MARIEB HUMAN ANATOMY & PHYSIOLOGY
12TH EDITION
AUTHOR(S)KATJA HOEHN; LAWRENCE W. HAYNES; MATTHEW
A. ABBOTT
PRACTICE QUESTIONS AND DETAILED RATIONALES
Question 1
Reference: Chapter 1 — Form Determines Function (Principle of Complementarity)
A histological evaluation of left ventricular cardiac muscle tissue demonstrates an exceptionally
high density of cristae-rich mitochondria, occupying nearly 40% of the cytoplasmic volume. In
contrast, fast-twitch skeletal muscle fibers contain significantly fewer mitochondria and rely
heavily on anaerobic glycolysis. Which physiological statement best illustrates the principle of
complementarity in this context?
A. Mitochondria adapt their inner membrane shape solely in response to cytoplasmic
intracellular pressure changes.
B. The structural abundance of mitochondria provides the continuous aerobic ATP synthesis
required to sustain uninterrupted cardiac contraction.
C. High mitochondrial density allows cardiac muscle to rapidly undergo cell division when
cardiac workload increases.
,D. Abundant mitochondria store glycogen reserves to prevent cardiac fatigue during oxygen
deprivation.
Correct Answer: B
Detailed Rationales:
A. Incorrect: Cristae density and mitochondrial abundance reflect metabolic demand for
oxidative phosphorylation, not cytoplasmic hydrostatic pressure changes.
B. Correct: The principle of complementarity states that function always reflects
structure; cardiac muscle's continuous mechanical work requires an overwhelming
structural capacity for aerobic respiration provided by abundant mitochondria.
C. Incorrect: Adult cardiomyocytes are mostly post-mitotic and do not undergo rapid
cell division; mitochondrial density supports ATP generation, not cellular proliferation.
D. Incorrect: Mitochondria are the primary sites of oxidative cellular respiration,
whereas glycogen is stored separately in cytoplasmic granules; mitochondria do not act
as anaerobic glycogen storage units.
Teaching Point: Anatomical structure directly determines physiological function; abundant
mitochondria structurally enable continuous aerobic cardiac energy production.
Simplified APA Citation: Hoehn, K., Haynes, L. W., & Abbott, M. A. Marieb Human Anatomy &
Physiology (12th ed.). Chapter 1: Form Determines Function.
Question 2
Reference: Chapter 1 — Form Determines Function (Microscopic Anatomy)
A patient presenting with chronic diarrhea and weight loss is diagnosed with celiac disease.
Small intestinal biopsies reveal severe blunting and flattening of the intestinal villi and microvilli
(brush border loss). Which structural-functional breakdown primary explains this patient's
inability to absorb nutrients adequately?
,A. Loss of microvillar surface area drastically reduces the available plasma membrane transport
proteins for nutrient absorption.
B. Blunted villi lose their smooth muscle layers, preventing peristaltic movement of chyme
along the gut lumen.
C. Destruction of microvilli prevents epithelial cells from secreting gastric acid necessary for
carbohydrate hydrolysis.
D. Microvillar atrophy destroys the thick basement membrane, causing rapid loss of blood from
intestinal capillaries.
Correct Answer: A
Detailed Rationales:
A. Correct: The extensive microscopic foldings of villi and microvilli maximize plasma
membrane surface area; structural flattening severely restricts the surface area
available for nutrient transport proteins.
B. Incorrect: Peristalsis is driven by the muscularis externa, not by smooth muscle within
individual microvilli or villous apices.
C. Incorrect: Gastric acid is secreted by parietal cells in the stomach mucosa, not by
intestinal microvilli.
D. Incorrect: Celiac microvillar blunting affects the apical mucosal epithelium rather
than primarily causing basement membrane rupture or primary vascular hemorrhage.
Teaching Point: Specialized cellular membrane extensions increase surface area, directly
optimizing transport and absorption efficiency.
Simplified APA Citation: Hoehn, K., Haynes, L. W., & Abbott, M. A. Marieb Human Anatomy &
Physiology (12th ed.). Chapter 1: Form Determines Function.
Question 3
Reference: Chapter 1 — Topics of Anatomy & Physiology
, An undergraduate research assistant is tasked with measuring the rate of pulmonary surfactant
secretion by type II alveolar cells under variable partial pressures of oxygen. Concurrently,
another student uses a transmission electron microscope to measure the thickness of the
respiratory membrane. Which distinction between anatomical and physiological study methods
is highlighted here?
A. The surfactant study represents microscopic anatomy, while membrane measurement
represents chemical physiology.
B. Measuring membrane thickness evaluates structural anatomy, while tracking surfactant
secretion rates evaluates dynamic cellular physiology.
C. Both studies evaluate systemic organ physiology without considering structural organization.
D. Surfactant secretion measurement evaluates gross anatomy, while membrane thickness
measurement evaluates systemic physiology.
Correct Answer: B
Detailed Rationales:
A. Incorrect: Membrane thickness measurement is microscopic anatomy
(histology/cytology), whereas surfactant secretion rate measurement is dynamic cellular
physiology.
B. Correct: Anatomy focuses on static or spatial structural measurements (membrane
thickness), whereas physiology focuses on dynamic operational mechanisms and rates
(surfactant secretion).
C. Incorrect: Measuring membrane thickness explicitly assesses structural
microanatomy, contradicting the assertion that both ignore structural organization.
D. Incorrect: Surfactant secretion is a physiological process, not gross anatomy, and
measuring membrane thickness requires microscopic tools rather than systemic
anatomical observation.
12TH EDITION
AUTHOR(S)KATJA HOEHN; LAWRENCE W. HAYNES; MATTHEW
A. ABBOTT
PRACTICE QUESTIONS AND DETAILED RATIONALES
Question 1
Reference: Chapter 1 — Form Determines Function (Principle of Complementarity)
A histological evaluation of left ventricular cardiac muscle tissue demonstrates an exceptionally
high density of cristae-rich mitochondria, occupying nearly 40% of the cytoplasmic volume. In
contrast, fast-twitch skeletal muscle fibers contain significantly fewer mitochondria and rely
heavily on anaerobic glycolysis. Which physiological statement best illustrates the principle of
complementarity in this context?
A. Mitochondria adapt their inner membrane shape solely in response to cytoplasmic
intracellular pressure changes.
B. The structural abundance of mitochondria provides the continuous aerobic ATP synthesis
required to sustain uninterrupted cardiac contraction.
C. High mitochondrial density allows cardiac muscle to rapidly undergo cell division when
cardiac workload increases.
,D. Abundant mitochondria store glycogen reserves to prevent cardiac fatigue during oxygen
deprivation.
Correct Answer: B
Detailed Rationales:
A. Incorrect: Cristae density and mitochondrial abundance reflect metabolic demand for
oxidative phosphorylation, not cytoplasmic hydrostatic pressure changes.
B. Correct: The principle of complementarity states that function always reflects
structure; cardiac muscle's continuous mechanical work requires an overwhelming
structural capacity for aerobic respiration provided by abundant mitochondria.
C. Incorrect: Adult cardiomyocytes are mostly post-mitotic and do not undergo rapid
cell division; mitochondrial density supports ATP generation, not cellular proliferation.
D. Incorrect: Mitochondria are the primary sites of oxidative cellular respiration,
whereas glycogen is stored separately in cytoplasmic granules; mitochondria do not act
as anaerobic glycogen storage units.
Teaching Point: Anatomical structure directly determines physiological function; abundant
mitochondria structurally enable continuous aerobic cardiac energy production.
Simplified APA Citation: Hoehn, K., Haynes, L. W., & Abbott, M. A. Marieb Human Anatomy &
Physiology (12th ed.). Chapter 1: Form Determines Function.
Question 2
Reference: Chapter 1 — Form Determines Function (Microscopic Anatomy)
A patient presenting with chronic diarrhea and weight loss is diagnosed with celiac disease.
Small intestinal biopsies reveal severe blunting and flattening of the intestinal villi and microvilli
(brush border loss). Which structural-functional breakdown primary explains this patient's
inability to absorb nutrients adequately?
,A. Loss of microvillar surface area drastically reduces the available plasma membrane transport
proteins for nutrient absorption.
B. Blunted villi lose their smooth muscle layers, preventing peristaltic movement of chyme
along the gut lumen.
C. Destruction of microvilli prevents epithelial cells from secreting gastric acid necessary for
carbohydrate hydrolysis.
D. Microvillar atrophy destroys the thick basement membrane, causing rapid loss of blood from
intestinal capillaries.
Correct Answer: A
Detailed Rationales:
A. Correct: The extensive microscopic foldings of villi and microvilli maximize plasma
membrane surface area; structural flattening severely restricts the surface area
available for nutrient transport proteins.
B. Incorrect: Peristalsis is driven by the muscularis externa, not by smooth muscle within
individual microvilli or villous apices.
C. Incorrect: Gastric acid is secreted by parietal cells in the stomach mucosa, not by
intestinal microvilli.
D. Incorrect: Celiac microvillar blunting affects the apical mucosal epithelium rather
than primarily causing basement membrane rupture or primary vascular hemorrhage.
Teaching Point: Specialized cellular membrane extensions increase surface area, directly
optimizing transport and absorption efficiency.
Simplified APA Citation: Hoehn, K., Haynes, L. W., & Abbott, M. A. Marieb Human Anatomy &
Physiology (12th ed.). Chapter 1: Form Determines Function.
Question 3
Reference: Chapter 1 — Topics of Anatomy & Physiology
, An undergraduate research assistant is tasked with measuring the rate of pulmonary surfactant
secretion by type II alveolar cells under variable partial pressures of oxygen. Concurrently,
another student uses a transmission electron microscope to measure the thickness of the
respiratory membrane. Which distinction between anatomical and physiological study methods
is highlighted here?
A. The surfactant study represents microscopic anatomy, while membrane measurement
represents chemical physiology.
B. Measuring membrane thickness evaluates structural anatomy, while tracking surfactant
secretion rates evaluates dynamic cellular physiology.
C. Both studies evaluate systemic organ physiology without considering structural organization.
D. Surfactant secretion measurement evaluates gross anatomy, while membrane thickness
measurement evaluates systemic physiology.
Correct Answer: B
Detailed Rationales:
A. Incorrect: Membrane thickness measurement is microscopic anatomy
(histology/cytology), whereas surfactant secretion rate measurement is dynamic cellular
physiology.
B. Correct: Anatomy focuses on static or spatial structural measurements (membrane
thickness), whereas physiology focuses on dynamic operational mechanisms and rates
(surfactant secretion).
C. Incorrect: Measuring membrane thickness explicitly assesses structural
microanatomy, contradicting the assertion that both ignore structural organization.
D. Incorrect: Surfactant secretion is a physiological process, not gross anatomy, and
measuring membrane thickness requires microscopic tools rather than systemic
anatomical observation.
