching is the perception of
gentle stimulation of nicceptors
What is used for detection of microtexture?
pacinian corpuscles
Depth of indentation and change in curvature of skin surface are encoded by discharges rates of
Slow adapting afferent fibers
Velocity and rate of change in skin surface curvature are encoded by discharge rates of
both slow adapting and rapidly adapting afferent fibers
What are the rapidly adapting cutaneous mechanoreceptors?
Meissner’s corpuscles, hair follie recptors, and pacinian corpuscles
Where are meissner’s corpuscles found?
in glabrous skin (non-hairy)
Where in glabrous skin are meissner’s heavily concentrated?
in fingertips
What do meissner’s detect in the fingertips?
singals edges, and registers sideways shearing of skin
What are the slow adapting cutaneous mechanoreceptors?
merkel’s discs and ruffini end organs
What do merkel’s disc’s sense?
curvature of an object’s surface
What activates ruffini end organs?
stretching of the skin
What are the superficial receptors of the skin?
meissner’s and merkel’s
What the deep receptors of the skin?
pacinian’s and ruffini’s