Pain/Endorphins/Enkephalins

Question 1

All pain is mediated by the nervous system in which there are two types of fibers, __ and __

Answer 1

A, C

Question 2

These mechanoreceptors are large (1-20 microns), myelinated, and fast!

Answer 2

Type A fibers

Question 3

These fibers are small (less than a micron), unmyelinated, and SLOW (relative)

Answer 3

Type C fibers

Question 4

Which fibers are mainly responsible for conveying pain?

Answer 4

Type C (small, unmyelinated)

Question 5

The ____ theory says that the substantia gelatinosa (SG) acts as a mediator, such as the type A fiber activity closes the gate, and the type C fiber activity opens the gate.

Answer 5

Gate pain

Question 6

Aspirin inhibits the formation of _____ (a group of lipids which cause an increased sensitivity to histamine and bradykinin-two chemicals that cause increased pain sensation)

Answer 6

Prostaglandin

Question 7

___ and ___ are opiates that are produced by the body (in the pituitary) in response to pain, stress, electrical stimulation, and other stimuli

Answer 7

Endorphins, enkephalins

Question 8

____ are 200 times more potent than morphine

Answer 8

Endorphins

Question 9

Endorphins are produced electrically at __-__ pulses per second (pps)

Answer 9

1-10

Question 10

The receptor sites for these are located in the substantia gelatinosa (dorsal horn). They are produced electrically at 80-120 pps

Answer 10

Enkephalins