Somatosensation Flashcards
What do the pacinian corpuscles sense?
Vibration and deep pressure
What is the function of meissner’s corpuscles?
- They sense 2 point discrimination or fine touch
- allow specific, precise, location of stimuli
What do merkel’s cells do?
They detect crude touch
What do the hair follicle receptors do?
they detect light touch
What do the ruffini corpuscles do?
they detect the stretching of the skin.
When are thermal receptors are inactive at which points?
above 122 degrees F (50 dg C) and below 41 degrees F (5 dg C)
What are the 4 types of nociceptors?
- mechanical- pinch of skin, median nerve compression.
- thermal hot
- thermal cold
- polymodal (activated by mechanical stimuli and chemicals released during inflammation)
Proprioceptors are located where?
-muscles
-tendons
-ligaments
joint capusle
What do muscle spindles sense?
detect the stretch in the muscle length
What is the function of the golgi tendon organ?
Senses the muscle and tendon tension.
What is somatosensation?
sensations experienced by the skin and subcutaneous tissue as well as by muscles, tendons, bones and joints
Touch receptors are
- receptors that contain specialized nerve endings
- when stimulated by touch, an action potential is created
- all touch receptors convert a mechanical stimulus into a nerve impulse
Where are pacinian corpuscles located?
- dermis
- subcutaneous tissue
- periosteum ligaments
- intramuscular connective tissue
- dorsal columns
Where are meissners corpuscles located?
- located in skin mostly on fingertips
- dorsal columns
Where are merkels cells located?
- fingertips
- lips
- external genitalia
- anterior spinothalamic
What are hair follicle receptors made from?
small nerve fibers that wrap around roots of hair
How do hair follicle receptors act?
they bend the hair which creates an action potential
where are hair follicle receptors found?
- all over hair skin
- anterior spinothalamic
Where are ruffini corpuscles found?
- near fold of skin at joints and beneath fingernails and toenails
- anterior spinothalamic
Where are thermal receptors located?
in subcutaneous tissue all over the body
Where are muscle spindles found?
- most skeletal muscle
- posture muscles
- extraocular muscles
- intrinsic muscles of the hand
Muscle spindles send info about
- if length is changing
- how quickly
Where is the golgi tendon organ located?
tendons of most skeletal muscle
Anterior spinothalamic sensations and destination
- pressure, texture, light touch, stretching of skin
- sensory cortex (contralateral side)
Lateral spinothalamic sensations and destination
- pain, temperature
- sensory cortex (contralateral side)
Dorsal columns sensations and destination
- vibration, 2 point discrimination, conscious proprioception
- sensory cortex (contralateral side)
Spinocerebellar sensation and destination
- unconscious proprioception
- cerebellum
C fibers
- small, unmyelinated
- slow, dull, aching
- long lasting
A delta fibers
- small myelinated
- quck but short
- sharp, stabbing, pricking
