What are sensory receptors?
Receptors define the sensitivity range of the senses
What is an adequate stimulus?
Each receptor is specialized to respond to a specific type of stimulus
What is a receptor potential?
The stimulus being TRANSDUCED into an electrical signal
What is a exteroreceptor?
CLose to the body surface and specialized
(anything to do with the exterior environment
What are proprioceptors?
Sensory information about body position
(are you lying down or sitting? is your elbow bent?)
What are interoreceptors?
Everything to do with the internal body
(PH, oxygenation levels, blood pressure)
What are the 3 somatosensory receptors?
What are nociceptors responsible for?
Sense noxious and painful stimuli.
Detects noxious sensory information elicited by tissue injury (you know youre hurt, but you dont feel the pain yet)
And then pain (evoking nerve endings)
What are thermoreceptors responsible for?
Responsive changes in temperature within or outside of the body
what are Mechanoreceptors responsible for?
Changes in skin
What does it mean by rate of adaptation?
When the receptors responding to an external stimuli the rate of pulses declines and returns to a resting level. Thus, the cells DO NOT provide info about static stimuli.
What are free nerve endings responsible for? and what are their characteristics?
Long dendrites that are unmyelinated on the ends. (superficial layers of skin) (cornea of eyes, muscles tendons, ligaments, teeth)
- Responsive to touch and light pressure, and temperature
- therefore, Touch, pressure, temperature, pain = variably adapting
What are merkels discs responsible for? and what are their characteristics?
- superficial areas and head looks like a golf club
- extremely sensitive to local skin curvature and vibration
- slow rate of adaption
- all over the skin (generalized mechanoreceptor)
What are meissner's corpuscles responsible for? and what are their characteristics?
Superficial area and head looks like mitochondria(flattened cells)
- found in glabrous skin, palms and sole of feet, mouth, lips, genitals
-known in primates
recognizes skin stretch (not pressure) and vibrations
- moderate rate of adaption
What are pacinian corpuscles responsible for? and what are their characteristics?
deeper parts of dermis and the heads look like onions cut in half
- free nerve endings in highly layered structure therefore very sensitive for detecting surface roughness and small vibrations and deformations
-very rapid rate of adaptation
- found in small numbers because receptive fields are massive
What are ruffini endings responsible for? and what are their characteristics?
Found in deep layers of the dermis
- directional skin stretch (pulling of skin in one direction)
Slow adaption rate
- modifying joint positions, enables you to hold onto an object
What are muscle spindles responsible for? and what are their characteristics?
-Specialized free nerve ending receptors localized in muscle
- detects muscle contraction and stretch
- muscle stretch and relaxation of muscles
What are golgi tendon organs responsible for? and what are their characteristics?
-Embedded in tendons
- detects stretch of the individual tendon fibers (contraction to extension)
- muscle stretch within tendons