CH 6 A&P LECTURE HW

False

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

True

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

True

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

False

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

Comminuted fracture

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?

Parathyroid Hormone (PTH)

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

True

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

Appositional growth

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

True

Calcitonin inhibits activity of osteoclasts, speeds blood Ca uptake by bone, and accelerates Ca deposition into bones.

Trabeculae

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

True

During a needle biopsy of a person's bone marrow, maybe to test for the presence of cancer, pain is felt when the needle passes thru the periosteum bc it is richly supplied with nerves.

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.

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

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 thru bone resorption?

True

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

False

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

It promotes normal bone remodeling, osteoblasts deposit more minerals salts and collagen fibers as a response to mechanical stress, being sedentary promotes bone loss thru resorption by osteoclasts, bone formation in stressed bone is stimulated by the tug of muscles when exercising.

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?

Metaphysis

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

Intramembranous ossification

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

Foramen

Near the center of the diaphysis, the nutrient artery and vein pass thru a hole in the compact bone called the nutrient _____.

Lacunae

Once osteoblasts have surrounded themselves with the ECM 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.

False

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

Stress fracture

Stan is a 35 yr 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?

Medullary cavity

The hollow, cylindrical space within the diaphysis that contains fatty, yellow bone marrow in adults is called the _____.

Ossification

The process of bone formation is referred to as _____.

Hyaline cartilage

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 _____.

True

The shaft of a long bone is called the diaphysis and the end of a long bone nearest the point of attachment to the trunk is called the proximal epiphysis.

True

The skeletal system can produce blood cells and store triglycerides.

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.

Open (compound) fracture

The type of bone fracture characterized by the broken ends of the bone protruding through the skin is known as a(n):

Nerve cells require extracellular Ca 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

What is a function of Ca in the body?

Osteon

What is the structural unit of compact bone?

Cells of the periosteum differentiating into osteoblasts

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

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

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

Osteoclast

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

Epithelium function

Which is not a function of Ca in the body?

Carbohydrate storage

Which is not a function of the skeletal system?

Collagen fibers

Which is secreted by osteoblasts during bone deposition?

A fracture hematoma forms and bone cells in the region of a fracture die; phagocytes and osteoclasts begin o remove the dead cells and damaged tissue around the hematoma; fibroblasts and chondrocytes from the periosteum form the dobro cartilage callus; osteoblasts form trabecular bone that joins together the fractured ends of the bone and bony callus replaces fibrocartilage callus; bone remodeling occurs and compact bone replaces the spongy bone around the periphery of the fracture site.

Which is the proper sequence of steps in the healing of a fracture?

Minerals, vitamins, hormones

Which of the following factors affect bone remodeling and growth?

Compact bone

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

Osteogenic cells -> osteoblasts -> osteocytes

Which represents the correct sequence of development of bone cells?

Periosteum

Which structure is 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?

Canaliculi

Which structure is 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.

Concentric lamellae

Which structure represents concentric lamellae, the layers of mineralized ECM in bone tissue?

Adipose tissue, nervous tissue, cartilage, osseous tissue

Which tissue could be found on or within a bone, such as the humerus?

Ca and P

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

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

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