Unit 4 - Ascending Sensory Information Flashcards
What are the 5 ascending sensory tracts?
- Posterior column medial lemniscus pathway
- Spinothalamic tract (Anterolaeral Pathway)
- Posterior spinocerebellar tract
- Cuneocerebellar tract
- Anterior spinocerebellar tract
Which ascending tracts do we have conscious awareness of?
Posterior column medial lemniscus pathway and Spinothalamic tract
(anterolateral pathway)
What are the 3 types of nerve fibers that make up the sensory/motor tracts?
- Long, ascending fibers going to thalamus, cerebellum, or various brainstem nuclei
- Long, descending fibers going from cerebral cortex or various brainstem nuclei to spinal cord grey matter
- Short, propriospinal fibers interconnecting different spinal cord levels
Which fibers help coordinate flexor reflexes?
Short, propriospinal fibers interconnecting spinal cord levels
Fibers with similar connections travel ____ and form tracts in the spinal cord.
together
Where in the spinal cord can you find ascending tracts?
anterior funiculi, lateral funiculi, and posterior funiculi
Where in the spinal cord do you find descending tracts?
anterior and lateral funiculi
Where in the spinal cord do you find propriospinal fibers?
surrounding the grey matter
___ ___ detect mechanical, chemical, or thermal changes.
Somatosensory receptors
Are somatosensory receptor neurons pseudounipolar, bipolar, unipolar, or multipolar?
pseudounipolar, with their cell body in the dorsal root ganglion
What do Pacinian corpuscles receptors detect?
vibration
What to Meissner’s corpuscle receptors detect?
two point touch discrimination
What do Ruffini ending receptors detect?
touch
What do Merkel ending receptors detect?
two point touch, fine touch, texture
What do free nerve ending receptors detect?
pain, temperature, itch, touch
