A
_____________ is the process of dissolving bone and returning its minerals to the bloodstream.
a. Mineralization
b. Mineral deposition
c. Crystallization
d. Resorption
e. Ossification
d. Resorption
The combination of all the concentric rings of bone built around a single blood vessel is called a(n)...
Osteon
is comprised of several concentric layers of lamella with an artery in the center providing nutrients. It is the basic unit of compact bone also called Haversian system)
Hydroxyapatite is composed of what materials?
Calcium Hydroxide, Calcium Carbonate (10%) and Calcium phosphate (85%)
Also Mg, Na, K
If a thyroid tumor secreted an excessive amount of calcitonin, we would expect
a. an elevated level of osteoclast activity.
b. an elevated level of osteoblast activity.
c. a reduced rate of endochondral ossification.
d. a rise in blood calcium concentration.
e. increasingly brittle bones.
b. an elevated level of osteoblast activity.
Which of the following is the correct sequence of events in the healing of a bone fracture?
a. bone remodeling → soft callus formation → hard callus formation → hematoma formation
b. bone remodeling → hard callus formation → soft callus formation → hematoma formation
c. hematoma formation → soft callus formation → hard callus formation → bone remodeling
d. hematoma formation → hard callus formation → soft callus formation → bone remodeling
e. soft callus formation → hard callus formation → hematoma formation → bone remodeling
c. hematoma formation → soft callus formation → hard callus formation → bone remodeling
Which of these cells are associated with osteogenesis?
a. lamellae.
b. osteoblasts
c. osteoclasts
d. osteocytes
e. b and c
b. osteoblasts
Osteoblasts build bone while Osteoclasts tears it down. And, Osteocytes are mature bone cells that maintain bone.
_______ connects the cell processes of osteocytes in the central or Haversian canals within the bone tissue to carry oxygen and waste from the osteocytes in the lacunae
Canaliculi
Parathyroid hormone (PTH) does not
a. promote calcium reabsorption by the kidneys
b. stimulate osteoclast activity
c. lower blood calcium
d. promote calcitriol synthesis
e. inhibit osteoblast activity
c. lower blood calcium. (increases blood calcium)
a. promote calcium reabsorption by the kidneys. (so Ca is not lost in urine)
b. stimulate osteoclast activity. (releasing stored calcium from the bones)
d. promote calcitriol synthesis. (vitamin D3 which aids in the absorption of Ca)
e. inhibit osteoblast activity. (stops Ca from being stored in bones)
A soft callus forms during
a. endochondral ossification.
b. intramembranous ossification.
c. bone growth at the metaphysis.
d. the remodeling of bone.
e. the healing of a fracture.
e. the healing of a fracture
Patches of fibrocartilage formed in the healing of a fracture are called ________, whereas the bony collar formed around the fracture is called _________.
a. fracture hematoma; granulation tissue
b. granulation tissue; soft callus
c. fracture hematoma; hard callus
d. granulation tissue; hard callus
e. soft callus; hard callus
e. soft callus; hard callus
Mature bone cells that maintain the bone
a. lamellae
b. osteogenic cells
c. osteocytes
d. osteochondral progenitor cells
e. osteoclasts
c. osteocytes
______ is the space or depression in bone that contains bone cells, osteocytes
lacunae
___________ is synthesized by the combined action of the skin, kidneys, and liver, and is important to the deposition of bone.
a. Growth hormone
b. Testosterone
c. Estrogen
d. Calcitonin
e. Calcitriol (vit D3)
e. Calcitriol (vit D3)
Osteoporosis is most common in elderly women because of the lack of ___________, which would otherwise inhibit ____________.
a. dietary calcium; estrogen production
b. osteoblasts; osteoclast activity
c. estrogen; osteoclast activity
d. parathyroid hormone; osteocyte activity
e. exercise; osteoblast activity
c. estrogen; osteoclast activity
____________ is synthesized by the combined action of the skin, kidneys, and liver, and is important to the deposition of bone.
a. Growth hormone
b. Testosterone
c. Estrogen
d. Calcitonin
e. Calcitriol
e. Calcitriol
Which of these are associated with osteolysis?
a. osteoclasts
b. osteogenic cells
c. osteochondral progenitor cells
d. osteon
a. osteoclasts
At which of the following ages would calcium loss from bone be more than calcium deposits into bone, even when a high calcium diet is eaten?
a. 18 months old
b. 10 years old
c. 18 years old
d. 50 years old
d. 50 years old
A 50 year old woman is likely to be postmenopausal. Therefore she is no longer secreting estrogen which protected her from bone loss.
*Testable numbers*
What is the % of the following three substances in bone of the total amount in the body -
Mg
Ca
P
Mg 50% / 0.5% composition of bone
Ca 99% / 39% composition of bone
P 88% / 0.2% composition of bone
A fracture in which the bone is broken into three or more pieces is called a __________ fracture.
a. linear
b. Comminuted
c. Greenstick
d. Compound
b. Comminuted
Bone elongation is a result of
a. cartilage growth.
b. muscle growth.
c. osseous tissue growth.
d. fibrous membrane addition.
e. dense irregular connective tissue addition.
a. cartilage growth.
A single concentric ring of bone built around a single blood vessel is called a(n)...
a. lamellae
b. osteon.
c. osteocyte.
d. canaliculi (connect the cell processes of osteocytes in the central or Haversian canals within the bone tissue to carry oxygen and waste from the osteocytes in the lacunae)
e. lacunae (space or depression in bone that contains bone cells, osteocytes)
a. lamellae
Osseous tissue is a solid matrix containing crystals mostly of
hydroxyapatite
Name the zones of the epiphyseal plate - starting at the center
1. Zone of reserve cartilage
2. Zone of cell proliferation - chondrocytes multiplying, lining in rows of flattened lacunae
3. Zone of hypertrophy - cessation of mitosis
4. Zone of Calcification - temp cartilage matrix between lacunae
5. Zone of bone deposition - breakdown of lacuna walls. open channels. death to chondrocytes
The result of calcium and phosphate levels in blood too low for normal deposition is a softness of the bones called ___________ in children and ___________ in adults.
a. osteomalacia; rickets
b. rickets; osteomalacia
c. osteoporosis; osteomalacia
d. osteomyelitis; osteosarcoma
e. osteomyelitis; osteomalacia
b. rickets; osteomalacia
The _____________ is a marginal zone of the epiphyseal plate where, in children and adolescents, bone can be seen replacing the hyaline cartilage.
a. metaphysis
b. primary ossification center
c. secondary ossification center
d. osteoid tissue
e. epiphyseal line
a. metaphysis