2- Receptors Flashcards
Define receptors ?
specialized structures present at peripheral end of AFFERENT neuron & sensitve to & can detect change in environment
Function of receptor ?
Respond to stimuli & transform them to electrical energy
physiological classification (5) ?
1) mechanoreceptors
2) thermoreceptors
3) nociceptors
4) electromagnetic receptors
5) chemoreceptors
Histological classification (2) ?
Free nerve ending
Expanding nerve ending
mechanoreceptors ex (5)?
- skin tactile (dermis & epidermis )
- deep tissue (muscle & tendon)
- hearing
- arterial pressure
- vestibular receptors (equilibrium)
Rods & Cones are example of which type of receptor ?
electromagnetic
chemoreceptors (4) examples ?
- taste
- smell
- arterial oxygen
- osmolality
free nerve ending for ?
Pain
Temperature
Crude touch
Markels disc: ———- adapting & ———- receptive field ?
Slow , small
Meissner courpuscle : —- adapting & —— receptive field ?
Rapid , small
pacininan corpuscle: —— adapting & —— receptive field ?
Rapid , large
Ruffinis ending : —— adapting & —— receptive feild ?
Slow , large
excitability of receptor by Mechanisms of ?
Receptor Potentials
Receptor Potentials excited by (4) ?
1) Mechanical deformation
(2) Application of a chemical
(3) Change of the temperature
(4) Electromagnetic radiation
define adequate stimulus?
Each type of the receptors is sensitive to a specific stimulus
Response of the receptors to non specific stimuli
Ex: hitting the eyes strongly causes flashes of light
This is know as ?
Muler’s law of specific nerve energy.
frequency of action potential in the nerve directly proportional to the logarithm of rate of increase in intensity is known as ?
Weber-fechner law (compression function)
Weber-fechner law (compression function) allows
————- range detection of intensity of stimuli
in spite of the———————-?
Wide range , limited number of action potential.
Define adaptation ?
Decrease response in spite of constant (stimulation)
MOA of adaptation in mechanoreceptors ?
due to
1- the Lamellae ( surrounds nerve ending)
2- Adaptation by inactivation of Na+ channels in the nerve membrane.
3- Dec sensitivity 1st ranvier node
4- dissipation of energy to surrounding tissue.
Ex of rapid adapting receptors ?
Skin
Posture (in muscle & tendons )
Ex of slow (tonic) adapting receptors?
Mechanoreceptors
Pain receptors
- macula in the vestibular apparatus.
-Pain - baroreceptors
- chemoreceptors of the carotid and aortic bodies
Ex of moderate adapting receptors?
Temperature receptors
Smell receptors
Taste receptors
Pressure receptors
