,CHAPTER LIST
Part I: Basic Cell Processes: Integration and Coordination
Chapter 1: Introduction to Physiology
Chapter 2: Molecular Interactions
Chapter 3: Compartmentation: Cells and Tissues
Chapter 4: Energy and Cellular Metabolism
Chapter 5: Membrane Dynamics
Chapter 6: Communication, Integration, and Homeostasis
Part II: Homeostasis and Control
Chapter 7: Introduction to the Endocrine System
Chapter 8: Neurons: Cellular and Network Properties
Chapter 9: The Central Nervous System
Chapter 10: Sensory Physiology
Chapter 11: Efferent Division: Autonomic and Somatic Motor Control
Chapter 12: Muscles
Chapter 13: Integrative Physiology I: Control of Body Movement
Part III: Integration of Function
Chapter 14: Cardiovascular Physiology
Chapter 15: Blood Flow and the Control of Blood Pressure
Chapter 16: Blood
Chapter 17: Mechanics of Breathing
Chapter 18: Gas Exchange and Transport
Chapter 19: The Kidneys
Chapter 20: Integrative Physiology II: Fluid and Electrolyte Balance
Part IV: Metabolism, Growth, and Aging
Chapter 21: The Digestive System
Chapter 22: Metabolism and Energy Balance
Chapter 23: Endocrine Control of Growth and Metabolism
Chapter 24: The Immune System
Chapter 25: Integrative Physiology III: Exercise
Chapter 26: Reproduction and Development
,Chapter 1: Introduction to Physiology
Section A: Multiple Choice (Fill-in-the-Blank)
1. Homeostasis is best described as a ______ process maintained by
______ feedback loops that continuously correct deviations from a
set point.
A) static equilibrium; positive
B) dynamic steady state; negative
C) dynamic steady state; positive
D) static equilibrium; negative
Correct Answer: B
Rationale: Homeostasis is dynamic — variables oscillate around a
set point rather than remaining fixed. Negative feedback is the
dominant mechanism: when a variable deviates from its set point,
sensors detect the change, a control center activates effectors that
oppose the deviation, and the variable returns toward normal. The
word 'negative' refers to the corrective direction, not suppression.
Positive feedback amplifies deviations and is reserved for all-or-
nothing completion events such as action potentials, parturition,
and blood clot formation.
2. The three components of a reflex arc, in order, are the ______,
which detects the stimulus, the ______, which processes information
and determines a response, and the effector, which carries out the
corrective action.
A) control center; receptor
B) receptor (sensor); control center (integrating center)
C) effector; receptor
D) control center; effector
Correct Answer: B
,Rationale: Homeostatic reflex arcs have three obligatory
components. The receptor or sensor detects changes in the
controlled variable and generates an afferent signal. The control
center (integrating center) compares incoming information to the set
point and determines the magnitude and type of response. The
effector receives efferent signals and produces the corrective
response. Misidentifying these roles is the most common error
students make in homeostasis questions. This framework applies
identically to baroreflex arcs, thermoregulation, hormonal feedback
loops, and blood glucose regulation.
3. Positive feedback loops are physiologically useful for events that
must be ______ once initiated, because positive feedback ______ the
original stimulus until a termination event occurs.
A) reversed; reduces
B) completed rapidly; amplifies
C) sustained indefinitely; amplifies
D) reversed; amplifies
Correct Answer: B
Rationale: Positive feedback moves the system further from the
initial state by amplifying the triggering stimulus. This is useful
only for events that benefit from rapid, decisive completion: the
action potential (depolarization opens more Na+ channels, causing
more depolarization), uterine contractions during childbirth (baby's
head pressure releases oxytocin, strengthening contractions), and
hemostasis (thrombin activates factors that produce more
thrombin). Each positive feedback loop requires an external
termination event — delivery of the baby, completion of clot
formation — otherwise the amplification would be destructive.
4. Claude Bernard's concept of the 'milieu intérieur' refers to the
______, which all body cells depend on for nutrient delivery and
waste removal.
A) intracellular fluid (ICF)
, B) extracellular fluid (ECF)
C) blood plasma only
D) lymphatic fluid only
Correct Answer: B
Rationale: Bernard recognized that multicellular organisms
insulate their cells from a variable external environment by
maintaining a stable internal fluid environment — the extracellular
fluid. The ECF includes plasma (within blood vessels) and
interstitial fluid (surrounding cells). Cells continuously exchange
materials with the ECF: extracting O2 and nutrients, depositing
CO2 and metabolic wastes. Walter Cannon later coined
'homeostasis' for the processes that maintain the ECF composition.
This concept unifies all of integrative physiology: every organ
system ultimately serves to maintain the composition of the ECF.
5. Feedforward regulation differs from negative feedback in that
feedforward ______ a deviation before it occurs, while negative
feedback ______ a deviation after it is detected.
A) corrects; anticipates
B) anticipates; corrects
C) amplifies; anticipates
D) detects; amplifies
Correct Answer: B
Rationale: Feedforward control is anticipatory — it acts based on a
predictive signal before the controlled variable actually changes.
The cephalic phase of digestion is the classic example: sight, smell,
and taste of food trigger gastric acid secretion, salivation, and
pancreatic enzyme release before food even enters the digestive
tract. This pre-loads the system. Negative feedback is reactive — it
responds after the variable has deviated. The combination of
feedforward and negative feedback provides both anticipatory
preparation and corrective fine-tuning.
,6. A patient's blood glucose rises from 90 mg/dL to 200 mg/dL
after a meal. Which sequence correctly describes the homeostatic
response?
A) Glucagon released → liver produces glucose → blood glucose
rises further
B) Pancreatic beta cells detect high glucose → insulin
released → cells uptake glucose → blood glucose falls
C) Pancreatic alpha cells detect high glucose → glucagon released
→ glycogen breakdown → blood glucose falls
D) Hypothalamus detects high glucose → ADH released →
kidneys excrete glucose → blood glucose falls
Correct Answer: B
Rationale: Elevated blood glucose is directly detected by pancreatic
beta cells, which secrete insulin. Insulin binds receptors on muscle,
liver, and adipose cells, promoting glucose uptake, glycolysis, and
glycogen synthesis, thereby lowering plasma glucose back toward
90 mg/dL — a textbook negative feedback loop. Glucagon (from
alpha cells) is released when glucose is low and promotes
glycogenolysis and gluconeogenesis. ADH regulates water balance,
not glucose directly. This sequence integrates endocrine signaling
with metabolic physiology.
7. Which of the following is the best example of an emergent
property in physiology?
A) A single ion channel conducting Na+ ions during membrane
depolarization
B) The pumping of blood by the coordinated contraction of
millions of cardiac muscle cells, producing circulatory flow
that no single cell can achieve
C) Glucose being oxidized in a mitochondrion to produce ATP
D) A hormone binding to its receptor on a target cell
,Correct Answer: B
Rationale: Emergent properties arise from the organized interaction
of simpler components and cannot be predicted from any individual
component alone. A single cardiac muscle cell can contract
rhythmically but cannot pump blood against arterial pressure
through a closed circulatory system. The coordinated, electrically
coupled contraction of billions of cells — organized into chambers
with valves — produces the emergent property of effective
circulation. Examples of emergence throughout physiology: action
potentials from ion channels, immunity from cellular networks,
consciousness from neural circuits.
8. Which of the following correctly identifies an error in describing
physiological levels of organization?
A) Atoms combine to form molecules, which form the basis of
cellular structures
B) Tissues are groups of similar cells working together to perform
a common function
C) Organs are composed of multiple tissue types working
together
D) An organism is the highest level of organization studied in
physiology
Correct Answer: D
Rationale: Physiology extends beyond the individual organism to
population physiology — studying how physiological parameters
vary across groups (e.g., VO2max distributions in athletes vs.
sedentary populations, genetic variation in drug metabolism). While
the organism is the highest level for most clinical physiology,
population-level physiology is a recognized field. Options A, B, and
C correctly describe anatomical and physiological levels of
organization as presented in Silverthorn's hierarchy.
, 9. In thermoregulation, when core body temperature falls below
37°C, the hypothalamic control center activates ______ and ______
as effector responses to restore temperature.
A) sweating; cutaneous vasodilation
B) shivering; cutaneous vasoconstriction
C) shivering; cutaneous vasodilation
D) sweating; cutaneous vasoconstriction
Correct Answer: B
Rationale: When core temperature falls below set point, the
hypothalamus activates two primary warming mechanisms: (1)
shivering — rapid involuntary skeletal muscle contractions that
generate heat through inefficient ATP hydrolysis; and (2) cutaneous
vasoconstriction — reducing blood flow to the skin surface,
minimizing heat loss by radiation and convection. Additional
responses include piloerection (limited in humans) and behavioral
responses (seeking warmth). Sweating and vasodilation are cooling
responses activated when temperature exceeds the set point. This
bidirectional effector control is possible because the skin has dual
sympathetic innervation.
10. A researcher discovers that blocking a specific receptor causes
a physiological variable to rise above normal even though the
hormone acting on that receptor is still being secreted. This finding
suggests the receptor is part of a ______ feedback loop because
blocking it ______ the corrective response.
A) positive; amplifies
B) negative; eliminates
C) positive; eliminates
D) negative; amplifies
Correct Answer: B
Part I: Basic Cell Processes: Integration and Coordination
Chapter 1: Introduction to Physiology
Chapter 2: Molecular Interactions
Chapter 3: Compartmentation: Cells and Tissues
Chapter 4: Energy and Cellular Metabolism
Chapter 5: Membrane Dynamics
Chapter 6: Communication, Integration, and Homeostasis
Part II: Homeostasis and Control
Chapter 7: Introduction to the Endocrine System
Chapter 8: Neurons: Cellular and Network Properties
Chapter 9: The Central Nervous System
Chapter 10: Sensory Physiology
Chapter 11: Efferent Division: Autonomic and Somatic Motor Control
Chapter 12: Muscles
Chapter 13: Integrative Physiology I: Control of Body Movement
Part III: Integration of Function
Chapter 14: Cardiovascular Physiology
Chapter 15: Blood Flow and the Control of Blood Pressure
Chapter 16: Blood
Chapter 17: Mechanics of Breathing
Chapter 18: Gas Exchange and Transport
Chapter 19: The Kidneys
Chapter 20: Integrative Physiology II: Fluid and Electrolyte Balance
Part IV: Metabolism, Growth, and Aging
Chapter 21: The Digestive System
Chapter 22: Metabolism and Energy Balance
Chapter 23: Endocrine Control of Growth and Metabolism
Chapter 24: The Immune System
Chapter 25: Integrative Physiology III: Exercise
Chapter 26: Reproduction and Development
,Chapter 1: Introduction to Physiology
Section A: Multiple Choice (Fill-in-the-Blank)
1. Homeostasis is best described as a ______ process maintained by
______ feedback loops that continuously correct deviations from a
set point.
A) static equilibrium; positive
B) dynamic steady state; negative
C) dynamic steady state; positive
D) static equilibrium; negative
Correct Answer: B
Rationale: Homeostasis is dynamic — variables oscillate around a
set point rather than remaining fixed. Negative feedback is the
dominant mechanism: when a variable deviates from its set point,
sensors detect the change, a control center activates effectors that
oppose the deviation, and the variable returns toward normal. The
word 'negative' refers to the corrective direction, not suppression.
Positive feedback amplifies deviations and is reserved for all-or-
nothing completion events such as action potentials, parturition,
and blood clot formation.
2. The three components of a reflex arc, in order, are the ______,
which detects the stimulus, the ______, which processes information
and determines a response, and the effector, which carries out the
corrective action.
A) control center; receptor
B) receptor (sensor); control center (integrating center)
C) effector; receptor
D) control center; effector
Correct Answer: B
,Rationale: Homeostatic reflex arcs have three obligatory
components. The receptor or sensor detects changes in the
controlled variable and generates an afferent signal. The control
center (integrating center) compares incoming information to the set
point and determines the magnitude and type of response. The
effector receives efferent signals and produces the corrective
response. Misidentifying these roles is the most common error
students make in homeostasis questions. This framework applies
identically to baroreflex arcs, thermoregulation, hormonal feedback
loops, and blood glucose regulation.
3. Positive feedback loops are physiologically useful for events that
must be ______ once initiated, because positive feedback ______ the
original stimulus until a termination event occurs.
A) reversed; reduces
B) completed rapidly; amplifies
C) sustained indefinitely; amplifies
D) reversed; amplifies
Correct Answer: B
Rationale: Positive feedback moves the system further from the
initial state by amplifying the triggering stimulus. This is useful
only for events that benefit from rapid, decisive completion: the
action potential (depolarization opens more Na+ channels, causing
more depolarization), uterine contractions during childbirth (baby's
head pressure releases oxytocin, strengthening contractions), and
hemostasis (thrombin activates factors that produce more
thrombin). Each positive feedback loop requires an external
termination event — delivery of the baby, completion of clot
formation — otherwise the amplification would be destructive.
4. Claude Bernard's concept of the 'milieu intérieur' refers to the
______, which all body cells depend on for nutrient delivery and
waste removal.
A) intracellular fluid (ICF)
, B) extracellular fluid (ECF)
C) blood plasma only
D) lymphatic fluid only
Correct Answer: B
Rationale: Bernard recognized that multicellular organisms
insulate their cells from a variable external environment by
maintaining a stable internal fluid environment — the extracellular
fluid. The ECF includes plasma (within blood vessels) and
interstitial fluid (surrounding cells). Cells continuously exchange
materials with the ECF: extracting O2 and nutrients, depositing
CO2 and metabolic wastes. Walter Cannon later coined
'homeostasis' for the processes that maintain the ECF composition.
This concept unifies all of integrative physiology: every organ
system ultimately serves to maintain the composition of the ECF.
5. Feedforward regulation differs from negative feedback in that
feedforward ______ a deviation before it occurs, while negative
feedback ______ a deviation after it is detected.
A) corrects; anticipates
B) anticipates; corrects
C) amplifies; anticipates
D) detects; amplifies
Correct Answer: B
Rationale: Feedforward control is anticipatory — it acts based on a
predictive signal before the controlled variable actually changes.
The cephalic phase of digestion is the classic example: sight, smell,
and taste of food trigger gastric acid secretion, salivation, and
pancreatic enzyme release before food even enters the digestive
tract. This pre-loads the system. Negative feedback is reactive — it
responds after the variable has deviated. The combination of
feedforward and negative feedback provides both anticipatory
preparation and corrective fine-tuning.
,6. A patient's blood glucose rises from 90 mg/dL to 200 mg/dL
after a meal. Which sequence correctly describes the homeostatic
response?
A) Glucagon released → liver produces glucose → blood glucose
rises further
B) Pancreatic beta cells detect high glucose → insulin
released → cells uptake glucose → blood glucose falls
C) Pancreatic alpha cells detect high glucose → glucagon released
→ glycogen breakdown → blood glucose falls
D) Hypothalamus detects high glucose → ADH released →
kidneys excrete glucose → blood glucose falls
Correct Answer: B
Rationale: Elevated blood glucose is directly detected by pancreatic
beta cells, which secrete insulin. Insulin binds receptors on muscle,
liver, and adipose cells, promoting glucose uptake, glycolysis, and
glycogen synthesis, thereby lowering plasma glucose back toward
90 mg/dL — a textbook negative feedback loop. Glucagon (from
alpha cells) is released when glucose is low and promotes
glycogenolysis and gluconeogenesis. ADH regulates water balance,
not glucose directly. This sequence integrates endocrine signaling
with metabolic physiology.
7. Which of the following is the best example of an emergent
property in physiology?
A) A single ion channel conducting Na+ ions during membrane
depolarization
B) The pumping of blood by the coordinated contraction of
millions of cardiac muscle cells, producing circulatory flow
that no single cell can achieve
C) Glucose being oxidized in a mitochondrion to produce ATP
D) A hormone binding to its receptor on a target cell
,Correct Answer: B
Rationale: Emergent properties arise from the organized interaction
of simpler components and cannot be predicted from any individual
component alone. A single cardiac muscle cell can contract
rhythmically but cannot pump blood against arterial pressure
through a closed circulatory system. The coordinated, electrically
coupled contraction of billions of cells — organized into chambers
with valves — produces the emergent property of effective
circulation. Examples of emergence throughout physiology: action
potentials from ion channels, immunity from cellular networks,
consciousness from neural circuits.
8. Which of the following correctly identifies an error in describing
physiological levels of organization?
A) Atoms combine to form molecules, which form the basis of
cellular structures
B) Tissues are groups of similar cells working together to perform
a common function
C) Organs are composed of multiple tissue types working
together
D) An organism is the highest level of organization studied in
physiology
Correct Answer: D
Rationale: Physiology extends beyond the individual organism to
population physiology — studying how physiological parameters
vary across groups (e.g., VO2max distributions in athletes vs.
sedentary populations, genetic variation in drug metabolism). While
the organism is the highest level for most clinical physiology,
population-level physiology is a recognized field. Options A, B, and
C correctly describe anatomical and physiological levels of
organization as presented in Silverthorn's hierarchy.
, 9. In thermoregulation, when core body temperature falls below
37°C, the hypothalamic control center activates ______ and ______
as effector responses to restore temperature.
A) sweating; cutaneous vasodilation
B) shivering; cutaneous vasoconstriction
C) shivering; cutaneous vasodilation
D) sweating; cutaneous vasoconstriction
Correct Answer: B
Rationale: When core temperature falls below set point, the
hypothalamus activates two primary warming mechanisms: (1)
shivering — rapid involuntary skeletal muscle contractions that
generate heat through inefficient ATP hydrolysis; and (2) cutaneous
vasoconstriction — reducing blood flow to the skin surface,
minimizing heat loss by radiation and convection. Additional
responses include piloerection (limited in humans) and behavioral
responses (seeking warmth). Sweating and vasodilation are cooling
responses activated when temperature exceeds the set point. This
bidirectional effector control is possible because the skin has dual
sympathetic innervation.
10. A researcher discovers that blocking a specific receptor causes
a physiological variable to rise above normal even though the
hormone acting on that receptor is still being secreted. This finding
suggests the receptor is part of a ______ feedback loop because
blocking it ______ the corrective response.
A) positive; amplifies
B) negative; eliminates
C) positive; eliminates
D) negative; amplifies
Correct Answer: B
