and Hearing
7th Edition
• Author(s)J. Anthony Seikel, David G.
Drumright, Daniel J. Hudock
TEST BANK
Chapter 11. Neuroanatomy
Overview
Sense, Sensor, and Stimulation
Divisions of the Nervous System
Central Nervous System and Peripheral Nervous System
Autonomic and Somatic Nervous Systems
Development Divisions
Anatomy of the Central Nervous System and Peripheral Nervous System
Neurons……..
,
,Question 1
Which glial cell forms the myelin sheath around axons of the
peripheral nervous system?
A. Astrocyte
B. Microglia
C. Oligodendrocyte
D. Schwann cell
Correct Answer: D
Rationale: Schwann cells are the glial cells responsible for
creating the myelin sheath in the peripheral nervous system
(PNS), which speeds nerve impulse conduction along PNS
axons. Astrocytes (Option A) are CNS support cells that
contribute to the blood–brain barrier and nutrient support;
they do not form myelin. Microglia (Option B) act as immune
cells in the CNS and do not produce myelin. Oligodendrocytes
(Option C) are the myelinating cells of the central nervous
system (CNS), not the PNS. Disruption of myelination (as by loss
of Schwann cells) would slow signal transmission in PNS nerves
affecting functions like sensory input and motor output in
speech and swallowing.
Why Option A is incorrect: Astrocytes do not produce myelin;
they support neurons in the CNS.
Why Option B is incorrect: Microglia are the CNS’s immune cells
, and do not form myelin.
Why Option C is incorrect: Oligodendrocytes form myelin in the
CNS (brain and spinal cord), not in the PNS.
Question 2
Which layer of the meninges lies directly under (deep to) the
dura mater?
A. Pia mater
B. Arachnoid mater
C. Subarachnoid mater
D. Epidural space
Correct Answer: B
Rationale: The arachnoid mater is the middle meningeal layer,
situated just beneath the tough dura mater. It spans over the
brain and is separated from the pia mater by the subarachnoid
space (which contains cerebrospinal fluid). The pia mater
(Option A) is the innermost layer, directly adherent to the brain
surface, so it is deeper than the arachnoid. “Subarachnoid
mater” (Option C) is not an official layer name – the correct
term is the subarachnoid space (a fluid-filled space between
arachnoid and pia). The epidural space (Option D) is outside the
dura in the spinal canal, not a meningeal layer. Correct layering
(dura → arachnoid → pia) is important clinically: infection or
hemorrhage under the dura (subdural) versus under the