CH. 6 review

During a needle biopsy of a person's bone marrow, (perhaps to test for the presence of cancer), pain is felt when the needle passes through the periosteum because it is richly supplied with nerves.

True

The trabeculae of spongy bone rearrange themselves as an infant learns to walk, so as to be oriented along the lines of stress the bones are subjected to.

True

In primary ossification, the first type of bone that forms and replaces the cartilage model is compact bone.

False

In the activities of secondary ossification centers, the medullary cavity forms later and is much smaller.

False

Near the diaphysis of a long bone, such as the femur, a large nutrient artery enters the bone through a perforating canal.

False

Osteocytes within lacunae are only found in compact bone and not within the trabeculae of spongy bone.

False

you would expect to find osteocytes active in bone building on the outside surface and osteoclasts active in dissolving bone on the medullary surface inside the bone.

False

Bone remodeling, especially bone resorption, plays a role in the maintenance of proper levels of calcium in the blood

True

Bones can only assist in providing movement when they tugged on by the appropriate skeletal muscles.

True

Which is the proper sequence of steps in the healing of a fracture (the steps are listed below but are not in the correct sequence of events): 1 osteoblasts form trabeclular bone that joins together the fractured ends of the bone and bony callus replaces fibrocartilage callus 2 bone remodeling occurs and compact bone replaces the spongy bone around the periphery of the fracture site 3 fibroblasts and chondrocytes from the periosteum form the fibrocartilage callus 4 a fracture hematoma forms and bone cells in the region of the fracture die 5 phagocytes and osteoclasts begin to remove the dead cells and damaged tissue around the hematoma

4, 5, 3, 1, 2

Which of the following tissues could be found on or within a bone, such as the humerus?

Adipose, nervous, cartilage, and osseous

By which process, as an individual grows to adulthood, is the thickness (diameter) of bone increased?

Appositional Growth

Which two minerals are stored in major quantities in bone tissue?

Calcium and Phosphorus

one of a series of small channels that connect adjacent osteocytes with each other and with central canals. These canals allow nutrients, oxygen, and wastes to be properly routed even when a cell isn't immediately next to a blood vessel?

Cannaliculi (B)

Long bones adds to its length at the epiphyseal plate. In this region, which type of cells proliferate, become calcified, and are eventually replaced with mature bone cells, thereby adding to the bone's length?

Chondrocytes

Which is secreted by osteoblasts during bone deposition?

Collagen Fibers

A greenstick fracture would only be seen in an elderly person with more fragile bones

False

As long bones form in the fetus, the formation of the medullary cavity occurs because of the actions of osteoblast cells.

False

During the process of bone formation in a fetus, a primary ossification center develops in the epiphysis of a cartilage model of a long bone.

False

The process of intramembranous ossification generates bone within a pre-existing template composed of mesenchymal tissue. In contrast, endochondral ossification generates bone within a pre-existing template composed of _____.

Hyaline Cartilage

Once osteoblasts have surrounded themselves with the extracellular matrix of bone tissue, they remain inside little chambers called __________ where they carry on the metabolic functions that maintain bone tissue. At this point, the cells are called osteocytes.

Lacunae

a structure that carries nerves, lymphatic vessels and blood vessels that enter from the periosteum and connects with central canals and other similar structures?

Medullary Canal (C)

In which region of a long bone, such as the humerus, would you find the epiphyseal plate (growth plate)?

Metaphysis

Which is formed from the fusion of as many as 50 monocytes (a type of white blood cell)?

Osteoclast

Which is NOT a part of the events that result in parathyroid hormone's control of blood calcium levels?

PTH acts on the parafollicular cells of the thyroid gland to increase the level of the hormone calcitonin

Compact bone is composed of units called osteons. In contrast, spongy bone is composed of _____.

Trabeculae

Bone can be classified as a connective tissue because it contains an extracellular matrix that surrounds widely spaced cells.

True

In a newborn, all bone marrow is red, which means all of the infant's marrow can make blood cells.

True

Males generally have lower rates of developing osteoporosis because, on average, they enter adulthood with a heavier bone mass than women and they don't experience the same dramatic decline in sex hormones as women do with aging

True

Parathyroid hormone (PTH) is able to regulate calcium levels in the blood through a series of steps that provide control through a negative feedback system

True

bone grows in diameter by adding new layers to the outside surface of the bone, while the medullary cavity is enlarged by the activity of cells on the inside surface.

True

Gravity and the pull of muscles against bone are the main mechanical stresses experienced by bone. Stress promotes deposition of mineral salts, collagen, and the strengthening of bone in stressed areas. Which of the following individuals would have a lower rate of bone deposition and would therefore be at greater risk for bone loss through bone resorption?

a secretary who works at a desk job and does not do any regular weight-bearing exercise

Which of the following best describes the process of bone resorption in bone remodeling?

acids and enzymes released by osteoclasts degrade collagen and dissolve away minerals, which diffuse through the interstitial fluid into nearby blood capillaries

When bones increase in thickness (diameter) as an individual grows to adulthood, which tissue or cells of the bone begin this growth process?

cells of the periosteum differentiating into osteoblasts

An elderly woman trips and falls. She puts out her hand to try to stop her fall, and ends up with a fracture of the lower arm. An x-ray shows that at the break, many pieces of bone have a splintered and fragmented appearance. Which type of fracture does this woman have?

comminuted fracture

Which of the following regions of bone would not undergo bone remodeling as frequently as the other regions?

compact bone

the layers of mineralized extracellular matrix in bone tissue?

concentric lamellae (B)

Which of the following hormones, in both adult males and females, ultimately ends growth of long bones at the epiphyseal plate? (This happens sooner in women than in men, and so men on average are taller than women).

estrogen

Most of the bones of the skull are formed by this process.

intramembranous ossification

In terms of bone health, why would a physician advise an older patient to do more weight-bearing activity such as walking, jogging, or use of moderate weights?

it promotes normal bone remodeling, osteoblasts deposit more minerals salts and collagen fibers as a response to mechanical stress, being sedentary (not physically active) promotes bone loss through resorption by osteoclasts, bone formation in stressed bones is stimulated by the tug of muscles (when exercising)

Which of the following is a function of calcium in the body?

nerve cells require extracellular calcium ions (Ca2+) for proper functioning, Ca2+ is a cofactor needed for many enzymes to function properly, Ca2+ is required for the process of blood clotting, Ca2+ is needed by muscle cells for contraction

Which represents the correct sequence of development of bone cells?

osteogenic cells → osteoblasts → osteocytes

Bone tissue stores 99% of the body's calcium. Calcium plays important roles beyond the mineralization of bones. The exchange of calcium between bone and body fluids (especially the blood) is regulated by several hormones. Which of the following is the most important hormone regulating calcium exchange?

parathyroid hormone (PTH)

a tissue that protects bone surfaces, assists in healing fractures, stabilizes the entry and exit points of blood vessels associated with bone tissue, and provides a firm attachment site for tendons and ligaments?

periosteum

Stan is a 35 year old man who is a dedicated long distance runner. He spends hours every week running along neighborhood streets. Recently Stan has had to go to the doctor due to pain in his lower legs that intensifies when he tries to run. There is no swelling or obvious damage, so he is surprised to hear the doctor say he has a fracture of his tibia. Stan is most likely to have which type of fracture?

stress fracture

With aging, bones can become more brittle. This brittleness is due to which factor?

with aging, there is a reduction in collagen synthesis by osteoblasts, which means a loss of tensile strength