WGU D312 Anatomy and Physiology Updated
Questions and Answers (2026/2027) | Practice
Review | A+ Verified
• Which part of the plasma membrane binds a specific molecule outside the cell?
CORRECT ANSWER: Receptor
A receptor is a type of recognition protein that can selectively bind a specific molecule
outside the cell, and this binding induces a chemical reaction within the cell.
• What does it mean if an anatomical structure is caudal? CORRECT ANSWER: If an
anatomical structure is described as caudal, it means it is located towards the tail or
lower part of the body. In humans, this typically refers to a position closer to the feet or
the lower end of the spine.
For example, the legs are caudal to the arms, meaning they are situated lower on the
body compared to the arms.
• What is the role of an effector in a negative feedback system? CORRECT ANSWER:
In a negative feedback system, the effector plays a crucial role in maintaining
homeostasis by carrying out the response to a stimulus. Here's how it works:
Detection: A receptor detects a change in a physiological variable (e.g., temperature,
blood sugar levels).
Signal Processing: The control center (often the brain or endocrine glands) processes
this information and determines the appropriate response.
Action: The effector enacts the response to counteract the initial change and bring the
variable back to its set point.
For example, if your body temperature drops, the effector (such as muscles shivering)
generates heat to raise your body temperature back to normal.
• What is the correct order of the epidermis layer arranged from deep to superficial?
CORRECT ANSWER: 1. Stratum basale (or stratum germinativum)
2. Stratum spinosum
3. Stratum granulosum
4. Stratum lucidum (only present in thick skin, such as the palms and soles)
5. Stratum corneum
• Which skin layer contains Langerhans cells? CORRECT ANSWER: Langerhans cells
are primarily found in the stratum spinosum layer of the epidermis. These cells play a
key role in the skin's immune defense by acting as antigen-presenting cells, which help
detect and fight pathogens.
• Which degree of burn affects the underlying bones and muscles? CORRECT
ANSWER: Fourth-degree burns are the most severe and affect not only all layers of the
skin but also the underlying bones, muscles, and tendons. These burns often appear
charred or white and are typically painless because the nerve endings are destroyed.
,• Which part of the long bone has an epiphyseal line? CORRECT ANSWER: The
epiphyseal line is located at the junction between the diaphysis (the shaft or central part
of the bone) and the epiphysis (the end part of the bone) in long bones. This line is a
remnant of the epiphyseal plate (growth plate) and indicates that the bone has
completed its growth in length.
• Which suture is present between the left and right parietal lobes? CORRECT
ANSWER: The suture present between the left and right parietal lobes is the sagittal
suture. This suture runs along the midline of the skull, connecting the two parietal
bones.
• Which two bones form the pectoral girdle? CORRECT ANSWER: The pectoral girdle,
also known as the shoulder girdle, is formed by two bones: the clavicle (collarbone) and
the scapula (shoulder blade). These bones work together to connect the upper limb to
the axial skeleton and provide a wide range of motion for the shoulder and arm.
• What are the periodic invaginations in sarcolemma called? CORRECT ANSWER: The
periodic invaginations in the sarcolemma are called T-tubules (transverse tubules).
These structures play a crucial role in conducting electrical impulses from the surface of
the muscle fiber to its interior, ensuring that the muscle contracts efficiently and
uniformly.
• Which medially placed group of muscles is part of the erector spinae? CORRECT
ANSWER: The spinalis muscles are the most medially placed group within the erector
spinae muscle group. These muscles are located closest to the spine and are
responsible for extending and laterally flexing the cervical and thoracic regions of the
spine.
• Which thigh muscle is situated below the adductor longus? CORRECT ANSWER:
The muscle situated below the adductor longus is the adductor magnus. This muscle is
a large, triangular muscle located in the medial compartment of the thigh and plays a
significant role in adducting and medially rotating the thigh
• What is the role of oligodendrocytes? CORRECT ANSWER: Oligodendrocytes play a
crucial role in the central nervous system (CNS) by producing the myelin sheath that
insulates axons. This myelination is essential for the efficient transmission of electrical
impulses along nerve fibers, which helps in the rapid and coordinated communication
between neurons. Additionally, oligodendrocytes provide metabolic support to neurons
and contribute to maintaining a stable microenvironment within the CNS.
• Which membrane channel is able to open due to a physical distortion? CORRECT
ANSWER: The membrane channel that opens due to physical distortion is the
mechanically gated channel. These channels respond to mechanical changes such as
stretch, pressure, or vibration and are crucial in sensory processes like touch and
hearing.
, • Which nerve controls the lifting of the upper eyelid? CORRECT ANSWER: The nerve
responsible for controlling the lifting of the upper eyelid is the oculomotor nerve (cranial
nerve III). It innervates the levator palpebrae superioris muscle, which is essential for
elevating the upper eyelid.
• Which hormones are secreted from the posterior pituitary gland? CORRECT
ANSWER: The posterior pituitary gland secretes two main hormones: oxytocin and
antidiuretic hormone (ADH), also known as vasopressin.
Oxytocin plays a crucial role in childbirth and lactation, stimulating uterine contractions
and milk ejection.
Antidiuretic hormone (ADH) helps regulate water balance in the body by increasing
water reabsorption in the kidneys.
• Which endocrine gland secretes glucagon? CORRECT ANSWER: Glucagon is
secreted by the pancreas. Specifically, it is produced by the alpha cells in the islets of
Langerhans within the pancreas.
Glucagon plays a crucial role in regulating blood sugar levels by promoting the
conversion of stored glycogen in the liver into glucose, which is then released into the
bloodstream.
• Which glycoprotein hormone is secreted from the anterior pituitary gland? CORRECT
ANSWER: The anterior pituitary gland secretes several glycoprotein hormones,
including:
Luteinizing hormone (LH): Stimulates the secretion of sex hormones by the ovaries and
testes.
Follicle-stimulating hormone (FSH): Promotes the growth and maturation of ovarian
follicles in females and spermatogenesis in males.
Thyroid-stimulating hormone (TSH): Stimulates the thyroid gland to produce thyroid
hormones.
These hormones play crucial roles in regulating various physiological processes,
including reproduction and metabolism.
• The cell's central organelle; contains the cell's DNA CORRECT ANSWER: Nucleus
• The jelly-like substance in which the cell organelles and nucleus are embedded
CORRECT ANSWER: Cytoplasm
• A thin and flexible membrane surrounding the cells that acts as a barrier between the
intracellular and the extracellular fluids CORRECT ANSWER: Cell membrane
• A membrane-associated protein that spans the entire width of the lipid bilayer.
CORRECT ANSWER: Integral protein
• A membrane-spanning protein that has an inner pore that allows the passage of one
or more substances. CORRECT ANSWER: Channel protein
Questions and Answers (2026/2027) | Practice
Review | A+ Verified
• Which part of the plasma membrane binds a specific molecule outside the cell?
CORRECT ANSWER: Receptor
A receptor is a type of recognition protein that can selectively bind a specific molecule
outside the cell, and this binding induces a chemical reaction within the cell.
• What does it mean if an anatomical structure is caudal? CORRECT ANSWER: If an
anatomical structure is described as caudal, it means it is located towards the tail or
lower part of the body. In humans, this typically refers to a position closer to the feet or
the lower end of the spine.
For example, the legs are caudal to the arms, meaning they are situated lower on the
body compared to the arms.
• What is the role of an effector in a negative feedback system? CORRECT ANSWER:
In a negative feedback system, the effector plays a crucial role in maintaining
homeostasis by carrying out the response to a stimulus. Here's how it works:
Detection: A receptor detects a change in a physiological variable (e.g., temperature,
blood sugar levels).
Signal Processing: The control center (often the brain or endocrine glands) processes
this information and determines the appropriate response.
Action: The effector enacts the response to counteract the initial change and bring the
variable back to its set point.
For example, if your body temperature drops, the effector (such as muscles shivering)
generates heat to raise your body temperature back to normal.
• What is the correct order of the epidermis layer arranged from deep to superficial?
CORRECT ANSWER: 1. Stratum basale (or stratum germinativum)
2. Stratum spinosum
3. Stratum granulosum
4. Stratum lucidum (only present in thick skin, such as the palms and soles)
5. Stratum corneum
• Which skin layer contains Langerhans cells? CORRECT ANSWER: Langerhans cells
are primarily found in the stratum spinosum layer of the epidermis. These cells play a
key role in the skin's immune defense by acting as antigen-presenting cells, which help
detect and fight pathogens.
• Which degree of burn affects the underlying bones and muscles? CORRECT
ANSWER: Fourth-degree burns are the most severe and affect not only all layers of the
skin but also the underlying bones, muscles, and tendons. These burns often appear
charred or white and are typically painless because the nerve endings are destroyed.
,• Which part of the long bone has an epiphyseal line? CORRECT ANSWER: The
epiphyseal line is located at the junction between the diaphysis (the shaft or central part
of the bone) and the epiphysis (the end part of the bone) in long bones. This line is a
remnant of the epiphyseal plate (growth plate) and indicates that the bone has
completed its growth in length.
• Which suture is present between the left and right parietal lobes? CORRECT
ANSWER: The suture present between the left and right parietal lobes is the sagittal
suture. This suture runs along the midline of the skull, connecting the two parietal
bones.
• Which two bones form the pectoral girdle? CORRECT ANSWER: The pectoral girdle,
also known as the shoulder girdle, is formed by two bones: the clavicle (collarbone) and
the scapula (shoulder blade). These bones work together to connect the upper limb to
the axial skeleton and provide a wide range of motion for the shoulder and arm.
• What are the periodic invaginations in sarcolemma called? CORRECT ANSWER: The
periodic invaginations in the sarcolemma are called T-tubules (transverse tubules).
These structures play a crucial role in conducting electrical impulses from the surface of
the muscle fiber to its interior, ensuring that the muscle contracts efficiently and
uniformly.
• Which medially placed group of muscles is part of the erector spinae? CORRECT
ANSWER: The spinalis muscles are the most medially placed group within the erector
spinae muscle group. These muscles are located closest to the spine and are
responsible for extending and laterally flexing the cervical and thoracic regions of the
spine.
• Which thigh muscle is situated below the adductor longus? CORRECT ANSWER:
The muscle situated below the adductor longus is the adductor magnus. This muscle is
a large, triangular muscle located in the medial compartment of the thigh and plays a
significant role in adducting and medially rotating the thigh
• What is the role of oligodendrocytes? CORRECT ANSWER: Oligodendrocytes play a
crucial role in the central nervous system (CNS) by producing the myelin sheath that
insulates axons. This myelination is essential for the efficient transmission of electrical
impulses along nerve fibers, which helps in the rapid and coordinated communication
between neurons. Additionally, oligodendrocytes provide metabolic support to neurons
and contribute to maintaining a stable microenvironment within the CNS.
• Which membrane channel is able to open due to a physical distortion? CORRECT
ANSWER: The membrane channel that opens due to physical distortion is the
mechanically gated channel. These channels respond to mechanical changes such as
stretch, pressure, or vibration and are crucial in sensory processes like touch and
hearing.
, • Which nerve controls the lifting of the upper eyelid? CORRECT ANSWER: The nerve
responsible for controlling the lifting of the upper eyelid is the oculomotor nerve (cranial
nerve III). It innervates the levator palpebrae superioris muscle, which is essential for
elevating the upper eyelid.
• Which hormones are secreted from the posterior pituitary gland? CORRECT
ANSWER: The posterior pituitary gland secretes two main hormones: oxytocin and
antidiuretic hormone (ADH), also known as vasopressin.
Oxytocin plays a crucial role in childbirth and lactation, stimulating uterine contractions
and milk ejection.
Antidiuretic hormone (ADH) helps regulate water balance in the body by increasing
water reabsorption in the kidneys.
• Which endocrine gland secretes glucagon? CORRECT ANSWER: Glucagon is
secreted by the pancreas. Specifically, it is produced by the alpha cells in the islets of
Langerhans within the pancreas.
Glucagon plays a crucial role in regulating blood sugar levels by promoting the
conversion of stored glycogen in the liver into glucose, which is then released into the
bloodstream.
• Which glycoprotein hormone is secreted from the anterior pituitary gland? CORRECT
ANSWER: The anterior pituitary gland secretes several glycoprotein hormones,
including:
Luteinizing hormone (LH): Stimulates the secretion of sex hormones by the ovaries and
testes.
Follicle-stimulating hormone (FSH): Promotes the growth and maturation of ovarian
follicles in females and spermatogenesis in males.
Thyroid-stimulating hormone (TSH): Stimulates the thyroid gland to produce thyroid
hormones.
These hormones play crucial roles in regulating various physiological processes,
including reproduction and metabolism.
• The cell's central organelle; contains the cell's DNA CORRECT ANSWER: Nucleus
• The jelly-like substance in which the cell organelles and nucleus are embedded
CORRECT ANSWER: Cytoplasm
• A thin and flexible membrane surrounding the cells that acts as a barrier between the
intracellular and the extracellular fluids CORRECT ANSWER: Cell membrane
• A membrane-associated protein that spans the entire width of the lipid bilayer.
CORRECT ANSWER: Integral protein
• A membrane-spanning protein that has an inner pore that allows the passage of one
or more substances. CORRECT ANSWER: Channel protein
