196.SWL is a 37-year-old woman with a suspected Schwanoma. The radi-
ology report reads as follows: “a soft tissue mass to the right of L1 at the level
of the L1-L2 neural foramen. The mass cannot be differentiated from the L1
nerve root and extends into the neural foramen such that it has a ‘dumbbell’
configuration with components lateral to the neural foramen, a waist in the
foramen itself, and a component within the spinal canal to the right of the
thecal sac.” The neurologist, Dr. Jane Motumbo, applies the base of a
vibrating 128 CPS tuning fork to the skin overlying SWL’s right and left
thighs and asks her to describe the sensation. She asks SWL to close her
eyes and then to tell her whether the tuning fork is vibrating or not. Vibra-
tion sense is impaired on the right side. Tests for pain and temperature
indicate impairment on the left side. Using the tuning fork, Dr. Motumbo
is primarily testing the function of which of the following sensory
receptors?
a. Ruffini endings
b. Pacinian corpuscle
c. Meissner corpuscle
d. Merkel corpuscle
e. Free nerve endings
Integumentary System 303