Chapter 6 A&P Lecture Mastering

Where does growth in length occur?

3, metaohysis

Drag the labels to the appropriate location in the figure.

Lacunae Lamellae Osteon Central canal

Which of the following is true of osteoclasts?

Osteoclasts secretes protein digesting enzymes and acids that dissolve matrix.

Drag the labels onto the diagram to identify the structures found in compact bone.

Osteons Circumferential lamellae Perforating fibers Trabeculae of spongy bone Perforating canal Periosteum Interstitial lamellae Central canal Concentric lamellae

A fracture at the ankle involving both lower leg bones is often called a ________ fracture.

Pott's

Drag the labels to classify bones by shape.

Short bones Flat bones Sutural bones Irregular bones Long bones Sesamoid bones

Drag the labels to identify the structures of a long bone.

Spongy bone Medullary cavity Proximal epiphysis Distal metaphysis Distal epiphysis Diaphysis (shaft) Compact bone Proximal metaphysis

Suppose that epiphyseal lines appear in a 10-year-old's long bones. Which of the following statements is, therefore, true?

The epiphyseal plates have ossified and further growth in length is not possible.

Drag the labels to identify types of fractures.

Transverse fracture Spiral fracture Epiphyseal fracture Compression fracture Comminuted fracture Colles fracture Displaced fracture Pott's fracture Greenstick fracture

The space occupied by an osteocyte is called-

a lacuna.

The process by which osteoblasts add layers to circumferential lamellae is-

appositional growth

________ prevents damaging bone-to-bone contact within movable joints.

articular cartilage

The central canal of an osteon contains-

blood vessels

Which of the following functions of the skeletal system is most affected by gravity?

body support

__________ are the main calcium reservoir for the body.

bones

During appositional growth,-

bones grow wider

If blood calcium levels drop below 8.5 mg/dL which hormone is likely to be activated?

both calcitriol and parathyroid hormone

A child with rickets often has-

bowed legs

This cell functions to __________.

break down bone

The deposition of calcium salts in bone tissues is referred to as-

calcification

If blood calcium levels rise above 11mg/dL which hormone is likely to be activated?

calcitonin

Bone growth in length occurs by mitosis of-

cartilage cells in the epiphyseal side of the metaphysis.

Endochondral ossification begins with the formation of a(n)-

cartilage model

A ________ fracture shatters the bone.

comminuted

An open or ________ fracture projects through the skin.

compound

The fracture of vertebrae subjected to extreme vertical stress is called a ________ fracture.

compression

What are the three ways in which lamellae are organized in compact bone? (Figure 6-7)

concentrically around an osteon, interstitially between osteons, and circumferentially around the entire bone

The hormone calcitonin functions to-

decrease the level of calcium ion in the blood

Primary ossification centers develop in long bones in the-

diaphysis

The shaft of long bones is called the-

diaphysis

Calcitonin causes what response in the kidneys?

elimination of calcium ions into the urine

The lining of the medullary cavity is called the-

endosteum

What structure is necessary for a bone to grow in length?

epiphyseal cartilage

The proximal and distal ends of a long bone are called the-

epiphyses

Where is spongy bone found in long bones? Where is spongy bone found in flat bones? (Figure 6-3)

epiphyses; between the compact bone layers

Migration of osteoblasts into the __________ creates the __________.

epiphysis; secondary ossification center

Damage to a bone because of extreme load, sudden impact, or stresses applied from an unusual direction is called a-

fracture

In a ________ fracture one side of the shaft is split and the other side is bent.

greenstick

When cartilage is produced at the epiphyseal side of the metaphysis at the same rate as bone is deposited on the opposite side, bones-

grow longer

Which of the following is formed immediately after a fracture?

hematoma

A hard ossified bone in an adult actually begins within the embryo as a miniature version composed of __________.

hyaline cartilage

The articular cartilage of a typical long bone is composed of what type of cartilage?

hyaline cartilage

What type of tissue is replaced in the embryo during endochondral ossification?

hyaline cartilage

Secondary ossification centers occur-

in the epiphyses

Parathyroid hormone functions in all of the following ways except-

inhibiting calcitonin secretion

Bones that have complex shapes are-

irregular bones

Which of these forms by intramembranous bone formation?

mandible

Which of the following labels best matches osteocyte?

mature bone cell

The region of a long bone between the end and the shaft is known as the-

metaphysis

Canaliculi are-

narrow passageways in the matrix connecting lacunae to blood supply.

During the process of ________, an existing tissue is replaced by bone.

ossification

The cell designated by the arrow is a(n) __________.

osteoblast

Cells that secrete the organic components of the bone matrix are called-

osteoblasts.

Cells that are found in small depressions on the endosteal surfaces are the-

osteoclasts

Cells that free calcium from bone to maintain blood calcium levels are called-

osteoclasts.

The most abundant cell type in bone is-

osteocytes.

Drag the labels onto the diagram to identify the types of bone cells.

osteogenic cell, osteocyte, osteoblast, osteoclast

Which three types of bone cells are developmentally related and what is their progression from the earliest to the latest stage? (Figure 6-5)

osteogenic to osteoblasts to osteocytes

In relationship to the diaphysis of a long bone, the osteons are-

parallel

What gland responds when the blood calcium level is too low? (Figure 6-16a)

parathyroid gland

Which hormone increases blood calcium upon secretion?

parathyroid hormone (PTH)

Blood is distributed from the surface of a bone to deeper central canals through channels known as-

perforating canals

The superficial membrane of a bone is called the-

periosteum

Identify the site in the center of the cartilage bone model where bone development first occurs.

primary ossification center

Intramembranous ossification-

produces flat bones, as in the bones of the roof of the skull.

Which of following is a function of the skeletal system?

protection of internal organs body support blood cell production calcium homeostasis All of the answers are correct.

________ marrow is found between the trabeculae of spongy bone.

red

The ongoing process of tearing down and rebuilding bone matrix is called-

remodeling

The carpal bones are examples of ________ bones.

short

The type of bone that is adapted to withstand stresses that arrive from many directions is ________ bone.

spongy

Small bones that fill gaps between bones of the skull are called ________ bones.

sutural

What is the classification of this bone according to its shape?

sutural bone

The interconnecting tiny arches of bone tissue found in spongy bone are called-

trabeculae

Which of the following bones is classified as "irregular" in shape?

vertebra