Question 1

Which substance is responsible for activating pain receptors?&#10;A)Gamma-aminobutyric acid&#10;B)Serotonin&#10;C)Bradykinin&#10;D)Beta-endorphin

Accepted Answer

Bradykinin is a peptide molecule that is released at sites of tissue injury, inflammation, or trauma. It directly activates pain receptors, causing the sensation of pain. Gamma-aminobutyric acid, serotonin, and beta-endorphin do not activate pain receptors.

Question 2

All the following stimuli are likely to cause bowel pain except:&#10;A)Chemical irritation&#10;B)Cut with sharp knife&#10;C)Ischemia&#10;D)Overextension&#10;E)Spasm

Accepted Answer

Bowel pain is caused by the activation of nerve fibers that transmit pain signals from the bowel to the brain. A cut with a sharp knife would cause acute pain localized to the site of injury, but it would not activate the nerve fibers in the same way as the other stimuli listed, which are known to cause bowel pain.

Question 3

Massaging the skin or application of an irritant to the skin can suppress the transmission of pain signals from the corresponding body area by suppressing the sensory fibers transmitting the pain signal. Which of the following best describes this phenomenon?

A)Release of enkephalin from local neurons in the spinal cord
B)Presynaptic and postsynaptic inhibition of type C fibers by serotonin
C)Lateral inhibition of pain fibers by tactile fibers from adjacent skin areas
D)Activation of periaqueductal gray neurons

C

Accepted Answer

This phenomenon is known as gate control theory, which proposes that non-painful input can suppress or "close the gate" to painful input. Tactile and pressure stimuli can activate large sensory fibers that compete with and ultimately suppress the transmission of pain signals through smaller fibers. This mechanism is believed to occur in the dorsal horn of the spinal cord.

Question 4

The highest degree of pain localization comes from which of the following?&#10;A)Simultaneous stimulation of free nerve endings and tactile fibers&#10;B)Stimulation of free nerve endings by bradykinin&#10;C)Nerve fibers traveling to the thalamus by way of the paleospinothalamic tract&#10;D)Stimulation of type A$\delta$ fibers

Accepted Answer

Simultaneous stimulation of free nerve endings and tactile fibers allows for a high degree of pain localization because it combines the detection of pain through free nerve endings with the precise touch information provided by tactile fibers. This combination enables the brain to accurately determine the location of the pain stimulus.

Question 5

Which of the following is paired correctly?&#10;A)Dorsal column system: pain and temperature sensation&#10;B)Layers I and II of somatosensory cortex: incoming signals from the thalamus&#10;C)Free nerve ending: type C fiber&#10;D)Large representation on post central gyrus: the foot

Accepted Answer

Free nerve endings are associated with type C fibers, which are unmyelinated nerve fibers that conduct slow pain, temperature, and itch sensations.

Question 6

The neospinothalamic tract transmits which of the following?&#10;A)Vibration sense&#10;B)Proprioceptive information&#10;C)Fast pain impulses&#10;D)Slow pain impulses

Accepted Answer

The neospinothalamic tract is responsible for transmitting fast pain impulses, allowing for the rapid localization and identification of painful stimuli.

Question 7

Which of the following sensory modalities uses unmyelinated fibers to convey information to the central nervous system?&#10;A)Proprioception&#10;B)Vision&#10;C)Vibration&#10;D)Pain

Accepted Answer

Pain is typically conveyed by unmyelinated fibers, which transmit their signals slower than myelinated fibers. This slower transmission is part of the reason why pain signals can feel dull or achy.

Question 8

Neurons located in which of the following areas release serotonin as their neurotransmitter?&#10;A)Periaqueductal gray area&#10;B)Interneurons of spinal cord&#10;C)Periventricular area&#10;D)Nucleus raphe magnus

Accepted Answer

Neurons located in the nucleus raphe magnus release serotonin as their neurotransmitter.

Question 9

Neurons involved with the endogenous analgesia system and cell bodies in the Raphe nucleus are most likely to secrete which of the following substances?&#10;A)Acetylcholine&#10;B)Enkephalin&#10;C)Glutamate&#10;D)Norepinephrine&#10;E)Serotonin

Accepted Answer

Neurons involved with the endogenous analgesia system and with cell bodies in the Raphe nucleus are most likely to secrete serotonin. The Raphe nuclei are a predominant source of serotonin in the brain, which plays a key role in modulating pain and analgesia among other functions.

Question 10

Referred pain results from an intermingling of pain fibers in which of the following structures?&#10;A)Anterolateral system&#10;B)Dorsal horn of spinal cord&#10;C)Midbrain periaqueductal gray&#10;D)Primary somatosensory cortex&#10;E)Ralph nuclei

Accepted Answer

Referred pain occurs when pain from one part of the body is felt in another part. This phenomenon is primarily due to the convergence of nerve fibers from different parts of the body onto the same neurons in the dorsal horn of the spinal cord. This convergence can cause the brain to misinterpret the origin of the pain signal.

Question 11

Slow pain (also called second pain) often occurs after injury to the surface of the body. Slow pain depends neurologically on the existence of fast pain (also called first pain).&#10;A)Both statements are correct&#10;B)Both statements are incorrect&#10;C)The first statement is correct; the second statement is not correct&#10;D)The first statement is not correct; the second statement is correct

Accepted Answer

The answer of Slow pain (also called second pain) often...

Question 12

Which of the following is true regarding the paleospinothalamic tract?&#10;A)Contains type A$\beta$ nerve fibers&#10;B)Terminates exclusively in the thalamus&#10;C)Transmits the &#34;fast pain&#34; sensation&#10;D)Terminates predominantly in the lower brain regions

Accepted Answer

The answer of Which of the following is true regarding...

Question 13

Stimulation of which brain area can modulate the sensation of pain?&#10;A)Superior olivary complex&#10;B)Locus coeruleus&#10;C)Periaqueductal gray&#10;D)Amygdala

Accepted Answer

The answer of Stimulation of which brain area can modulate...

Question 14

Which of the following is paired correctly?&#10;A)Nucleus raphe magnus and $\beta$-endorphin&#10;B)Periaqueductal gray and serotonin&#10;C)Enkephalin and presynaptic inhibition of type A$\delta$ fibers&#10;D)Intracranial headache and eye strain

Accepted Answer

The answer of Which of the following is paired correctly?&#10;A)Nucleus...

Deck 49: Somatic Sensations: II Pain, Headache, and Thermal Sensations