Review Questions:
Which of the following tissues is not found as part of a mature long bone?
a. Yellow bone marrow
b. Nervous tissue
c. Osteons
d. Simple cuboidal epithelium
e. Hyaline cartilage
A long bone is covered externally with a sheath called the periosteum, whereas the marrow
cavity is lined with the endosteum.
Osteoblast - secrete soft collagenous osteoid (prebone)
Osteocyte - trapped in the matrix it depends
Osteoclast - dissolve bone matrix
Osteogenic cell - multiply to give rise to osteoblasts
The scapula (shoulder blade) is a flat bone which is primarily formed through
intramembranous ossification.
T/F: Bone elongation is a result of cartilage growth and calcification at epiphyseal plate.
True
In juvenile long bones that are undergoing endochondral ossification, the metaphysis is a
region of transition between hyaline cartilage in the epiphyseal region and the primary marrow
cavity.
T/F: Appositional growth, or growth at the bone surface, results in a continual thickening of the
bone and is primarily achieved through intramembranous ossification.
True
Mineral deposition (Mineralization) - process in which calcium, phosphate, and other ions are
taken from blood and deposited in bone
- Begins in fetal ossification
- Positive feedback
Mineral resorption - dissolving bone and releasing minerals into blood
- Performed by osteoclasts at ruffled border
Hypocalcemia - low level of calcium in blood (not enough calcium)
- Caused by vitamin D deficiency, diarrhea, thyroid tumors,underactive parathyroid glands
- Pregnancy and lactation increase risk of hypocalcemia
Hypercalcemia - excessive levels of calcium in blood (too much calcium)
- Can cause emotional disturbances, muscle weakness, sluggish reflexes, and cardiac
arrest
, Draw a negative feedback loop that represents the actions of parathyroid stimulating hormone
correcting for hypocalcemia.
Include the actions of PTH and the organ functions that are influenced.
¿→Parathyroid →PTH → Bone resorption
↙ ↓
Kidneys ↑ Calcitrol syn
↓
↑ GI
The process of dissolving bone and returning its minerals to the bloodstream is known as
resorption.
Which of the following is an inorganic component of the bone matrix?
a. Proteoglycans
b. Glycoproteins
c. Collagen
d. Hydroxyapatite
e. Glycosaminoglycans
Synthesized by the combined action of the skin, kidneys, and liver, calcitriol is important to the
deposition of bone.
Which of the following exemplifies a positive feedback process happenings in bone mineral
deposition?
a. The first few crystals that form attract more calcium and phosphate
b. Osteoblasts neutralize inhibitors that prevent bone resorption
c. Osteoclasts secrete acid phosphatase that digests collagen
d. Collagen is digested by enzymes and hydroxyapatite by hydrochloric acid
e. Solubility product is reached in the tissue fluids
Calcium plays an essential role in all of the following except __________.
a. Muscle contraction
b. Exocytosis
c. Blood clotting
d. DNA synthesis
e. Communication among neurons
T/F: Hypercalcemia causes depression of the nervous system
True
Which of the following tissues is not found as part of a mature long bone?
a. Yellow bone marrow
b. Nervous tissue
c. Osteons
d. Simple cuboidal epithelium
e. Hyaline cartilage
A long bone is covered externally with a sheath called the periosteum, whereas the marrow
cavity is lined with the endosteum.
Osteoblast - secrete soft collagenous osteoid (prebone)
Osteocyte - trapped in the matrix it depends
Osteoclast - dissolve bone matrix
Osteogenic cell - multiply to give rise to osteoblasts
The scapula (shoulder blade) is a flat bone which is primarily formed through
intramembranous ossification.
T/F: Bone elongation is a result of cartilage growth and calcification at epiphyseal plate.
True
In juvenile long bones that are undergoing endochondral ossification, the metaphysis is a
region of transition between hyaline cartilage in the epiphyseal region and the primary marrow
cavity.
T/F: Appositional growth, or growth at the bone surface, results in a continual thickening of the
bone and is primarily achieved through intramembranous ossification.
True
Mineral deposition (Mineralization) - process in which calcium, phosphate, and other ions are
taken from blood and deposited in bone
- Begins in fetal ossification
- Positive feedback
Mineral resorption - dissolving bone and releasing minerals into blood
- Performed by osteoclasts at ruffled border
Hypocalcemia - low level of calcium in blood (not enough calcium)
- Caused by vitamin D deficiency, diarrhea, thyroid tumors,underactive parathyroid glands
- Pregnancy and lactation increase risk of hypocalcemia
Hypercalcemia - excessive levels of calcium in blood (too much calcium)
- Can cause emotional disturbances, muscle weakness, sluggish reflexes, and cardiac
arrest
, Draw a negative feedback loop that represents the actions of parathyroid stimulating hormone
correcting for hypocalcemia.
Include the actions of PTH and the organ functions that are influenced.
¿→Parathyroid →PTH → Bone resorption
↙ ↓
Kidneys ↑ Calcitrol syn
↓
↑ GI
The process of dissolving bone and returning its minerals to the bloodstream is known as
resorption.
Which of the following is an inorganic component of the bone matrix?
a. Proteoglycans
b. Glycoproteins
c. Collagen
d. Hydroxyapatite
e. Glycosaminoglycans
Synthesized by the combined action of the skin, kidneys, and liver, calcitriol is important to the
deposition of bone.
Which of the following exemplifies a positive feedback process happenings in bone mineral
deposition?
a. The first few crystals that form attract more calcium and phosphate
b. Osteoblasts neutralize inhibitors that prevent bone resorption
c. Osteoclasts secrete acid phosphatase that digests collagen
d. Collagen is digested by enzymes and hydroxyapatite by hydrochloric acid
e. Solubility product is reached in the tissue fluids
Calcium plays an essential role in all of the following except __________.
a. Muscle contraction
b. Exocytosis
c. Blood clotting
d. DNA synthesis
e. Communication among neurons
T/F: Hypercalcemia causes depression of the nervous system
True
