Ch 47 (test 1) Flashcards
touch pressure and vibration are all associates with what kind of receptor
tactile–>mechanoreceptor
6 types of tactile receptors, where found, detect what kind of senses
1) Free n. endings-on skin, touch and pressure
2) Meissners corpuscle-fingertips-touch
3) Merkels disc-fingertips-touch
4) tactile hair-initial contact-hair end organ
5) Ruffinis endings-deep skin-continuous deep sensation
6) Pacinian corpuscles-super and deep skin-rapid compression (adapts quickly)
receptive field size and adaptation rate of meissners, pacinian, merkels disk, ruffinis ending
Meissners–Small/Rapid
Pacinian–Large/Rapid
Merkels–Small/Slow
Ruffinis–Large/Slow
most tactile receptors are what type of sensory fiber
type A beta
free nerve endings are what type of sensory fiber
A delta and C
what are the 2 sensory pathways to the CNS
- Dorsal column-Medial Lemniscal (DC-ML)
- Anterolateral
what senses use the anterolateral pathway
- pain
- thermal
- touch
- tickle
- sexual sensations
what senses use the DC-ML
- localized touch
- rapid transmission touch
- vibrations
- proprioception
- fine pressure
which fibers are smaller, those that use the DC-ML or Anterolateral pathway
anterolateral–small, unmyelinated
define pathway of DC-ML
- enter cord and ascend thru dorsal column
- synapse and decussates in medulla
- continues to thalamus via medial lemniscus
- synapse in thalamas, sent to SSA1
define pathway of anterolateral path
- synapses and decussates in cord
- ascends thru spinothalamic/anterolateral column to thalamus
- synapse in thalamus, sent to SSA1
what are the subregions of the dorsal column
fasciculus cuneatus
fasciculus gracilis
which subregion of the dorsal column is lateral/medial
lateral-fasciculus cuneatus
medial–fasciculus gracilis
the ____ subregion of the dorsal column gets sensory info from C1-T6
fasciculus cuneatus
the ____ subregion of the dorsal column gets sensory info from T7-down
fasciculus gracilis
the sensory signal enters in which region of the cerebral cortex cell bodies
section IV
which area of the SSA1 is known as Brodmans areas
5 and 7a
define lateral inhibition
blocks lateral spread of excitatory signals
muscle spindles determin what via proprioception
joint angulation
what sensors are used for extreme joint angulation and movements of tendons, ligaments, and deep tissues
- ruffinis
- golgi tendon apparatus
- pacinian
characteristics of the anterolateral pathway system
- -slower velocities (A delta and C)
- -poor degree of spatial localization (less lateral inhibition)
- -less accurate gradations of intensities
- -low ability to transmit rapid changing or repetitive signals
