,BIOL251/BIOL 251 Module 4 Exam | Human Anatomy &
Physiology I w/ Lab | Portage Learning | Q & A | 2026/2027
(PDF)
**1. What is the primary role of the nervous system?**
A) To produce and secrete hormones into the bloodstream
B) To provide structural support for the body
C) To monitor the internal and external environment, process information, and coordinate responses
D) To transport oxygen and nutrients throughout the body
Correct Answer: To monitor the internal and external environment, process information, and coordinate
responses
Rationale: The nervous system acts as the body's control and communication network. It receives
sensory input, integrates that information, and generates motor output and other responses. Hormone
production is the role of the endocrine system, support is provided by the skeletal system, and transport
is the function of the cardiovascular system.
**2. A neuron is exposed to a toxin that blocks voltage-gated sodium channels. Which phase of the
action potential would be most directly affected?**
A) Resting membrane potential
B) Depolarization
C) Repolarization
D) Hyperpolarization
Correct Answer: Depolarization
Rationale: Depolarization depends on the rapid influx of Na⁺ through voltage-gated sodium channels.
Blocking these channels prevents the membrane from becoming more positive. The resting membrane
potential relies on ion gradients (primarily K⁺), while repolarization involves K⁺ efflux.
**3. What is the primary effect of increased myelination on a neuron?**
,A) Decreased action potential speed
B) Increased speed of signal conduction via saltatory conduction
C) Increased production of neurotransmitters
D) Decreased size of the axon
Correct Answer: Increased speed of signal conduction via saltatory conduction
Rationale: Myelination insulates the axon and allows action potentials to "jump" between Nodes of
Ranvier, a process called saltatory conduction. This greatly increases the speed of signal transmission. It
does not decrease speed, increase neurotransmitter production, or decrease axon size.
**4. Which of the following is the correct sequence for the flow of information through a simple reflex
arc?**
A) Motor neuron → Receptor → Interneuron → Sensory neuron → Effector
B) Receptor → Sensory neuron → Interneuron → Motor neuron → Effector
C) Receptor → Motor neuron → Interneuron → Sensory neuron → Effector
D) Sensory neuron → Receptor → Interneuron → Motor neuron → Effector
Correct Answer: Receptor → Sensory neuron → Interneuron → Motor neuron → Effector
Rationale: The reflex arc begins with a stimulus activating a receptor. The signal travels via a sensory
(afferent) neuron to the CNS, where it may synapse with an interneuron, then to a motor (efferent)
neuron, and finally to the effector (muscle or gland) that produces the response.
**5. Which of the following structures is NOT a part of the central nervous system (CNS)?**
A) Brain
B) Spinal cord
C) Cranial nerves
D) Cerebellum
, Correct Answer: Cranial nerves
Rationale: The central nervous system (CNS) consists of the brain and spinal cord. Cranial nerves (12
pairs) and spinal nerves are part of the peripheral nervous system (PNS), which connects the CNS to the
rest of the body.
**6. Which of the following correctly identifies the function of the frontal lobe?**
A) Processing visual information
B) Processing auditory information
C) Motor control, decision-making, and problem-solving
D) Receiving and processing general somatic sensations
Correct Answer: Motor control, decision-making, and problem-solving
Rationale: The frontal lobe is responsible for higher-level cognitive functions, including motor control,
decision-making, and problem-solving. The occipital lobe processes visual information, the temporal
lobe processes auditory information, and the parietal lobe processes somatic sensations.
**7. Which labeled structure on a lateral view of the brain is responsible for the processing of visual
information?**
A) Frontal lobe
B) Parietal lobe
C) Occipital lobe
D) Temporal lobe
Correct Answer: Occipital lobe
Rationale: The occipital lobe is the primary visual processing center of the brain. The frontal lobe is
associated with motor control and executive functions, the parietal lobe with sensory integration, and
the temporal lobe with auditory processing and memory.
Physiology I w/ Lab | Portage Learning | Q & A | 2026/2027
(PDF)
**1. What is the primary role of the nervous system?**
A) To produce and secrete hormones into the bloodstream
B) To provide structural support for the body
C) To monitor the internal and external environment, process information, and coordinate responses
D) To transport oxygen and nutrients throughout the body
Correct Answer: To monitor the internal and external environment, process information, and coordinate
responses
Rationale: The nervous system acts as the body's control and communication network. It receives
sensory input, integrates that information, and generates motor output and other responses. Hormone
production is the role of the endocrine system, support is provided by the skeletal system, and transport
is the function of the cardiovascular system.
**2. A neuron is exposed to a toxin that blocks voltage-gated sodium channels. Which phase of the
action potential would be most directly affected?**
A) Resting membrane potential
B) Depolarization
C) Repolarization
D) Hyperpolarization
Correct Answer: Depolarization
Rationale: Depolarization depends on the rapid influx of Na⁺ through voltage-gated sodium channels.
Blocking these channels prevents the membrane from becoming more positive. The resting membrane
potential relies on ion gradients (primarily K⁺), while repolarization involves K⁺ efflux.
**3. What is the primary effect of increased myelination on a neuron?**
,A) Decreased action potential speed
B) Increased speed of signal conduction via saltatory conduction
C) Increased production of neurotransmitters
D) Decreased size of the axon
Correct Answer: Increased speed of signal conduction via saltatory conduction
Rationale: Myelination insulates the axon and allows action potentials to "jump" between Nodes of
Ranvier, a process called saltatory conduction. This greatly increases the speed of signal transmission. It
does not decrease speed, increase neurotransmitter production, or decrease axon size.
**4. Which of the following is the correct sequence for the flow of information through a simple reflex
arc?**
A) Motor neuron → Receptor → Interneuron → Sensory neuron → Effector
B) Receptor → Sensory neuron → Interneuron → Motor neuron → Effector
C) Receptor → Motor neuron → Interneuron → Sensory neuron → Effector
D) Sensory neuron → Receptor → Interneuron → Motor neuron → Effector
Correct Answer: Receptor → Sensory neuron → Interneuron → Motor neuron → Effector
Rationale: The reflex arc begins with a stimulus activating a receptor. The signal travels via a sensory
(afferent) neuron to the CNS, where it may synapse with an interneuron, then to a motor (efferent)
neuron, and finally to the effector (muscle or gland) that produces the response.
**5. Which of the following structures is NOT a part of the central nervous system (CNS)?**
A) Brain
B) Spinal cord
C) Cranial nerves
D) Cerebellum
, Correct Answer: Cranial nerves
Rationale: The central nervous system (CNS) consists of the brain and spinal cord. Cranial nerves (12
pairs) and spinal nerves are part of the peripheral nervous system (PNS), which connects the CNS to the
rest of the body.
**6. Which of the following correctly identifies the function of the frontal lobe?**
A) Processing visual information
B) Processing auditory information
C) Motor control, decision-making, and problem-solving
D) Receiving and processing general somatic sensations
Correct Answer: Motor control, decision-making, and problem-solving
Rationale: The frontal lobe is responsible for higher-level cognitive functions, including motor control,
decision-making, and problem-solving. The occipital lobe processes visual information, the temporal
lobe processes auditory information, and the parietal lobe processes somatic sensations.
**7. Which labeled structure on a lateral view of the brain is responsible for the processing of visual
information?**
A) Frontal lobe
B) Parietal lobe
C) Occipital lobe
D) Temporal lobe
Correct Answer: Occipital lobe
Rationale: The occipital lobe is the primary visual processing center of the brain. The frontal lobe is
associated with motor control and executive functions, the parietal lobe with sensory integration, and
the temporal lobe with auditory processing and memory.
