Chamberlain University BIOS-256 Anatomy &
Physiology IV with Lab – Comprehensive Study
Guide, Original Practice Questions & Answers, BIOS
256 Exam Preparation, A&P IV Review, Digestive
System, Urinary System, Reproductive System,
Nutrition & Metabolism, Fluid & Electrolyte
Balance, Acid-Base Balance, Cardiovascular
Physiology, Endocrine Regulation, Homeostasis &
Lab Practicum Preparation
Question 1: Which of the following structures is responsible for the production
of cerebrospinal fluid (CSF)?
A. Arachnoid granulations
B. Choroid plexus
C. Cerebral aqueduct
D. Fourth ventricle
CORRECT ANSWER: B. Choroid plexus
Rationale: The choroid plexus, located within the ventricles of the brain, is a network of
ependymal cells and capillaries that actively secretes cerebrospinal fluid. Arachnoid
granulations are responsible for the reabsorption of CSF, while the cerebral aqueduct
and fourth ventricle are passageways and cavities that transport or contain CSF but do
not produce it.
Question 2: Which lobe of the brain is primarily responsible for processing
auditory information and language comprehension?
A. Frontal lobe
B. Occipital lobe
C. Temporal lobe
D. Parietal lobe
CORRECT ANSWER: C. Temporal lobe
Rationale: The temporal lobe houses the primary auditory cortex and Wernicke's area,
which is crucial for language comprehension. The frontal lobe is involved in motor
function and speech production (Broca's area), the occipital lobe processes visual
information, and the parietal lobe processes somatosensory information.
Question 3: The resting membrane potential of a neuron is primarily
maintained by which of the following mechanisms?
A. The sodium-potassium pump actively transporting 3 Na+ out and 2 K+ in
B. The diffusion of large, negatively charged proteins out of the cell
,C. The high permeability of the membrane to sodium ions at rest
D. The equal distribution of ions across the plasma membrane
CORRECT ANSWER: A. The sodium-potassium pump actively transporting 3
Na+ out and 2 K+ in
Rationale: The sodium-potassium pump establishes and maintains the resting
membrane potential by actively transporting three sodium ions out of the cell for every
two potassium ions it brings in, creating an electrochemical gradient. The membrane is
more permeable to potassium at rest, and negatively charged proteins are trapped
inside, not diffusing out.
Question 4: An action potential is propagated along an axon. Which event
directly triggers the opening of voltage-gated sodium channels?
A. Hyperpolarization of the membrane to -90 mV
B. Binding of a neurotransmitter to a receptor
C. A local depolarization that reaches threshold potential (-55 mV)
D. The inactivation of voltage-gated potassium channels
CORRECT ANSWER: C. A local depolarization that reaches threshold potential
(-55 mV)
Rationale: Voltage-gated sodium channels open when the membrane potential
depolarizes to a critical level known as the threshold, typically around -55 mV. This
opening allows a rapid influx of sodium ions, leading to the rising phase of the action
potential.
Question 5: The synaptic cleft is a crucial component of a chemical synapse.
What is its primary function?
A. To physically connect the presynaptic and postsynaptic neurons for electrical signal
transmission
B. To store neurotransmitters in vesicles before they are released
C. To allow neurotransmitters to diffuse from the presynaptic neuron to the postsynaptic
neuron
D. To reuptake neurotransmitters back into the presynaptic neuron for recycling
CORRECT ANSWER: C. To allow neurotransmitters to diffuse from the
presynaptic neuron to the postsynaptic neuron
Rationale: The synaptic cleft is the small gap between two neurons. Its primary function
is to provide a space for neurotransmitters to diffuse across from the presynaptic
terminal to the postsynaptic membrane, where they bind to receptors and initiate a
response.
,Question 6: Which neurotransmitter is most commonly associated with the
"fight-or-flight" response in the sympathetic nervous system?
A. Acetylcholine
B. Dopamine
C. Norepinephrine
D. Serotonin
CORRECT ANSWER: C. Norepinephrine
Rationale: Norepinephrine is the primary neurotransmitter released by postganglionic
sympathetic neurons and is a key mediator of the "fight-or-flight" response, increasing
heart rate, blood pressure, and blood glucose levels. Acetylcholine is the main
neurotransmitter for the parasympathetic system and at the neuromuscular junction.
Question 7: The central nervous system (CNS) is composed of which of the
following structures?
A. Brain and cranial nerves
B. Brain and spinal cord
C. Spinal cord and peripheral nerves
D. All nerves throughout the body
CORRECT ANSWER: B. Brain and spinal cord
Rationale: The central nervous system (CNS) consists of the brain and the spinal cord.
The peripheral nervous system (PNS) includes all the nerves outside of the CNS,
including cranial and spinal nerves.
Question 8: Which of the following is a function of the hypothalamus?
A. Coordinating fine motor movements and balance
B. Relaying sensory information to the cerebral cortex
C. Regulating body temperature, hunger, and thirst
D. Controlling conscious thought and decision-making
CORRECT ANSWER: C. Regulating body temperature, hunger, and thirst
Rationale: The hypothalamus is a crucial homeostatic control center in the brain. It
regulates body temperature, hunger, thirst, sleep-wake cycles, and the endocrine system
through its control of the pituitary gland.
Question 9: Which of the following correctly describes the sequence of events
in a reflex arc?
, A. Effector → Motor neuron → Interneuron → Sensory neuron → Receptor
B. Receptor → Sensory neuron → Interneuron → Motor neuron → Effector
C. Sensory neuron → Receptor → Interneuron → Motor neuron → Effector
D. Motor neuron → Receptor → Sensory neuron → Interneuron → Effector
CORRECT ANSWER: B. Receptor → Sensory neuron → Interneuron → Motor
neuron → Effector
Rationale: A reflex arc is a neural pathway that controls a reflex action. The correct
sequence is: stimulus detected by a receptor, transmission via a sensory (afferent)
neuron to the CNS, synapse with an interneuron, then to a motor (efferent) neuron,
which finally stimulates an effector (muscle or gland).
Question 10: The blood-brain barrier (BBB) is essential for maintaining a
stable environment for the brain. Which cell type forms the structural basis of
the BBB?
A. Astrocytes
B. Microglia
C. Oligodendrocytes
D. Ependymal cells
CORRECT ANSWER: A. Astrocytes
Rationale: Astrocytes are a type of glial cell whose foot processes surround the
capillaries in the brain. These end-feet induce and maintain the tight junctions between
endothelial cells, forming the structural and functional basis of the blood-brain barrier,
which restricts the passage of many substances from the blood into the brain.
Question 11: Damage to which cranial nerve would result in the inability to
move the tongue?
A. Cranial Nerve VII (Facial)
B. Cranial Nerve X (Vagus)
C. Cranial Nerve XI (Accessory)
D. Cranial Nerve XII (Hypoglossal)
CORRECT ANSWER: D. Cranial Nerve XII (Hypoglossal)
Rationale: The hypoglossal nerve (Cranial Nerve XII) is the motor nerve that innervates
all the intrinsic and extrinsic muscles of the tongue. Damage to this nerve would result
in difficulty or inability to move the tongue, affecting speech and swallowing.
Question 12: What is the primary function of the myelin sheath that surrounds
many axons in the nervous system?
Physiology IV with Lab – Comprehensive Study
Guide, Original Practice Questions & Answers, BIOS
256 Exam Preparation, A&P IV Review, Digestive
System, Urinary System, Reproductive System,
Nutrition & Metabolism, Fluid & Electrolyte
Balance, Acid-Base Balance, Cardiovascular
Physiology, Endocrine Regulation, Homeostasis &
Lab Practicum Preparation
Question 1: Which of the following structures is responsible for the production
of cerebrospinal fluid (CSF)?
A. Arachnoid granulations
B. Choroid plexus
C. Cerebral aqueduct
D. Fourth ventricle
CORRECT ANSWER: B. Choroid plexus
Rationale: The choroid plexus, located within the ventricles of the brain, is a network of
ependymal cells and capillaries that actively secretes cerebrospinal fluid. Arachnoid
granulations are responsible for the reabsorption of CSF, while the cerebral aqueduct
and fourth ventricle are passageways and cavities that transport or contain CSF but do
not produce it.
Question 2: Which lobe of the brain is primarily responsible for processing
auditory information and language comprehension?
A. Frontal lobe
B. Occipital lobe
C. Temporal lobe
D. Parietal lobe
CORRECT ANSWER: C. Temporal lobe
Rationale: The temporal lobe houses the primary auditory cortex and Wernicke's area,
which is crucial for language comprehension. The frontal lobe is involved in motor
function and speech production (Broca's area), the occipital lobe processes visual
information, and the parietal lobe processes somatosensory information.
Question 3: The resting membrane potential of a neuron is primarily
maintained by which of the following mechanisms?
A. The sodium-potassium pump actively transporting 3 Na+ out and 2 K+ in
B. The diffusion of large, negatively charged proteins out of the cell
,C. The high permeability of the membrane to sodium ions at rest
D. The equal distribution of ions across the plasma membrane
CORRECT ANSWER: A. The sodium-potassium pump actively transporting 3
Na+ out and 2 K+ in
Rationale: The sodium-potassium pump establishes and maintains the resting
membrane potential by actively transporting three sodium ions out of the cell for every
two potassium ions it brings in, creating an electrochemical gradient. The membrane is
more permeable to potassium at rest, and negatively charged proteins are trapped
inside, not diffusing out.
Question 4: An action potential is propagated along an axon. Which event
directly triggers the opening of voltage-gated sodium channels?
A. Hyperpolarization of the membrane to -90 mV
B. Binding of a neurotransmitter to a receptor
C. A local depolarization that reaches threshold potential (-55 mV)
D. The inactivation of voltage-gated potassium channels
CORRECT ANSWER: C. A local depolarization that reaches threshold potential
(-55 mV)
Rationale: Voltage-gated sodium channels open when the membrane potential
depolarizes to a critical level known as the threshold, typically around -55 mV. This
opening allows a rapid influx of sodium ions, leading to the rising phase of the action
potential.
Question 5: The synaptic cleft is a crucial component of a chemical synapse.
What is its primary function?
A. To physically connect the presynaptic and postsynaptic neurons for electrical signal
transmission
B. To store neurotransmitters in vesicles before they are released
C. To allow neurotransmitters to diffuse from the presynaptic neuron to the postsynaptic
neuron
D. To reuptake neurotransmitters back into the presynaptic neuron for recycling
CORRECT ANSWER: C. To allow neurotransmitters to diffuse from the
presynaptic neuron to the postsynaptic neuron
Rationale: The synaptic cleft is the small gap between two neurons. Its primary function
is to provide a space for neurotransmitters to diffuse across from the presynaptic
terminal to the postsynaptic membrane, where they bind to receptors and initiate a
response.
,Question 6: Which neurotransmitter is most commonly associated with the
"fight-or-flight" response in the sympathetic nervous system?
A. Acetylcholine
B. Dopamine
C. Norepinephrine
D. Serotonin
CORRECT ANSWER: C. Norepinephrine
Rationale: Norepinephrine is the primary neurotransmitter released by postganglionic
sympathetic neurons and is a key mediator of the "fight-or-flight" response, increasing
heart rate, blood pressure, and blood glucose levels. Acetylcholine is the main
neurotransmitter for the parasympathetic system and at the neuromuscular junction.
Question 7: The central nervous system (CNS) is composed of which of the
following structures?
A. Brain and cranial nerves
B. Brain and spinal cord
C. Spinal cord and peripheral nerves
D. All nerves throughout the body
CORRECT ANSWER: B. Brain and spinal cord
Rationale: The central nervous system (CNS) consists of the brain and the spinal cord.
The peripheral nervous system (PNS) includes all the nerves outside of the CNS,
including cranial and spinal nerves.
Question 8: Which of the following is a function of the hypothalamus?
A. Coordinating fine motor movements and balance
B. Relaying sensory information to the cerebral cortex
C. Regulating body temperature, hunger, and thirst
D. Controlling conscious thought and decision-making
CORRECT ANSWER: C. Regulating body temperature, hunger, and thirst
Rationale: The hypothalamus is a crucial homeostatic control center in the brain. It
regulates body temperature, hunger, thirst, sleep-wake cycles, and the endocrine system
through its control of the pituitary gland.
Question 9: Which of the following correctly describes the sequence of events
in a reflex arc?
, A. Effector → Motor neuron → Interneuron → Sensory neuron → Receptor
B. Receptor → Sensory neuron → Interneuron → Motor neuron → Effector
C. Sensory neuron → Receptor → Interneuron → Motor neuron → Effector
D. Motor neuron → Receptor → Sensory neuron → Interneuron → Effector
CORRECT ANSWER: B. Receptor → Sensory neuron → Interneuron → Motor
neuron → Effector
Rationale: A reflex arc is a neural pathway that controls a reflex action. The correct
sequence is: stimulus detected by a receptor, transmission via a sensory (afferent)
neuron to the CNS, synapse with an interneuron, then to a motor (efferent) neuron,
which finally stimulates an effector (muscle or gland).
Question 10: The blood-brain barrier (BBB) is essential for maintaining a
stable environment for the brain. Which cell type forms the structural basis of
the BBB?
A. Astrocytes
B. Microglia
C. Oligodendrocytes
D. Ependymal cells
CORRECT ANSWER: A. Astrocytes
Rationale: Astrocytes are a type of glial cell whose foot processes surround the
capillaries in the brain. These end-feet induce and maintain the tight junctions between
endothelial cells, forming the structural and functional basis of the blood-brain barrier,
which restricts the passage of many substances from the blood into the brain.
Question 11: Damage to which cranial nerve would result in the inability to
move the tongue?
A. Cranial Nerve VII (Facial)
B. Cranial Nerve X (Vagus)
C. Cranial Nerve XI (Accessory)
D. Cranial Nerve XII (Hypoglossal)
CORRECT ANSWER: D. Cranial Nerve XII (Hypoglossal)
Rationale: The hypoglossal nerve (Cranial Nerve XII) is the motor nerve that innervates
all the intrinsic and extrinsic muscles of the tongue. Damage to this nerve would result
in difficulty or inability to move the tongue, affecting speech and swallowing.
Question 12: What is the primary function of the myelin sheath that surrounds
many axons in the nervous system?
