MechanoRs

Question 1

Two Rs Near Epidermal Surface

Answer 1

Meissner’s corpuscle and Merkel cells

Question 2

Smallest Receptive Field

Answer 2

Merkel Cells, used to read braille

Question 3

Two Rapidly Adapting and Two Slow Adapting (fire throughout) Rs

Answer 3

Meissner’s and Pacinians vs. Merkel cells and Ruffini endings

Question 4

2 Factors of Stimulus Intensity

Answer 4

AP freq and population of neurons firing

Question 5

Sensitivity to Electrical Stimulation vs. Local Anesthetic Blocking

Answer 5

Proprio (largest), then touch, then As and C for pain vs. opposite for LA

Question 6

Syphilis

Answer 6

Degeneration of primary sensory afferents, so different than lesion

Question 7

Receptive Fields of Principal Cells in Dorsal Column Nucleus

Answer 7

Excited DRG neurons project to stimulate DCN Principal Cells, but DRG neurons just surrounding excite inhibitory interneurons in DCN that inhibit both excited DRG and P cell to sharpen receptive field and enhance 2 point descrimination. Descending inputs also activate these interneurons as additional checks

Question 8

Cortical Somatic Sensory Area S1

Answer 8

Receive thalamic input from contra for proprio, fine grain discrim, texture, stereognosis

Question 9

Cortical Somatic Sensory Area S2

Answer 9

Receive ipsi and contra modalities of S1 and movement