Receptors and Reflexes Flashcards
what is the definition fo a receptor
any structure specialized to detect a stimulus
if a stimulus is strong enough it will create a __ on the __
postsynaptic potential, sensory neuron
it is an __ if you become aware of the stimulus
EPSP
an ___ is any receptor monitoring something outside the body and are found within__
exteroreceptor, the mouth, lungs, and gut because they lead to the outside.
an ___ is only looking at stimuli that is occurring inside the body.
interoreceptor
anytime a receptor undergoes __ it can alter its sensitivity to that stimulus.
adaptation
___ are fast fast adapting while __ are slow adapting but generate signals more steadily.
phasic receptors, tonic receptors
a __ is a quick and involuntary response to a stimulus
reflex
___ reflexes are reflexes we are born with
somatic
a __ involves a stimulus or sensory neuron that carries it to gray matter and integrates sometimes with an interneuron then to a motor neuron leading to an effector organ.
reflex arc
__contain vesicles containing neurotransmitters.
varicosities
Any reflex arc that lacks an __ is considered a monosynaptic reflex arc.
interneuron
Reflexes that have one or more ___ are polysynaptic reflex arc.
interneurons
what is the stimulus for a stretch reflex
stretch
a muscle spindle is composed of how many muscle fibers
3-10
a muscle spindle is the location of __
receptors
do intramural fibers cause movement of the joints when they contract?
no, but they can change the length of the muscle
In order for muscle spindle to be sensitive it needs to ____. This is when reflex arcs are being put into use.
adjust in length as muscles are being stretched
the ___sensory is the only one that can monitor the rate of stretch.
primary
do both primary and secondary sensory monitor degree?
yes
does alpha or gamma cause contraction?
alpha
the __ reflex causes contraction and the ___causes relaxation of the antagonist.
monosynaptic, polysynaptic
define reciprocal activation
activation of the antagonistic muscles
a __ is any structure specialized to detect a stimulus
receptor
a receptor is classified as part of the ___ system
peripheral nervous
most receptors are the receptive endings of __
unipolar, first-order neurons.
the receptors are found on __ and __ neurons
somatic sensory and visceral sensory
The stimulus will cause a ___ on the sensory neuron.
postsynaptic potential
The intensity of a stimulus is encoded by ___
the sensory neuron(s) transmitting the sense to the CNS
A weak stimulus only stimulates __
neurons with the greatest sensitivity.
As stimulus intensity rises___ will be stimulated, the frequency of nerve impulses ___, and the ___of nerve fibers will take place.
less sensitive neurons, increases, recruitment
The __ is the particular region monitored by a single sensory neuron, large ___ is often associated with less acute two-point discrimination.
receptive field,
The __ receptor field is often associated with more acute two-point discrimination.
smaller
Sensory receptors are capable of transmitting what four kinds of information?
modality (the kind of stimulus), location, intensity, and duration
Mechanoreceptors respond to
mechanical force; touch, vibration, pressure, stretch.
Thermoreceptors respond to changes in
temperature both internal and external.
Photoreceptors respond to
light
Chemoreceptors respond to
chemicals in the air we breathe, our food, our blood and intestinal fluids.
Osmoreceptors respond to changes in
blood osmolarity.
Baroreceptors respond to changes in
blood pressure
Nociceptors respond to
stimuli which would result in pain.
Exteroreceptors detect stimuli
external to the body.
Interoceptors detect stimuli
located inside the internal viscera and blood vessels.
Proprioceptors detect changes in
position and body movement; skeletal muscles, ligaments, tendons, joints and connective tissue covering bones and muscles.
Duration of a stimulus is encoded by
changes in firing frequency with the passage of time.
Most receptors can undergo
sensory adaption
Adaptation is
a change in sensitivity in the presence of a constant stimulus.
If the stimulus is prolonged, the firing of the neuron gets__over time, and we become ___ aware of the stimulus.
slower, less
__receptors are fast adapting and transmit a burst of impulses at the onset of stimulation then cease firing despite continuation of the stimulus
phasic
__ receptors include smell, hair, movement, and pressure
phasic
__receptors adapt more slowly and generate signals more steadily.
Tonic
__ are the most slowly adapting tonic receptors.
Proprioceptors
Sensory receptors are classified by receptor __
structure.`
___ or free nerve endings are receptive endings of unipolar sensory neurons which are often associated with epithelial tissues.
nonencapsulated
__nerve endings are one or more fiber terminals of sensory neurons enclosed in a connective tissue capsule
encapsulated
Receptors of special senses are usually associated with a __
specialized sensory organ such as the cochlea of the ear, retina of the eye, etc.
are tactile corpuscles inter, proprio, or exteroreceptors
exteroreceptors
what kind of modality is a tactile corpuscle
mechanoreceptor
are lamellar corpuscles inter, proprio, or exteroreceptors
all three
are tactile corpuscles rapidly or slowly adapting
rapidly
what modality are lamellar corpuscles
mechanoreceptors
are lamellar corpuscles rapid or slow adapting
rapid
are bulbous corpuscles inter, proprio, or exteroreceptors
extra and proprioreceptors
are muscle spindles inter, proprio, or exteroreceptors
proprioreceptors
are tendon organs inter, proprio, or exteroreceptors
proprioreceptors
are joint kinesthetic receptors inter, proprio, or exteroreceptors
proprioreceptors
are free nerve endings of sensory neurons inter, proprio, or exteroreceptors
all three
are modified free nerve endings or tactile discs inter, proprio, or exteroreceptors
exteroreceptors
are hair follicle receptors inter, proprio, or exteroreceptors
exterorecptors
what modality are bulbous corpuscles
mechanoreceptors
what modality are muscle spindles
mechanoreceptors
what modality are tendon organs
mechanoreceptors
what modality are joint kinesthetic receptors
mechano and nociceptors
what modality are free nerve endings of sensory neurons
thermoreceptors, chemoreceptors, mechanoreceptors, and nociceptors
what modality are tactile discs
mechanoreceptors
what modality are hard follicle receptors
mechanoreceptors
are bulbous corpuscles rapid or slow adapting
rapid
are tactile discs rapid or slow adapting
slow
are hair follicle receptors rapid or slow adapting
rapid
reflexes require stimulation of __
specific receptors
reflexes are quick and involuntary meaning they do not require the involvement of the ___and they are stereotypes meaning ___
primary motor cortex , they occur the same way every time.
__ reflexes are those that are learned.
Conditioned
__are unlearned reflexes which affect skeletal muscles
Somatic reflexes
___ are unlearned reflexes of the cardiac muscle, smooth muscles, and glands.
Autonomic reflexes
___ are reflexes which lack an interneuron in the spinal cord gray matters.
Monosynaptic reflex arc
___ synapse directly on efferent motor neurons and are very prompt responses.
Afferent neurons
___ are reflex arcs that travel over many synapses and often involve one or more interneurons and allow for more delayed reflex responses.
Polysynaptic reflex arc
what is the purpose of stretch reflexes
to maintain equilibrium and body posture by “setting” the appropriate length of a muscle
what is a good example of a stretch reflex
tendon reflex, receptor type is a muscle spindle, and a stimulus is stretch activates the sensory neurons of the muscle spindles.
The length of skeletal muscles, ligaments and tendons are monitored by specialized receptors called __
proprioceptors.
___wrap around the muscle spindle center
Primary sensory fibers
primary sensory fibers monitor both __ and __ of stretch and are __adapting
rate, degree, fast
___wrap around the poles of the muscle fibers
Secondary sensory fibers
Secondary sensory fibers are __adapting, and monitor what of the muscle fibers
non, length
The incoming sensory fibers form both __ and __-synapses in the spinal cord.
polysynaptic, monosynaptic
__ is when the somatic sensory neurons activate somatic motor neurons which innervate the stretch muscle.
Monosynaptic reflex
__ induce contraction in extrafusal muscle fibers of stretched muscle.
Alpha motor neurons
___ adjust sensitivity of muscle spindle fibers.
Gamma motor neurons
The___ reflex is when somatic sensory neurons also activate interneurons in the spinal cord gray matter.
polysynaptic
what happens after sensory neurons activate interneurons in the spinal cord gray matter during p a polysynaptic reflex?
The activated interneurons then inhibit somatic motor neurons which innervate the antagonistic muscles which results in relaxation or reciprocal inhibition of antagonistic muscles.
During coactivation of alpha and gamma the muscles spindle of an un-stretched muscle will send __frequency nerve impulses to the __.
low, CNS
whenever the muscle spindle is stretched its associated sensory neurons transmit nerve impulses at a __ frequency to the spinal cord.
higher
Sensation of stretch can occur under what two conditions?
when external force lengthens the entire muscle and when gamma motor neurons stimulate the intrafusal fibers to contract causing the internal spindle to stretch.
During voluntary muscle contraction, alpha motor neurons stimulate__fibers, causing the whole muscle to ___.
extrafusal, shorten
Tendon organs are __ located in tendons they monitor tension not stretch.
proprioceptors
what is the purpose of Tendon organs
they respond to excessive tension to prevent muscles and tendons from tearing when they are subjected to possibly damaging stretching force.
what is the function of Flexor or withdrawal reflex
painful or threatening stimulus initiates the withdrawal of the threatened body part.
what is the stimulus of Flexor or withdrawal reflex
pain or threat to the limbs
what is the response of Flexor or withdrawal reflex
Sensory afferents form polysynaptic synapses in the spinal cord, activation of ipsilateral flexor muscles to withdraw the threatened limb. Reciprocal inhibition of extensor muscles to allow flexion.
some interneurons undergo ___ this results in the contralateral reciprocal activation of extensor muscles and the contralateral inhibition of flexor muscles during flexor or withdrawal reflex
gray matter decussation,
Superficial reflexes are induced by__
gentle cutaneous sensation.
__ is stroking the lateral portion of the sole of the foot stimulates plantar flexion
Plantar reflex
plantar reflex tests the __ tracts from L4-S2,
corticospinal
what reflex is tested by stroking the abdomen results in contraction of abdominal muscles in order to maintain integrity of the spinal column.
te abdominal reflex
the abdominal reflex test the function of
ventral rami T8-T12 and absences can indicate lesions in the corticospinal tracts.
