Anatomy Chapter 5: The Skeletal System: Osseous Tissue and Skeletal Structure

Which of the following describes a central canal:

1. Contains an artery 2. Contains a vein 3. Runs parallel to osteons 4. Also called Haversian canal

In addition to osseous tissue, a typical bone contains:

1. Other Connective Tissue 2. Smooth Muscle Tissues (in blood vessel walls) 3. Neural Tissue

A(n)________________ fracture occurs at the ankle and affects both leg bones:

Pott

A fracture of a bone that is the result of a twisting stress that spreads along the length of the bone is called a:

Spiral fracture

A bone cell that secretes the organic components of bone matrix is:

An osteoblast

What is the fate of the chondrocytes that are present where bone is forming:

They die and disintegrate, leaving cavities within the cartilage

During Endochondral bone formation:

1. The matrix of the cartilage model becomes calcified 2. Cells of the perichondrium differentiate into osteoblasts 3. Capillaries and osteoblasts migrate into the heart of the cartilage 4. Osteoclasts erode the center of the new bone to form a marrow cavity

Each year, approximately ________________ of the adult skeleton is demolished and then rebuilt or replaced:

1/5 (20%)

Bone mass reduction occurs initially between the ages of:

30-40

The endosteum is usually many layers thick:

FALSE

A small, flat articular surface is a:

Facet

The scapula is an example of what type of bone:

Flat

Diploë is spongy bone found in:

Flat bones

Which of the following is most likely to have a nerve pass through it:

Foramen

After a fracture occurs, a(n)_______________ forms as a network of spongy bone unites the inner edges:

Internal callus

The skeletal system participates in:

Maintaining blood calcium levels

Because they resist stretch:

The collagen fibers provide the tensile strength of bone

A break in a none is called:

A fracture

Which diagnostic procedure detects abnormalities in synovial fluid:

Arthrocentesis

Calcium phosphate interacts with _____________ to form hydroxyapatite:

Calcium hydroxide

As cartilage enlarges in step 1 of endochondral ossification:

Chondrocytes near the center of the shaft increase in size

Layers of bone that occur at the external and internal surfaces of the bone are referred to as:

Circumferential lamellae

Organic Components of the matrix of bone include:

Collage fibers; make up 1/3 of matrix

Flat bones have a diaphysis, two metaphyses, two epiphyses, and a medullary cavity:

FALSE

An elongated cleft is a(n):

Fissure

A shallow depression on the surface of a bone is called a:

Fossa

The expanded articular end of an epiphysis, separated from the shaft by a narrower neck, is a(n):

Head

Which of the following statements is true of the growth of the skeleton:

It begins to ossify at 6 weeks of gestational age

The vessels supplying blood to the inner (diaphyseal) surface of each epiphyseal plate, where bone is replacing cartilage are called:

Metaphyseal vessels

The epiphyseal cartilage connects to the diaphysis by a narrow zone called the:

Metaphysis

The degenerative effects of osteoporosis are most likely to affect:

Older women

If a long bone that was found at an archeological dig contained functional epiphyseal plates. what inference is most accurate:

The person was not mature

How do hormones regulate the pattern of bone growth:

They change the rates of osteoblast and osteoclast activity

Which of the following is an example of an irregular bone:

Vertebra

The endosteum is best described as:

1. A tissue that is active during the growth or repair of bone 2. The lining of the central canals and perforating canals 3. A layer that covers the trabeculae of spongy bone 4. An incomplete layer that sometimes leaves matrix exposed

The two types of osseous tissue are:

1. Compact Bone 2. Spongy Bone

The physical process of bone formation is called:

Osteogenesis

Which type of cell divides to produce daughter cells that can differentiate readily after a bone is cracked or broken:

Osteoprogenitor cell; bone stem cells found on innermost layer of periosteum and inner lining of endosteum

Which of the following acts on the intestine, requiring calcitriol production by the kidneys:

Parathyroid hormone

Endochondral ossification begins with:

Hyaline cartilage

The central canals connect the lacunae to one another:

FALSE

The diaphysis is the region at each end of a long bone:

FALSE

The lacuna contains osteoblasts and osteoclasts:

FALSE

The metaphysis is the tubular shaft of a long bone:

FALSE

An individual with otherwise normal features, but having very short limbs, may have a condition known as:

Achondroplasia, in which epiphyseal cartilages grow unusually slowly

The yellow marrow that fills the medullary cavities of many bones is dominated by:

Adipocytes

What is the mechanism of marrow cavity enlargement in a long bone:

As bone matrix is added to the external surface, osteoclasts remove matrix in the center of the bone to enlarge the cavity.

Which of the following is produced within red bone marrow:

Blood cells

The simultaneous process of adding new bone and removing previously formed bone is called:

Bone remodeling

How does an extensive exercise program affect the appearance of the skeleton? Why do these changes occur?

Bones are adaptable and for this reason their shapes and surface features can change due to forces applied to them. For example, bumps and ridges on the surface of a bone mark the sites of attachment to the bone. If muscles become more powerful, as what happens as a result of an extensive exercise program, the corresponding bumps and ridges enlarge to withstand the increased forces. Heavily stressed bones become thicker and stronger while unstimulated bones become thinner and weaker.

The deposit of calcium salts within a tissue is called:

Calcification

Increased levels of calcium in the blood of a pregnant woman would stimulate the secretion of:

Calcitonin which would increase calcium loss in the urine

Because they are strong and relatively inflexible:

Calcium phosphate crystals enable bone to withstand the stress of compression

During track and field practice one of the runners trips over a hurdle and falls forward. Fortunately, he is able to break his fall with his hands. However, he stands up holding his wrist in pain. What type of fracture might he have sustained:

Colles Fracture; fracture of the distal forearm in which the broken end of the radius is bent backwards

The walls of bones are composed of:

Compact bone

A _____________ is a smooth rounded articular process:

Condyle

Osseous tissue is classified as which of the following:

Connective Tissue

The periosteum:

Covers the outside of bones

A prominent ridge on a bone is called a(n):

Crest

Which of the following type of fracture produces new and abnormal bone arrangements:

Displaced fracture

A long bone increases in length until:

Epiphyseal closure occurs; this typically occurs around age 25

Blood vessels that supply the ends of long bones are called:

Epiphyseal vessels

An example of pneumatized bone is the

Ethmoid bone

A displaced fracture retains the normal alignment of the bone elements or fragments:

FALSE

A transverse fracture is produced by twisting stresses and spreads along the length of the bone:

FALSE

Periosteum lines the medullary cavity:

FALSE

Roofing bones of the skull form via:

Intramembranous Ossification

In osseous tissue, which of the following is always removing matrix and releasing minerals:

Osteoclasts

Mature bone cells that maintain and monitor the protein and mineral content surrounding matrix are called:

Osteocytes; key word is "mature"

As a long bone develops, the point where osteoblasts first replace calcified cartilage with spongy bone becomes the:

Primary ossification center from which further development proceeds

Regarding long bone formation, bone development proceeds from the:

Primary ossification center in the shaft

An extension of a bone that is set at an angle to the rest of the bone is usually called:

Ramus

Which of the following is important as a stimulus that maintains normal bone structure, especially in growing children, postmenopausal women, and elderly men:

Regular excercise

Treating a compound fracture differs from other fractures most significantly due to:

Risk of infection

Which of the following is a classification of bone shape

Sesamoid

Differences in body size and proportions between males and females result from the different effects of:

Sex hormones which affect the growth of the bones

A chamber within a bone, normally filled with air, is a(n):

Sinus

What is an example of a major function of the skeletal system:

Support of the body

Small, flat, oddly shaped bones that develop between the flat bones of the skull are called:

Sutured bones

A comminuted fracture shatters the area into a multitude of bony fragments:

TRUE

A compression fracture occurs particularly in vertebrae subjected to extreme stress, such as when landing on the sacrum after a fall:

TRUE

Periosteum covers the outer surface of a bone:

TRUE

The central canal of an osteon usually runs parallel to the surface of a bone:

TRUE

The perforating canals of osteons extend roughly perpendicular to the surface of a bone:

TRUE

Which of the following occurs during endochondral ossification:

The bone grows in length and in diameter

A boy returns to school to begin 7th grade after summer vacation only to find that he is at least four inches taller than several classmates that were the same height as him before the summer. Propose a reason for such a difference.

The boy has most likely entered puberty and his classmates have not. He has experienced raped growth as a result of increasing sex hormone levels in his body. These hormones stimulate osteoblasts to produce bone faster than the rate of epiphyseal cartilage expansion. Over time, the epiphyseal cartilages will narrow and eventually ossify, or "close."

What kind of tissue would most likely be found in a tissue sample taken from the interior of the epiphysis of the femur:

The internal framework of the epiphyses of long bones is made up of spongy bone which contains extensive areas of red bone marrow. Red bone marrow is important for the formation of blood cells which fill empty spaces in the spongy bone.

Which of the following describes how bones are innervated:

The periosteum, endosteum, medullary cavity, and epiphyses are innervated by sensory nerves.

The function of an osteoclast in osseous tissue is:

To dissolve old bone matrix and release amino acids and stored calcium phosphate; Ca3(P04)2

Which of the following is a special characteristic of spongy bone:

Trabecula; form branching plates that create lightweight nature of bones and create strength against stress from the side

Spongy bone is made up of a network of bony spicules arranged into parallel struts or thick branching plates called:

Trabeculae

Struts or plates within spongy bone which assist in withstanding stresses in a specific direction:

Trabeculae

What is the significance of the orientation of the trabeculae in spongy bone? Provide a specific example, discussing how trabecular structure lends to its function.

Trabeculae grow in response to stresses on the bone aligning at 90 degree angles to the direction of the stress. For example, the trabecular alignment helps direct the forces across the knee joint to the leg. This type of structure also helps provide support and protection for the cells of the bone marrow.

Perforating canals:

Transmit blood vessels to osteons deep inside the bone

A smooth, grooved articular process, shaped like a pulley, is a(n):

Trochlea

Processes that form where tendons or ligaments attach to a bone include:

Tronchanters, tuberosities, and tubercles

Bones have a vascular supply that is:

Very extensive, including many arteries and veins branching throughout the bone

Which of the following is the active form of calcitriol:

Vitamin D