Nokea
Which term conceptualizes that the greater the myocardial fiber stretch, within physiologic limits, the more forceful the ventricular contraction, thereby increasing stroke volume?
- A. Frank-Starling's Law
- B. Automaticity
- C. Contractility
- D. Excitability
Correct Answer: A
Rationale: The correct answer is A: Frank-Starling's Law. This law states that within physiologic limits, the greater the myocardial fiber stretch, the more forceful the ventricular contraction, leading to increased stroke volume. This is because increased fiber stretch results in optimal overlap of actin and myosin filaments in the sarcomeres, enhancing contractile force.
Summary:
B: Automaticity refers to the ability of cardiac cells to spontaneously generate electrical impulses.
C: Contractility is the intrinsic ability of cardiac muscle to generate force.
D: Excitability refers to the ability of cardiac cells to respond to electrical stimuli.
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What is a condition where the lungs become stiff and scarred, making it difficult to breathe and get enough oxygen into the bloodstream?
- A. Pulmonary fibrosis
- B. Pulmonary edema
- C. Pulmonary embolism
- D. Pulmonary hypertension
Correct Answer: A
Rationale: Pulmonary fibrosis is the correct answer because it is a condition characterized by stiff and scarred lungs, leading to breathing difficulties and reduced oxygen intake. This occurs due to the formation of excessive connective tissue in the lungs, impairing their ability to expand and contract properly. Pulmonary edema is the accumulation of fluid in the lungs, not scarring. Pulmonary embolism is the blockage of a blood vessel in the lungs by a blood clot. Pulmonary hypertension is high blood pressure in the arteries of the lungs, not related to lung stiffness or scarring.
Which condition is characterized by the sudden onset of shortness of breath, often occurring at night and associated with heart failure?
- A. Paroxysmal nocturnal dyspnea
- B. Sleep apnea
- C. Orthopnea
- D. Dyspnea
Correct Answer: A
Rationale: The correct answer is A: Paroxysmal nocturnal dyspnea. This condition is characterized by sudden onset of shortness of breath at night, often associated with heart failure. It occurs when a person lies down due to fluid redistribution in the body, leading to increased pressure on the lungs and heart. Sleep apnea (B) is a separate condition characterized by pauses in breathing during sleep. Orthopnea (C) is difficulty breathing while lying flat, relieved by sitting up. Dyspnea (D) is a general term for shortness of breath but does not specifically refer to the sudden onset at night associated with heart failure.
The nurse is monitoring a client on dobutamine. What adverse effect should the nurse watch for?
- A. Tachycardia
- B. Bradycardia
- C. Hypertension
- D. Respiratory distress
Correct Answer: A
Rationale: The correct answer is A: Tachycardia. Dobutamine is a beta-adrenergic agonist that stimulates the heart, increasing heart rate and contractility. Therefore, tachycardia is an expected adverse effect. Bradycardia (B) would be unlikely due to dobutamine's cardiac stimulant effects. Hypertension (C) could occur but is less common than tachycardia. Respiratory distress (D) is not a common adverse effect of dobutamine.
Which test measures how much and how quickly you can move air out of your lungs?
- A. Spirometry
- B. Peak flow meter
- C. Lung volume test
- D. Arterial blood gas
Correct Answer: A
Rationale: Spirometry is the correct answer because it measures the volume of air exhaled in a specific time frame, assessing lung function and capacity. It is commonly used to diagnose conditions like asthma and COPD. Peak flow meter measures only the maximum speed of exhalation, not volume. Lung volume test measures the total lung capacity, not the speed of air movement. Arterial blood gas measures oxygen and carbon dioxide levels in the blood, not lung function.
This is a branch of the left coronary arteries which supplies the LEFT ATRIUM, posterior lateral surface of the left ventricle.
- A. Right coronary artery
- B. Left circumflex artery
- C. Left anterior descending artery
- D. Posterior descending artery
Correct Answer: B
Rationale: The correct answer is B, the Left circumflex artery. This artery branches off the left coronary artery and supplies the left atrium and the posterior lateral surface of the left ventricle. The Left anterior descending artery (C) supplies the anterior surface of the left ventricle. The Right coronary artery (A) supplies the right atrium and right ventricle. The Posterior descending artery (D) is a branch of the right coronary artery and supplies the posterior wall of the left ventricle. Therefore, B is the correct answer based on the specific areas supplied by each artery.