when educating a client about to undergo a pacemaker insertion the nurse explains the normal phases of cardiac muscle tissue during the repolarization

ATI RN

Pathophysiology Exam 1 Quizlet

1. When educating a client about to undergo a pacemaker insertion, the nurse explains the normal phases of cardiac muscle tissue. During the repolarization phase, the nurse will stress that membranes must be repolarized before they can be re-excited. Within the cell, the nurse understands that:

A. Potassium channels open while sodium channels close, causing repolarization to the resting state.
B. The influx of calcium is the primary stimulus for the repolarization of cardiac tissue.
C. Only the electrical activity within the heart will determine when repolarization occurs.
D. The cell membranes need to stay calm, resulting in muscle tissue becoming refractory.

Correct answer: A

Rationale: During the repolarization phase of cardiac muscle tissue, potassium channels open while sodium channels close. This process is crucial for the cardiac muscle to return to its resting state after depolarization. Potassium moving out of the cell and sodium staying out helps reset the membrane potential and prepare the cell for the next depolarization phase. The influx of calcium is not the primary stimulus for repolarization in cardiac tissue; it is mainly involved in the depolarization phase. While electrical activity within the heart influences repolarization, the specific ion movements described in choice A are what physiologically drive repolarization. Cell membranes need to be in an active state during repolarization, not calm, to facilitate the necessary ion movements for muscle tissue to properly function.

2. A patient has been diagnosed with a fungal infection and is to be treated with itraconazole (Sporanox). Prior to administration, the nurse notes that the patient is taking carbamazepine (Tegretol) for a seizure disorder. Based on this medication regime, which of the following will be true regarding the medications?

A. The serum level of carbamazepine will be increased.
B. The patient's carbamazepine should be discontinued.
C. The patient's antiseizure medication should be changed.
D. The patient will require a higher dosage of itraconazole (Sporanox).

Correct answer: A

Rationale: When itraconazole is administered with carbamazepine, itraconazole may increase the serum levels of carbamazepine, potentially leading to toxicity. Therefore, choice A is correct. Discontinuing carbamazepine (choice B) or changing the antiseizure medication (choice C) is not necessary unless advised by a healthcare provider. Choice D, requiring a higher dosage of itraconazole, is not accurate in this scenario.

3. Women who have breast cancer due to a BRCA1 gene mutation are usually:

A. positive for human epidermal growth factor receptor 1 and 2.
B. negative for estrogen receptor.
C. positive for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2.
D. negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2.

Correct answer: D

Rationale: Women with breast cancer due to a BRCA1 gene mutation commonly have a triple-negative breast cancer subtype, which means they are negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2). This subtype tends to be more aggressive and harder to treat. Choice A is incorrect as they are typically negative for HER2. Choice B is incorrect because they are usually negative for estrogen receptor. Choice C is incorrect as they are usually negative for progesterone receptor and HER2.

4. A patient with breast cancer is prescribed tamoxifen (Nolvadex). What critical information should the nurse provide during patient education?

A. Tamoxifen may increase the risk of venous thromboembolism, so patients should be educated about the signs and symptoms of blood clots.
B. Tamoxifen may decrease the risk of osteoporosis, so adequate calcium intake is important.
C. Tamoxifen may cause weight gain, so patients should monitor their diet.
D. Tamoxifen may increase the risk of breast cancer, so regular mammograms are essential.

Correct answer: A

Rationale: When a patient is prescribed tamoxifen, a critical piece of information that the nurse should provide during patient education is that tamoxifen may increase the risk of venous thromboembolism. Therefore, patients should be educated about the signs and symptoms of blood clots and advised to seek immediate medical attention if they occur. Choice B is incorrect because tamoxifen does not decrease the risk of osteoporosis. Choice C is incorrect as weight gain is a possible side effect of tamoxifen, but it is not a critical piece of information compared to the risk of venous thromboembolism. Choice D is incorrect because tamoxifen is actually used to treat breast cancer, not increase its risk.

5. Which of the following disorders is more likely to be associated with blood in the stool?

A. Gastroesophageal reflux
B. Crohn's disease
C. Irritable bowel syndrome
D. Colon cancer

Correct answer: D

Rationale: The correct answer is D, Colon cancer. Colon cancer commonly presents with blood in the stool due to bleeding from the tumor. Gastroesophageal reflux (Choice A) is associated with heartburn and regurgitation of stomach contents into the esophagus. Crohn's disease (Choice B) is a type of inflammatory bowel disease that can cause symptoms like abdominal pain, diarrhea, and weight loss, but it does not typically present with blood in the stool as a primary symptom. Irritable bowel syndrome (Choice C) is a functional gastrointestinal disorder characterized by symptoms such as abdominal pain, bloating, and changes in bowel habits, but it does not usually involve blood in the stool as a prominent feature.