a. are less common than neurons in the human nervous system.
b. are responsible for transmitting information within the peripheral nervous system.
c. are the “glue” that holds all of the neurons together in the brain.
*d. are not as well studied as neurons but have been shown to perform many important functions in the nervous system.
47. What type of glia helps to synchronize the activity of axons?
a. Oligodendrocytes
*b. Astrocytes
c. Radial glia
d. Schwann cells
48. Which type of glia remove waste material in the nervous system?
*a. Astrocytes
b. Schwann cells
c. Oligodendrocytes
d. Radial glia
49. What type of glial cells myelinate axons in the brain and spinal cord?
*a. oligodendrocytes
b. Schwann cells
c. radial glia
d. astrocytes
50. Which type of glia release chemicals that modify the activity of neighboring neurons?
*a. Astrocytes
b. Schwann cells
c. Oligodendrocytes
d. Radial glia
51. Which type of glia builds myelin sheaths around axons in the periphery of the body?
a. Astrocytes
*b. Schwann cells
c. Oligodendrocytes
d. Radial glia
52. ____ in the brain and spinal cord and ____ in the periphery are specialized types of glia that build the myelin sheaths that surround neurons.
*a. Oligodendrocytes; Schwann cells
b. Schwann cells; oligodendrocytes
c. Microglia; oligodendrocytes
d. Radial glia; Schwann cells
53. Dr. Pautz studies the immune system and has recently become interested in the glial cells that function similar to other cells in the immune system. What cells has Dr. Pautz started exploring?
a. Schwann cells
*b. Microglia
c. Astrocytes
d. Radial glia
54. Radial glia ____.
*a. guide the migration of neurons during embryonic development
b. synchronize the activity of axons
c. wrap around the presynaptic terminals of several axons
d. build the myelin sheaths that surround and insulate certain axons
55. What mechanism prevents or slows some chemicals from entering the brain, while allowing others to enter?
a. A threshold
*b. A blood-brain barrier
c. An endoplasmic wall
d. A differential-drug inhibitor
56. Andrew was exposed to the chicken pox virus as a child. What happened to that virus after it crossed the blood-brain barrier and entered Andrew’s brain?
a. Andrew’s natural killer cells were able to quickly destroy it.
b. The glia in his brain engulfed the virus and then natural killer cells destroyed them both.
c. Nothing happened since the chicken pox virus cannot cross the blood-brain barrier.
*d. Nothing happened at first, but the virus remained there and caused negative effects for Andrew as he got older.
57. Molecules that can cross the blood-brain barrier are usually ____.
a. large, uncharged molecules, such as lactose
b. large, charged molecules
c. neurotransmitters, such as dopamine
*d. molecules that can dissolve in the fats of the capillary walls
58. The major disadvantage of a blood-brain barrier is that ____.
a. many chemicals can easily diffuse into the brain
b. so much glucose is required to maintain it
*c. certain required chemicals must be actively transported
d. viruses cannot escape
59. Marquitta is studying for a quiz and records in her notes that glucose is the main source of fuel for the nervous system and enters the brain via _____.
*a. active transport
b. passive transport
c. gaps in the ventricles
d. gaps in the blood-brain barrier
60. What is the main source of nutrition for vertebrate neurons?
a. Fats
*b. Glucose
c. Sodium
d. Complex carbohydrates
61. Professor Nuno explained to her class that glucose is so important to the brain because ______.
a. neurons and glial cells can only metabolize glucose.
b. glial cells can only breakdown glucose into energy that the neurons can use.
*c. glucose is unique and can cross the blood-brain barrier to be used by neurons.
d. all other forms of energy are used up by the body and don’t make it to the brain.
62. Why does the brain need thiamine?
a. To enable glucose to cross the blood-brain barrier
b. As a source of fuel in case there is not enough glucose