Chapter 6 Pre Test Flashcards
Which of the following is not a function of the skeletal system?
leverage
blood cell production
*mineral absorption
calcium storage
Which type of bones provides protection of underlying soft tissues?
irregular bones
sutural bones
sesamoid bones
*flat bones
Which of the following is a characteristic of spongy bone?
consists of a network of trabeculae
does not possess lamellae
consists of parallel osteons
possesses capillaries and venules in its matrix
*consists of a network of trabeculae
does not possess lamellae
consists of parallel osteons
possesses capillaries and venules in its matrix
Structures that connect osteons with one another, and which radiate through the lamellae of bone, are called:
lacunae.
central canals.
*canaliculi.
trabeculae.
During appositional bone growth, which of the following are deposited?
Howship’s lacunae
circumferential lamellae
concentric lamellae
interstitial lamellae
Howship’s lacunae
*circumferential lamellae
concentric lamellae
interstitial lamellae
During endochondral ossification, fibroblasts migrating with blood vessels differentiate into which structures?
osteoprogenitor cells
*osteoblasts
osteoclasts
osteocytes
Near the end of the endochondral ossification process, the:
epiphyses are filled with compact bone.
epiphyses are filled with fibrous cartilage.
*epiphyses are filled with spongy bone.
diaphyses are filled with elastic cartilage.
Intramembranous ossification:
occurs in most long bones of the human skeleton.
occurs as chondrocytes cluster together and start to secrete the bony matrix.
*starts during approximately the eighth week of embryonic development.
requires a hyaline cartilage precursor.
Acromegaly results from which of the following?
*growth hormone levels rising abnormally after epiphyseal cartilages close
when, under abnormal conditions, mesenchymal stem cells in the connective tissue around bone develop into osteoblasts
Marfan syndrome
an overproduction of growth hormone before puberty
Bones do not contain most of the body’s ______.
*potassium
calcium
carbonate
phosphate
Accounting for most of the cell population in bone,
X are mature bone cells that occupy pockets sandwiched between layers of matrix.
osteocytes???
_____ are passageways, other than the central canals, that extend roughly perpendicular to the surface of the bone. (2 words)
perforating canals
Inadequate production of growth hormones leads to reduced epiphyseal cartilage activity and abnormally short bones in the condition known as
pituitary growth failure
Parathyroid hormone (PTH) stimulates the increased release of ______ by the kidneys, enhancing its effects on the intestines and resulting in an increase in the rate of intestinal calcium absorption.
not calcitriol…?
In a _______ fracture, the affected area of the bone is shattered into a multitude of bony fragments.
comminuted
_____ bones are small, flat irregularly shaped bones that are typically found between the flat bones of the skull.
sutural
_____ is a highly vascular tissue that fills the medullary cavity. (3 words)
red bone marrow
Osteogenic cells are mesenchymal cells present in the inner layer, or _____, that lines medullary cavities.
endosteum
The endosteum consists of a simple flattened layer of cells that covers the ______, generally without any intervening connective tissue fibers. (2 words)
medullary cavity
In intramembranous ossification, the developing bone grows outward from the ossification center in small struts called
spicules
A rare single-gene mutation results in the deposition of bone around skeletal muscles.
Fibrodysplasia ossificans progressiva (FOP)
Inadequate production of growth hormone leads to reduced epiphyseal cartilage activity and abnormally short bones.
Pituitary growth failure
Abnormal increase of growth hormone levels after epiphyseal cartilages close results in thicker, not longer, bones, especially those in the face, jaw, and hands.
Acromegaly
Overproduction of growth hormone before puberty results in very tall individuals.
Gigantism
Excessive cartilage formation at the epiphyseal cartilages results in very tall individuals whose limbs are very long and slender.
Marfan syndrome
The epiphyseal cartilages of the long bones grow unusually slowly and are replaced by bone early in life.
Achondroplasia
calcium effect of PTH stimulates osteoclasts so that they accelerate their erosion of bone matrix.
Calcium is released into body fluids.
calcium effect of PTH stimulates the increased release of calcitriol by the kidneys and enhances the effects of calcitriol on the intestines
Calcium is absorbed quickly.
calcium effect of Calcitriol is continuously secreted by the kidneys at low levels sufficient to keep pace with the rate of calcium ion reabsorption at the kidneys.
Calcium is conserved.
calcium effect of Calcitonin inhibits osteoclasts but does not affect osteoblasts, which continue to deposit calcium ions within the bone matrix.
Calcium is stored.
calcium effect of Increased calcitonin secretion causes decreasing PTH or calcitriol levels, resulting in a decrease in the rate of calcium ion absorption from the intestines.
Calcium is absorbed slowly.
calcium effect of Increased calcitonin levels have an inhibitory effect on the kidneys and suppress calcium ion reabsorption.
Calcium is excreted.
The break occurs across the long axis of a bone.
Transverse fracture
Twisting stresses that spread along the length of the bone produce the break.
Spiral fracture
This type of break produces new and abnormal bone arrangements in addition to the break.
Displaced fracture
The break shatters the affected area into a multitude of bony fragments.
Comminuted fracture
The break tends to occur where the bone matrix is undergoing calcification and chondrocytes are dying.
Epiphyseal fracture
The break occurs at the ankle and affects both the medial malleolus of the distal tibia and the lateral malleolus of the distal fibula.
Pott fracture
Expanded area found at each end of the bone
Epiphysis
Narrow zone that connects the expanded area of the epiphysis to the shaft of the bone
Metaphysis
Long and tubular shaft of the bone
Diaphysis
The space within the hollow shaft of the bone
Medullary cavity
A small, rounded passageway through which blood vessels or nerves penetrate the bone
Foramen
An elongated cleft or gap
Fissure
A small, rounded projection
A small, rounded projection
A small, rough projection that may occupy a broad area of the bone surface
Tuberosity
A large, rough projection
Trochanter
A shallow depression or recess in the surface of the bone
Fossa
Process in which new bone matrix is produced when osteoid is converted to bone
Osteogenesis
Resorption process in which the acids and proteolytic enzymes secreted by osteoclasts dissolve the matrix and release the stored minerals
Osteolysis
The process through which the diameter of a bone is enlarged by addition of successive layers of circumferential lamellae to the outer surface of the bone
Appositional growth
The process through which cartilaginous bones are gradually converted to bone, resulting in increased length of the bone as the cartilaginous plate continues to grow at the epiphyseal side of the cartilage
Endochondral ossification
The formation of bone without a prior cartilaginous model
Intramembranous ossification
A highly vascular tissue involved in the production of blood cells
Red bone marrow
Adipose tissue important in the storage of energy reserves
Yellow bone marrow
The organic bone matrix before calcium salts are deposited
Osteoid
Produced during the growth and maintenance of the bone
Circumferential lamella
Remnant of osteons whose matrix components have been almost completely recycled by osteoclasts
Interstitial lamella
chronological order (Steps 1 through 6) in the process of endochondral ossification.
- Chondrocytes near the center of the shaft increase greatly in size.
- The cells of the perichondrium are converted to osteoblasts around the edges of the cartilage.
- Fibroblasts migrating with the blood vessels differentiate into osteoblasts as the vessels invade the central region.
- The osseous tissue of the shaft becomes thicker, and the cartilage near each epiphysis is replaced by shafts of bone.
- Capillaries and osteoblasts migrate into the epiphyses.
- The epiphyses are filled with spongy bone.
Which surface feature of the skull is a large passageway through the substance of a bone?
meatus
Articular cartilage is not/does not:
cover portions of the epiphysis.
*highly vascularized.
rely on synovial fluid diffusion for several processes.
avascular.
The long, tubular portion of a typical long bone is known as which of the following?
diaphysis
What are giant, multinucleated cells that remove and recycle bone matrix called?
osteoclasts
Which statement is incorrect regarding hydroxyapatite?
p 217
It is formed by the interaction of calcium phosphate with calcium hydroxide.
It is inflexible and brittle.
Its crystals incorporate other calcium salts and ions, such as sodium, magnesium, and fluoride.
*If it is compressed, it will bend.
Which of the following is NOT a characteristic of endosteum?
p 221
It is an incomplete layer that lines the medullary cavity.
It is active during bone growth, repair, and remodeling.
It consists of a simple, flattened layer of osteoprogenitor cells that covers the bone matrix.
*It has a fibrous outer layer and a cellular inner layer. (there is just the 1 cellular layer)
During intramembranous ossification, as the rate of growth slows, the connective tissue around the bone becomes organized into which of the following?
the fibrous layer of the periosteum
A rare single-gene mutation disorder that involves the deposition of bone around skeletal muscles is called:
fibrodysplasia ossificans progressive (FOP).
The parathyroid glands secrete parathyroid hormone (PTH) in response to which condition?
low calcium ion levels in plasma
What happens to bones when large numbers of calcium ions are mobilized into the blood?
Bones become weaker.
During fracture repair, an internal callus forms as a network of ______ ______ unites the inner edges.
spongy bone
Which fracture type tends to occur where the bone matrix is undergoing calcification and chondrocytes are dying?
epiphyseal fracture
The
_______ includes the bones of the limbs and the pectoral and pelvic girdles. (2 words)
appendicular skeleton
In a typical long bone, the
is a narrow zone that connects the expanded area, located at each end of the bone, to the shaft.
metaphysis
In appositional growth,
____ in the inner layer of the periosteum differentiate into osteoblasts and add bone matrix to the surface. (2 words)
osteoprogenitor cells (aka osteogenic cells)
When bone formation begins in the embryo, the cartilaginous skeletal elements are gradually converted to bone through the process of
______. (2 words)
endochondral ossification
______ begins when mesenchymal cells differentiate into osteoblasts within embryonic or fibrous connective tissue. (2 words)
intramembranous ossification
In spongy bone, the trabeculae are oriented along stress lines and are
-______ extensively. (2 words)
cross-braced
Match the internal feature of bone to its anatomical description.
p. 218
Thin layers of matrix
Lamellae
Match the internal feature of bone to its anatomical description.
p. 218
A pocket sandwiched between layers of matrix
Lacuna
Match the internal feature of bone to its anatomical description.
p. 218
Narrow passageways that penetrate the layers of matrix
Canaliculi
Match the internal feature of bone to its anatomical description.
p. 218
Network of struts and plates formed by the matrix in spongy bone
Trabeculae
Match the internal feature of bone to its anatomical description.
p. 218
Passageway that extends roughly perpendicular to the surface of the bone
Perforating canal
