Using Figure 6.1, match the following bone types with the numbered
structure:
1) Bone 1
2) Bone 2
3) Bone 3
4) Bone 4
5) Bone 5
6) Bone 6
7) Bone 7
A. Long
B. Short
C. Flat
D. Irregular
E. Sesamoid
1) Bone 1 C
2) Bone 2 A
3) Bone 3 C
4) Bone 4 D
5) Bone 5 A
6) Bone 6 E
7) Bone 7 B
Using Figure 6.2, match the following:
8) Compact bone
9) Location of the epiphyseal line
10) Area where yellow
marrow is found
11) Area with articular cartilage
8) C
9) B
10) D
11) A
Bones are porous and thin but bone composition is normal.
A) Osteomalacia
B) Paget's disease
C) Osteoporosis
C) Osteoporosis
Bone formed is poorly mineralized and soft. Deforms on weight
bearing.
A) Osteomalacia
B) Paget's disease
C) Osteoporosis
A) Osteomalacia
Abnormal bone formation and reabsorption.
A)
Osteomalacia
B) Paget's disease
C) Osteoporosis
B) Paget's disease
An incomplete fracture or cracking of the bone without actual
separation of the parts. Common in children.
A)
Comminuted
B) Spiral
C) Greenstick
C) Greenstick
Bone fragments into many pieces.
A) Comminuted
B)
Spiral
C) Greenstick
A) Comminuted
Common sports fracture resulting from a twisting force.
A) Comminuted
B) Spiral
C) Greenstick
B) Spiral
The lining of the marrow cavity.
A) Endosteum
B)
Canaliculi
C) Osteoblasts
D) Osteoclasts
E) Lamellae
A) Endosteum
Cells that can dissolve the bony matrix.
A) Endosteum
B) Canaliculi
C) Osteoblasts
D) Osteoclasts
E) Lamellae
D) Osteoclasts
Layers of bone matrix.
A) Endosteum
B) Canaliculi
C) Osteoblasts
D) Osteoclasts
E) Lamellae
E) Lamellae
Small channels that radiate through the matrix of bone.
A) Endosteum
B) Canaliculi
C) Osteoblasts
D)
Osteoclasts
E) Lamellae
B) Canaliculi
Cells that can build bony matrix.
A) Endosteum
B)
Canaliculi
C) Osteoblasts
D) Osteoclasts
E) Lamellae
C) Osteoblasts
The cells responsible for the early stages of endochondral
ossification.
A) Chondrocytes
B) Appositional
growth
C) Epiphyseal line
D) Diaphysis
E) Epiphyseal plate
A) Chondrocytes
The growth pattern of bone in which matrix is laid down on the
surface.
A) Chondrocytes
B) Appositional growth
C) Epiphyseal line
D) Diaphysis
E) Epiphyseal plate
B) Appositional growth
The area of long bones where cartilage cells are replaced by bone
cells.
A) Chondrocytes
B) Appositional growth
C) Epiphyseal line
D) Diaphysis
E) Epiphyseal plate
D) Diaphysis
The appearance of this structure signals the end of bone growth.
A) Chondrocytes
B) Appositional growth
C)
Epiphyseal line
D) Diaphysis
E) Epiphyseal plate
C) Epiphyseal line
Area where bone longitudinal growth takes place.
A)
Chondrocytes
B) Appositional growth
C) Epiphyseal line
D) Diaphysis
E) Epiphyseal plate
E) Epiphyseal plate
Radius.
A) Short bone
B) Long bone
C)
Irregular bone
D) Flat bone
E) Sesamoid bone
B) Long bone
Carpals.
A) Short bone
B) Long bone
C)
Irregular bone
D) Flat bone
E) Sesamoid bone
A) Short bone
Patella.
A) Short bone
B) Long bone
C)
Irregular bone
D) Flat bone
E) Sesamoid bone
E) Sesamoid bone
Scapula.
A) Short bone
B) Long bone
C)
Irregular bone
D) Flat bone
E) Sesamoid bone
D) Flat bone
Hip bones.
A) Short bone
B) Long bone
C)
Irregular bone
D) Flat bone
E) Sesamoid bone
C) Irregular bone
True/False?
1) Hematopoiesis refers to the formation of
blood cells within the red marrow cavities of certain
bones.
TRUE
True/False?
Compact bone is replaced more often than
spongy bone.
FALSE
True/False?
Bones are classified by whether they are
weight bearing or protective in function.
FALSE
True/False?
The periosteum is a tissue that serves only
to protect the bone because it is not supplied with
nerves or
blood vessels.
FALSE
True/False?
Short, irregular, and flat bones have large
marrow cavities in order to keep the weight of the
bones light.
FALSE
True/False?
In newborn infants, the medullary cavity
and all areas of spongy bone contain yellow bone
marrow.
FALSE
True/False?
The structural unit of compact bone
(osteon) resembles the growth rings of a tree trunk.
TRUE
True/False?
The term osteoid refers to the organic part
of the matrix of compact bones.
TRUE
True/False?
Sixty-five percent of the mass of bone is a
compound called hydroxyapatite.
TRUE
True/False?
All bones formed by intramembranous
ossification are irregular bones.
FALSE
True/False?
An osteon contains osteocytes, lamellae,
and a central canal, and is found in compact bone
only.
TRUE
True/False?
The trabeculae of spongy bone are oriented
toward lines of stress.
TRUE
True/False?
Bone tissue in the skeleton of a human
fetus is completely formed at six months' gestation.
FALSE
True/False?
Each consecutive bone lamella has collagen
fibers that wrap in alternating directions.
TRUE
True/False?
Cartilage has a flexible matrix that can
accommodate mitosis of chondrocytes.
TRUE
True/False?
Closure of the epiphyseal plate stops all
bone growth.
FALSE
The structure of bone tissue suits the function. Which of the
following bone tissues is adapted to support weight and withstand
tension stress?
A) spongy bone
B) irregular bone
C) compact bone
D) trabecular bone
C) compact bone
Yellow bone marrow contains a large percentage of ________.
A) fat
B) blood-forming cells
C) elastic tissue
D) Sharpey's fibers
A) fat
The cell responsible for secreting the matrix of bone is the
________.
A) osteocyte
B) osteoblast
C)
osteoclast
D) chondrocyte
B) osteoblast
What kind of tissue is the forerunner of long bones in the embryo?
A) elastic connective tissue
B) dense fibrous
connective tissue
C) fibrocartilage
D) hyaline cartilage
D) hyaline cartilage
What can a deficiency of growth hormone during bone formation cause?
A) inadequate calcification of bone
B) decreased
osteoclast activity
C) decreased proliferation of the epiphyseal
plate cartilage
D) increased osteoclast activity
C) decreased proliferation of the epiphyseal plate cartilage
A fracture in the shaft of a bone would be a break in the ________.
A) epiphysis
B) metaphysis
C) diaphysis
D) articular cartilage
C) diaphysis
The term diploë refers to the ________.
A)
double-layered nature of the connective tissue covering the bone
B) fact that most bones are formed of two types of bone tissue
C) internal layer of spongy bone in flat bones
D) two
types of marrow found within most bones
C) internal layer of spongy bone in flat bones
Which of the following is a bone marking name that indicates a
projection that helps to form
joints?
A) meatus
B) ramus
C) foramen
D) fossa
E) epicondyle
B) ramus
Factors in preventing (or delaying) osteoporosis include ________.
A) drinking fluoridated water
B) decreasing
weight-bearing exercise
C) increasing dietary vitamin C
D) decreasing exposure to the sun
A) drinking fluoridated water
Ossification of the ends of long bones ________.
A) is
a characteristic of intramembranous bone formation
B) involves
medullary cavity formation
C) is produced by secondary
ossification centers
D) takes twice as long as diaphysis
C) is produced by secondary ossification centers
Which structure allows the diaphysis of the bone to increase in
length until early childhood,
as well as shaping the articular
surfaces?
A) lacunae
B) Haversian system
C)
epiphyseal plate
D) epiphyseal line
C) epiphyseal plate
The most abundant skeletal cartilage type is ________.
A) hyaline
B) elastic
C) fibrocartilage
D) epiphyseal
A) hyaline
Which of the following is not a function of the skeletal system?
A) support
B) storage of minerals
C)
production of blood cells (hematopoiesis)
D) communication
D) communication
What is the structural unit of compact bone?
A) osseous
matrix
B) spongy bone
C) lamellar bone
D) the osteon
D) the osteon
Bones are covered and lined by a protective tissue called periosteum.
The inner (osteogenic)
layer consists primarily of ________.
A) cartilage and compact bone
B) marrow and
osteons
C) osteoblasts and osteoclasts
D) chondrocytes
and osteocytes
C) osteoblasts and osteoclasts
The periosteum is secured to the underlying bone by dense connective
tissue called
________.
A) Volkmann's canals
B) a bony matrix with hyaline cartilage
C) perforating
(Sharpey's) fibers
D) the struts of bone known as spicules
C) perforating (Sharpey's) fibers
The canal that runs through the core of each osteon (the Haversian
canal) is the site of
________.
A) cartilage and
interstitial lamellae
B) osteoclasts and osteoblasts
C)
yellow marrow and spicules
D) blood vessels and nerve fibers
D) blood vessels and nerve fibers
What are the small spaces in bone tissue that are holes in which
osteocytes live called?
A) lacunae
B) Volkmann's
canals
C) Haversian canals
D) trabeculae
A) lacunae
For intramembranous ossification to take place, which of the
following is necessary?
A) A bone collar forms around
the cartilage model.
B) An ossification center forms in the
fibrous connective tissue.
C) The cartilage matrix begins to
deteriorate.
D) A medullary cavity forms.
B) An ossification center forms in the fibrous connective tissue.
The process of bones increasing in width is known as ________.
A) closing of the epiphyseal plate
B) long bones reaching
adult length and width
C) appositional growth
D)
concentric growth
C) appositional growth
Bones are constantly undergoing resorption for various reasons. Which
of the following cells
accomplishes this process?
A) osteoclast
B) osteocyte
C) osteoblast
D)
stem cell
A) osteoclast
Which hormone increases osteoclast activity to release more calcium
ions into the bloodstream?
A) calcitonin
B)
thyroxine
C) parathyroid hormone
D) estrogen
C) parathyroid hormone
The universal loss of mass seen in the skeleton, which begins about
the age of 40, ________.
A) is slower in females than in
males
B) is absolutely uniform throughout the skeleton
C)
reflects incomplete osteon formation and mineralization
D) is
greater in African Americans than in Northern Europeans
C) reflects incomplete osteon formation and mineralization
Wolff's law is concerned with ________.
A) vertical
growth of bones being dependent on age
B) the thickness and
shape of a bone being dependent on stresses placed upon it
C)
the function of bone being dependent on shape
D) the diameter
of the bone being dependent on the ratio of osteoblasts to osteoclasts
B) the thickness and shape of a bone being dependent on stresses placed upon it
Cranial bones develop ________.
A) from cartilage
models
B) within fibrous membranes
C) from a tendon
D) within osseous membranes
B) within fibrous membranes
Which of the following glands or organs produces hormones that tend
to decrease blood
calcium levels?
A) pineal gland
B) thyroid
C) parathyroid
D) spleen
B) thyroid
Osteomyelitis is ________.
A) partially due to
insufficient dietary calcium
B) literally known as "soft
bones"
C) due to pus-forming bacteria
D) caused by
altered vitamin D metabolism
C) due to pus-forming bacteria
Cartilage grows in two ways, appositional and interstitial. What is
appositional growth?
A) growth at the epiphyseal plate
B) the secretion of new matrix against the external face of
existing cartilage
C) along the edges only
D) the
lengthening of hyaline cartilage
B) the secretion of new matrix against the external face of existing cartilage
Which of the following statements best describes interstitial growth?
A) Growth occurs in the lining of the long bones.
B) Fibroblasts give rise to chondrocytes that differentiate and
form cartilage.
C) Unspecialized cells from mesenchyme develop
into chondrocytes, which divide and form
cartilage.
D)
Chondrocytes in the lacunae divide and secrete matrix, allowing the
cartilage to grow from
within.
D) Chondrocytes in the lacunae divide and secrete matrix, allowing
the cartilage to grow from
within.
In the epiphyseal plate, cartilage grows ________.
A)
by pulling the diaphysis toward the epiphysis
B) by pushing the
epiphysis away from the diaphysis
C) from the edges inward
D) in a circular fashion
B) by pushing the epiphysis away from the diaphysis
Spongy bones are made up of a framework called ________.
A) osteons
B) lamellar bone
C) trabeculae
D)
osseous lamellae
C) trabeculae
Osteogenesis is the process of ________.
A) making a
cartilage model of the fetal bone
B) bone destruction to
liberate calcium
C) bone formation
D) making collagen
fibers for calcified cartilage
C) bone formation
Lengthwise, long bone growth during infancy and youth is exclusively
through ________.
A) interstitial growth of the
epiphyseal plates
B) the secretion of bone matrix into the
medullary cavity
C) differentiation of osteoclasts
D)
calcification of the matrix
A) interstitial growth of the epiphyseal plates
Growth of bones is controlled by a symphony of hormones. Which
hormone is important for bone growth during infancy and childhood?
A) thyroid hormone
B) somatomedins
C) growth
hormone
D) prolactin
C) growth hormone
In some cases the epiphyseal plate of the long bones of children
closes too early. What might
be the cause?
A)
overproduction of thyroid hormone
B) elevated levels of sex
hormones
C) too much vitamin D in the diet
D) osteoblast
activity exceeds osteoclast activity
B) elevated levels of sex hormones
Normal bone formation and growth are dependent on the adequate intake
of ________.
A) calcium, phosphate, and vitamin D
B) potassium, phosphate, and vitamin D
C) sodium,
calcium, and vitamin E
D) vitamin D, phosphate, and chloride
A) calcium, phosphate, and vitamin D
Ostealgia is ________.
A) a defect called clubfoot
B) a disease of the bone
C) pain in a bone
D)
fractured bone
C) pain in a bone
Blood cell formation is called ________.
hematopoiesis
A bone embedded in a tendon is called a(n) ________ bone.
sesamoid
A central (Haversian) canal may contain arteries, veins, capillaries,
lymph vessels, and
________ fibers.
nerve
A long bone forms by a process known as ________ ossification.
endochondral
________ growth is growth in the diameter of long bones.
Appositional
________ are multinucleated cells that destroy bone.
Osteoclasts
________ is a disease of the bone in which bone reabsorption outpaces bone deposit, leaving the person with thin and often very fragile bones.
Osteoporosis
A round or oval hole through a bone that contains blood vessels
and/or nerves is called a(n)
________.
foramen
List the steps in the repair process of a simple fracture.
Hematoma formation, fibrocartilaginous callus formation, bony callus
formation, and
remodeling.
What is found in a Haversian canal?
Blood vessels and nerve fibers.
Several hormones control the remodeling of bones. Which two respond to changing blood calcium levels?
To keep bones in proper dimensions, PTH and calcitonin are the major determinants of whether and when remodeling will occur in response to changing blood calcium.
Why are the bones of young children much more flexible than those of the elderly?
Bones of children are not completely calcified, with a higher ratio of more flexible organic fibers. Bones in the elderly are more completely calcified, which gives the characteristic of rigidity.
Inflammation of bony tissue is called ________.
osteitis
Bones appear to be lifeless structures. Does bone material renew itself?
Bone only appears lifeless in gross anatomy. Microscopically, bone is full of cells and blood vessels that maintain and renew bone tissue. Approximately 5% to 7% of our bone mass is recycled each week. Up to 0.5 g of calcium may enter or leave the bones each day, depending on the negative feedback hormonal mechanism and gravitational forces.
Compare the function of the organic materials in the bone matrix with
the function of the
inorganic materials in the matrix.
The organic matrix contributes to the bone structure and its tensile
strength, while the
inorganic matrix contributes to hardness and
resistance to compression.
What are the differences between the diaphysis and the epiphyses of long bones?
The diaphysis bone is composed almost entirely of compact bone (except in irregular and short bones), while the epiphyses are composed almost entirely of spongy bone. The epiphyses are on the ends of the bone; the diaphysis is the "shank" of the bone. The diaphysis in long bones has a large medullary cavity, whereas the epiphyses do not.
Describe how oxygen is carried from outside a bone to an individual osteocyte.
Blood vessels enter through the periosteum into a perforating canal.
The vessel may follow along the axis of the bone through a central
canal. Osteocytes have long, almost dendritic-like extensions or arms
that reach out through tiny holes called canaliculi. The canaliculi
connect one cell to another and to the central canal. Oxygen would
leave the blood vessel in the central canal and travel through the
canaliculi from cell to cell until it reaches the
cell in question.
How is the beginning of intramembraneous ossification different from
endochondral
ossification?
Intramembraneous ossification starts in connective tissue from
mesenchymal cells that become osteoblasts. These osteoblasts cluster
together into an ossification center. Endochondral
ossification
starts with a hyaline cartilage "template." Mesenchymal
cells become osteoblasts
and begin forming bone around the cartilage.
If your doctor notices a marked decrease in calcium ion levels in
your blood, what gland
might he suspect is not functioning
properly and why?
Answer: T
The parathyroid gland normally responds to low calcium ion levels in the blood and releases PTH, which mobilizes osteoclasts to step up bone destruction, releasing more calcium into the bloodstream. If the parathyroid is not functioning properly it may release too much PTH or not respond at all, which seems to be the case here.
Clinical Questions
While on vacation last spring, June fell on
the pavement and broke her wrist. At the emergency room, a resident
placed a cast on her wrist after manipulating the bones. It seemed to
heal within a few months. However, recently she has noticed lumps in
the area where the break happened and she has been complaining of
pain. What could be causing the lumps and the pain?
June probably has "bony spurs," which are abnormal projections from a bone due to bone overgrowth.
Clinical Questions
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 rickets, a condition caused by poor diet, especially one deficient in vitamin D. The parents were told to increase her intake of calcium and vitamin D and to make sure that she gets some sunshine every day.
Clinical Questions
Emily, a 64-year-old obese woman, was
brought to the hospital suffering pain in her legs, and an X ray
revealed that she had a simple fracture in her right femur and a crack
in her left tibia. Other tests revealed that her bones were brittle
and porous. What might have happened to Emily, and what advice would
she have been given by the physician?
Emily has osteoporosis, a debilitating bone disease that strikes more women than men after age 45-50. The bones become weak and brittle due to leaching of calcium from the bone. Emily has been told that she needs to lose weight because her bones may not have the strength to support her body mass.
Clinical Questions
A 75-year-old woman and her 9-year-old
granddaughter were victims of a train crash. In both cases, trauma to
the chest was sustained. X rays of the grandmother revealed several
fractured
ribs, but her granddaughter had none. Explain these
different findings.
The child had more organic material in her bones, which allows them to bend, while her grandmother's bones are extensively calcified, with little organic material, and are probably thin due to osteoporosis.
Clinical Questions
Johnny fractured the lower third of his
right tibia in a skiing accident. The soft tissues in the
area
were severely damaged and their surgical removal was necessary. After
prolonged
immobilization, it was found that Johnny was healing
very poorly. The explanation offered by
the orthopedic surgeon
was that vascularization of the fracture site was still inadequate and
good
healing was absolutely dependent upon an adequate blood
supply. Describe how a long bone receives its blood supply and trace
the path of nutrient delivery to the osteocytes.
Long bones are nourished by nutrient arteries that frequently enter the shaft. Removal of the soft tissues probably reduced the flow of blood to the affected area. The pathway would include diffusion of nutrients from blood vessels to periosteum to Volkmann's canals to Haversian canals to canaliculi to lacunae.
Clinical Questions
People who live in the north should take
supplemental calcium with vitamin D. Explain why.
Vitamin D is manufactured by sunlight and is needed for absorption of dietary calcium. People who live in the north where the winter months are severe may need supplemental vitamin D because of the decreased amount of sunlight exposure.
Clinical Questions
When does prevention of osteoporosis start?
The prevention of osteoporosis should begin with children. Parents need to provide children with the opportunity to develop as much bone as they have inherited the ability to develop. If people increase their peak bone mass as young adults, they will have additional protection from osteoporotic fractures in the future.
Clinical Questions
If your elderly patient's blood calcium
level is normal, does that mean the patient does not
have
osteoporosis? Explain.
No. The level of calcium in the blood is expected to be normal, even in advanced cases of osteoporosis. The calcium in the bones will be low, but that is not indicated by the blood nourishment.
Clinical Questions
Mrs. Brown was outside on her patio cleaning
windows when she fell off her step ladder and
fractured her
right hip. She had emergency surgery for an open reduction and
internal fixation of
the right hip. Three days postoperative,
she asks you if she will have trouble going through
airport
security. What has prompted her concern?
Open reduction is the correction of the bone alignment through a surgical incision. It may include internal fixation of the fracture with the use of rods, wire, screws, pins, or nails, metal items that may trigger security alarms.
Clinical Questions
How can a tooth be moved in a bony socket
during orthodontic treatment?
Because bone deposition and reabsorption can occur, and because bone responds to mechanical stress (Wolff's law), a tooth can be moved. 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.
Clinical Questions
Explain why swimming is not generally
recommended as an exercise to prevent osteoporosis.
Mechanical stress and gravity help to promote skeletal remodeling. Swimming is not considered a weight-bearing exercise. The water, not bones, supports the body's weight while swimming.