HESI A2 Anatomy and Physiology Exam
Questions with Verified Answers 100%
Correct
Question 1
What is the function of Motor (efferent) neurons?
Correct Answer
Transmit nerve impulses away from the CNS toward the effector organs such as
muscles, glands, and digestive organs.
Question 1: Which of the following best describes the primary function of the
mitochondria within a human body cell, and why is this organelle particularly
abundant in cells with high energy demands such as cardiac muscle cells?
A. Storage of genetic material and control of cellular reproduction
B. Synthesis of proteins through translation of messenger RNA
C. Production of adenosine triphosphate (ATP) through cellular respiration,
providing usable energy for cellular processes
D. Modification, packaging, and distribution of proteins and lipids for secretion or
use within the cell
CORRECT ANSWER: C. Production of adenosine triphosphate (ATP) through
cellular respiration, providing usable energy for cellular processes
Rationale: Mitochondria are the primary sites of ATP production via oxidative
phosphorylation and the Krebs cycle. Cells with high metabolic activity, such as
cardiac muscle cells, contain numerous mitochondria to meet continuous energy
requirements for contraction and ion pumping.
Question 2: In the hierarchical organization of the human body, which level of
structural organization is represented by a group of similar cells working
together to perform a specific function, such as the epithelial lining of the
digestive tract?
A. Chemical level
B. Cellular level
C. Tissue level
D. Organ system level
CORRECT ANSWER: C. Tissue level
Rationale: Tissues are collections of similar cells and their extracellular matrix that
perform a common function. Epithelial tissue, for example, forms continuous sheets
that line body cavities and cover surfaces, representing the tissue level of
organization.
Question 3: Which of the following statements accurately describes the
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,structure and primary function of the plasma membrane in a typical human
cell?
A. It is a rigid, impermeable barrier composed solely of proteins that completely
isolates the cell from its environment
B. It is a selectively permeable phospholipid bilayer with embedded proteins that
regulates the movement of substances into and out of the cell
C. It is a double membrane containing DNA that controls all cellular activities
D. It is a network of protein filaments that provides internal structural support and
facilitates cell movement
CORRECT ANSWER: B. It is a selectively permeable phospholipid bilayer with
embedded proteins that regulates the movement of substances into and out of
the cell
Rationale: The plasma membrane consists of a phospholipid bilayer with cholesterol
and proteins that control selective permeability, allowing the cell to maintain
homeostasis by regulating ion, nutrient, and waste exchange.
Question 4: During the process of protein synthesis, which organelle is
primarily responsible for the translation of messenger RNA into a polypeptide
chain?
A. Nucleus
B. Smooth endoplasmic reticulum
C. Ribosome
D. Golgi apparatus
CORRECT ANSWER: C. Ribosome
Rationale: Ribosomes, whether free in the cytoplasm or attached to the rough
endoplasmic reticulum, are the sites where transfer RNA molecules deliver amino
acids according to the sequence coded by messenger RNA, forming polypeptide
chains.
Question 5: Which type of epithelial tissue is specialized for diffusion and
filtration and is commonly found lining the air sacs of the lungs and the walls
of blood capillaries?
A. Stratified squamous epithelium
B. Simple cuboidal epithelium
C. Simple squamous epithelium
D. Transitional epithelium
CORRECT ANSWER: C. Simple squamous epithelium
Rationale: Simple squamous epithelium consists of a single layer of flattened cells
that provides a thin barrier ideal for rapid diffusion of gases and filtration of
substances, as seen in alveoli and capillary walls.
Question 6: What is the primary structural difference between dense regular
connective tissue and dense irregular connective tissue, and where is dense
regular connective tissue most commonly located?
A. Dense regular tissue has randomly arranged collagen fibers and is found in the
dermis of the skin
B. Dense regular tissue has parallel collagen fibers and is found in tendons and
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,ligaments
C. Dense regular tissue contains more elastic fibers and is found in the walls of large
arteries
D. Dense regular tissue is avascular and is found exclusively in cartilage
CORRECT ANSWER: B. Dense regular tissue has parallel collagen fibers and is
found in tendons and ligaments
Rationale: Dense regular connective tissue features tightly packed collagen fibers
aligned in parallel, providing high tensile strength in one direction, which is ideal for
tendons and ligaments that transmit force along a single axis.
Question 7: Which of the following best describes the function of melanocytes
located in the stratum basale of the epidermis?
A. Production of keratin to waterproof the skin surface
B. Synthesis of melanin pigment that protects underlying tissues from ultraviolet
radiation
C. Secretion of sebum to lubricate the skin and hair
D. Detection of light touch and pressure through specialized sensory endings
CORRECT ANSWER: B. Synthesis of melanin pigment that protects underlying
tissues from ultraviolet radiation
Rationale: Melanocytes produce melanin, which is transferred to nearby
keratinocytes. Melanin absorbs and scatters ultraviolet radiation, reducing DNA
damage in deeper skin layers and contributing to skin color variation.
Question 8: In the process of bone remodeling, which cells are primarily
responsible for the resorption of bone matrix, releasing calcium into the
bloodstream?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Chondrocytes
CORRECT ANSWER: C. Osteoclasts
Rationale: Osteoclasts are large, multinucleated cells that secrete acids and enzymes
to dissolve mineralized bone matrix, thereby releasing calcium and phosphate ions
into the blood and allowing bone remodeling or repair.
Question 9: Which of the following statements correctly identifies the location
and primary function of the red bone marrow in an adult human skeleton?
A. It is found primarily in the medullary cavities of long bones and stores fat
B. It is located in the epiphyses of long bones and flat bones and is the site of
hematopoiesis
C. It is distributed throughout all bone tissue and produces only white blood cells
D. It is confined to the periosteum and is responsible for bone growth in width
CORRECT ANSWER: B. It is located in the epiphyses of long bones and flat
bones and is the site of hematopoiesis
Rationale: In adults, red bone marrow is concentrated in the proximal epiphyses of
long bones and in flat bones such as the sternum and pelvis, where it produces
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, erythrocytes, leukocytes, and platelets.
Question 10: What is the functional significance of the sarcoplasmic reticulum
within a skeletal muscle fiber?
A. It stores and releases calcium ions that trigger muscle contraction
B. It synthesizes ATP exclusively through anaerobic pathways
C. It forms the contractile filaments of actin and myosin
D. It transmits nerve impulses from the neuromuscular junction to the muscle
interior
CORRECT ANSWER: A. It stores and releases calcium ions that trigger muscle
contraction
Rationale: The sarcoplasmic reticulum is a specialized endoplasmic reticulum that
sequesters calcium ions. Upon depolarization, it releases calcium, which binds to
troponin and initiates the cross-bridge cycle leading to contraction.
Question 11: During the sliding filament mechanism of skeletal muscle
contraction, which of the following events occurs immediately after calcium
ions bind to troponin?
A. ATP is hydrolyzed to provide energy for the power stroke
B. Tropomyosin shifts, exposing the myosin-binding sites on actin
C. The myosin head detaches from actin
D. Calcium is actively transported back into the sarcoplasmic reticulum
CORRECT ANSWER: B. Tropomyosin shifts, exposing the myosin-binding sites
on actin
Rationale: Binding of calcium to troponin causes a conformational change that
moves tropomyosin away from the myosin-binding sites on actin, allowing cross-
bridge formation and subsequent contraction.
Question 12: Which division of the nervous system is responsible for the
involuntary control of smooth muscle, cardiac muscle, and glands?
A. Somatic nervous system
B. Autonomic nervous system
C. Central nervous system
D. Sensory (afferent) division
CORRECT ANSWER: B. Autonomic nervous system
Rationale: The autonomic nervous system regulates visceral functions without
conscious control. It is subdivided into sympathetic and parasympathetic divisions
that often exert opposing effects on target organs.
Question 13: What is the primary function of the myelin sheath that surrounds
many axons in the peripheral and central nervous systems?
A. To produce neurotransmitters at the synaptic terminal
B. To increase the speed of action potential conduction through saltatory
conduction
C. To store calcium ions for release during synaptic transmission
D. To form the blood-brain barrier that protects neural tissue
CORRECT ANSWER: B. To increase the speed of action potential conduction
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Questions with Verified Answers 100%
Correct
Question 1
What is the function of Motor (efferent) neurons?
Correct Answer
Transmit nerve impulses away from the CNS toward the effector organs such as
muscles, glands, and digestive organs.
Question 1: Which of the following best describes the primary function of the
mitochondria within a human body cell, and why is this organelle particularly
abundant in cells with high energy demands such as cardiac muscle cells?
A. Storage of genetic material and control of cellular reproduction
B. Synthesis of proteins through translation of messenger RNA
C. Production of adenosine triphosphate (ATP) through cellular respiration,
providing usable energy for cellular processes
D. Modification, packaging, and distribution of proteins and lipids for secretion or
use within the cell
CORRECT ANSWER: C. Production of adenosine triphosphate (ATP) through
cellular respiration, providing usable energy for cellular processes
Rationale: Mitochondria are the primary sites of ATP production via oxidative
phosphorylation and the Krebs cycle. Cells with high metabolic activity, such as
cardiac muscle cells, contain numerous mitochondria to meet continuous energy
requirements for contraction and ion pumping.
Question 2: In the hierarchical organization of the human body, which level of
structural organization is represented by a group of similar cells working
together to perform a specific function, such as the epithelial lining of the
digestive tract?
A. Chemical level
B. Cellular level
C. Tissue level
D. Organ system level
CORRECT ANSWER: C. Tissue level
Rationale: Tissues are collections of similar cells and their extracellular matrix that
perform a common function. Epithelial tissue, for example, forms continuous sheets
that line body cavities and cover surfaces, representing the tissue level of
organization.
Question 3: Which of the following statements accurately describes the
Page 1 of 62
,structure and primary function of the plasma membrane in a typical human
cell?
A. It is a rigid, impermeable barrier composed solely of proteins that completely
isolates the cell from its environment
B. It is a selectively permeable phospholipid bilayer with embedded proteins that
regulates the movement of substances into and out of the cell
C. It is a double membrane containing DNA that controls all cellular activities
D. It is a network of protein filaments that provides internal structural support and
facilitates cell movement
CORRECT ANSWER: B. It is a selectively permeable phospholipid bilayer with
embedded proteins that regulates the movement of substances into and out of
the cell
Rationale: The plasma membrane consists of a phospholipid bilayer with cholesterol
and proteins that control selective permeability, allowing the cell to maintain
homeostasis by regulating ion, nutrient, and waste exchange.
Question 4: During the process of protein synthesis, which organelle is
primarily responsible for the translation of messenger RNA into a polypeptide
chain?
A. Nucleus
B. Smooth endoplasmic reticulum
C. Ribosome
D. Golgi apparatus
CORRECT ANSWER: C. Ribosome
Rationale: Ribosomes, whether free in the cytoplasm or attached to the rough
endoplasmic reticulum, are the sites where transfer RNA molecules deliver amino
acids according to the sequence coded by messenger RNA, forming polypeptide
chains.
Question 5: Which type of epithelial tissue is specialized for diffusion and
filtration and is commonly found lining the air sacs of the lungs and the walls
of blood capillaries?
A. Stratified squamous epithelium
B. Simple cuboidal epithelium
C. Simple squamous epithelium
D. Transitional epithelium
CORRECT ANSWER: C. Simple squamous epithelium
Rationale: Simple squamous epithelium consists of a single layer of flattened cells
that provides a thin barrier ideal for rapid diffusion of gases and filtration of
substances, as seen in alveoli and capillary walls.
Question 6: What is the primary structural difference between dense regular
connective tissue and dense irregular connective tissue, and where is dense
regular connective tissue most commonly located?
A. Dense regular tissue has randomly arranged collagen fibers and is found in the
dermis of the skin
B. Dense regular tissue has parallel collagen fibers and is found in tendons and
Page 2 of 62
,ligaments
C. Dense regular tissue contains more elastic fibers and is found in the walls of large
arteries
D. Dense regular tissue is avascular and is found exclusively in cartilage
CORRECT ANSWER: B. Dense regular tissue has parallel collagen fibers and is
found in tendons and ligaments
Rationale: Dense regular connective tissue features tightly packed collagen fibers
aligned in parallel, providing high tensile strength in one direction, which is ideal for
tendons and ligaments that transmit force along a single axis.
Question 7: Which of the following best describes the function of melanocytes
located in the stratum basale of the epidermis?
A. Production of keratin to waterproof the skin surface
B. Synthesis of melanin pigment that protects underlying tissues from ultraviolet
radiation
C. Secretion of sebum to lubricate the skin and hair
D. Detection of light touch and pressure through specialized sensory endings
CORRECT ANSWER: B. Synthesis of melanin pigment that protects underlying
tissues from ultraviolet radiation
Rationale: Melanocytes produce melanin, which is transferred to nearby
keratinocytes. Melanin absorbs and scatters ultraviolet radiation, reducing DNA
damage in deeper skin layers and contributing to skin color variation.
Question 8: In the process of bone remodeling, which cells are primarily
responsible for the resorption of bone matrix, releasing calcium into the
bloodstream?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Chondrocytes
CORRECT ANSWER: C. Osteoclasts
Rationale: Osteoclasts are large, multinucleated cells that secrete acids and enzymes
to dissolve mineralized bone matrix, thereby releasing calcium and phosphate ions
into the blood and allowing bone remodeling or repair.
Question 9: Which of the following statements correctly identifies the location
and primary function of the red bone marrow in an adult human skeleton?
A. It is found primarily in the medullary cavities of long bones and stores fat
B. It is located in the epiphyses of long bones and flat bones and is the site of
hematopoiesis
C. It is distributed throughout all bone tissue and produces only white blood cells
D. It is confined to the periosteum and is responsible for bone growth in width
CORRECT ANSWER: B. It is located in the epiphyses of long bones and flat
bones and is the site of hematopoiesis
Rationale: In adults, red bone marrow is concentrated in the proximal epiphyses of
long bones and in flat bones such as the sternum and pelvis, where it produces
Page 3 of 62
, erythrocytes, leukocytes, and platelets.
Question 10: What is the functional significance of the sarcoplasmic reticulum
within a skeletal muscle fiber?
A. It stores and releases calcium ions that trigger muscle contraction
B. It synthesizes ATP exclusively through anaerobic pathways
C. It forms the contractile filaments of actin and myosin
D. It transmits nerve impulses from the neuromuscular junction to the muscle
interior
CORRECT ANSWER: A. It stores and releases calcium ions that trigger muscle
contraction
Rationale: The sarcoplasmic reticulum is a specialized endoplasmic reticulum that
sequesters calcium ions. Upon depolarization, it releases calcium, which binds to
troponin and initiates the cross-bridge cycle leading to contraction.
Question 11: During the sliding filament mechanism of skeletal muscle
contraction, which of the following events occurs immediately after calcium
ions bind to troponin?
A. ATP is hydrolyzed to provide energy for the power stroke
B. Tropomyosin shifts, exposing the myosin-binding sites on actin
C. The myosin head detaches from actin
D. Calcium is actively transported back into the sarcoplasmic reticulum
CORRECT ANSWER: B. Tropomyosin shifts, exposing the myosin-binding sites
on actin
Rationale: Binding of calcium to troponin causes a conformational change that
moves tropomyosin away from the myosin-binding sites on actin, allowing cross-
bridge formation and subsequent contraction.
Question 12: Which division of the nervous system is responsible for the
involuntary control of smooth muscle, cardiac muscle, and glands?
A. Somatic nervous system
B. Autonomic nervous system
C. Central nervous system
D. Sensory (afferent) division
CORRECT ANSWER: B. Autonomic nervous system
Rationale: The autonomic nervous system regulates visceral functions without
conscious control. It is subdivided into sympathetic and parasympathetic divisions
that often exert opposing effects on target organs.
Question 13: What is the primary function of the myelin sheath that surrounds
many axons in the peripheral and central nervous systems?
A. To produce neurotransmitters at the synaptic terminal
B. To increase the speed of action potential conduction through saltatory
conduction
C. To store calcium ions for release during synaptic transmission
D. To form the blood-brain barrier that protects neural tissue
CORRECT ANSWER: B. To increase the speed of action potential conduction
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