Principles of Human Physiology Exam/ All Chapters
Covered/ Actual Questions with Correct Verified
Answers – Latest 2026 / Rated A+
1. The smallest living units capable of carrying out their own
basic life functions are called:
A. Organs
B. Organ systems
C. Tissues
D. Cells
E. Organelles
Correct Answer: D
Rationale: Cells are the smallest living units capable of carrying
out their own basic life functions . Organelles are subcellular
structures, tissues are collections of cells, organs are collections of
tissues, and organ systems are collections of organs. Cells are the
fundamental unit of life.
1
,2. Cells are classified into which of the following four broad
categories?
A. Squamous, cuboidal, columnar, and basement membranes
B. Skeletal, cardiac, endocrine, and nervous
C. Neurons, muscle, epithelial, and connective tissue
D. Atoms, tissues, organs, and organ systems
E. Endocrine, nervous, integumentary, and reproductive
Correct Answer: C
Rationale: Cells are classified into four broad categories: neurons
(nerve cells), muscle cells, epithelial cells, and connective tissue
cells . Each type has specialized functions: neurons conduct
electrical signals, muscle cells generate force, epithelial cells form
barriers, and connective tissue cells provide structural support.
3. Homeostasis refers to:
A. A constant external environment
B. A constant internal environment
C. The process whereby the body affects the external
2
,environment
D. A variable internal environment
E. A constant internal and external environment
Correct Answer: B
Rationale: Homeostasis describes the process whereby the body
maintains a relatively constant internal environment compatible
for life . The internal environment is the extracellular fluid that
bathes the cells. Homeostasis is maintained by various regulatory
mechanisms, primarily negative feedback.
4. The two fluids maintained in homeostasis are:
A. Plasma and serum
B. Interstitial fluid and cytoplasm
C. Cytoplasm and plasma
D. Plasma and interstitial fluid
E. Intracellular fluid and extracellular fluid
Correct Answer: E
Rationale: Homeostasis maintains both intracellular fluid (ICF) and
3
, extracellular fluid (ECF) . The internal environment consists of the
extracellular fluid (plasma and interstitial fluid), which bathes the
cells and is directly maintained in homeostasis. Intracellular fluid
is also maintained, but it is the ECF that is directly regulated.
5. Skin is made of epithelial, connective, muscle, and nerve
tissues. Therefore, skin is best labeled as:
A. Organ
B. Cell
C. Atom
D. Organelle
E. Tissue
Correct Answer: A
Rationale: Skin is an organ because it is composed of multiple
tissue types that work together to perform a specific function .
Organs are defined as combinations of two or more tissues that
make up a structure which performs a specific function .
4
Covered/ Actual Questions with Correct Verified
Answers – Latest 2026 / Rated A+
1. The smallest living units capable of carrying out their own
basic life functions are called:
A. Organs
B. Organ systems
C. Tissues
D. Cells
E. Organelles
Correct Answer: D
Rationale: Cells are the smallest living units capable of carrying
out their own basic life functions . Organelles are subcellular
structures, tissues are collections of cells, organs are collections of
tissues, and organ systems are collections of organs. Cells are the
fundamental unit of life.
1
,2. Cells are classified into which of the following four broad
categories?
A. Squamous, cuboidal, columnar, and basement membranes
B. Skeletal, cardiac, endocrine, and nervous
C. Neurons, muscle, epithelial, and connective tissue
D. Atoms, tissues, organs, and organ systems
E. Endocrine, nervous, integumentary, and reproductive
Correct Answer: C
Rationale: Cells are classified into four broad categories: neurons
(nerve cells), muscle cells, epithelial cells, and connective tissue
cells . Each type has specialized functions: neurons conduct
electrical signals, muscle cells generate force, epithelial cells form
barriers, and connective tissue cells provide structural support.
3. Homeostasis refers to:
A. A constant external environment
B. A constant internal environment
C. The process whereby the body affects the external
2
,environment
D. A variable internal environment
E. A constant internal and external environment
Correct Answer: B
Rationale: Homeostasis describes the process whereby the body
maintains a relatively constant internal environment compatible
for life . The internal environment is the extracellular fluid that
bathes the cells. Homeostasis is maintained by various regulatory
mechanisms, primarily negative feedback.
4. The two fluids maintained in homeostasis are:
A. Plasma and serum
B. Interstitial fluid and cytoplasm
C. Cytoplasm and plasma
D. Plasma and interstitial fluid
E. Intracellular fluid and extracellular fluid
Correct Answer: E
Rationale: Homeostasis maintains both intracellular fluid (ICF) and
3
, extracellular fluid (ECF) . The internal environment consists of the
extracellular fluid (plasma and interstitial fluid), which bathes the
cells and is directly maintained in homeostasis. Intracellular fluid
is also maintained, but it is the ECF that is directly regulated.
5. Skin is made of epithelial, connective, muscle, and nerve
tissues. Therefore, skin is best labeled as:
A. Organ
B. Cell
C. Atom
D. Organelle
E. Tissue
Correct Answer: A
Rationale: Skin is an organ because it is composed of multiple
tissue types that work together to perform a specific function .
Organs are defined as combinations of two or more tissues that
make up a structure which performs a specific function .
4
