Skeletal System Quiz

Answer: C. Calcium

Bones primarily store calcium, which is essential for maintaining strong and healthy bone structure, allowing bones to support the body effectively.

Answer: C. 206

An adult human skeleton typically consists of 206 bones, which provide support, protection, and facilitate movement.

Answer: D. Muscles pull on bones to create movement

The muscular system pulls on bones to create movement, with tendons transferring muscle forces to skeletons for joint motion and posture maintenance.

Answer: C. Fat storage

Yellow bone marrow primarily stores fat, which can serve as an energy reserve.

Answer: C. Hematopoiesis

Red bone marrow is responsible for hematopoiesis, the production of blood cells, including red and white blood cells and platelets.

Answer: B. Cancellous bone

The epiphysis consists of cancellous, or spongy bone, which contains red marrow vital for producing blood cells.

Answer: D. Provide nutrients to the bone tissue

The periosteum is a dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints, providing nutrients and facilitating bone repair and growth.

Answer: C. Break down bone tissue

Osteoclasts are responsible for bone resorption, breaking down bone tissue, critical for maintenance, repair, and remodeling of bones.

Answer: D. Osteoblasts

Osteoblasts are specialized cells responsible for bone formation, secreting the matrix that becomes mineralized to form hard bone.

Answer: B. Flat bones are thin and often protect organs; long bones are longer than wide and act as levers

Flat bones are thin, often curved bones that protect organs and provide muscle attachment sites. Long bones are longer than they are wide and act as levers when muscles contract.

Answer: B. Calcium phosphate

Calcium phosphate forms the mineral component of bone, providing hardness and strength, which is essential for support and movement.

Answer: A. Contain osteocytes

Lacunae are small cavities within bone tissue that contain osteocytes, helping maintain the bone matrix.

Answer: C. Compact bone

Compact bone contains Haversian canals, part of the osteon system, which provide passageways for blood vessels and nerves.

Answer: A. Red marrow

Red marrow occupies the spaces between trabeculae in blood-cell-producing regions of spongy bone.

Answer: B. Collagen fibers

Collagen fibers provide tensile strength and flexibility to bone tissue.

Answer: D. Bone is mineralized and rigid; cartilage is flexible and less dense

Bone is dense and mineralized, providing support and structure, while cartilage is flexible and cushions joints.

Answer: C. Provide structure and channel blood vessels

Osteons are structural units in compact bone, providing strength and channels for blood vessels and nerves.

Answer: B. Longer than they are wide

Long bones, like the femur, are characterized by an elongated shape, being longer than they are wide.

Answer: D. Yellow marrow

In adults, the medullary cavity of long bones usually contains yellow marrow, primarily a fat storage site.

Answer: C. Both are long bones with similar structural features

The femur and humerus are both long bones, each with a shaft called the diaphysis and expanded ends called epiphyses.

Answer: C. Support weight distribution and protect marrow

Trabeculae are supporting struts arranged along lines of stress. They help distribute loads and surround spaces that can contain red marrow.

Answer: C. Osteoporosis; weight-bearing exercise

Osteoporosis is characterized by decreased bone density and increased fracture risk. Weight-bearing exercise can help increase bone strength by stimulating bone formation.

Answer: D. Stunted growth or asymmetry

Premature closure of an epiphyseal plate can stop growth in length, producing a shortened limb or uneven growth.

Answer: A. The bony remnant of a former growth plate

The epiphyseal line is the bony remnant left when an epiphyseal plate closes and growth in length ends.

Answer: A. It adapts bone to stress; involves osteoblasts and osteoclasts

Bone remodeling is a dynamic process involving osteoclasts (resorption) and osteoblasts (formation), allowing bones to adapt to stress and maintain strength.

Answer: A. Impaired bone mineralization; restore adequate vitamin D intake

Vitamin D supports calcium absorption, and deficiency can cause rickets in children or osteomalacia in adults. Adequate intake can come from vitamin D-rich or fortified foods and supplements when needed.

Answer: A. Reduced blood supply and impaired healing

Damage to blood vessels at a shaft fracture can reduce the supply of oxygen and nutrients, causing bone-cell death and impairing repair.

Answer: C. Its collateral connections may provide insufficient blood flow, impairing healing

Functional end arteries have connections to other arteries, but these may not maintain adequate blood flow when the main supply is interrupted. Inadequate blood flow can impair fracture repair.

Answer: C. Reduced bone density and balance; suggest calcium, vitamin D, and balance exercises

Elderly people often face reduced bone density and balance, making hip fractures more likely. Calcium, vitamin D, and exercise, improving balance, can help prevent these injuries.

Answer: A. Hematoma, soft callus, bony callus, remodeling

A fracture hematoma forms first, followed by a soft callus that is replaced by a bony callus. Remodeling then reshapes the repaired bone.

Answer: B. Osteopetrosis

Osteopetrosis results from impaired bone resorption by osteoclasts. Bone becomes abnormally dense but fragile, and marrow space may be reduced.

Answer: A. Reduces bone mass and strength

Prolonged immobilization can lead to bone degradation, as mechanical stress is vital for maintaining bone mass and strength.

Answer: B. Causes bone brittleness due to collagen defects

Most cases of osteogenesis imperfecta involve reduced production or abnormal structure of type I collagen. These defects weaken bone and increase its susceptibility to fractures.

Answer: A. Maintains bone structure through diet and hormonal regulation

Calcium homeostasis is vital for bone structure and function, maintained by dietary intake and hormones like parathyroid hormone and calcitonin.

Answer: A. Restore strength and mobility through prescribed exercises

Rehabilitation uses prescribed exercises to rebuild muscle strength and restore mobility after a hip fracture.

Answer: D. Imbalance in calcium and phosphate, leading to osteodystrophy

Chronic kidney disease can disrupt calcium and phosphate balance, leading to renal osteodystrophy, affecting bone mineralization and strength.

Answer: C. Causes abnormal bone remodeling; treatments include bisphosphonates

Paget's disease causes abnormal bone remodeling, leading to weakened, misshapen bones; treated with medications like bisphosphonates to regulate bone metabolism.

Answer: C. Restores blood cell production; potential immune reaction

Bone marrow transplantation can restore blood cell production in diseases like leukemia, but carries risks like immune rejection and graft-versus-host disease.

Answer: A. Weight-bearing exercise and adequate calcium and vitamin D intake

Weight-bearing exercise and adequate calcium and vitamin D support bone maintenance and can help reduce bone loss after menopause. Supplements can address an intake shortfall when needed.

Answer: B. Facilitates lengthwise bone growth

The epiphyseal plate, or growth plate, allows for lengthwise growth of long bones during development, eventually closing to form the epiphyseal line.

Answer: B. Adequate intake is vital for bone density and strength

Adequate dietary intake of calcium and vitamin D is essential for maintaining bone density and preventing disorders like osteoporosis.

Answer: D. They stimulate bone formation and maintenance

Estrogen and testosterone are crucial in promoting bone formation and maintaining bone density; their decline with age can reduce bone mass.

Answer: C. It helps assess fracture risk and informs treatment alongside other clinical factors

Lower bone mineral density is associated with greater fracture risk. Clinicians consider the result together with age and other fracture risk factors when making treatment decisions.

Answer: B. It helps in calcium binding; deficiency may weaken bones

Vitamin K aids in synthesizing proteins for bone metabolism, facilitating calcium binding; deficiency can weaken bone structure.

Answer: C. Children's periosteum has greater bone-forming capacity

The periosteum in children has greater bone-forming capacity, supporting faster fracture repair. Healing time also varies with age, fracture type, and location.

Answer: B. Helps maintain bone density

Hormone replacement therapy can help maintain bone density in postmenopausal women, counteracting the effects of declining estrogen.

Answer: A. Protect vital organs

The axial skeleton includes the skull, vertebral column, and rib cage, primarily functioning to protect vital organs like the brain, spinal cord, and thoracic organs.

Answer: A. Mandible

The mandible is the lower jawbone, holding the lower set of teeth and allowing movement necessary for chewing and speaking.

Answer: B. Sternum

The sternum is part of the thoracic cage, not the cranium, which consists of bones that encase and protect the brain.

Answer: B. Vomer

The vomer is an unpaired bone in the human skull, forming part of the nasal septum.

Answer: B. Protect the heart and lungs

The rib cage protects vital organs like the heart and lungs.

Answer: C. Ethmoid

The perpendicular plate of the ethmoid forms the upper bony portion of the nasal septum.

Answer: D. Occipital bone

The occipital bone forms the posterior skull and posterior cranial base. It contains the foramen magnum, through which the spinal cord passes.

Answer: B. Hyoid bone

The hyoid bone, located in the neck, supports the tongue and is involved in swallowing and speech.

Answer: D. Femur

The femur, or thigh bone, is the longest bone in the human body, providing structural support for walking and standing.

Answer: A. Appendicular skeleton

The appendicular skeleton consists of bones in the limbs and girdles, facilitating movement and interaction with the environment.

Answer: C. Clavicle

The clavicle, or collarbone, connects the arm to the body, playing a crucial role in shoulder mobility and stability.

Answer: B. Tibia

The tibia is one of the two bones in the lower leg, crucial for supporting body weight.

Answer: A. Sesamoid bone

The patella is a sesamoid bone, developed in tendons.

Answer: A. Clavicle

The clavicle is the most commonly fractured bone due to its position.

Answer: B. Lower arm

The ulna is one of the two bones in the forearm, located on the side opposite the thumb.

Answer: D. Scapula

The scapula, or shoulder blade, articulates with the humerus at the shoulder joint, forming the glenohumeral joint.

Answer: D. Patella

The patella, or kneecap, is a small sesamoid bone within the quadriceps tendon that protects the knee joint.

Answer: D. Sternum

The sternum is part of the axial skeleton; the appendicular skeleton includes the bones of the limbs and girdles.

Answer: B. Synovial joint

Synovial joints have a joint cavity filled with synovial fluid, allowing for a wide range of motion.

Answer: D. Hyaline cartilage

At most synovial joints, the articular surfaces are covered by hyaline cartilage, which reduces friction between the bones.

Answer: C. Ligaments connect bone to bone

Ligaments connect bones at joints, providing stability, whereas tendons connect muscles to bones, facilitating movement.

Answer: A. Loss of cartilage and synovial fluid disruption

Synovial joints rely on both hyaline cartilage for smooth motion and synovial fluid for lubrication. Damage to either component can lead to pain and reduced mobility.

Answer: A. Hinge joint

The elbow joint, formed by the articulation of the humerus with the ulna, is a hinge joint, allowing flexion and extension.

Answer: C. They provide stability and guide joint movement

Ligaments are fibrous tissues that stabilize joints, preventing excessive movement and ensuring proper alignment during motion.

Answer: D. Improves joint function; include physical therapy

Joint replacement can significantly improve function and reduce pain; postoperative care should include physical therapy to enhance recovery and maintain mobility.

Answer: A. Fibrous joint

Sutures are fibrous joints that tightly unite most cranial bones and allow little or no movement.

Answer: C. Rotation

Pivot joints allow rotational movement around a single axis, such as the articulation between the atlas and axis.

Answer: A. Ball-and-socket joint

Ball-and-socket joints, like the shoulder and hip, allow for the greatest range of motion, including rotation, flexion, and extension.

Answer: D. Reduce friction in joints

Articular cartilage covers the ends of bones in synovial joints, reducing friction and absorbing shock during movement.