NU 545 Advance Pathophysiology Unit 2 Exam – University of
South Alabama Latest 2026 Update | Comprehensive Study Guide
| Bold Answers with Explanations
Introduction
This comprehensive study guide covers the NU 545 Advanced Pathophysiology Unit 2
Exam at the University of South Alabama, focusing on neurological pathophysiology. Unit
2 covers foundational concepts of the nervous system, including nerve injury and
regeneration, brain anatomy and function, pain mechanisms, and various neurological
disorders .
Section 1: Nerve Injury & Regeneration (Questions 1-20)
1. Which nerves are incapable of regeneration?
A. Peripheral nerves
B. Neurons in the Central Nervous System (CNS)
C. Myelinated fibers in the PNS
D. Unmyelinated fibers
Rationale: Mature neurons in the CNS do not divide, and injury causes permanent loss of
damaged neurons. CNS neurons lack the capacity for regeneration due to glial scar
formation (gliosis) and the different nature of myelin formed by oligodendrocytes .
2. Which type of nerve injury has better outcomes?
A. Crushed nerves
B. Severed/cut nerves
C. Chemically burned nerves
D. Thermally damaged nerves
Rationale: Crushed nerves recover better than cut nerves because a crush injury often
leaves the nerve's connective tissue sheaths (endoneurium) intact, providing a physical
pathway for regenerating axons to follow back to their target .
,3. How do peripheral nerves repair themselves?
A. Apoptosis
B. Axonal Reaction
C. Neurogenesis
D. Synaptic pruning
Rationale: Peripheral nerves repair themselves through a process called axonal reaction,
which involves a series of cellular and molecular changes in response to injury .
4. Which of the following correctly describes the process of anterograde (Wallerian)
degeneration that occurs in the distal segment of an axon after it is severed?
A. The cell body undergoes chromatolysis, swelling, and loss of Nissl bodies
B. The distal axon degenerates and is phagocytized by macrophages and Schwann
cells
C. Schwann cells proliferate to form a new myelin sheath
D. New terminal sprouts project from the proximal segment
Rationale: Wallerian degeneration is the process where the distal portion of a severed axon
degenerates and is phagocytized by macrophages and Schwann cells. This "clean-up"
process is triggered by the separation of the axon from its cell body .
5. Name the 8 local changes that occur when an axon is severed.
Answer:
1. Cut end retracts and the axolemma covers the cut end, reducing escape of
axoplasm
2. Macrophages and Schwann cells begin to phagocytize damaged tissue
3. Cell body undergoes chromatolysis, loss of Nissl bodies, and lateral migration of
nucleus
4. Antegrade (Wallerian) degeneration occurs in the distal axon
5. Swelling in axon terminal; it degenerates and loses contact with postsynaptic
membrane within 7 days
6. Macrophages and Schwann cells phagocytize remnants of axon terminal
, 7. Schwann cells proliferate, forming a column or tube of Schwann cells enclosed by
the original basal lamina of the endoneurium
8. Retrograde changes occur at the proximal end of the injured axon, similar to
antegrade changes but only back to the next node of Ranvier
6. Retrograde changes to the proximal end of an injured axon only go back to what?
A. The cell body
B. The next node of Ranvier
C. The myelin sheath
D. The axon hillock
Rationale: Retrograde changes at the proximal end of an injured axon extend only to the
next node of Ranvier, not all the way to the cell body .
7. In what time span do new terminal sprouts project from the proximal segment of an
injured axon?
A. 1-3 days
B. 7-14 days
C. 14-21 days
D. 21-28 days
Rationale: New terminal sprouts project from the proximal segment of an injured axon within
7-14 days after injury .
8. What is the length of growth per day of an injured axon?
A. 0.5 mm/day
B. 1 mm/day
C. 2 mm/day
D. 5 mm/day
Rationale: Injured axons regenerate at approximately 1 mm per day. Regrowth is limited to
myelinated fibers in the Peripheral Nervous System (PNS) .
South Alabama Latest 2026 Update | Comprehensive Study Guide
| Bold Answers with Explanations
Introduction
This comprehensive study guide covers the NU 545 Advanced Pathophysiology Unit 2
Exam at the University of South Alabama, focusing on neurological pathophysiology. Unit
2 covers foundational concepts of the nervous system, including nerve injury and
regeneration, brain anatomy and function, pain mechanisms, and various neurological
disorders .
Section 1: Nerve Injury & Regeneration (Questions 1-20)
1. Which nerves are incapable of regeneration?
A. Peripheral nerves
B. Neurons in the Central Nervous System (CNS)
C. Myelinated fibers in the PNS
D. Unmyelinated fibers
Rationale: Mature neurons in the CNS do not divide, and injury causes permanent loss of
damaged neurons. CNS neurons lack the capacity for regeneration due to glial scar
formation (gliosis) and the different nature of myelin formed by oligodendrocytes .
2. Which type of nerve injury has better outcomes?
A. Crushed nerves
B. Severed/cut nerves
C. Chemically burned nerves
D. Thermally damaged nerves
Rationale: Crushed nerves recover better than cut nerves because a crush injury often
leaves the nerve's connective tissue sheaths (endoneurium) intact, providing a physical
pathway for regenerating axons to follow back to their target .
,3. How do peripheral nerves repair themselves?
A. Apoptosis
B. Axonal Reaction
C. Neurogenesis
D. Synaptic pruning
Rationale: Peripheral nerves repair themselves through a process called axonal reaction,
which involves a series of cellular and molecular changes in response to injury .
4. Which of the following correctly describes the process of anterograde (Wallerian)
degeneration that occurs in the distal segment of an axon after it is severed?
A. The cell body undergoes chromatolysis, swelling, and loss of Nissl bodies
B. The distal axon degenerates and is phagocytized by macrophages and Schwann
cells
C. Schwann cells proliferate to form a new myelin sheath
D. New terminal sprouts project from the proximal segment
Rationale: Wallerian degeneration is the process where the distal portion of a severed axon
degenerates and is phagocytized by macrophages and Schwann cells. This "clean-up"
process is triggered by the separation of the axon from its cell body .
5. Name the 8 local changes that occur when an axon is severed.
Answer:
1. Cut end retracts and the axolemma covers the cut end, reducing escape of
axoplasm
2. Macrophages and Schwann cells begin to phagocytize damaged tissue
3. Cell body undergoes chromatolysis, loss of Nissl bodies, and lateral migration of
nucleus
4. Antegrade (Wallerian) degeneration occurs in the distal axon
5. Swelling in axon terminal; it degenerates and loses contact with postsynaptic
membrane within 7 days
6. Macrophages and Schwann cells phagocytize remnants of axon terminal
, 7. Schwann cells proliferate, forming a column or tube of Schwann cells enclosed by
the original basal lamina of the endoneurium
8. Retrograde changes occur at the proximal end of the injured axon, similar to
antegrade changes but only back to the next node of Ranvier
6. Retrograde changes to the proximal end of an injured axon only go back to what?
A. The cell body
B. The next node of Ranvier
C. The myelin sheath
D. The axon hillock
Rationale: Retrograde changes at the proximal end of an injured axon extend only to the
next node of Ranvier, not all the way to the cell body .
7. In what time span do new terminal sprouts project from the proximal segment of an
injured axon?
A. 1-3 days
B. 7-14 days
C. 14-21 days
D. 21-28 days
Rationale: New terminal sprouts project from the proximal segment of an injured axon within
7-14 days after injury .
8. What is the length of growth per day of an injured axon?
A. 0.5 mm/day
B. 1 mm/day
C. 2 mm/day
D. 5 mm/day
Rationale: Injured axons regenerate at approximately 1 mm per day. Regrowth is limited to
myelinated fibers in the Peripheral Nervous System (PNS) .
