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. What is the characteristic of the condition of leukemia?

A. A benign growth of skin cells
B. A malignant growth of skin cells
C. A malignant growth of white blood cells
D. A benign growth of white blood cells

Correct answer: C

Rationale: The correct answer is C: 'A malignant growth of white blood cells.' Leukemia is a type of cancer that affects the blood and bone marrow, leading to an overproduction of abnormal white blood cells. These cells are malignant and impair the normal function of healthy blood cells. Choices A, B, and D are incorrect because leukemia does not involve skin cells or benign growths; instead, it specifically refers to the abnormal proliferation of white blood cells.

3. A client has experienced a pontine stroke which has resulted in severe hemiparesis. What priority assessment should the nurse perform prior to allowing the client to eat or drink from the food tray?

A. Evaluate the client's gag reflex.
B. Assess the client's bowel sounds.
C. Check the client's pupil reaction.
D. Monitor the client's heart rate.

Correct answer: A

Rationale: The correct answer is to evaluate the client's gag reflex. When a client has experienced a stroke resulting in severe hemiparesis, assessing the gag reflex is crucial before allowing them to eat or drink. This assessment helps prevent aspiration, a serious complication that can occur due to impaired swallowing ability. Assessing bowel sounds (Choice B), pupil reaction (Choice C), or heart rate (Choice D) are important assessments but are not the priority in this situation where the risk of aspiration is higher.

4. 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.

5. When discussing the risks associated with hormone replacement therapy (HRT) with a patient who has a history of coronary artery disease, what should the nurse emphasize?

A. HRT may increase the risk of cardiovascular events such as heart attack and stroke.
B. HRT may increase the risk of osteoporosis.
C. HRT may decrease the risk of venous thromboembolism.
D. HRT may increase the risk of breast cancer.

Correct answer: A

Rationale: The correct answer is A. Hormone replacement therapy (HRT) is associated with an increased risk of cardiovascular events, such as heart attack and stroke, especially in patients with a history of coronary artery disease. Choice B is incorrect because HRT is actually known to decrease the risk of osteoporosis. Choice C is incorrect as HRT is associated with an increased risk of venous thromboembolism. Choice D is also incorrect as HRT may slightly increase the risk of breast cancer.