chapter review 6
Sam was a 60 year old man. As a result of picking up a heavy object he fractured the radius and ulna of his right arm. X-rays indicated that he had severe osteoporosis. His blood calcium levels were above normal and the pathologist found cancer cells that produced a hormone-like substance. That substance was most likely
parathyroid hormone.
The covering of the outer surface of bone is the
periosteum
Important functions of the skeletal system include
protection of the brain and soft organs
Which of the following is correctly matched?
short bone - carpal bone
Which type of bone appears porous?
spongy bone
Some marrow of long bones is termed "yellow" marrow under normal conditions. The function of yellow marrow is to
store adipose tissue.
The proportion of collagen to hydroxyapatite in bone determines the
strength of the bone.
The longitudinal growth of long bones ceases when
the epiphyseal plate is completely replaced with bone tissue.
The primary mineral in bone is
Calcium
Which of the following statements regarding calcium homeostasis is true?
When blood calcium levels are too low, osteoclast activity increases.
Osteomalacia is
a disease in adults characterized by softening of bones resulting from calcium depletion.
Haversian systems or osteons
are the basic units in compact bone tissue
What type of tissue covers the ends of long bones?
articular cartilage
Collagen and calcium hydroxyapatite are the primary constituents of
bone matrix.
What chemical causes a decrease in the blood calcium level
calcitonin
A passageway connecting neighboring osteocytes in an osteon is a
canaliculus.
Chondroblasts produce
cartilage matrix
Osteogenesis imperfecta can be caused by abnormally formed
collagen
Which type of bone is considered dense bone?
compact bone
Spongy bone tissue
contains interconnecting plates called trabeculae.
An X-ray determines that Peter fractured the shaft of his humerus. The break is in the _____________ of the bone.
diaphysis
Ossification that involves replacing cartilage with bone is
endochondral.
What is the membrane that lines the medullary cavity?
endosteum
What is the site of long bone growth?
epiphyseal plate
What is the site of longitudinal growth in long bones?
epiphyseal plate
What is the end of a long bone?
epiphysis
The spaces between developing skull bones that have not ossified are called
fontanels.
Intramembranous ossification
forms the bones of the roof of the skull.
The most common bone disease is osteoporosis. The most common consequence of this disease is
fractures.
The compression (weight-bearing) strength of bone matrix is due to the presence of
hydroxyapatite crystals.
The primary function of osteoblasts is to
lay down bone matrix
Some marrow of long bones is termed "red" marrow. The function of red marrow is to
manufacture blood cells.
What is the area where marrow is located?
medullary cavity
The stem cells of osteoclasts are
monocytes
Appositional growth deposits a new layer of bone
on the surface of the bone.
The remodeling of bone tissue is a function of
osteoblast and osteoclast activity
Which type of bone cells combine hydroxyapatite and collagen to form extracellular bone matrix?
osteoblasts
Which type of bone cells possess extensive ER and ribosomes?
osteoblasts
Which of the following cell types is responsible for breaking down bone matrix?
osteoclast
When blood calcium levels are low
osteoclast activity increases
Which type of bone cells are large cells that form from fusion of monocytes?
osteoclasts
Which of the following is correctly matched?
osteoclasts - responsible for reabsorption
The cell type that is responsible for maintaining bone once it has been formed is the
osteocyte.
What are the maintenance cells in bone tissue?
osteocytes
Which type of bone cells lie in lacunae?
osteocytes
Brittle bone disorder is another name for
osteogenesis imperfecta
Osteoclast activity is increased by
parathyroid hormone
