Lecture 7 Flashcards
what is stimulated by mechanical desplacement of tissue
mechanoreceptive somatic senses
what detects heat and cold
thermoreceptive somatic senses
what is activated by any factor that damages the tissue
pain somatic senses
sensations from the surface of the body
exteroceptive sensations
what has to do with the physical state of the body including position sensations, tendon and muscle sensations, pressure sense from the bottom of the feet, and even sense of equilibrium
proprioceptive sensations
sensation from those of the internal organs of the body
visceral sensations
sensations that come from deep tissues such as fascia, muscle, and bone. mainly include deep pressure, pain, and vibration.
deep sensations
what results from the stimulation of touch receptors in the skin or tissues immediately beneath the skin
touch sensation
what results from deformation of deeper tissues
pressure sensations
what results from rapidly repetitive sensory signals, however, some of the same receptors for touch and pressure are used
vibration sensations
types of tactile receptors
glaborous skin
hairy skin
what is glaborous skin
hairless skin
superficial
detect touch and pressure on glaborous skin
free nerve endings
superficial
tapping and low frequency vibration in glabrous skin
meissner’s corpuscles
superficial
touch or well localized pressure on glabrous skin
expanded tip receptor
deep
poorly localized touch and pressure (glaborous)
ruffini’s endings
deep
vibration (glaborous)
pacinian corpuscles
superficial
vibration (glaborous)
krause’s corpuscles
superficial
touch and pressure (hairy skin)
free nerve endings
superficial
touch or well localized pressure (hairy skin)
expanded tip receptors
deep
vibration (hairy skin)
pacinian corpuscles
superficial
light touch and low frequency vibration (hairy skin)
hair follicle endings
order of receptors from closest to skin to deeper
free nerve endings
meissner corpuscle
merkel cell
ruffini
pacinian corpuscle
a resting membrane potential and areas is ______, this sents action potential, and it is scent down the line toward the brain.
deformed
two possibilities of transmission of intensity by receptors
spatial summation
temporal summation
what is spatial summation
signal strength is determined by the number of fibers stimulated, and the area that the stimulus overs
what is temporal summation?
frequency of stimulation of a single fiber or group of fibers increases intensity of sensation
classification of peripheral nerve fibers is based on what 2 characteristics?
degree of myelination
conduction velocity
what are the 2 classifications of peripheral nerve fibers
motor fibers - I, II, III, IV
- (away from brain)
cutaneous fibers - Aα (alpha), Aβ (Beta), Aδ (lowercase Delta), C
- (toward brain)
afferent nerve fibers are
toward the brain
Aα and Aβ
- myelination?
- Conduction velocity?
- modality?
heavily myelinated
very fast (30-120 m/sec)
mechanoreception cutaneous, muscle
Aδ
- myelination?
- Conduction velocity?
- modality?
finely myelinated
fast (5-15 m/sec)
mechanoreception pain, temperature
C
- myelination?
- Conduction velocity?
- modality?
unmyelinated
slow (0.2-2 m/sec)
Pain, Temperature
Pain can be elicited by _______, ______, and _____ pain stimuli
mechanical
thermal
chemical
_______ stimuli detects extremes of temperature-freezing cold or burning hot above ___ degrees C
thermal
45 degrees C
______ stimuli involves intense tissue damage causing release fo chemicals that enhance the sensitivity of pain sensing free nerve endings.
chemical
an increase in the sensitivity of pain receptors is called ______
hyperalgesia
pain is detected/transmitted through _____
nociceptors
what are nociceptors
free nerve endings
responds to potentially damaging stimuli
what prevents the individual from “forgetting” the potential tissue damage that is occuring
diminish perception
types of nociceptors
C-polymodal nociceptors
A-delta nociceptors
Silent or mechanically insensitive nociceptors
C-polymodal nociceptors
unmyelinated
CV=0.5-2 m/s
types of stimuli that elicit a response for c-polymodal nociceptors
noxious mechanical
noxious thermal (above 45 degrees C)
noxious chemical