Free Physician Assistant Scientific Knowledge Questions and Answers — Questions and Answers

Question 1: Which of the following lung diseases is marked by dyspnea, pursed lips during breathing, a thin, wasted appearance, a hardly audible cough, and diminished breathing sounds?

Asthma
Emphysema (Correct answer)
Chronic bronchitis
Atelectasis

Correct answer: Emphysema

Emphysema is a form of chronic obstructive pulmonary disease (COPD) characterized by the destruction of alveolar walls and loss of lung elasticity. Patients with emphysema often present as 'pink puffers' – appearing thin and wasted, experiencing dyspnea, using pursed-lip breathing, and having a quiet chest with diminished breath sounds due to poor air movement and hyperinflation.

Question 2: For chronic obstructive pulmonary disease, all of the following are suggested treatment options EXCEPT:

Beta agonists
Systemic or inhaled corticosteroids
Anticholinergics
Beta blockers (Correct answer)

Correct answer: Beta blockers

Beta blockers are generally contraindicated or used with extreme caution in patients with chronic obstructive pulmonary disease (COPD). Non-selective beta blockers can block beta-2 receptors in the airways, leading to bronchoconstriction and worsening airflow obstruction. Standard treatments for COPD include bronchodilators like beta agonists and anticholinergics, as well as corticosteroids.

Question 3: Which of the following cardiomyopathies on a chest radiograph exhibits an inflated balloon-like heart and pulmonary congestion?

Both restrictive and hypertrophic cardiomyopathies
Restrictive cardiomyopathy
Dilated cardiomyopathy (Correct answer)
Hypertrophic cardiomyopathy

Correct answer: Dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is characterized by significant enlargement of the heart chambers, particularly the ventricles. On a chest radiograph, this appears as marked cardiomegaly, often described as an 'inflated balloon-like heart.' The impaired pumping function also frequently leads to pulmonary congestion and edema, which would be visible on the X-ray.

Question 4: Which of the following DON'T add to the causes of atrial fibrillation?

Hypothyroidism (Correct answer)
Pulmonary disease
Ischemia
Rheumatic heart disease

Correct answer: Hypothyroidism

Hypothyroidism is generally associated with bradycardia and a *decreased* risk of atrial fibrillation (AFib), or at least is not a direct cause. In contrast, hyperthyroidism (thyrotoxicosis) is a well-established cause of AFib due to increased adrenergic tone and myocardial excitability. Pulmonary disease, ischemia, and rheumatic heart disease are all recognized risk factors for developing AFib.

Question 5: Which of the following cardiovascular disorders frequently exhibits an irregularly irregular pulse as a typical clinical sign?

CHF
Atrial fibrillation (Correct answer)
Ventricular fibrillation
Cardiomegaly

Correct answer: Atrial fibrillation

Atrial fibrillation is characterized by chaotic electrical activity in the atria, leading to uncoordinated atrial contractions. This results in an irregular transmission of impulses to the ventricles, causing the heart to beat in a completely unpredictable and irregular rhythm. This distinct pattern is clinically recognized as an irregularly irregular pulse, making it a hallmark sign of atrial fibrillation.

Question 6: Which of the following negative effects of beta channel blockers is NOT one of them?

Hypotension
Impotence
Bradycardia
Hypertension (Correct answer)

Correct answer: Hypertension

Beta-blockers work by blocking beta-adrenergic receptors, which leads to a decrease in heart rate, reduced myocardial contractility, and vasodilation. These actions collectively result in a *reduction* of blood pressure, making hypotension a common side effect. Therefore, hypertension is not a negative effect; instead, beta-blockers are frequently prescribed to *treat* hypertension.

Question 7: Which of the following side effects is most frequently experienced after using angiotensin converting enzyme inhibitors for an extended period of time?

Cough (Correct answer)
CHF
Hypertension
Dyspnea

Correct answer: Cough

Angiotensin-converting enzyme (ACE) inhibitors prevent the breakdown of bradykinin, a potent vasodilator, which contributes to their blood pressure-lowering effect. However, the accumulation of bradykinin in the respiratory tract can irritate the airways. This irritation frequently manifests as a persistent, dry cough, which is a well-known and common side effect leading many patients to discontinue the medication.

Question 8: Which of the following does NOT contribute to left-sided heart failure?

Endocarditis
Pulmonary hypertension (Correct answer)
Mitral regurgitation
Aortic valve disease

Correct answer: Pulmonary hypertension

Left-sided heart failure occurs when the left ventricle cannot effectively pump blood to the systemic circulation, often due to conditions affecting the left heart like mitral regurgitation or aortic valve disease. While severe left-sided heart failure can *lead to* pulmonary hypertension as blood backs up into the lungs, primary pulmonary hypertension itself is a condition of high pressure in the pulmonary arteries that primarily causes *right-sided* heart failure, as the right ventricle struggles to pump against this increased resistance.

Question 9: Of the following cells, which one develops into osteoblasts, which create bone for remodeling and repair?

Osteocytes
Osteoclasts
Osteogenic cells (Correct answer)
Osteons

Correct answer: Osteogenic cells

Osteogenic cells, also known as osteoprogenitor cells, are undifferentiated stem cells found in the periosteum and endosteum of bones. These specialized cells have the unique capacity to differentiate into osteoblasts. Osteoblasts are then responsible for synthesizing and secreting the organic matrix of bone, known as osteoid, and initiating its mineralization, which is crucial for bone formation, remodeling, and repair.

Question 10: Which heart valves are shutting when the first heart sound is made?

Aortic and mitral valves
Mitral and tricuspid valves (Correct answer)
Aortic and tricuspid valves
Aortic and pulmonic valves

Correct answer: Mitral and tricuspid valves

The first heart sound, S1, commonly referred to as the 'lub' sound, marks the beginning of ventricular systole (contraction). It is produced by the simultaneous closure of the atrioventricular (AV) valves: the mitral valve, located between the left atrium and left ventricle, and the tricuspid valve, located between the right atrium and right ventricle. This closure prevents the backflow of blood into the atria as the ventricles begin to contract.

Question 11: Which of the following tests is most accurate for determining whether someone has primary hypothyroidism?

Determining T4 levels
Determining thyroid stimulating hormone (TSH) levels (Correct answer)
Determining thyroxine levels
Determining triiodothyronine levels

Correct answer: Determining thyroid stimulating hormone (TSH) levels

In primary hypothyroidism, the thyroid gland itself is underactive, leading to insufficient production of thyroid hormones (T3 and T4). The pituitary gland, sensing these low hormone levels, compensates by increasing the secretion of Thyroid Stimulating Hormone (TSH) in an attempt to stimulate the thyroid. Therefore, an elevated TSH level is the most sensitive and accurate indicator of primary hypothyroidism, often rising even before T4 levels significantly drop.

Question 12: Which of the following diseases, which can be brought on by heart failure, features bouts of deep breathing interspersed with periods of no breathing?

Tachypnea
Ataxic breathing
Obstructive breathing
Kussmaul breathing (Correct answer)

Correct answer: Kussmaul breathing

Kussmaul breathing is characterized by deep, rapid, and labored breathing, which is a compensatory mechanism for severe metabolic acidosis. While typically associated with conditions like diabetic ketoacidosis, advanced heart failure can lead to poor tissue perfusion and lactic acidosis, triggering this profound breathing pattern to expel excess carbon dioxide. Although the description 'interspersed with periods of no breathing' more accurately describes Cheyne-Stokes respiration, Kussmaul breathing represents a severe, deep respiratory effort that can manifest in the context of advanced heart failure and its metabolic complications.

Question 13: Which of the following is NOT a tetralogy of fallot feature?

Right ventricular outflow obstruction
Large ventricular septal defect
A left to right cardiac shunt (Correct answer)
Right ventricular hypertrophy

Correct answer: A left to right cardiac shunt

Tetralogy of Fallot is a complex congenital heart defect defined by four key features: a large ventricular septal defect (VSD), pulmonary stenosis (right ventricular outflow obstruction), an overriding aorta, and right ventricular hypertrophy. Due to the pulmonary stenosis and right ventricular hypertrophy, pressure in the right ventricle is typically higher than in the left, causing a *right-to-left* shunt of deoxygenated blood through the VSD. A left-to-right cardiac shunt is therefore not a characteristic feature of Tetralogy of Fallot.

Question 14: What clinical characteristics characterize esophageal achalasia?

Dysphagia to both liquid and solid foods (Correct answer)
Food regurgitation
Fever
Epigastric pain

Correct answer: Dysphagia to both liquid and solid foods

Esophageal achalasia is a motility disorder of the esophagus characterized by the incomplete relaxation of the lower esophageal sphincter (LES) and the absence of peristalsis in the esophageal body. This dysfunction prevents food and liquids from easily passing into the stomach. Consequently, patients typically experience progressive difficulty swallowing (dysphagia) for both solid foods and liquids from the onset of the condition.

Question 15: Which of the following is the Rocky Mountain spotted fever-causing organism?

Rickettsia rickettsii (Correct answer)
Bordetella pertussis
Corynebacterium
Rickettsia siberica

Correct answer: Rickettsia rickettsii

Rocky Mountain spotted fever (RMSF) is a serious bacterial infection transmitted to humans through the bite of infected ticks. The specific causative agent for this disease is the bacterium *Rickettsia rickettsii*. This organism infects the endothelial cells lining blood vessels, leading to vasculitis and the characteristic rash associated with RMSF.

Question 16: Which one of the following conditions is NOT a long-term side effect of essential hypertension?

Asthma (Correct answer)
Diabetes
Renal failure
Neuropathy

Correct answer: Asthma

Essential hypertension, if left unmanaged over time, can lead to severe long-term complications affecting various organ systems, including renal failure, neuropathy due to vascular damage, and an increased risk of cardiovascular disease and diabetes. Asthma, however, is a chronic inflammatory disease of the airways and is not a direct long-term side effect or complication that develops as a result of essential hypertension.

Free Physician Assistant Scientific Knowledge Questions and Answers

Which of the following lung diseases is marked by dyspnea, pursed lips during breathing, a thin, wasted appearance, a hardly audible cough, and diminished breathing sounds?