Unit 6: Ch 47 (Porth's 5th Ed) - Structure and Function of the Musculoskeletal System Flashcards
- Which of the following individuals demonstrates a health problem with his or her axial
skeleton?
A) A 21-year-old male who fractured his humerus while snowboarding.
B) A 40-year-old man who has a contusion to the left temporal bone of his skull
following a motor vehicle accident.
C) A 79-year-old female who has undergone hemiarthroplasty (hip replacement
surgery).
D) A 30-year-old pregnant woman who has a separated pubic symphysis.
Ans: B
Feedback:
The skull is considered to be a part of the axial skeleton, while the arm, hips, and pelvis
are components of the appendicular skeleton.
- Which of the following characteristics most accurately applies to compact (cortical)
bone?
A) It is found along lines of stress in the body.
B) The bone is arranged in an interwoven, lattice-like pattern.
C) It is relatively light but still strong.
D) The surface of the bone is lined with osteogenic cells
Ans: A
Feedback:
Due to its rigidity and strength, compact bone is placed along lines of high stress in the
body. Spongy bone exists in a lattice like pattern that is lined with osteogenic cells and
is relatively light compared with compact bone.
- While reviewing the bones in anatomy class, the instructor discusses this type of bone
that protects the underlying structures. A good example of a flat bone is:
A) metatarsal bones.
B) vertebrae.
C) femur.
D) skull.
Ans: D
Feedback:
Flat bones are composed of a layer of cancellous bone between two layers of compact
bone. They are found in areas such as the skull and rib cage, where extensive protection
of underlying structures is needed, or as in the scapula, where a broad surface for
muscle attachment must be provided. Vertebrae are irregular bones, while the metatarsal
bones and the femur are long bones.
- While explaining to the parents of a 5-year-old why the child’s fractured femur has so
much swelling and bruising, the nurse will include which of the following statements?
A) “Your child fell out of the tree with so much force that the body is trying to send
extra fluid to the area of the break.”
B) “All bone fractures have lots of bruising so it’s nothing to worry about.”
C) “This bone is hollowed out, and the inside of the shaft produces marrow where
red blood cells are formed.”
D) “There are a lot of cartilage attaching to the shaft of the femur, so when you break
that bone, it ruptures the cartilage and causes more swelling.”
Ans: C
Feedback:
Long bones usually are narrow in the mid-portion and broad at the ends so that the
weight they bear can be distributed over a wider surface. The shaft of a long bone is
formed mainly of compact bone roughly hollowed out to form a marrow-filled
medullary canal. The edema and bruising following femur fracture are due primarily to
disruption of the shaft of the bone. Cartilage attaches at the end of long bones, not the
shaft.
5. During pathophysiology class, a nursing student asks the faculty what purpose do the osteoprogenitor cells serve. From the following list, identify the purpose of these cells. Select all that apply. A) Formation of red blood cells B) Growth and remodeling of bone C) Anchorage point for blood vessels D) Repair of bone E) Supply nerves to the bone matrix
Ans: B, D
Feedback:
The endosteum is the membrane that lines the spaces of spongy bone, the marrow
cavities, and the haversian canals of compact bone. It is composed mainly of
osteoprogenitor cells that contribute to the growth and remodeling of bone and are
necessary for bone repair. The osteons consist of concentric lamellae of the bone matrix,
surrounding a central canal, called the Haversian canal that contains blood vessels and
supply nerves to the bone matrix. The periosteum acts as an anchorage point for blood
vessels to enter and leave the bone. RBC formation occurs in the shaft of long bones.
- A 30-year-old woman has just given birth to a boy. How will the mother’s bone marrow
differ from that of her son?
A) Her bone marrow performs additional functions for the maintenance of
homeostasis that her son is not able to yet perform.
B) The son will have a greater proportion of adipose tissue in his bone marrow.
C) Proportionately, the infant will have more red marrow and less yellow marrow
than his mother.
D) The amount of yellow marrow in the son’s bones will decrease as he develops.
Ans: C
Feedback:
At birth, nearly all of the marrow is red and hematopoietically active. As the need for
red blood cell production decreases during postnatal growth, red marrow is gradually
replaced with yellow bone marrow in most of the bones.
7. While studying bones in pathophysiology class, the nursing students learn that the Haversian canals are composed of A) calcium salts. B) collagen. C) lymphatics. D) glycosaminoglycans
Ans: C
Feedback:
Haversian canals are spaces in the b one of the cortex that move parallel through the long
axis of the bone for a short distance and then branch and communicate with other,
similar canals. Each canal carries one or two blood vessels, lymphatics, and some nerve
fibers.
- Bone is connective tissue, in which the intercellular matrix has been impregnated with
inorganic calcium salts, that has great tensile and compressible strength but is light
enough to be moved by coordinate muscle contractions. One third of the dry weight of
bone is composed of which of the following?
A) Bone cells, inorganic salts, and blood vessels
B) Hydroxyapatite, calcium carbonate, and calcium fluoride
C) Bone cells, blood vessels, and nerves
D) Organic matter and inorganic salts
Ans: C
Feedback:
The intercellular matrix is composed of two types of substances: organic matter and
inorganic salts. The organic matter (bone cells, blood vessels, and nerves) constitutes
approximately one third of the dry weight of bone; the inorganic salts (including
hydroxyapatite, calcium carbonate, and calcium fluoride) make up the other two thirds.
- Which of the following patients would the nurse expect to find woven bone scaffolding
in place to facilitate healing? Select all that apply.
A) A 14-year-old patient recovering from a head injury following a diving accident
B) A 22-year-old patient recovering from an auto accident where he incurred a
fracture of his femur
C) An 85-year-old nursing home patient who is undergoing rehabilitation therapy for
the arthritis in his knee
D) A 55-year-old prostate cancer patient undergoing radiation therapy for bone
metastasis
Ans: B, D
Feedback:
Woven bone, often referred to as bundle bone, is deposited more rapidly than lamellar
bone. It is of low tensile strength, serving as temporary scaffolding for support. It is
found in developing fetus, in areas surrounding tumors and infections, and as part of a
healing fracture.
- Following a fall 4 weeks prior that was caused by orthostatic hypotension, an
83-year-old male has fractured his femoral head. His care provider has stated that the
healing process is occurring at a reasonable pace and that the man will regain full
function after healing and rehabilitation. Which of the following cells is most
responsible for restoring the integrity of the man’s broken bone?
A) Osteocyte
B) Osteoclast
C) Osteoblast
D) Osteoma
Ans: C
Feedback:
The osteoblasts, or bone-building cells, are responsible for the formation of the bone
matrix and would participate in the healing process. Osteocytes are mature bone cells,
while osteoclasts reabsorb bone cells. An osteoma is a bone tumor.
- Which of the following endocrine functions are responsible for increased resorption of
bone that results in a reduction of the number and function of osteoclasts? Select all that
apply.
A) Calcitonin secretion
B) Decrease in estrogen levels
C) Stimulation of excess thyroid hormone
D) Release of catecholamines
E) Increase movement of calcium and phosphate from bone into the extracellular
fluid
Ans: A, B
Feedback:
Parathyroid hormone increases the number of resorptive function of the osteoclasts.
Calcitonin is thought to reduce the number and resorptive function of the osteoclasts.
Estrogen also reduces the number and function of the osteoclasts. Thus, the decrease in
estrogen levels that occurs at menopause results in increased resorption of bone. Release
of catecholamines has no influence over osteoclast function. Increased movement of
calcium and phosphate from bone into extracellular fluid is regulated by parathyroid
hormone.
- Which of the following individuals who has recently presented to a hospital emergency
department is displaying an injury that involves his or her fibrocartilage?
A) A 7-year-old girl whose ear has been lacerated during a dog attack
B) A 24-year-old male who has had his trachea crushed in a workplace accident
C) A 15-year-old boy who has suffered a knee injury during a football game
D) A 78-year-old man who has fallen and is suspected of having a “slipped disc” in
his back
Ans: D
Feedback:
Intervertebral discs are constructed of fibrocartilage, while the ear is largely constructed
of elastic cartilage. Cartilage of the respiratory system and joints is most often hyaline
cartilage
- While reviewing the role of the parathyroid hormone in the balance of calcium and
phosphate levels, the nursing faculty will emphasize that the kidney responds to
parathyroid stimulation by
A) increasing reabsorption of sodium in the distal tubules.
B) reducing the reabsorption of phosphate.
C) stimulating production of red blood cells.
D) decreasing the reabsorption of calcium.
Ans: B
Feedback:
In the kidney, PTH stimulates tubular reabsorption of calcium while reducing the
reabsorption of phosphate. The latter effect ensures that increased release of phosphate
from bone during mobilization of calcium does not produce an elevation in serum
phosphate levels.
- An 80-year-old female with a diagnosis of osteoporosis receives daily supplements of
calcitonin in the form of a nasal spray that she instills each morning. Which of the
following phenomenon would her care providers expect to result from her
supplementation?
A) Decreased serum calcium levels
B) Increased bone resorption
C) Acceleration of osteoclast action
D) An increase in bone formation
Ans: A
Feedback:
Calcitonin lowers both the rate of bone resorption and serum calcium levels. It does not
accelerate osteoclast action, and it is not noted to increase bone formation.
- A 70-year-old woman’s family physician has recommended a vitamin D supplement.
The woman states that she tries hard to take as few pills as possible and questions her
physician on the rationale and necessity of the hormone. How can the physician most
accurately reply to the client’s concerns?
A) “Vitamin D can prevent osteoporosis by increasing the density of your bones.”
B) “Vitamin D is important in order for your body to absorb the calcium that you
consume in your diet.”
C) “When your liver is unable to produce enough on its own, it’s important to take
vitamin D supplements to promote bone strength.”
D) “Vitamin D slows down the rate that your body breaks down your bones.”
Ans: B
Feedback:
Vitamin D facilitates intestinal absorption of calcium. It does not directly increase bone
density, and the liver does not independently produce vitamin D. Vitamin D does not
decrease the rate of bone resorption
