BIOL 251 MODULE 3 EXAM | HUMAN ANATOMY &
PHYSIOLOGY I WITH LAB | QUESTIONS AND ANSWERS
WITH RATIONALE | PORTAGE LEARNING 2026/2027
130 Questions with Answers and Detailed Rationales
100 PERCENT GUARANTEED PASS
INSTANT DOWNLOAD ANSWERS INCLUDED
IMPORTANCE OF THIS DOCUMENT
This comprehensive examination preparation guide has been meticulously developed to help you succeed in the
BIOL 251 MODULE 3 EXAM | HUMAN ANATOMY & PHYSIOLOGY I WITH LAB | QUESTIONS AND ANSWERS
WITH RATIONALE | PORTAGE LEARNING 2026/2027. It contains 130 carefully selected questions that reflect
the most current exam content and testing strategies. Each question is accompanied by a correct answer and a
detailed rationale that explains the underlying pathophysiology, pharmacology, or clinical reasoning.
Self-Assessment – Test your knowledge and Exam Preparation – Familiarize yourself with the
identify areas requiring further question format and content
study areas
Concept Reinforcement – Deepen your Confidence Building – Develop test-taking
understanding through strategies and reduce
evidence-based exam anxiety
rationales
Time Management – Practice answering
questions under simulated
exam conditions
Review Summary 130 Questions
Foundations - Application - BIOL 251 Module 3 Human Anatomy & Physiology I WITH LAB AND WITH
Rationale Portage Learning 2026/2027 Human Anatomy & Physiology I WITH LAB Undergraduate YEAR 3
All answers with rationales
,Table of Contents
Content Area Questions Key Topics
Skeletal System BONE 1-22 Potential, Immediate, Muscle, Effect, Neuron
Tissue AND Structure
Skeletal System Axial 23-44 Potential, Muscle, Researcher, Describes, Skeletal
Skeleton
Skeletal System 45-66 Effect, Hormone, Immediate, Explains, Likely
Appendicular Skeleton
Joints AND Articulations 67-88 Potential, Muscle, Mechanism, Fracture, Skeletal
Muscular System Muscle 89-110 Muscle, Potential, Skeletal, Describes, Explains
Tissue AND Physiology
Muscular System Axial 111-130 Describes, Condition, Likely, Muscle, Potential
Muscles
TOTAL 130 All questions include answers and detailed rationales
,Section A - Skeletal System BONE Tissue AND Structure
Q1.
In a neuron, the Na+/K+-ATPase maintains the resting membrane potential. If this pump is
selectively inhibited, which of the following immediate changes would be observed in the
resting membrane potential and ion gradients?
A. Membrane potential depolarizes to 0 mV; B. Membrane potential hyperpolarizes
Na+ and K+ gradients dissipate slowly. slightly; Na+ and K+ gradients remain
unchanged.
C. Membrane potential becomes more D. Membrane potential stays constant; Na+
negative; Na+ gradient increases, K+ and K+ gradients are maintained by leak
gradient decreases. channels.
Correct: A - Membrane potential depolarizes to 0 mV; Na+ and K+ gradients dissipate
slowly.
Rationale:The Na+/K+-ATPase actively transports 3 Na+ out and 2 K+ in, maintaining the
electrochemical gradients. Inhibition stops this, allowing leak channels to gradually dissipate
the gradients, and the membrane potential drifts toward 0 mV as the equilibrium potentials are
lost.
Why the other answers are wrong:
B. Hyperpolarization would require increased outward positive charge, not pump inhibition.
C. Pump inhibition would not increase the Na+ gradient; it would decrease it.
D. Leak channels alone cannot maintain gradients without the pump.
Reference: Tortora & Derrickson, Principles of Anatomy and Physiology, 16th Ed., Ch. 11
Q2.
During fracture repair, a patient develops a non-union. Histological analysis reveals an
abundance of chondrocytes but minimal osteoblasts. Which stage of healing is likely
arrested?
A. Hematoma formation B. Fibrocartilaginous callus formation
C. Bony callus formation D. Bone remodeling
Correct: C - Bony callus formation
Rationale:The fibrocartilaginous callus, composed of cartilage and fibrous tissue, must be
replaced by a bony callus through osteoblast activity. Arrest at this transition, with
chondrocytes persisting and few osteoblasts, indicates failure of bony callus formation.
Why the other answers are wrong:
A. Hematoma formation occurs immediately and does not involve chondrocytes.
Page 3
, Section A - Skeletal System BONE Tissue AND Structure
B. Fibrocartilaginous callus formation is actually abundant in chondrocytes.
D. Bone remodeling occurs after bony callus and would show osteoclasts and osteoblasts.
Reference: Tortora & Derrickson, Principles of Anatomy and Physiology, 16th Ed., Ch. 6
Q3.
Which of the following best explains why skeletal muscle fibers have a higher density of
mitochondria compared to smooth muscle fibers?
A. Skeletal muscle relies primarily on B. Smooth muscle uses creatine phosphate
oxidative phosphorylation for ATP during as its primary energy source.
sustained contraction.
C. Skeletal muscle fibers are smaller and D. Smooth muscle has a lower metabolic
require more ATP per unit volume. rate due to the absence of myosin ATPase.
Correct: A - Skeletal muscle relies primarily on oxidative phosphorylation for ATP during
sustained contraction.
Rationale:Skeletal muscle fibers, especially type I, rely heavily on oxidative metabolism for
sustained ATP production, requiring abundant mitochondria. Smooth muscle has lower
energy demands and can rely more on glycolysis, hence fewer mitochondria.
Why the other answers are wrong:
B. Creatine phosphate is used by skeletal muscle, not smooth muscle.
C. Skeletal muscle fibers are larger, not smaller, and mitochondrial density relates to metabolic
demand, not size alone.
D. Smooth muscle does have myosin ATPase, though its regulation differs.
Reference: Silverthorn, Human Physiology, 8th Ed., Ch. 12
Q4.
A drug blocks voltage-gated sodium channels in the axon hillock. Which of the following
will occur in response to a suprathreshold stimulus?
A. Generation of an action potential with B. Generation of an action potential with
reduced amplitude slower conduction velocity
C. No action potential generation D. Generation of an action potential with
prolonged depolarization
Correct: C - No action potential generation
Rationale:Voltage-gated sodium channels are essential for the depolarization phase of the
action potential. Blocking them prevents the regenerative influx of Na+, so no action potential
is generated regardless of stimulus strength.
Why the other answers are wrong:
A. Amplitude is all-or-none; if channels are blocked, no AP occurs.
B. Conduction velocity is irrelevant if no AP is generated.
Page 4
PHYSIOLOGY I WITH LAB | QUESTIONS AND ANSWERS
WITH RATIONALE | PORTAGE LEARNING 2026/2027
130 Questions with Answers and Detailed Rationales
100 PERCENT GUARANTEED PASS
INSTANT DOWNLOAD ANSWERS INCLUDED
IMPORTANCE OF THIS DOCUMENT
This comprehensive examination preparation guide has been meticulously developed to help you succeed in the
BIOL 251 MODULE 3 EXAM | HUMAN ANATOMY & PHYSIOLOGY I WITH LAB | QUESTIONS AND ANSWERS
WITH RATIONALE | PORTAGE LEARNING 2026/2027. It contains 130 carefully selected questions that reflect
the most current exam content and testing strategies. Each question is accompanied by a correct answer and a
detailed rationale that explains the underlying pathophysiology, pharmacology, or clinical reasoning.
Self-Assessment – Test your knowledge and Exam Preparation – Familiarize yourself with the
identify areas requiring further question format and content
study areas
Concept Reinforcement – Deepen your Confidence Building – Develop test-taking
understanding through strategies and reduce
evidence-based exam anxiety
rationales
Time Management – Practice answering
questions under simulated
exam conditions
Review Summary 130 Questions
Foundations - Application - BIOL 251 Module 3 Human Anatomy & Physiology I WITH LAB AND WITH
Rationale Portage Learning 2026/2027 Human Anatomy & Physiology I WITH LAB Undergraduate YEAR 3
All answers with rationales
,Table of Contents
Content Area Questions Key Topics
Skeletal System BONE 1-22 Potential, Immediate, Muscle, Effect, Neuron
Tissue AND Structure
Skeletal System Axial 23-44 Potential, Muscle, Researcher, Describes, Skeletal
Skeleton
Skeletal System 45-66 Effect, Hormone, Immediate, Explains, Likely
Appendicular Skeleton
Joints AND Articulations 67-88 Potential, Muscle, Mechanism, Fracture, Skeletal
Muscular System Muscle 89-110 Muscle, Potential, Skeletal, Describes, Explains
Tissue AND Physiology
Muscular System Axial 111-130 Describes, Condition, Likely, Muscle, Potential
Muscles
TOTAL 130 All questions include answers and detailed rationales
,Section A - Skeletal System BONE Tissue AND Structure
Q1.
In a neuron, the Na+/K+-ATPase maintains the resting membrane potential. If this pump is
selectively inhibited, which of the following immediate changes would be observed in the
resting membrane potential and ion gradients?
A. Membrane potential depolarizes to 0 mV; B. Membrane potential hyperpolarizes
Na+ and K+ gradients dissipate slowly. slightly; Na+ and K+ gradients remain
unchanged.
C. Membrane potential becomes more D. Membrane potential stays constant; Na+
negative; Na+ gradient increases, K+ and K+ gradients are maintained by leak
gradient decreases. channels.
Correct: A - Membrane potential depolarizes to 0 mV; Na+ and K+ gradients dissipate
slowly.
Rationale:The Na+/K+-ATPase actively transports 3 Na+ out and 2 K+ in, maintaining the
electrochemical gradients. Inhibition stops this, allowing leak channels to gradually dissipate
the gradients, and the membrane potential drifts toward 0 mV as the equilibrium potentials are
lost.
Why the other answers are wrong:
B. Hyperpolarization would require increased outward positive charge, not pump inhibition.
C. Pump inhibition would not increase the Na+ gradient; it would decrease it.
D. Leak channels alone cannot maintain gradients without the pump.
Reference: Tortora & Derrickson, Principles of Anatomy and Physiology, 16th Ed., Ch. 11
Q2.
During fracture repair, a patient develops a non-union. Histological analysis reveals an
abundance of chondrocytes but minimal osteoblasts. Which stage of healing is likely
arrested?
A. Hematoma formation B. Fibrocartilaginous callus formation
C. Bony callus formation D. Bone remodeling
Correct: C - Bony callus formation
Rationale:The fibrocartilaginous callus, composed of cartilage and fibrous tissue, must be
replaced by a bony callus through osteoblast activity. Arrest at this transition, with
chondrocytes persisting and few osteoblasts, indicates failure of bony callus formation.
Why the other answers are wrong:
A. Hematoma formation occurs immediately and does not involve chondrocytes.
Page 3
, Section A - Skeletal System BONE Tissue AND Structure
B. Fibrocartilaginous callus formation is actually abundant in chondrocytes.
D. Bone remodeling occurs after bony callus and would show osteoclasts and osteoblasts.
Reference: Tortora & Derrickson, Principles of Anatomy and Physiology, 16th Ed., Ch. 6
Q3.
Which of the following best explains why skeletal muscle fibers have a higher density of
mitochondria compared to smooth muscle fibers?
A. Skeletal muscle relies primarily on B. Smooth muscle uses creatine phosphate
oxidative phosphorylation for ATP during as its primary energy source.
sustained contraction.
C. Skeletal muscle fibers are smaller and D. Smooth muscle has a lower metabolic
require more ATP per unit volume. rate due to the absence of myosin ATPase.
Correct: A - Skeletal muscle relies primarily on oxidative phosphorylation for ATP during
sustained contraction.
Rationale:Skeletal muscle fibers, especially type I, rely heavily on oxidative metabolism for
sustained ATP production, requiring abundant mitochondria. Smooth muscle has lower
energy demands and can rely more on glycolysis, hence fewer mitochondria.
Why the other answers are wrong:
B. Creatine phosphate is used by skeletal muscle, not smooth muscle.
C. Skeletal muscle fibers are larger, not smaller, and mitochondrial density relates to metabolic
demand, not size alone.
D. Smooth muscle does have myosin ATPase, though its regulation differs.
Reference: Silverthorn, Human Physiology, 8th Ed., Ch. 12
Q4.
A drug blocks voltage-gated sodium channels in the axon hillock. Which of the following
will occur in response to a suprathreshold stimulus?
A. Generation of an action potential with B. Generation of an action potential with
reduced amplitude slower conduction velocity
C. No action potential generation D. Generation of an action potential with
prolonged depolarization
Correct: C - No action potential generation
Rationale:Voltage-gated sodium channels are essential for the depolarization phase of the
action potential. Blocking them prevents the regenerative influx of Na+, so no action potential
is generated regardless of stimulus strength.
Why the other answers are wrong:
A. Amplitude is all-or-none; if channels are blocked, no AP occurs.
B. Conduction velocity is irrelevant if no AP is generated.
Page 4
