Neurophys I Flashcards
(21 cards)
Labeled line principle
Gives sensory modality telling the “what”
Define Lateral inhibition
A way to enhance boundary contrasts to improve two point discrimination.
What is the frequency code?
Signal strength increase by frequency of nerve impulses.
What s the population code?
Increasing the number of fibers that are activated to increase the strength of a signal.
Merkel cels, Ruffini end organs, and Baroreceptors are all part of what adaptation class?
Slowly adapting also known as tonic.
Pacinian corpuscles, and meissers corpuscles are all known as what class of adapting cells?
Rapidly adapting aka phasic.
Aalpha Type I nerve fibers have what function?
These are the axons to:
motor neuron muscles
spindle primary endings (1a) and
Golgi tendon organ afferent.
A-Beta type II nerve fibers have what function?
Muscle spindle secondary endings
Axons of cutaneous mechanoreceptors.
“Touch receptors”
A-Gamma nerve fibers have what function?
Axons of gamma motor neuron to muscle spindle fibers.
A-Delta (type III) nerve fibers have what function?
Fast Pain information Some temp (Group III)
B type nerve fibers have what function?
Sympathetic preganglionic axons.
C type IV fibers have what function?
UNMYELINATED Slow pain Some temperature and Sympathetic postganglionic axons.
which cell type is non-adapting?
Nociceptors!
Which receptors are involved in proprioception?
Joint receptors
Muscle spindle and golgi tendon organs
Skin tactile receptors.
What information is carried by the dorsal column?
Temperature Vibration Fine touch Proprioception Visceral pain
Where does the dorsal column cross the midline?
In the descussation of the medial lemniscus in the brainstem.
What deficits are seen with lesion to dorsal columns?
Tactile discrimination loss Graphesthesia Stereognosis Vibratory sence Proprioception
What sort of information is carried by the Anterolateral spinal cord pathways?
Nociception and temperature
Some tactile info
(Lesions of dorsal columns will not eliminate all tactile sensation)
Where does the anterolateral spinal cord pathway cross?
In the spinal cord
What deficits are seen in the enterolateral spinal cord pathway is damaged?
Loss of pain sense
Loss of thermal sense
Diminished tactile sense.
Where is the somatosensory cortex located?
Parietal lobe.
Foot is always in medial cortex!!!
