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BIOL331/ BIOL 331 Module 6 Exam – Pathophysiology
(2026/2027) | Complete Practice Questions & 100% Accurate
Answers | Portage Learning
List the 2 major divisions of the nervous system and the structures found in each.
The 2 divisions of the nervous system are the central nervous system (CNS) containing
the brain and spinal cord and the peripheral nervous system (PNS) containing spinal
nerves, cranial nerves, and ganglia that are outside of the PNS.
Describe the meninges and their function.
The meninges are connective tissue sheaths that surround the brain and spinal cord.
The pia mater is the innermost layer of the meninges. It is thin and delicate and contains
surface level blood vessels that perfuse the brain and spinal cord. The second layer of
the meninges is the arachnoid layer. It encases the entire CNS and is delicate,
nonvascular, and waterproof. Cerebrospinal fluid (CSF) circulates in an area just below
the arachnoid layer called the subarachnoid space. The third layer of the meninges is
known as the dura mater. The dura mater is a strong, continuous connective tissue
sheath that provides the brain and spinal cord with most of its protection.
Describe how CSF is produced and its function.
CSF serves as a cushion for the brain and spinal cord protecting them from outside
physical force. It maintains a constant ionic environment that allows for the diffusion of
essential nutrients, electrolytes, and metabolic waste products into the extracellular
fluid surrounding the CNS neurons. A thin layer of neuroglial cells, collectively known as
the ependyma, line the ventricles of the brain and the central canal of the spinal cord.
Specialized ependymal cells called the choroid plexus project into the ventricles and
produce CSF.
What is the difference between afferent and efferent neurons?
Afferent neurons carry sensory information from the periphery to the spinal cord and
brain while efferent neurons carry motor output from the brain and spinal cord to the
periphery.
List the neuroglial cells of the CNS and PNS.
CNS: oligodendrocytes, astrocytes, microglia, and the ependymal cells.
PNS: satellite cells and Schwann cells
Describe each phase of an action potential.
Phase 1: Resting Potential: During the resting phase, both sodium and potassium gates
are closed.
Phase 2: Depolarization: The sodium gates open, and sodium rushes into the axon
during the depolarization phase of the action potential. Voltage travels to zero and then
up to +40 mV.
Phase 3: Repolarization: The sodium gates close, and potassium gates open allowing
BIOL331/ BIOL 331 Module 6 Exam – Pathophysiology
(2026/2027) | Complete Practice Questions & 100% Accurate
Answers | Portage Learning
List the 2 major divisions of the nervous system and the structures found in each.
The 2 divisions of the nervous system are the central nervous system (CNS) containing
the brain and spinal cord and the peripheral nervous system (PNS) containing spinal
nerves, cranial nerves, and ganglia that are outside of the PNS.
Describe the meninges and their function.
The meninges are connective tissue sheaths that surround the brain and spinal cord.
The pia mater is the innermost layer of the meninges. It is thin and delicate and contains
surface level blood vessels that perfuse the brain and spinal cord. The second layer of
the meninges is the arachnoid layer. It encases the entire CNS and is delicate,
nonvascular, and waterproof. Cerebrospinal fluid (CSF) circulates in an area just below
the arachnoid layer called the subarachnoid space. The third layer of the meninges is
known as the dura mater. The dura mater is a strong, continuous connective tissue
sheath that provides the brain and spinal cord with most of its protection.
Describe how CSF is produced and its function.
CSF serves as a cushion for the brain and spinal cord protecting them from outside
physical force. It maintains a constant ionic environment that allows for the diffusion of
essential nutrients, electrolytes, and metabolic waste products into the extracellular
fluid surrounding the CNS neurons. A thin layer of neuroglial cells, collectively known as
the ependyma, line the ventricles of the brain and the central canal of the spinal cord.
Specialized ependymal cells called the choroid plexus project into the ventricles and
produce CSF.
What is the difference between afferent and efferent neurons?
Afferent neurons carry sensory information from the periphery to the spinal cord and
brain while efferent neurons carry motor output from the brain and spinal cord to the
periphery.
List the neuroglial cells of the CNS and PNS.
CNS: oligodendrocytes, astrocytes, microglia, and the ependymal cells.
PNS: satellite cells and Schwann cells
Describe each phase of an action potential.
Phase 1: Resting Potential: During the resting phase, both sodium and potassium gates
are closed.
Phase 2: Depolarization: The sodium gates open, and sodium rushes into the axon
during the depolarization phase of the action potential. Voltage travels to zero and then
up to +40 mV.
Phase 3: Repolarization: The sodium gates close, and potassium gates open allowing
