Due to her progressing osteoarthritis (OA), an 80-year-old woman ...

[mrsjacobs44]

Due to her progressing osteoarthritis (OA), an 80-year-old woman is no longer able to perform her activities of daily living without assistance.
 
  Which of the following phenomena most likely underlies the woman's situation?
  A)
  Inappropriate T-cell-mediated immune responses have resulted in articular cartilage degeneration.
  B)
  Loss of articular cartilage and synovitis has resulted from inflammation caused when joint cartilage attempted to repair itself.
  C)
  Excessive collagen deposits have accumulated in the woman's synovial joints.
  D)
  Bone overgrowth in synovial joints has resulted in fusing of adjacent bones that normally articulate.

Question 2

A patient asks the nurse why his hip fracture (head of the femur) bone has died (osteonecrosis). The nurse responds based on which of the following pathophysiological principles?
 
  A)
  All fractured bones interrupt blood supply and thereby results in death of the bone no matter where it is located.
  B)
  Most of the time when the head of the femur breaks, the entire neck region is disconnected to the rest of the bone so the blood vessels are severed.
  C)
  Since the head of the femur has only limited collateral circulation, interruption in the blood flow from the fracture causes necrosis and irreversible damage.
  D)
  When the femur head breaks, it dislocates and crushes the surrounding area causing the blood vessels to be occluded.

[tofugiraffe]

Answer to Question 1

Ans:
B

Feedback:

The joint changes associated with osteoarthritis, which include a progressive loss of articular cartilage and synovitis, result from the inflammation caused when cartilage attempts to repair itself, creating osteophytes or spurs. These changes are accompanied by joint pain, stiffness, limitation of motion, and in some cases by joint instability and deformity. Immune etiology is more associated with rheumatoid arthritis, and collagen deposits are characteristic of scleroderma. Bones do not tend to fuse in the pathogenesis of OA.

Answer to Question 2

Ans:
C

Feedback:

Bone has a rich blood supply that varies from site to site. The flow in the medullary portion of bone originates in nutrient vessels from an interconnecting plexus that supplies the marrow, trabecular bone, and endosteal half of the cortex. Some bony sites, such as the head of the femur, have only limited collateral circulation, so that interruption of the flow, such as with a hip fracture, can cause necrosis of a substantial portion of medullary and cortical bone and irreversible damage. Not all fractures interrupt blood supply to the bone. It is not common for the entire head of the femur to break off leaving the area with no blood supply.

[mrsjacobs44]

Excellent

[aliotak]

Gracias!