biology : class11 Peripheral Nerve Structure : CNS, PNS, Visceral Nervous System : Human Nervous System MCQ Questions and Answers
Practice important
Peripheral Nerve Structure
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. A transverse section of a peripheral nerve shows several bundles of nerve fibers, each bundle surrounded by a distinct cellular sheath. Which structure surrounds each such bundle?
A.
Endoneurium
B.
Perineurium
C.
Epineurium
D.
Neurilemma
Correct Answer:
Perineurium
Explanation:
The perineurium is the connective-tissue sheath that encloses a fascicle, which is a bundle of nerve fibers. Endoneurium surrounds individual fibers, while epineurium encloses the entire nerve.
2. Which sequence correctly arranges the connective-tissue coverings of a peripheral nerve from the individual axon outward?
Explanation:
Endoneurium surrounds individual nerve fibers, perineurium surrounds fascicles, and epineurium forms the outer connective-tissue covering of the whole peripheral nerve.
3. A microscopic lesion selectively destroys the delicate connective tissue surrounding each individual myelinated peripheral nerve fiber but leaves the fascicular and outer coverings intact. Which layer has been damaged?
A.
Epineurium
B.
Perineurium
C.
Endoneurium
D.
Dura mater
Correct Answer:
Endoneurium
Explanation:
The endoneurium is the fine connective-tissue layer surrounding each individual axon and its Schwann-cell covering within a peripheral nerve.
4. Which feature of the perineurium is most directly associated with maintaining the internal chemical environment of a peripheral nerve fascicle?
A.
Its formation by concentric layers of specialized perineurial cells
B.
Its production of myelin around every axon
C.
Its attachment to skeletal muscle fibers
D.
Its storage of cerebrospinal fluid
Correct Answer:
Its formation by concentric layers of specialized perineurial cells
Explanation:
Perineurial cells form concentric layers around a fascicle and contribute to the blood–nerve barrier, helping regulate the fascicle's internal environment.
5. A peripheral nerve is cut and examined from outside inward. Which structure would be encountered first, assuming the nerve is intact and the cut is made perpendicular to its long axis?
A.
Axoplasm
B.
Perineurium
C.
Epineurium
D.
Endoneurium
Correct Answer:
Epineurium
Explanation:
The epineurium is the outermost connective-tissue sheath of a peripheral nerve. The perineurium lies deeper around fascicles, and the endoneurium surrounds individual fibers.
6. Which statement best distinguishes a peripheral nerve fascicle from a whole peripheral nerve?
A.
A fascicle contains only unmyelinated fibers, whereas a nerve contains myelinated fibers
B.
A fascicle is enclosed by perineurium, whereas the entire nerve is enclosed by epineurium
C.
A fascicle is enclosed by epineurium, whereas the entire nerve is enclosed by endoneurium
D.
A fascicle contains cell bodies, whereas a nerve contains only axons
Correct Answer:
A fascicle is enclosed by perineurium, whereas the entire nerve is enclosed by epineurium
Explanation:
A fascicle is a bundle of nerve fibers surrounded by perineurium. Multiple fascicles, along with associated connective tissue and vessels, form a peripheral nerve enclosed by epineurium.
7. Which component is normally found within the epineurium and helps support the metabolic requirements of a large peripheral nerve?
A.
Blood vessels
B.
Cerebrospinal fluid
C.
Oligodendrocyte cell bodies
D.
Synaptic vesicles
Correct Answer:
Blood vessels
Explanation:
The epineurium contains connective tissue, including blood vessels that supply the nerve and its fascicles. Cerebrospinal fluid and oligodendrocytes are not normal structural components of a peripheral nerve.
8. In a peripheral nerve, which arrangement most effectively explains why damage to the outer sheath can affect several fascicles at once?
A.
The epineurium encloses the entire nerve containing multiple fascicles
B.
The endoneurium encloses all fascicles collectively
C.
The perineurium surrounds the entire nerve externally
D.
The neurilemma forms a single sheath around every fascicle
Correct Answer:
The epineurium encloses the entire nerve containing multiple fascicles
Explanation:
The epineurium is the external sheath enclosing the whole peripheral nerve. Since multiple fascicles lie within it, injury to this outer region can influence several fascicles.
9. Which pairing correctly matches a peripheral nerve structure with what it surrounds?
Explanation:
Endoneurium surrounds an individual nerve fiber, including its axon and associated Schwann-cell covering. Perineurium surrounds a fascicle, and epineurium surrounds the entire nerve.
10. A researcher removes the epineurium while preserving the perineurium and endoneurium. Which structural organization would remain immediately recognizable?
A.
Individual axons would still be grouped into fascicles
B.
The entire nerve would still have its outermost sheath
C.
Each fascicle would lose its specialized boundary
D.
Every axon would lose its Schwann-cell covering
Correct Answer:
Individual axons would still be grouped into fascicles
Explanation:
Removing the epineurium does not directly remove the perineurium around individual fascicles or the endoneurium around individual fibers. Therefore, the fascicular organization can remain recognizable.
Short Questions and Answers
Practice short questions and answers related to
Peripheral Nerve Structure
.
Short questions are currently unavailable for this page.