13. The Peripheral Nervous System

Which of the following is TRUE regarding phasic receptors?

Thermoreceptors tend to be phasic receptors because they:

The large onion-shaped receptors that are found deep in the dermis and in subcutaneous tissue and that respond to deep pressure are

a. Epithelial tactile complexes

b. Lamellar corpuscles

c. Free nerve endings

d. Muscle spindles

Place the following sequence of events for the detection of somatic sensation in the proper order. Place a 1 by the first event, a 2 by the second event, and so on.     

a. ______The central process transmits the action potential to a second-order sensory neuron in the CNS.     

b. ______The action potential is transferred to the central process in the posterior root ganglion.     

c. ______The stimulus triggers an action potential.     

d. ______The signal is transferred to other CNS sensory neurons for eventual perception and interpretation.     

e. ______The action potential is propagated along the peripheral process of the neuron.

Jason presents for evaluation after a severe shoulder injury during which his entire brachial plexus suffered damage. What effects would you expect Jason to have from this injury?

Maria is a 3-year-old who has been diagnosed with CIPA, or congenital insensitivity to pain with anhidrosis. This disease results from a genetic mutation that causes essentially all general sensory neurons to not function properly. What types of sensations will Maria be unable to detect (be specific)? Predict what problems she might face from her condition.