21) Osteocytes
A) giant cells with 50 or more nuclei.
B) immature : 1200484.
21) Osteocytes
A) are giant cells with 50 or more nuclei.
B) are immature bone cells.
C) are the cells responsible for the production of new bone.
D) secrete acids and enzymes.
E) maintain normal bone structure by recycling the calcium salts in the bony matrix around themselves.
22) The organic component of the matrix, which makes up around one-third of the mass of bone, is dominated by
A) calcium phosphate.
B) collagen fibers.
C) calcium carbonate.
D) calcium carbonate and calcium phosphate.
E) dendritic fibers.
23) Perforating canals
A) are arranged parallel to the long axis of the central canal.
B) are always associated with osteons in cancellous bone.
C) provide passageways for linking the blood vessels of the central canals with those of the periosteum and the marrow cavity.
D) occur in growing juvenile bone, but are obliterated in adult bone.
E) are arranged in concentric layers around a central canal.
24) Which of the following accounts for almost two-thirds of the mass of bone tissue?
A) cells
B) protein fibers
C) calcium phosphate
D) osteons
E) polysaccharides
25) An increase in the diameter of growing bone is termed ________ growth.
A) epiphyseal
B) endochondral
C) intramembranous
D) appositional
E) ossification
26) Which of the following is formed via intramembranous ossification?
A) tibia
B) humerus
C) carpal bones
D) femur
E) mandible
27) Rickets is a condition marked by a softening and bending of bones that occurs in growing children, as a result of ________ deficiency.
A) vitamin A
B) vitamin D3
C) growth hormone
D) vitamin C
E) thyroid hormone
28) The presence of an epiphyseal line indicates
A) epiphyseal growth has ended.
B) epiphyseal growth is just beginning.
C) growth in bone diameter is just beginning.
D) the bone is fractured at that location.
E) The presence of an epiphyseal line does not indicate any particular event.
29) During the process of ________, an existing tissue is replaced with bone.
A) blood cell production
B) calcification
C) resorption
D) ossification
E) osteolysis
30) The presence of ________ strongly indicates that the long bone is still growing.
A) an epiphyseal plate
B) an articular cartilage
C) an epiphyseal line
D) an epiphysis
E) trabeculae
21) Osteocytes
A) giant cells with 50 or more nuclei.
B) immature : 1200484
