Sensory Physiology intro Flashcards
What is SOMATIC SENSATION
Nervous mechanisms that collect sensory information from the body.
Types of SOMATIC SENSATION
mechanosensation thermosensation pain sensation (noiceosensation) extereosensation viscerosensation deep sensations from muscle,bone, or fascia
intereosensation
What are MODALITIES OF SENSATION
Each principal type of sensation is called a modality of sensation
nerve fibers can transmit various modalities
T/F
F. nerve fibers only transmit impulses
Specificity of nerve fibers for transmitting only one modality of sensation is called
“ labeled Line Principle”
SENSORY RECEPTORS first generate——- before——
receptor potential
action potential
What is signal transduction
converting stimulus to electrical signal
Types of Exteroceptors
And define them
teleoreceptors: receptors that respond to distant external stimuli
- contact receptor: require direct contact of the stimulus with the body.
What is Proprioception
Proprioception: transmit sensory information from muscles, tendons, and joints about the position of a body part, such as a limb in space.
Types of Proprioception
And define them
static position
-kinesthetic position
Is the the vestibular system considered a Proprioceptor?
If yes, why
If no, why
Yes.
the vestibular system in the ear relaying info on orientation,movement and balance
Mechanoreceptors detect ——-
Thermoreceptors detect———-
Nociceptors detects ————
Electromagnetic / Photoreceptors detect——
chemoreceptors detect ——-
mechanical deformation of receptors or tissues adjacent to the receptor
detects changes in temperature
detect damages occurring in the tissues which could be mechanical or chemical.
detect light on retina
detect taste in mouth and smell in nose, and stuff in blood
MECHANORECEPTORS may be encapsulated or non-encapsulated
T/F
T.
Examples of encapsulated and non-encapsulated Mechanoreceptors
Encap: pacinian,meissner,ruffinian
Non encap: free nerve endings,petrichial nerve,Merkel’s discs
Of the Mechanoreceptors, which are slow adapting and which are fast adapting
Slow: free nerve ending,Merkel’s,ruffinian
Fast:petrchial,meissner, pacinian
Of the Mechanoreceptors, state the fibers of each
A delta and C fibers = free nerve endings
The rest are A beta fibers
Presence of Schwann cells in free nerve endings
T/F
F.
Lack of myelin sheath in free nerve endings
T/F
T
Describe petrichial nerve endings
free nerve endings that wrap around the bases of hair follicles below its sebaceous gland
What stimulates petrichial nerve fibers
stimulated when hair is being bent
Location of free nerve endings Mechanoreceptors
present in dermis, epidermis, cornea, dental pulp, and mucous membrane of everywhere
Merkel’s discs are also called?
Tactile receptors
Describe Merkel’s discs
disc shaped peripheral nerve endings
Each disc-shaped terminal is associated with a specialized epithelial cell, the Merkel cell, located in the stratum basale of the epidermis.
Where do we have more of Merkel’s discs
Hairless or Hairy skin?
Hairless skin
Another name for hairless is ?
Glaborous
Location of Meissner’s corpuscles
present in the dermal papillae of glabrous skin of the lips, forearm, palm, and sole, and in the connective tissue papillae of the tongue
Contents of Meissner’s capsule
unmyelinated axon terminals,Schwann, lamellar flattened cells,
Capsule of meissner’s corpuscles are continuous with the endoneurium
T/F
T
Meissner’s corpuscles are especially sensitive to ——?
sensitive to two-point touch discrimination
Which Mechanoreceptor is of great importance to the visually impaired, permitting them to read Braille
Meissner’s corpuscles
Largest of the mechanoreceptors is ???
Pacinian corpuscles
Describe the Pacinian corpuscles
- resemble an onion in cross-section.
- modified fibroblasts form the layers (lamella)of the onions
Location of Pacinian corpuscles
dermis,hypodermis,external genitalia,ligaments,peritoneum, and even in the pancreas
Pacinian corpuscles respond to —- stimulus
pressure,vibratory, and tickling sensations
Location of Ruffini’s end organs.
the dermis, and the underlying hypodermis of hairy skin.
Describe Ruffini’s end organs. And say what they respond to
They intertwine around the core of collagen fibers, which is surrounded by a lamellated cellular capsule.
-respond to stretching of collagen fibers in the skin and ligaments and may provide proprioception info
Ruffini’s end organs can’t provide proprioception information
T/F
F. They can
Thermoreceptors:
Fast or slow adapting
slow adapting
Types of Thermoreceptors
cold receptors
warm receptors
temperature sensitive noiceceptors
temperature sensitive noiceceptors is sensitive to——-
extreme temperatures
Types of fibers found with cold receptors and warm receptors
cold receptors:Adelta
-warm receptors: C
Type of fibers associated with Nociceptors are?
type Aδ fibers and C fibers
Which are more common
Cold or heat receptors
cold thermoreceptors 3.5 times more common than heat receptors.
Nociceptors are sensitive to———
sensitive to noxious or painful stimuli.
Nociceptors are found in ——
found in the epidermis, dermis,muscle,joint capsule, cornea.
All noiceoceptors are sensitive to only one type of painful stimuli
T/F
F. -most noiceoceptors are sensitive to one type of painful stimuli but some can respond to two or more
Types of noiceoceptors and the fibers they are associated with and what stimulus they respond to
mechanosensitive noiceoceptors:Adelta;intense mechanical stimulation or injury to tissues;pinch with pliers
thermosensitive: Adelta;intense heat or cold
polymoidal: Cfibers; noxious stimuli that are mechanical,chemical or thermal in nature
Receptor potential is also called——
generator potential
Immediate effect of the stimulus on a receptor is to——-
is to change membrane potential of the receptor
Threshold of receptor potential is —-?
100mV
Relationship between intensity of receptor potential and frequency of action potential generated is???
Directly proportional.. Higher the rp rises above threshold,the higher the frequency of AP
Mechanism of receptor potential generation ???
Mechanical deformation by stretching the receptor membrane
- Chemical changes by opening the ion channel
- Change in temperature to alter the membrane permeability
RECEPTOR ADAPTATION is the ——- following continuous application of a stimulus
Decline in frequency of receptor firing
non-adapting fibers are also called
Rapid adapting fibers are also called
Tonic fibers
Phasic fibers
Example of non adapting receptors
pain receptors, baroreceptors and chemoreceptors
Examples of fast adapting receptors
Tactile receptors
Examples of slow adapting receptors
golgi tendon and muscle spindle and receptors of the macula in the vestibule apparatus
Functions of sensory nerves of Muscle spindles and Golgi tendon organs
detect sensory input from the skeletal muscle and transmit it to the spinal cord where it plays important roles that involve the cerebellum
Sensory input from Muscle spindles and Golgi tendon organs is related through which pathway to reach the cortex?
DCML pathway
Differences and similarities between nuclear bag fibers and nuclear chain fibers
D: bag detect onset of stretch with AAlpha group 1a fibers while chain detect stretch in progress with Aalpha group 1b fibers
S: they are both rapid adapting
hair cells on the organ of Corti is an example of — receptor
Mechanoreceptor
Sensory transduction is the process by which an——- activates a——- and is converted into——
environmental stimulus
receptor
electrical energy
Receptor potentials are graded.
T/F
T
The smaller the receptive field, the—— the sensation can be——-
more precisely
localized or identified
the higher the order of the CNS neuron, the——— the receptive field
more complex
Most rapidly of all mechanoreceptors is —-??
Pacinian corpuscles
Classify the following in terms of adaptation and hairy or hairless skin
Pacinian corpuscle Meissner corpuscle Hair follicles Ruffini corpuscle Merkel receptors Tactile discs
Subcutaneous Very rapidly Nonhairy skin Rapidly Hairy skin Rapidly Hairy skin Slowly Nonhairy skin Slowly Hairy skin Slowly
Tactile disc is like —— mechanoreceptor but is found in —— skin instead
Merkel’s disc
Hairy
At moderate temperature range e.g., at 36°C, ——thermo receptor is active
Both
warm receptors signal pain from extreme heat.
T/F
F. warm receptors do not signal pain from extreme heat
—— receptor signals pain from extreme heat.
Polymodal receptors
why do people describe the taste of chili peppers as “hot.”
Transduction of warm temperatures involves tran sient receptor potential (TRP) channels in the family of vanilloid receptors (i.e., TRPV). These channels are activated by compounds in the vanilloid class, which includes capsaicin, an ingredient in spicy foods
