Neurobiology Exam 2

Somatic Sensory Pathways on Modality

• Discriminative touch

• Pain and Temp

Brodmann’s Area

• 1-Cuatneous 

• 2-Cutanepous and Proprioceptive

• 3a-proprioceptive

•  3b-Cutaneous

Brodmann’s Areas- anterior to posterior

• 3a-propriocptive

• 3b-cutaneous

• 1-cutaneous

• 2-cutaneous and proprioceptive

How is stimuli interpreted? 

• quality 

• quantity, or strength, of stimuli

Quality

• what and where the stimulus is

• Determined by: type of receptor responding, location of central target on body

Quantity

• frequency of action potential

Types of Mechanosensory Discrimination 

• Two-point discrimination 

• Receptor Density 

• Receptive Fields

Two point Discrimination

method of measuring minimal distance needed to sense two different and simultaneous stimuli

How are receptor density and receptive field related?

Inversely

Stimulus Duration 

• size of receptor and frequency of AP can decline if the stimulus persists 

• Sensory Adaption

Example of Sensory Adaption

• phasic

• tonic

Phasic

Rapidly Adapting

Tonic 

Slowly Adapting