bones

Which is false regarding the periosteum?

It is composed of dense regular connective tissue.

The zones found in an epiphyseal plate are

a. Calcified cartilage

b. Hypertrophic cartilage

c. Ossification

d. Resting cartilage

e. Proliferating cartilage

The correct order for these zones, beginning with the edge closest to the epiphysis and proceeding toward the diaphysis, is

d - e - b - a - c

Chondrocytes occupy spaces in the matrix called ________.

lacunae

Which bone forms by intramembranous ossification?

zygomatic

The type of bone tissue that is replaced more frequently is _________ bone; the part of the femur that is replaced more frequently is the _________.

spongy; distal epiphysis

The formation of bone from a cartilaginous model is termed

endochondral ossification

Interstitial growth of cartilage increases its _________ and occurs in the _________ region of the cartilage.

length; internal

Which hormone normally has a more significant effect on blood calcium levels in adults?

Parathyroid hormone

Calcidiol circulates in the blood and is converted to calcitriol in the

kidney

Which is false regarding bone remodeling?

It occurs only at articular surfaces.

An example of a flat bone would be the

sternum (breast bone)

Glucocorticoids increase bone_________; high levels of serotonin lead to_________ bone density.

loss; low

Mechanical stress of bones, such as that caused by weight lifting, is detected by

osteocytes, which then communicate to osteoblasts to increase synthesis of osteoid.

When during human development does the process of endochondral ossification begin?

8th week of embryonic development.

During appositional growth of cartilage, the cells that produce the matrix are the

chondroblasts

A fracture parallel to the long axis of the bone is a(n)_________ fracture.

linear

T/F

Further lengthwise bone growth cannot occur once the epiphyseal lines have formed.

true

Which affects osteoblast and osteoclast activity?

1. Gravity

2. All of the choices are correct.

3. Calcitonin and parathyroid hormone levels

4. Blood calcium level

5. Mechanical stress

All of the choices are correct.

The epiphyseal plates in the_________ are the last ones in the body to ossify.

clavicle

Parathyroid hormone release is triggered by_________ levels of calcium in the blood.

low

Which is an accurate description of appositional bone growth?

Osteoblasts build bone at thecircumferential lamellae while osteoclasts widen the medullary cavity

In the kidneys, parathyroid hormone acts to_________ production of calcitriol and to_________ excretion of calcium in urine.

increase; decrease

T/F

In adults, an area of compact bone called the epiphyseal tract replaces the epiphyseal plate.

false

The break of a bone that has been weakened by disease is a_________fracture; when a broken end of the bone pierces the skin, the fracture is_________.

pathologic; compound

The shaft of a long bone is called the ________.

diaphysis

If a bone is immersed in a weak acid such as vinegar for several days, its inorganic components will dissolve. What will be the result of such an experiment?

The bone will become soft and bendable

During the process of endochondral ossification, chondrocytes in the cartilage model die. Why does this occur?

Nutrients cannot diffuse to the chondrocytes through the calcified matrix.

Which is not involved in the process of bone repair following a fracture?

No exceptions; all of the choices are involved in the process of bone repair.

Within which zone of the epiphyseal plate do cartilage cells undergo mitosis?

The second closest zone to the epiphysis.

The periosteum is anchored to the bone by collagen fibers called_________ fibers.

perforating

Which is the definition for a greenstick fracture?

Only one side of the bone is broken; the other side is bent.

T/F

Osteons run perpendicular to the diaphysis of a long bone.

false

What explains the dramatic acceleration in lengthwise bone growth at puberty?

Increased secretion of sex hormones promotes epiphyseal plate growth.

T/F

Since cartilage must be continuously replaced in the body, appositional and interstitial growth of cartilage continues throughout life.

false

What is the incomplete layer of cells and connective tissue that covers all internal surfaces of the bone within the medullary cavity?

endosteum

T/F

Once we reach adulthood and our bones are fully formed and hardened, they cannot be remodeled.

false

During bone formation, calcium phosphate and calcium hydroxide interact to form crystals of, which serve to harden the matrix.

hydroxyapatite

A fracture of the distal end of the radius is a fracture.

distal radius

Which is not a function of bone?

Generation of heat

Which is characteristic of cartilage connective tissue?

1. Gel-like ground substance

2. Cells called chondrocyte

3. Matrix of protein fibers

4. All of the choices are correct.

5. Avascular

All of the choices are correct

When bone forms by intramembranous ossification, the ossification centers are within

mesenchyme

Which is an alternate term for compact bone?

cortical bone

The bones of the fingers and toes (phalanges) are categorized as_________ bones.

long

What helps bone resist compression?

Inorganic salts

Which is not correct about spongy bone?

It is composed of tubular units called osteons.

Which vitamin is required for the normal synthesis of collagen?

Vitamin C

Bone growth in which the bone increases in diameter is called

appositional growth.

The spongy bone found within a flat bone is called ________.

diploe

Which type of cell produces new bone tissue by secreting matrix?

osteoblasts

T/F

Endochondral ossification is a form of bone growth in which a cartilaginous model is replaced by bone.

true

Bone is considered an important storage reservoir for

calcium, phosphate, and lipids.

T/F

Neither short nor flat bones contain a medullary cavity.

true

Place in correct order the following steps in the process of appositional growth of cartilage.

a. New matrix is produced and secreted.

b. Chondrocytes differentiate, each in its own lacuna.

c. Stem cells undergo mitosis.

d. Committed cells differentiate into chondroblasts.

c. - d. - a. - b

T/F

Calcitriol stimulates absorption of calcium in the small intestine.

true

T/F

Spongy bone makes up less than half of total bone mass, and is located internal to compact bone.

true

Osteoid is the

organic part of the bone matrix that gives it tensile strength

T/F

An osteoclast has a ruffled border and multiple nuclei.

true

What are the matrix rings of compact bone that surround the central canal of each osteon?

Concentric lamellae

Which type of cartilage is found in the intervertebral discs?

fibrocartilage

Before beginning orthopedic treatment, a patient may have an x-ray of their wrist and hand to determine their stage of growth. What feature of the long bones will the orthopedist use to assess this?

Epiphyseal plate

T/F

The flat bones of the cranium form by intramembranous ossification.

true

Bone is _________ (2 words) and contains mainly _________ nerves.

highly vascularized; sensory

Parathyroid hormone and calcitriol

stimulate osteoclasts to resorb bone and release calcium into the blood.

Osteons are also called __________ systems.

Haversian

Blood vessels enter the diaphysis of a long bone through an opening called the foramen.

nutrient

High blood calcium and exercise cause calcitonin release to

increase

If a clinician were looking to harvest bone marrow that made blood cells, which bone of a donor would be sampled?

hip bone

T/F

Mature cartilage is avascular

true

Severe anemia may trigger an adaptive conversion of

yellow marrow to red marrow.

Which region of a growing bone contains the epiphyseal plate?

Metaphysis

Flat bones

protect underlying soft tissue and may be slightly curved

To trigger bone growth, growth hormone stimulates the

liver to produce somatomedin.

T/F

Parathyroid hormone is released by the thyroid gland and causes the small intestine to increase calcium absorption.

false

Compact bone

is composed of tubular units called osteons.

Which choice places the steps of intramembranous ossification in correct chronological order?

a. Formation of lamellar bone.

b. Osteoid undergoes calcification.

c. Ossification centers form.

d. Formation of woven bone and its periosteum.

c - b - d - a

Bone cells called _________ break down bone by secreting hydrochloric acid and enzymes that dissolve the matrix.

osteoclasts

Which of the following is likely to lose more bone mass with aging?

An individual who is postmenopausal

As the bone matrix calcifies and the secreting cells become walled in,

osteoblasts become osteocytes.

Found within both the periosteum and endosteum, _________ cells are derived from mesenchyme and serve as the stem cells of bone.

osteoprogenitor

Consider the classifications of bone, and examples of each. Which classification comprises bones used primarily for movement rather than protection?

long bones

The knobby region of a long bone at the end that is farthest from the trunk is the

distal epiphysis

T/F

In general, the mechanical stresses on bones that result from exercise tend to weaken them and lead to more frequent fractures.

false

Where does hematopoiesis occur?

Red bone marrow

Endochondral ossification begins with a(n)_________ model.

hyaline cartilage

Calcitonin _________ osteoclast activity, which will _________ blood calcium levels.

inhibits; decrease

What is the function of cartilage located in the epiphyseal plates?

Site of bone elongation and growth

T

Most of the bones of the upper and lower limbs are formed by intramembranous ossification.

The process of bone repair includes these steps:

a. Fracture hematoma forms

b. Bone is remodeled

c. Fibrocartilaginous callus forms

d. Bony callus forms

The correct chronological order for these steps is

a - c - d - b

T/F

About 80% of the human skeleton is replaced yearly as a result of bone remodeling.

false

In compact bone, _________ connect adjacent lacunae, thereby providing pathways for nutrients and other materials to pass between osteocytes.

canaliculi

The bones of the wrist are classified as_________ bones.

short

Which is a change in bone architecture or mass related to aging?

1. Loss of flexibility and increase in brittleness

2. Demineralization

3. Insufficient calcification

4. Reduction in the organic content of the matrix

5. All of the choices are correct

All of the choices are correct

Which hormone inhibits bone growth?

Parathyroid hormone

Which is a sesamoid bone?

patella

T/F

For most individuals a common source of vitamin D is dietary intake of milk.

true

T/F

Osteoblasts are bone-forming cells; osteoclasts are bone-dissolving cells.

true

With aging comes insufficient ossification of bone, a condition known as _________.

osteopenia

Rickets, a disease characterized by overproduction and deficient calcification of osteoid tissue, is caused by a lack of sufficient

Vitamin D

Achondroplastic dwarfism is a disorder that affects endochondral ossification. Which of the following bones will be affected?

Most bones of the body.

T/F

In adults, the medullary cavities of most long bones contain red marrow.

false