A client's ankle is edematous after an ankle sprain. Which physiological mechanism is responsible for the swelling?
Histamine-mediated vascular permeability leading to fluid transudation.
Bradykinin cascade resulting in the accumulation of substance P.
Thromboxane A activation of chemical mediators.
Neutrophil migration secondary to chemotaxis.
The Correct Answer is A
A) Histamine-mediated vascular permeability leading to fluid transudation:
Correct. Ankle edema following an ankle sprain is often due to inflammation and increased vascular permeability. Histamine, released from mast cells and basophils during the inflammatory response, causes vasodilation and increases vascular permeability. This leads to the leakage of fluid from the blood vessels into the surrounding tissues, resulting in edema.
B) Bradykinin cascade resulting in the accumulation of substance P:
While bradykinin is involved in the inflammatory response and can contribute to pain and vasodilation, it does not directly cause fluid transudation leading to edema in the context of an ankle sprain.
C) Thromboxane A activation of chemical mediators:
Thromboxane A is involved in platelet aggregation and vasoconstriction rather than increasing vascular permeability and edema formation.
D) Neutrophil migration secondary to chemotaxis:
Neutrophil migration is part of the inflammatory response and can contribute to tissue damage and inflammation, but it is not the primary mechanism responsible for the development of edema following an ankle sprain.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Renal calculi, also known as kidney stones, are solid masses made up of crystals that form in the kidneys due to various factors, including supersaturation of urine with stone-forming substances, inadequate urine volume, and conditions that promote crystal precipitation and retention in the urinary tract. Here's the breakdown of the pathological process contributing to the client's clinical presentation:
A) Excessive urine output:
Excessive urine output (polyuria) is not typically associated with the formation of renal calculi. In fact, low urine output (oliguria) or concentrated urine may increase the risk of stone formation by reducing the volume of urine available to dilute stone-forming substances.
B) Excessive fluid intake:
Excessive fluid intake is generally beneficial in preventing kidney stone formation by increasing urine volume and diluting stone-forming substances. Therefore, it is not likely to contribute to the development of renal calculi in this scenario.
C) Increased calcium reabsorption:
Correct. Increased calcium reabsorption in the renal tubules can lead to hypercalcemia and hypercalciuria, which are risk factors for the formation of calcium-containing kidney stones (calcium oxalate or calcium phosphate stones). Excessive calcium reabsorption may occur due to various factors, including hormonal imbalances (e.g., hyperparathyroidism) or medications that affect calcium metabolism.
D) Increased serum alkalinity:
Increased serum alkalinity (alkalosis) is not typically associated with the formation of renal calculi. Urinary pH may influence the formation of certain types of kidney stones (e.g., uric acid stones are more likely to form in acidic urine), but alkalosis alone is not a primary factor in stone formation.
Correct Answer is A
Explanation
A) The usual types of reactions are mediated by antibodies:
Correct. Types I, II, and III hypersensitivity reactions are mediated by antibodies (IgE, IgG, or IgM) that bind to antigens and trigger immune responses. In contrast, Type IV hypersensitivity reactions are T-cell mediated and do not involve antibodies.
B) B-lymphocytes produce the offending substances:
This statement is incorrect. B-lymphocytes are involved in antibody-mediated immune responses (types I, II, and III hypersensitivity reactions), not Type IV hypersensitivity reactions, which are primarily mediated by T-lymphocytes.
C) They typically occur with the first exposure to an antigen:
This statement is incorrect. Type IV hypersensitivity reactions usually require sensitization upon initial exposure to an antigen, and subsequent exposures elicit the delayed hypersensitivity response. This is similar to types I, II, and III hypersensitivity reactions, which also involve sensitization upon initial exposure.
D) Delayed reactions are characterized by cytokine release:
This statement is partially correct. Type IV hypersensitivity reactions are characterized by a delayed onset (typically 24 to 72 hours after exposure) and involve the release of cytokines from activated T-lymphocytes, leading to inflammation and tissue damage. However, other types of hypersensitivity reactions may also involve cytokine release, so this feature alone does not differentiate Type IV from other types of reactions.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.
