Bones are constantly undergoing resorption for various reasons. Which of the following cells accomplishes this process?
A. stem cell
The notable hardness of bone is attributed to ________.
the presence of glycoproteins
the presence of cartilage
the presence of proteoglycans
the presence of inorganic hydroxyapatites
the presence of collagen fibers
When should prevention of osteoporosis start?
The prevention of osteoporosis should begin with children while bones are still growing. Children should increase their bone mass to provide additional protection from osteoporosis in the future.
The prevention of osteoporosis should start in early old age, to prevent a decrease in bone density in the future.
The prevention of osteoporosis should begin young adults, to increase the bone mass to provide additional protection from osteoporosis.
The prevention of osteoporosis should start in middle age, to counter the gradual loss of bone density as we get old.
The term diploë refers to the ________.
fact that most bones are formed of two types of bone tissue
double-layered nature of the connective tissue covering the bone
internal layer of spongy bone in flat bones
two types of marrow found within most bones
Cartilage grows in two ways, appositional and interstitial. What is appositional growth?
the secretion of new matrix against the external face of existing cartilage
the lengthening of hyaline cartilage
growth at the epiphyseal plate
along the edges only of existing osteons, making each osteon larger
In adults, yellow marrow is located ________.
in the epiphyseal plates of long bones
in the central canals of osteons
in the medullary cavity of long bones
primarily in flat bones
The osteon is ________.
a fibrous membrane that covers and protects bone
the structural unit of compact bone
the structural unit of spongy bone
a network of red marrow
The pituitary gland is housed in the ________.
sinuses of the ethmoid bone
sella turcica of the sphenoid bone
Why, or why not, is swimming recommended as an exercise to prevent osteoporosis?
Swimming is not recommended to prevent osteoporosis, as it is not considered a weight-bearing exercise.
Swimming is not recommended to prevent osteoporosis, as forces are applied in all directions on the bones simultaneously in swimming.
Swimming is recommended to prevent osteoporosis, as forces are applied in all directions on the bones simultaneously.
Swimming is recommended to prevent osteoporosis, as it is considered a weight-bearing exercise.
What is the structural unit of compact bone?
Which hormone increases osteoclast activity to release more calcium ions into the bloodstream?
Cranial bones develop ________.
from cartilage models
from a tendon
within fibrous membranes
within osseous membranes
Hematopoiesis refers to the formation of blood cells within the red marrow cavities of certain bones.
For intramembranous ossification to take place, which of the following is necessary?
An ossification center forms in the fibrous connective tissue.
A medullary cavity forms.
A bone collar forms around the cartilage model.
The cartilage matrix begins to deteriorate
Which description of bone cells is INCORRECT?
Osteoclasts secrete digestive enzymes and hydrogen ions.
Osteogenic cells can differentiate into osteoclasts.
Bone lining cells on the internal surfaces of bone are also called endosteal cells.
Osteoblasts secrete collagen and calcium-binding proteins.
Which of the following glands or organs produces hormones that tend to decrease blood calcium levels?
In some cases the epiphyseal plate of the long bones of children closes too early. What might be the cause?
osteoblast activity exceeds osteoclast activity
elevated levels of sex hormones
overproduction of thyroid hormone
too much vitamin D in the diet
The canal that runs through the core of each osteon (the Haversian canal) is the site of ________.
yellow marrow and spicules
cartilage and interstitial lamellae
adipose tissue and nerve fibers
blood vessels and nerve fibers
Ossification of the ends of long bones ________.
takes twice as long as diaphysis ossification
involves medullary cavity formation
is a characteristic of intramembranous bone
is produced by secondary ossification centers
The periosteum is a tissue that serves only to protect the bone because it is not supplied with nerves or blood vessels.
Short, irregular, and flat bones have large marrow cavities in order to keep the weight of the bones light.
The hormone that is primarily involved in the control of bone remodeling is the parathyroid hormone.
Which of the following is a bone marking name that indicates an armlike bar of bone?
How can a tooth be moved in a bony socket during orthodontic treatment?
Teeth are avascular, allowing part of the tooth to be removed for repositioning.
By applying slight pressure to a tooth, the bone on the forward side will reformed, while the bone on the reverse side will be reabsorbed.
By applying slight pressure to a tooth, the gums will be reabsorbed and reformed to the new position of the tooth.
By applying slight pressure to a tooth, the bone on the forward side will reabsorb, while the bone on the reverse side will be reformed.
What tissue forms the model for endochondrial ossification?
Which hormone is produced in bone and regulates bone formation, but also protects against diabetes mellitus?
Osteomyelitis is ________.
caused by altered vitamin D metabolism
partially due to insufficient dietary calcium
due to pus-forming bacteria
literally known as "soft bones"
What controls bone remodeling?
the nervous system and hormones
mechanical stress and hormones
hormones and diet
mechanical stress and diet
The suture that connects the two parietal bones together is the ________.
A Pott's fracture could result in damage to all of the following except ____________.
inferior tibiofibular joint
In newborn infants, the medullary cavity and all areas of spongy bone contain yellow bone marrow.
The correct order (from start to finish) of fracture repair is ________.
bone remodeling, hematoma formation, fibrocartilaginous callus formation, and bony callus formation
bony callus formation, hematoma formation, fibrocartilaginous callus formation, and bone remodeling
hematoma formation, fibrocartilaginous callus formation, bony callus formation, and bone remodeling
hematoma formation, bony callus formation, bone remodeling, and fibrocartilaginous callus formation
Yellow bone marrow contains a large percentage of ________.
Hematopoiesis is a term for which of the following physiological processes?
bone formation during growth
bone formation during growth
blood cell formation
release of minerals into the blood
energy storage in fat tissue
Choose the TRUE statement.
Most bones in the body are formed by intramembranous ossification.
Endochondral ossification converts hyaline cartilage "bone" models into true bones (i.e., hyaline cartilage serves as a template for bone formation).
Endochondral ossification leads to the formation of the clavicles and cranial bones.
Endochondral ossification occurs within fibrous connective tissue membranes.
Hyaline cartilage ________.
is the rarest of the skeletal cartilages
gives shape to the external ear
forms "shock-absorbing" pads between the vertebrae
is found on the ends of bones that form movable joints
Which bone acts as a moveable base for the tongue?
Bones are covered and lined by a protective tissue called periosteum. The inner (osteogenic) layer consists primarily of ________.
chondrocytes and osteocytes
marrow and osteons
cartilage and compact bone
osteoblasts and osteoclasts
The structure of bone tissue suits the function. Which of the following bone tissues is adapted to support weight and withstand tension stress?
During infancy and childhood, the most important stimulus of epiphyseal plate activity is ________.
the thyroid hormones
In the epiphyseal plate, cartilage grows ________.
from the edges inward
in a circular fashion
by pulling the diaphysis toward the epiphysis
by pushing the epiphysis away from the diaphysis
Which of the following is not a function of the skeletal system?
storage of minerals
houses the bone marrow which produces blood cells (hematopoiesis)
The resilience of bone is primarily due to which of the following?
amount of mineral salts in the bone
sacrificial bonds in or between collagen molecules
amount of mineral salt and protein in the bone
presence of osteoblasts in the bone
What is the final stage in the healing of a bone fracture?
formation of a bony callus
formation of a hematoma
formation of a fibrocartilaginous callus
Lengthwise, long bone growth during infancy and youth is exclusively through ________.
differentiation of osteoclasts into osteocytes
the secretion of bone matrix into the medullary cavity
calcification of the matrix of the zone underlying articular cartilage
interstitial growth of the epiphyseal plates
Which of the following is not a movement that can occur between vertebrae?
flexion and extension
Which of the following is an abnormal lateral curvature of the vertebral column often seen in the thoracic region?
What makes up the axial skeleton?
the skull, vertebral column, and rib cage
arms, legs, hands, and feet
the skull, vertebral column, and pelvis
shoulder and pelvic girdles
Which of the following is true about paranasal sinuses?
Paranasal sinuses open into the oral cavity.
Paranasal sinuses contain passages acting as one-way valves.
Paranasal sinuses are found in maxillary, ethmoid, and lacrimal bones.
Paranasal sinuses enhance the resonance of the voice and lighten the skull.
What causes osteoporosis?
heritage such as African or Mediterranean
abnormal PTH receptors
Osteoclasts out-pace osteoblasts due to low hormone production of the ovaries.
When chondrocytes in lacunae divide and form new matrix, it leads to an expansion of the cartilage tissue from within. This process is called ________.
Which of the following refers to a bone disorder found most often in the aged and resulting in the bones becoming porous and light?
Which of the following phrases best describes the function of the vertebral curves?
to accommodate muscle attachment
to improve cervical center of gravity
to provide resilience and flexibility
to accommodate the weight of the pelvic girdle
Choose the CORRECT pairing.
osteomalacia: excessive mineralization of the bone
paget's disease: excessive and haphazard bone deposition and resorption
osteoporosis: increased bone density
rickets: deficiency of vitamin A
What is endochondral ossification?
the formation of bone from fibrous membranes
the formation of bone from pre-existing fibrocartilage models
the formation of bone from pre-existing hyaline cartilage models
the formation of bone from pre-existing elastic cartilage models
Mrs. Mulligan goes to her dentist and, after having a couple of cavities filled, her dentist strongly suggests that she reduce her intake of sodas and increase her intake of calcium phosphates in the foods she eats. Why?
Sodas are strong bases that can dissolve the calcium phosphate in bone and teeth.
Sodas are strong acids that can dissolve the calcium phosphate in bone and teeth.
Sodas contain lots of sugar that can dissolve the calcium carbonate in bone and teeth.
Sodas contain lots of sugar that can dissolve the calcium phosphate in bone and teeth.
Sodas are carbonated, and the increased carbon dioxide can dissolve the calcium carbonate in bone and teeth.
Which structure allows the diaphysis of the bone to increase in length until early childhood, as well as shaping the articular surfaces?
What is absolutely required for bone growth or healing from a fracture?
dietary intake of calcium and vitamin D
Choose the FALSE statement.
Long bones include all limb bones except the patella.
Irregular bones include the vertebrae and hip bones.
The sternum is an example of a flat bone.
Sesamoid bones form within certain tendons.
Wolff's law is concerned with ________.
the thickness and shape of a bone being dependent on stresses placed upon it
the diameter of the bone being dependent on the ratio of osteoblasts to osteoclasts
the function of bone being dependent on shape
vertical growth of bones being dependent on age
Which of the following is UNLIKELY to affect bone remodeling?
low blood Ca2+ concentration
The process of bones increasing in width is known as ________.
epiphyseal plate closure
closing of the epiphyseal plate
An osteon contains osteocytes, lamellae, and a central canal, and is found in compact bone only.
A fracture in the shaft of a bone would be a break in the ________.
The periosteum is secured to the underlying bone by dense connective tissue called ________.
the struts of bone known as spicules
perforating (Sharpey's) fibers
a bony matrix with hyaline cartilage
Alice and James adopted a 3-year-old child from a developing country. They noticed that her legs were bowed and there were some deformities in her cranial and pelvic bones. They brought her to a physician for a diagnosis. What was the diagnosis, and what was the treatment for the disorder?
The child most likely has Paget's disease. Treatment includes drug therapy with administration of calcitonin and bisphosphonates.
The child most likely has rickets. Treatment is to increase the intake of calcium and vitamin D in the diet, and to get some sunshine every day.
The child most likely has osteomalacia. Treatment is to increase the intake of calcium and vitamin D in the diet, and to get some sunshine every day.
The child most likely has osteoporosis. Treatment is to increase the intake of calcium and vitamin D, and performance of weight-bearing exercises.
Osteogenesis is the process of ________.
making collagen fibers for calcified cartilage
making a cartilage model of the fetal bone
bone destruction to liberate calcium
Which of the following hormones is currently thought to decrease plasma calcium levels in pregnant women and children?
parathyroid hormone (PTH)
PTH promotes the formation of which hormone?
Which of the following would NOT be a way that parathyroid hormone (PTH) could alter plasma calcium levels? (Which one of the following is FALSE?)
increase osteoblasts on bone
increase reabsorption of calcium in the kidney
Which hormone works directly in the intestine to increase plasma calcium levels?
parathyroid hormone (PTH)
Bones do NOT have a role in ________.
blood cell formation
The membranous areas between the cranial bones of the fetal skull are called ________.
What is osteoid?
the outer surface of bone
the organic part of the matrix of bone
the inorganic part of the matrix of bone
one of the cell types found in bone
The cell responsible for secreting the matrix of bone is the ________.
What can a deficiency of growth hormone during bone formation cause?
inadequate calcification of bone
decreased osteoclast activity
increased osteoclast activity
decreased proliferation of the epiphyseal plate cartilage
Which type of cartilage covers and protects the ends of bones at freely moveable joints?
both hyaline and elastic cartilage
What indicates that a long bone has reached its adult length?
the presence of hyaline cartilage on the ends of the bone
the presence of osteons
the presence of osteoblasts
closure of the epiphyseal plate
Hypercalcemia can be caused by_________.
insufficient vitamin D levels in the body
hypersecretion of parathyroid hormone
reduced parafollicular cell activity
All of the listed responses are correct
break down bone
form new bone
form skeletal cartilage
calcify bone matrix
What kind of tissue is the forerunner of long bones in the embryo?
elastic connective tissue
dense fibrous connective tissue
Which of the following is stored in bones?
The structural unit of spongy is called ________.
Which of the following statements best describes interstitial growth?
Fibroblasts give rise to chondrocytes that differentiate and form cartilage.
Growth occurs in the lining of the long bones.
Chondrocytes in the lacunae divide and secrete matrix, allowing the cartilage to grow from within.
Unspecialized cells from mesenchyme develop into chondrocytes, which divide and form cartilage.
Which bone serves as an enclosure for the pituitary gland?
Growth of bones is controlled by a symphony of hormones. Which hormone is of greatest importance for bone growth during infancy and childhood?
In adults, hematopoietic tissue is NOT found in ________.
the medullary cavity of long bones
the hip bones and vertebrae
the flat bones of the skull and sternum
the heads of the femur and humerus
Which of the following is the single most important stimulus for epiphyseal plate activity during infancy and childhood?
The epiphyseal plate is ________.
the site of red bone marrow production
where long bone lengthening occurs
where yellow bone marrow is produced
the long axis of a bone
Which of the following is CORRECTLY matched?
nondisplaced fracture: the fractured bone ends are misaligned
linear fracture: the break is perpendicular to the bone's long axis
compound fracture: the fractured bone ends penetrate the skin
incomplete fracture: the bone is broken through
Normal bone formation and growth are dependent on the adequate intake of ________.
vitamin D, phosphate, and chloride
calcium, phosphate, and vitamin D
potassium, phosphate, and vitamin D
sodium, calcium, and vitamin E