Cogs 101a- Lectures 13-16 2 Flashcards
** What are the three components to the somatosensory system?
Proprioception, Kinesthesis, Cutaneous senses
** What is proprioception?
It is the ability to sense the POSITION of the body and the limbs. (is our perception of our bodies caused by feedback from the skin, muscles and joints.)
** What is kinesthesis?
It is the ability to sense MOVEMENT in the body and limbs.(tracking of our body as it is in motion)
**What is cutaneous senses?
It is the perception of touch and pain from stimulation of the skin.
Who is Ian Waterman and what is unique about him?
- No sensory input from the PROPRIOCEPTORS in his muscles and joints.
- No information from the MECHANORECEPTORS in his skin that would respond to physical objects in his environment.
How did Ian Waterman cope with his condition?
able to compensate by using his VISUAL INFORMATION to update his brain on his body’s positon. – This shows underlying multimodal nature or proprioception
What is proprioceptors?
When information is sent to the spinal cord and brain from the golgi tendon organ and muscle spindles.
What are the 4 mechanoreceptors listed in lecture?
Merkel receptors, meissner corpuscles, ruffini cylinders and pacinian corpuscles
What does the Merkle receptor in charge of?
Fine detail
What does the meissner corpuscles in charge of?
Handgrip
What is the ruffini cylinders in charge of?
stretching
What is the pacinian corpuscles in charge of?
rapid vibration, fine texture.
What are the two types of mechanoreceptors located CLOSE to the surface of the skin? What do they have in common?
Merkle and Meissner corpuscle. They both have SMALL response fields and HIGH acuity.
How does the merkle receptor fire?
It fires continuously while stimulus is present.
How does the meissner corpus receptor fire?
Fires only when a stimulus is first applied and when it is removed.
What are the two types of mechanoreceptors DEEPER in the skin and what do they have in common?
Ruffini cyliners and pacinian corpuscle. Both have a LARGE receptive field with LOW acuity
How does the ruffini cylinders fire?
Fires continuously
How does the pacinian corpuscle fire?
fires only when a stimulus is first applied and when it is removed.
What is the duplex theory of texture proposed by David Katz?
That two receptors acting together may be responsible for this process (Merkle and pacinian corpuscle) (spatial cues and temporal cues)
What are the two major pathways in the spinal cord?
Spinothamalic pathway and Medial lemniscal pathway
What is the spinothalamic pathway?
consist of small fibers that carry temperature and pain information.
What is the medial lemniscal pathway?
consist of large fibers that carry proprioceptive and touch information.
What do both pathways pass through?
The ventral posterolateral nucleus in the thalamus.
How are signals pass through(skin to cortex)
signals travel from the thalamus to somatosenory receiving area (S1) and the secondary receiving area (S2) in the parietal lobe.