Mastering A&P Chapter 6

What is the major advantage or advantages of bones undergoing continual remodeling? It may change the total amount of minerals deposited in the bones. It may change the internal structure of a bone. It may change the shape of a bone.

All of the listed responses are correct.

Why is vitamin C essential to bone health? Answer It is needed in the enzymatic reactions used to make collagen. It stimulates osteoblast activity. It prevents the development of scurvy.

All of the listed responses are correct.

Which of the following functions of the skeletal system is possible because bone has a hard and strong extracellular matrix? Support Protection Leverage

All of these functions occur because of the hard and strong matrix.

Which bones are not formed by intramembranous ossification? Bones of the appendages Flat bones of the skull Mandible Clavicles

Bones of the appendages

Which of the following is NOT a function of the skeletal system? Contraction Support Protection Blood cell production

Contraction

Which of the following does NOT occur during fracture repair? Dead tissue next to the break is left in the break area and is covered by new bone tissue. Cells from the periosteum and endosteum divide and differentiate into osteoblasts to secrete new bone matrix into the injured area. A fracture hematoma forms. Remodeling of the external callus takes place.

Dead tissue next to the break is left in the break area and is covered by new bone tissue.

Which of the following is not brought about by parathyroid hormone? Decreased production of calcitriol Increased osteoclast activity Increased absorption of calcium by the small intestine Decreased rate of excretion of calcium by the kidneys

Decreased production of calcitriol

In which of the following does bone replace existing cartilage? Endochondral ossification Dermal ossification Osteolysis Intramembranous ossification

Endochondral ossification

The presence of which structure is a clear indication that the person has reached their adult height and has stopped growing?

Epiphyseal line

The term for the expanded end of a long bone where the joint surfaces are located is the __________.

Epiphysis

At maturity, why are women generally shorter than men?

Estrogen promotes faster closure of epiphyseal plates than androgen does.

Spongy bone is found primarily at which part of long bones?

Expanded ends, where long bones articulate with other skeletal elements

Which anatomical term describes a rounded passageway for blood vessels or nerves?

Foramen

What are the circulating hormones that stimulate bone growth?

Growth hormone and thyroxine

What is a potential problem that can arise from the continual remodeling of bone matrix?

Incorporation of heavy metals into the bone matrix

Which of the following statements about bone tissue is FALSE? It is made primarily of cells. It contains four different cell types. It contains collagen. It is made primarily of calcium phosphate.

It is made primarily of cells.

The humerus and the femur are examples of what shape of bone?

Long bones

A tall, slender person with unusually long, slender limbs because of excess cartilage formation at the epiphyseal cartilages has what disorder?

Marfan's syndrome

What type of tissue is replaced by bone in intramembranous ossification?

Mesenchyme or embryonic fibrous connective tissue

Calcium is a very important substance for the proper functioning of various body systems. Which function of the skeletal system helps maintain calcium homeostasis?

Mineral storage

Where is a sesamoid bone most often found?

Near joints at the knees, the hands, and the feet

A girl born with nonfunctioning ovaries could be expected to have a deficiency in the activity of which type of cell?

Osteoblasts

Which of the following types of bone cells are responsible for removing and recycling bone? Osteoclasts Osteoprogenitor cells Osteocytes Osteoblasts

Osteoclasts

What is the condition that produces a reduction in bone mass sufficient to compromise normal function?

Osteoporosis

What is the term for a reduction in bone mass that is large enough to compromise the normal function of bone?

Osteoporosis

If the level of calcium in the blood drops below normal levels, which hormone is produced to correct this homeostatically?

Parathyroid hormone

Shielding the soft organs like the brain, spinal cord, and heart with its hard, strong matrix is an example of which function of the skeletal system?

Protection

Which component of bone is responsible for blood cell formation?

Red bone marrow

One function of bone is to produce red and white blood cells. These cells are made in what substance in bone?

Red marrow

What is the term for the process in which the organic and mineral components of bone are continuously recycled and renewed?

Remodeling

Homogenized milk fortified with vitamin D is effective in preventing what bone disorder in children?

Rickets

Which of the following is an effect of stress on a bone? The bone will become thicker. The activity of osteoblasts decreases and cannot keep pace with osteoclasts. The bone will lose collagen fibers. The bone will become weaker.

The bone will become thicker.

How is the tendon connected to a bone so that it will withstand the force that must be applied by the muscle to move the bone?

The collagen fibers of the tendon as well as the periosteum are incorporated into the bone tissue.

A person who chooses to eat a diet of junk food and has a sedentary job is NOT likely to experience which of the following? Thickened, prominent ridges on bones in places of muscle attachment Bones that become thin and brittle Decreased ability to resist stresses to bone structures Decreased activity of osteoblasts

Thickened, prominent ridges on bones in places of muscle attachment

The thyroid regulates bone growth and maintenance through its production of what hormone?

Thyroxine

Which of the following are NOT structural components of compact bone? Trabeculae Concentric lamellae Central canals Osteons

Trabeculae

Which of the following bones is accurately described as an irregular bone? Vertebra Rib Metacarpal bone Radius

Vertebra

__________ is required for collagen synthesis, and a deficit of it results in a condition called scurvy.

Vitamin C

Which vitamin(s) is/are specifically required for normal bone growth? Answer Vitamins A and C Vitamin D Vitamins B12 and K

Vitamins A, B12, C, D, and K

Which component of the bone stores energy?

Yellow marrow

Appositional growth on the outer surface of bones results in __________.

an increase in the diameter of a growing bone

Darcy wrecks her bike and experiences a break in the distal portion of her radius, which now projects out of her skin. Which type of fracture does she have?

an open Colles' fracture

The basic functional unit(s) of compact bone tissue is/are __________.

an osteon

Unlike compact bone, spongy bone (also called cancellous bone) resembles a network of bony struts separated by spaces that are normally filled with __________.

bone marrow

The hormone synthesized in the kidneys that regulates absorption of calcium and phosphate ions in the digestive tract is __________.

calcitriol

Osteomalacia results from a diet deficient in __________.

calcium or vitamin D

The small passageways that exist in the bone matrix to allow living bones cells to obtain nutrients and get rid of wastes are called __________.

canaliculi

The region known as the epiphyseal plate is the area where __________.

cartilage is not replaced by bone until after puberty

Fractures that shatter a bone into many small fragments are called __________ fractures.

comminuted

The type of fracture that occurs in vertebrae that are subject to extreme stresses is a __________ fracture.

compression

The endosteum is found in all of the following places except the __________. covering the outside surface of the bones lining the medullary cavity of long bones covering the trabeculae of spongy bone lining the central canals of compact bone

covering the outside surface of the bones

A prominent ridge where ligaments or tendons attach to the bone is called a __________.

crest

A fracture in which one side of the shaft is broken and the other side is bent is a __________.

greenstick fracture

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

An expanded joint surface shaped like a ball and found on the articular end of the epiphysis is called a __________.

head

Appositional growth __________. involves both osteoblasts and osteoclasts forms circumferential lamellae increases the diameter of a long bone

increases the diameter of a long bone, forms circumferential lamellae, and involves both osteoblasts and osteoclasts

When the calcium ion concentration of the blood rises above the normal level, secretion of the hormone calcitonin __________.

increases the rate of calcium ion excretion

The outer dense connective tissue of a bone, the periosteum, ________.

isolates the bone from surrounding tissues, provides a route for circulatory and nervous supply, and actively participates in bone growth and repair

The spaces in the bony matrix where osteocytes exist are __________.

lacunae

Changing the magnitude and direction of forces generated by skeletal muscles is an illustration of the skeletal function of __________.

leverage

Which of the following is the term for a fracture in which the broken bone breaks through the skin? open or compound compression greenstick closed or simple

open or compound

The process of replacing other tissues with bone is called __________.

ossification

Cells that produce new bone matrix are called __________.

osteoblasts

Giant, multinucleated cells involved in the process of osteolysis are __________.

osteoclasts

Mature bone cells found in lacunae are called __________.

osteocytes

Even as an adult, we have populations of primitive cells that can produce osteoblasts. These primitive cells are called __________.

osteogenic cells

The process of bone breakdown or erosion is called __________.

osteolysis

The condition in which a child's leg bones bend under the weight of the body is called __________.

rickets

The carpals or wrist bones are examples of __________.

short bones

The fibers of tendons intermingle with those of the periosteum, attaching __________.

skeletal muscles to bones

The meshwork of supporting bundles of fibers that make up spongy bone are __________.

trabeculae

A muscle attachment site, which appears as a slightly raised and roughened area on the bone is called a __________.

tuberosity

Depressions, grooves, and tunnels in bone indicate __________.

where blood vessels or nerves lay alongside or penetrated bones

The bony skeleton begins to form about __________ after fertilization and usually does NOT stop growing until about age __________ years.

6 weeks; 25

Which statement concerning endochondral ossification is the most accurate? A primary ossification center begins replacing cartilage in the central region of the cartilage rod. A bone collar forms around the ends of the cartilage rod. The ends of the cartilage rod are converted into bone first. The epiphyseal plate is an area of bone that joins the shaft of the cartilage rod to the ends of the rod.

A primary ossification center begins replacing cartilage in the central region of the cartilage rod.