Chapter 6 Homework Flashcards
Which of the following bones is accurately described as an irregular bone?
*Vertebra
Rib
Metacarpal bone
Radius
An expanded joint surface shaped like a ball and found on the articular end of the epiphysis is called a __________.
condyle
facet
trochlea
*head
A large, rounded, articulating (relating to joints) process of bone is a _________.
*condyle (large, rounded, articulating)
tubercle (small, rounded)
tuberosity (rough projections)
trochanter (large, rough)
Changing the magnitude and direction of forces generated by skeletal muscles is an illustration of the skeletal function of __________.
- leverage - Changing the magnitude and direction of forces generated by skeletal muscles is an illustration of the function of leverage.
energy reserve in bones
storage capability of bones
protection
A smooth, grooved articulating process of bone shaped like a pulley is a ___________.
trochlea
Thin bones that form the roof of the skull, the sternum, and the scapulae are considered ________.
flat bones
Where is a sesamoid bone most often found?
near joints at the knees, hands, and feet
Depressions, grooves, and tunnels in bone indicate __________.
where blood vessels or nerves lay alongside or penetrated bones
Mature bone cells found in lacunae are called __________.
osteocytes
The process of bone breakdown or erosion is called __________.
osteolysis
The meshwork of supporting bundles of fibers that make up spongy bone are __________.
trabeculae
Which of the following types of bone cells are responsible for removing and recycling bone?
Osteoclasts
Which component of the bone stores energy?
yellow marrow - adipose tissue
Found in this medullary cavity is yellow marrow. This yellow marrow is predominately adipose tissue. This is an important energy reserve for the body.
One function of bone is to produce red and white blood cells. These cells are made in what substance in bone?
Red marrow
Which of the following is an effect of stress on a bone?
The bone will become thicker.
Our bodies get bigger and heavier, which puts more stress on our bones. Furthermore, if we are active, even more stress is applied. To compensate for the effects of stress, the bone will become thicker. However, the opposite is also true. If the stress on a bone decreases (for example, when a broken leg is placed in a cast for six weeks), the bone will become weaker. There is a direct relationship between amount of stress and bone thickness.
Which of the following are NOT structural components of compact bone?
Trabeculae
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 spaces made by the irregular pattern of struts in spongy bone are normally filled with bone marrow, which functions to produce blood cells or store lipids.
Two-thirds of a bone’s weight is composed of calcium phosphate which interacts with calcium hydroxide to form crystals of __________.
hydroxyapatite
Which of the following statements about bone tissue is FALSE?
*It is made primarily of cells.
It contains collagen.
It is made primarily of calcium phosphate.
It contains four different cell types.
Bone is an unusual substance. It is composed of proteins (collagen) and mineral crystals (calcium phosphate). Once ossified, bone has a tensile strength that is four to eight times stronger than reinforced concrete. This hard matrix—which supports and protects soft tissue, aids in movement, and produces red blood cells—is the product of four different cell types. But these cell types make up only 2 percent of the total skeletal system. Therefore, osseous tissue is NOT made up primarily of cells; rather, the cooperation among these cells yields the bone matrix.
The term for the expanded end of a long bone where the joint surfaces are located is the __________.
epiphysis
As osteoclasts absorb and remove bone matrix, they leave shallow depressions called a(n) _________.
meatus
lamella
ruffled border
*osteoclastic crypt
As osteoclasts resorb bone they release acid. The release of acid and degrading enzymes dissolves the matrix and creates an osteoclastic crypt (Howship’s lacunae). The osteoclastic crypt develops a ruffled border to increase the surface area to increase the erosion process. A meatus is a tube-like passageway in a bone and lamellae are the layers seen in osteons.
Giant, multinucleated cells involved in the process of osteolysis are __________.
osteoclasts
Even as an adult, we have populations of primitive cells that can produce osteoblasts. These primitive cells are called __________.
osteogenic cells
Compact bone is characterized by many cylindrical osteons. Osteons are formed by layers of nested cylinders each called a(n) _____________.
osteocyte
*lamella
canaliculus
lacuna
Compact bone is composed of multiple osteons each of which is composed of cylinders called lamellae (plural for lamella). These lamellae are named differently for their location (e.g., circumferential are around the outer edge of bone and interstitial lamellae for the space filling layers found between osteons). Most lamellae are concentric lamellae which surround the central canals of osteons. Osteocytes are bone cells found in lacunae and communicate through small cytoplasmic extensions called canaliculi.
Unlike compact bone, spongy bone (also called cancellous bone) resembles a network of bony struts separated by spaces that are normally filled with __________.
?
Narrow passageways that allow osteocytes to communicate with neighboring osteocytes are called _____________.
osteons
central canals
*canaliculi
lacuna
Canaliculi are narrow passageways that allow for communication with neighboring cells. Although surrounded by osteoid, osteocytes must still receive oxygen and nutrients, get rid of waste products, and respond to hormones. Canaliculi allow for the rapid exchange of ions and smaller molecules. Lacunae are the pockets in which osteocytes reside. Osteons are the functional units of bone. Central canals are passageways that carry blood vessels and nerves within bone.
