CHAMBERLAIN UNIVERSITY
BIOS-255 ANATOMY &
PHYSIOLOGY III EXAM 2026
149 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
CHAMBERLAIN UNIVERSITY BIOS-255 ANATOMY & PHYSIOLOGY III EXAM 2026. It contains 149 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 149 Questions
Foundations - Application - Chamberlain University Bios-255 Anatomy & Physiology III 2026 Human
Anatomy & Physiology III BIO 255 Equivalent Advanced Systems Integration Undergraduate YEAR 3
Junior-level Pre-licensure Bsn/allied Health
All answers with rationales
,Table of Contents
Content Area Questions Key Topics
THE Endocrine System 1-25 Blood, Hormone, Primarily Responsible, Primary, Directly
THE Cardiovascular System 26-50 Primarily, Likely, Hormone, Kidney, Effect
Blood
THE Cardiovascular System 51-75 Blood, Primary, Describes, Directly, Patient S
THE Heart
THE Cardiovascular System 76-100 Hormone, Primary, Describes, Blood, Cycle
Blood Vessels AND
Circulation
THE Lymphatic System AND 101-125 Likely, Patient S, Blood, Primary, Acid-base
Immunity
THE Respiratory System 126-149 Blood, Describes, Hormone, Calcium, Directly
TOTAL 149 All questions include answers and detailed rationales
,Section A - THE Endocrine System
Q1.
During ventricular ejection, which valve is open and which is closed?
A. Aortic valve open; mitral valve closed B. Aortic valve closed; mitral valve open
C. Pulmonary valve closed; tricuspid valve D. Both AV and semilunar valves open
open
Correct: A - Aortic valve open; mitral valve closed
Rationale:During ventricular ejection, pressure in the ventricles exceeds aortic/pulmonary
pressure, forcing the semilunar valves open while the AV valves (mitral and tricuspid) remain
closed to prevent backflow into the atria. Option B describes ventricular filling, C is incorrect
because the pulmonary valve opens during ejection, and D is impossible due to pressure
gradients.
Why the other answers are wrong:
B. This describes ventricular filling, not ejection, when AV valves are open and semilunar
valves are closed.
C. The pulmonary valve opens during ejection, not closes, and the tricuspid valve is closed
during ejection.
D. AV and semilunar valves are never open simultaneously because opposing pressure
gradients prevent it.
Reference: Hall, J.E. (2021). Guyton and Hall Textbook of Medical Physiology, 14th Ed., Ch. 9
Q2.
A patient's arterial blood gas shows pH 7.28, PaCO2 55 mmHg, and HCO3- 26 mEq/L.
Which acid-base imbalance is present?
A. Metabolic acidosis B. Respiratory acidosis
C. Respiratory alkalosis D. Metabolic alkalosis
Correct: B - Respiratory acidosis
Rationale:An elevated PaCO2 with a low pH indicates respiratory acidosis; the normal
HCO3- suggests no metabolic compensation yet. Metabolic acidosis would show low HCO3-
and low pH, while alkalosis would show elevated pH.
Why the other answers are wrong:
A. Metabolic acidosis would present with low HCO3- and a normal or low PaCO2, not an
elevated PaCO2.
C. Respiratory alkalosis would show an elevated pH and low PaCO2, opposite of the values
given.
Page 3
, Section A - THE Endocrine System
D. Metabolic alkalosis would show an elevated pH and elevated HCO3-, neither of which is
present.
Reference: Lewis, S.L. et al. (2023). Medical-Surgical Nursing, 12th Ed., Ch. 16
Q3.
Which segment of the nephron is primarily responsible for creating the medullary osmotic
gradient essential for urine concentration?
A. Proximal convoluted tubule B. Distal convoluted tubule
C. Loop of Henle D. Collecting duct
Correct: C - Loop of Henle
Rationale:The loop of Henle, particularly the thick ascending limb, establishes the medullary
osmotic gradient via countercurrent multiplication, which is critical for water reabsorption in
the collecting duct. Other segments contribute to solute and water handling but do not
generate the gradient.
Why the other answers are wrong:
A. The proximal tubule reabsorbs the majority of filtrate but does not create the medullary
osmotic gradient.
B. The distal tubule fine-tunes electrolyte balance but is not the primary site of gradient
formation.
D. The collecting duct uses the gradient to concentrate urine but does not generate it.
Reference: Hall, J.E. (2021). Guyton and Hall Textbook of Medical Physiology, 14th Ed., Ch. 28
Q4.
Which hormone increases blood calcium levels by stimulating osteoclast activity and
renal calcium reabsorption?
A. Calcitonin B. Parathyroid hormone (PTH)
C. Insulin D. Aldosterone
Correct: B - Parathyroid hormone (PTH)
Rationale:PTH raises blood calcium by promoting osteoclast-mediated bone resorption,
enhancing renal calcium reabsorption, and activating vitamin D to increase intestinal
absorption. Calcitonin lowers blood calcium, while insulin and aldosterone do not primarily
regulate calcium.
Why the other answers are wrong:
A. Calcitonin decreases blood calcium by inhibiting osteoclasts and promoting renal calcium
excretion.
C. Insulin regulates glucose metabolism, not calcium homeostasis.
D. Aldosterone regulates sodium and potassium balance, not calcium levels.
Page 4
BIOS-255 ANATOMY &
PHYSIOLOGY III EXAM 2026
149 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
CHAMBERLAIN UNIVERSITY BIOS-255 ANATOMY & PHYSIOLOGY III EXAM 2026. It contains 149 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 149 Questions
Foundations - Application - Chamberlain University Bios-255 Anatomy & Physiology III 2026 Human
Anatomy & Physiology III BIO 255 Equivalent Advanced Systems Integration Undergraduate YEAR 3
Junior-level Pre-licensure Bsn/allied Health
All answers with rationales
,Table of Contents
Content Area Questions Key Topics
THE Endocrine System 1-25 Blood, Hormone, Primarily Responsible, Primary, Directly
THE Cardiovascular System 26-50 Primarily, Likely, Hormone, Kidney, Effect
Blood
THE Cardiovascular System 51-75 Blood, Primary, Describes, Directly, Patient S
THE Heart
THE Cardiovascular System 76-100 Hormone, Primary, Describes, Blood, Cycle
Blood Vessels AND
Circulation
THE Lymphatic System AND 101-125 Likely, Patient S, Blood, Primary, Acid-base
Immunity
THE Respiratory System 126-149 Blood, Describes, Hormone, Calcium, Directly
TOTAL 149 All questions include answers and detailed rationales
,Section A - THE Endocrine System
Q1.
During ventricular ejection, which valve is open and which is closed?
A. Aortic valve open; mitral valve closed B. Aortic valve closed; mitral valve open
C. Pulmonary valve closed; tricuspid valve D. Both AV and semilunar valves open
open
Correct: A - Aortic valve open; mitral valve closed
Rationale:During ventricular ejection, pressure in the ventricles exceeds aortic/pulmonary
pressure, forcing the semilunar valves open while the AV valves (mitral and tricuspid) remain
closed to prevent backflow into the atria. Option B describes ventricular filling, C is incorrect
because the pulmonary valve opens during ejection, and D is impossible due to pressure
gradients.
Why the other answers are wrong:
B. This describes ventricular filling, not ejection, when AV valves are open and semilunar
valves are closed.
C. The pulmonary valve opens during ejection, not closes, and the tricuspid valve is closed
during ejection.
D. AV and semilunar valves are never open simultaneously because opposing pressure
gradients prevent it.
Reference: Hall, J.E. (2021). Guyton and Hall Textbook of Medical Physiology, 14th Ed., Ch. 9
Q2.
A patient's arterial blood gas shows pH 7.28, PaCO2 55 mmHg, and HCO3- 26 mEq/L.
Which acid-base imbalance is present?
A. Metabolic acidosis B. Respiratory acidosis
C. Respiratory alkalosis D. Metabolic alkalosis
Correct: B - Respiratory acidosis
Rationale:An elevated PaCO2 with a low pH indicates respiratory acidosis; the normal
HCO3- suggests no metabolic compensation yet. Metabolic acidosis would show low HCO3-
and low pH, while alkalosis would show elevated pH.
Why the other answers are wrong:
A. Metabolic acidosis would present with low HCO3- and a normal or low PaCO2, not an
elevated PaCO2.
C. Respiratory alkalosis would show an elevated pH and low PaCO2, opposite of the values
given.
Page 3
, Section A - THE Endocrine System
D. Metabolic alkalosis would show an elevated pH and elevated HCO3-, neither of which is
present.
Reference: Lewis, S.L. et al. (2023). Medical-Surgical Nursing, 12th Ed., Ch. 16
Q3.
Which segment of the nephron is primarily responsible for creating the medullary osmotic
gradient essential for urine concentration?
A. Proximal convoluted tubule B. Distal convoluted tubule
C. Loop of Henle D. Collecting duct
Correct: C - Loop of Henle
Rationale:The loop of Henle, particularly the thick ascending limb, establishes the medullary
osmotic gradient via countercurrent multiplication, which is critical for water reabsorption in
the collecting duct. Other segments contribute to solute and water handling but do not
generate the gradient.
Why the other answers are wrong:
A. The proximal tubule reabsorbs the majority of filtrate but does not create the medullary
osmotic gradient.
B. The distal tubule fine-tunes electrolyte balance but is not the primary site of gradient
formation.
D. The collecting duct uses the gradient to concentrate urine but does not generate it.
Reference: Hall, J.E. (2021). Guyton and Hall Textbook of Medical Physiology, 14th Ed., Ch. 28
Q4.
Which hormone increases blood calcium levels by stimulating osteoclast activity and
renal calcium reabsorption?
A. Calcitonin B. Parathyroid hormone (PTH)
C. Insulin D. Aldosterone
Correct: B - Parathyroid hormone (PTH)
Rationale:PTH raises blood calcium by promoting osteoclast-mediated bone resorption,
enhancing renal calcium reabsorption, and activating vitamin D to increase intestinal
absorption. Calcitonin lowers blood calcium, while insulin and aldosterone do not primarily
regulate calcium.
Why the other answers are wrong:
A. Calcitonin decreases blood calcium by inhibiting osteoclasts and promoting renal calcium
excretion.
C. Insulin regulates glucose metabolism, not calcium homeostasis.
D. Aldosterone regulates sodium and potassium balance, not calcium levels.
Page 4
