ANAT 260 | ANAT260 Exam 2: Anatomy - WCU
Updated and Latest Questions and Correct
Answers with Rationale
1. Which type of bone cell is responsible for the resorption and breakdown of bone matrix?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Osteoprogenitor cells
Correct Answer: C
Rationale: Osteoclasts are large multinucleated cells derived from monocytes that dissolve
bone minerals. They secrete acid and enzymes to break down the bone matrix during
remodeling. This process is essential for maintaining blood calcium levels in the body.
Osteoblasts, in contrast, are responsible for building new bone tissue. The balance between
these two cell types determines overall bone density and health.
2. The structural unit of compact bone is known as a(n):
A. Trabecula
B. Osteon
C. Canaliculus
D. Lacuna
Correct Answer: B
Rationale: An osteon, also called a Haversian system, is the fundamental functional unit of
compact bone. It consists of concentric layers of bone matrix called lamellae surrounding a
central canal. These units are aligned parallel to the long axis of the bone to provide
strength. Spongy bone lacks these units and instead features a lattice called trabeculae.
Understanding this architecture helps explain how bones resist mechanical stress
efficiently.
3. During muscle contraction, calcium ions bind to which specific protein to initiate the
process?
A. Myosin
B. Actin
C. Tropomyosin
D. Troponin
,Correct Answer: D
Rationale: Calcium ions are released from the sarcoplasmic reticulum upon excitation of
the muscle fiber. These ions bind specifically to troponin, which causes a conformational
change in the protein complex. This shift moves tropomyosin away from the active sites on
the actin filament. Once the sites are exposed, myosin heads can bind to form cross-bridges.
This sequence of events is a critical component of the sliding filament theory.
4. Which bone is considered part of the axial skeleton?
A. Sphenoid
B. Scapula
C. Clavicle
D. Femur
Correct Answer: A
Rationale: The axial skeleton consists of the bones that form the central axis of the body.
This includes the skull, vertebral column, and the thoracic cage. The sphenoid bone is a
complex bone located within the cranium of the skull. The scapula, clavicle, and femur are
all part of the appendicular skeleton. Categorizing bones this way helps students learn
regional anatomy and functional groupings.
5. What type of joint is the elbow joint, primarily allowing for flexion and extension?
A. Ball-and-socket
B. Pivot
C. Saddle
D. Hinge
Correct Answer: D
Rationale: A hinge joint allows for movement in only one plane, similar to a door hinge. In
the elbow, the trochlea of the humerus articulates with the trochlear notch of the ulna. This
structure limits the joint’s movement to flexion and extension. Other examples of hinge
joints include the knee and the interphalangeal joints. These joints are characterized by
strong collateral ligaments that provide lateral stability.
6. Which hormone is released when blood calcium levels are too low, stimulating bone
resorption?
A. Calcitonin
B. Thyroxine
C. Parathyroid hormone (PTH)
D. Insulin
, Correct Answer: C
Rationale: Parathyroid hormone (PTH) is produced by the parathyroid glands in response
to hypocalcemia. It functions by stimulating osteoclasts to break down bone and release
calcium into the blood. PTH also increases calcium reabsorption in the kidneys and
activates vitamin D. Calcitonin has the opposite effect, working to lower blood calcium
levels. This feedback loop is essential for maintaining homeostasis within the skeletal and
nervous systems.
7. The epiphyseal plate is the site where:
A. Bone grows in thickness
B. Muscle tendons attach
C. Red blood cells are produced
D. Bone grows in length
Correct Answer: D
Rationale: The epiphyseal plate is a layer of hyaline cartilage found in children and
adolescents. It is located between the epiphysis and diaphysis of a long bone. New cartilage
is produced on the epiphyseal side while being ossified on the diaphyseal side. This process
allows the bone to elongate during the growth years. Once growth is complete, the plate
ossifies into the epiphyseal line.
8. Which of the following movements increases the angle between two bones at a joint?
A. Extension
B. Flexion
C. Abduction
D. Adduction
Correct Answer: A
Rationale: Extension is a movement that straightens a joint and increases the angle
between body parts. It is the opposite of flexion, which decreases the joint angle. When you
stand up from a seated position, you are extending your knees and hips. Over-extension
beyond the normal anatomical position is referred to as hyperextension. Proper
terminology is vital for describing clinical findings and athletic movements.
9. Which muscle is a member of the rotator cuff group?
A. Teres major
B. Subscapularis
C. Deltoid
D. Biceps brachii
Updated and Latest Questions and Correct
Answers with Rationale
1. Which type of bone cell is responsible for the resorption and breakdown of bone matrix?
A. Osteoblasts
B. Osteocytes
C. Osteoclasts
D. Osteoprogenitor cells
Correct Answer: C
Rationale: Osteoclasts are large multinucleated cells derived from monocytes that dissolve
bone minerals. They secrete acid and enzymes to break down the bone matrix during
remodeling. This process is essential for maintaining blood calcium levels in the body.
Osteoblasts, in contrast, are responsible for building new bone tissue. The balance between
these two cell types determines overall bone density and health.
2. The structural unit of compact bone is known as a(n):
A. Trabecula
B. Osteon
C. Canaliculus
D. Lacuna
Correct Answer: B
Rationale: An osteon, also called a Haversian system, is the fundamental functional unit of
compact bone. It consists of concentric layers of bone matrix called lamellae surrounding a
central canal. These units are aligned parallel to the long axis of the bone to provide
strength. Spongy bone lacks these units and instead features a lattice called trabeculae.
Understanding this architecture helps explain how bones resist mechanical stress
efficiently.
3. During muscle contraction, calcium ions bind to which specific protein to initiate the
process?
A. Myosin
B. Actin
C. Tropomyosin
D. Troponin
,Correct Answer: D
Rationale: Calcium ions are released from the sarcoplasmic reticulum upon excitation of
the muscle fiber. These ions bind specifically to troponin, which causes a conformational
change in the protein complex. This shift moves tropomyosin away from the active sites on
the actin filament. Once the sites are exposed, myosin heads can bind to form cross-bridges.
This sequence of events is a critical component of the sliding filament theory.
4. Which bone is considered part of the axial skeleton?
A. Sphenoid
B. Scapula
C. Clavicle
D. Femur
Correct Answer: A
Rationale: The axial skeleton consists of the bones that form the central axis of the body.
This includes the skull, vertebral column, and the thoracic cage. The sphenoid bone is a
complex bone located within the cranium of the skull. The scapula, clavicle, and femur are
all part of the appendicular skeleton. Categorizing bones this way helps students learn
regional anatomy and functional groupings.
5. What type of joint is the elbow joint, primarily allowing for flexion and extension?
A. Ball-and-socket
B. Pivot
C. Saddle
D. Hinge
Correct Answer: D
Rationale: A hinge joint allows for movement in only one plane, similar to a door hinge. In
the elbow, the trochlea of the humerus articulates with the trochlear notch of the ulna. This
structure limits the joint’s movement to flexion and extension. Other examples of hinge
joints include the knee and the interphalangeal joints. These joints are characterized by
strong collateral ligaments that provide lateral stability.
6. Which hormone is released when blood calcium levels are too low, stimulating bone
resorption?
A. Calcitonin
B. Thyroxine
C. Parathyroid hormone (PTH)
D. Insulin
, Correct Answer: C
Rationale: Parathyroid hormone (PTH) is produced by the parathyroid glands in response
to hypocalcemia. It functions by stimulating osteoclasts to break down bone and release
calcium into the blood. PTH also increases calcium reabsorption in the kidneys and
activates vitamin D. Calcitonin has the opposite effect, working to lower blood calcium
levels. This feedback loop is essential for maintaining homeostasis within the skeletal and
nervous systems.
7. The epiphyseal plate is the site where:
A. Bone grows in thickness
B. Muscle tendons attach
C. Red blood cells are produced
D. Bone grows in length
Correct Answer: D
Rationale: The epiphyseal plate is a layer of hyaline cartilage found in children and
adolescents. It is located between the epiphysis and diaphysis of a long bone. New cartilage
is produced on the epiphyseal side while being ossified on the diaphyseal side. This process
allows the bone to elongate during the growth years. Once growth is complete, the plate
ossifies into the epiphyseal line.
8. Which of the following movements increases the angle between two bones at a joint?
A. Extension
B. Flexion
C. Abduction
D. Adduction
Correct Answer: A
Rationale: Extension is a movement that straightens a joint and increases the angle
between body parts. It is the opposite of flexion, which decreases the joint angle. When you
stand up from a seated position, you are extending your knees and hips. Over-extension
beyond the normal anatomical position is referred to as hyperextension. Proper
terminology is vital for describing clinical findings and athletic movements.
9. Which muscle is a member of the rotator cuff group?
A. Teres major
B. Subscapularis
C. Deltoid
D. Biceps brachii
