Week 9 Flashcards
What do our skins and touch sensations do?
- Protect inner organ systems
- Maintain homeostasis
- Provide strong social feedback
- Enable planned motion
- Detect objects and textures
The ability to sense the ** position** of the body and limbs.
Proprioception
The ability to sense ** movement ** of the body and limb.
Kinethesis
Perception of touch and pain from stimulation of the skin.
Cutaneous senses
Proprioception
Our (static) perception of our bodies, caused by feedback rom the skin, muscles, and joints.
Kinethesis
Tracking our body as it moves
- information is sent to the spinal cord and brain from Corgi tendon organs (monitor tension) and muscle spindles (monitor stretch and speed). These are proprioceptors.
- motor signals return to the muscle to execute both planned and automatic movements.
Mechanoreceptors
Provide detail about items we touch and hold.
The receptors that establish our ** cutaneous receptive fields ** include:
- Merkel receptors
- Meissen corpuscles
- Ruffini cylinders
- Pacinian corpuses
Merkel receptors
Fire continuously while stimulus is present.
Slow adapting - DETAIL
Have small cutaneous and high acuity. Located close to surface of skin.
Meissen corpuscles
Fires only when a stimulus is first applied and when it is removed.
Rapid Adapting - responsible fro controlling HANDGRIP.
Have small cutaneous and high acuity. Located close to surface of skin.
Ruffini cylinders
Fires continuously to stimulation
Slow adapting - associated with STRETCHING of the skin around objects and gross movements.
Larger cutaneous receptive fields and low acuity. Located deeper in the skin.
Pacinian corpuscles
Fires only when a stimulus is first applied and when it is removed.
Rapid Adapting - associated with sensing FAST VIBRATIONS and FINE TEXTURE.
Larger cutaneous receptive fields and low acuity. Located deeper in the skin.
SA
Slow Adapting
RA
Rapid Adapting
Which mechanoreceptors seems most useful for kinethesis?
A. Golgi tendon organ
B. Merkel
C. Meissner corpuscles
D. Ruffini cylinders
E. Pacinian corpuscles
D
Tactile Acuity
Sensitivity to details on the skin
Two-point threshold
Minimum separation needed between two points to perceive them as two points.
Grating acuity
Place a grooved stimulus on the skin and the participants to indicate the orientation of the grating.
Raised pattern indentification
Using letters or simple shapes to determine the smallest size that can be identified
Which mechanoreceptors do you expect to have the greatest acuity in the somatosensory system?
A. Merkel
B. Meissner corpuscles
C. Ruffini cylinders
D. Pacinian corpuscles
A
What does the high density of Merkel disk receptors in the fingerprints (glamorous skin) mean?
That its sensitive to small differences in the grating space.
What does the firing of the Merkel disk reflect?
The pattern in the grooves on a grating acuity test
Pacinian does not
Cortical Magnification
Strong correlation between areas of the hand and tactile acuity.
Finger tip > Base of finger > Palm
The Pacinian corpuscle CP is primarily responsible for
Sensing vibration