MDS PREP
A patient with severe asthma is prescribed a combination of albuterol and ipratropium. What is the primary mechanism of action for each medication?
(1) Albuterol: beta2-adrenergic agonist; Ipratropium: muscarinic antagonist
(2) Albuterol: muscarinic antagonist; Ipratropium: beta2-adrenergic agonist
(3) Albuterol: beta-adrenergic agonist; Ipratropium: muscarinic antagonist
(4) Albuterol: muscarinic agonist; Ipratropium: beta2-adrenergic antagonist
Albuterol is a beta2-adrenergic agonist that relaxes bronchial smooth muscles, while ipratropium is a muscarinic antagonist that blocks the parasympathetic effects on the airways, leading to bronchodilation.
What is the target INR range for a patient on warfarin therapy to undergo minor oral surgery?
(1) Less than 2
(2) 2-3
(3) 3-4
(4) Less than 1.5
For a patient on warfarin therapy, the target INR (International Normalized Ratio) for undergoing minor oral surgery is typically 2-3. This range provides adequate thromboprophylaxis while minimizing the risk of excessive bleeding. However, the decision to proceed with surgery should be made on a case-by-case basis, considering the patient's overall health and surgical risks.
What is the primary function of the mitral valve in the heart?
1) To prevent backflow of blood from the aorta into the left ventricle during diastole
2) To prevent backflow of blood from the pulmonary artery into the right ventricle during systole
3) To prevent backflow of blood from the left atrium into the left ventricle during systole
4) To prevent backflow of blood from the vena cava into the right atrium during systole
The mitral valve is crucial in preventing the backflow of blood from the left atrium to the left ventricle during systole, ensuring that blood flows in the correct direction through the heart during the cardiac cycle.
Which of the following is a characteristic of the rash seen in scarlet fever?
(1) Small, flat, red spots that are not elevated.
(2) Small, raised, red bumps that feel like sandpaper.
(3) Large, fluid-filled blisters.
(4) Thin, red streaks that spread out from the central lesion.
The rash in scarlet fever is characterized by small, raised, red bumps that feel like sandpaper when touched. These bumps, known as "Pastia lines," are particularly prominent in skin folds. The rash is caused by the exotoxins produced by Streptococcus pyogenes and typically occurs with a strep throat infection.
What is the most common cause of death in patients with pulmonary embolism?
1) Right ventricular failure
2) Respiratory failure
3) Recurrent embolism
4) Hemorrhagic stroke
The most common cause of death in patients with pulmonary embolism is right ventricular failure. This occurs when the right ventricle of the heart is unable to pump blood effectively due to the sudden increase in pulmonary vascular resistance from the embolism.
Which of the following is NOT a lifestyle risk factor for atherosclerosis?
1) Obesity (BMI ? 30 kg/m2)
2) Physical inactivity
3) High LDL cholesterol
4) Impaired fasting glucose
While high LDL cholesterol is a significant risk factor for atherosclerosis, it is not a lifestyle factor. It is a metabolic condition that can be influenced by diet and physical activity.
A patient has been prescribed mefloquine for malaria prophylaxis. What is the primary mechanism of action of mefloquine?
(1) Inhibition of folic acid synthesis
(2) Inhibition of DNA replication
(3) Inhibition of fatty acid synthesis
(4) Inhibition of sodium channels
Mefloquine is effective against malaria because it inhibits the DNA replication in the parasites' asexual erythrocytic stages, thus preventing their proliferation.
What is the primary mechanism of action of antiphospholipid syndrome in promoting thrombosis?
1) Inhibition of protein C and protein S
2) Activation of platelets
3) Enhancement of fibrinolysis
4) Induction of antibodies against phospholipids
Antiphospholipid syndrome is an autoimmune disorder characterized by the presence of antiphospholipid antibodies. These antibodies can bind to phospholipids in cell membranes, leading to a prothrombotic state and an increased risk of thrombosis. The exact mechanism by which these antibodies induce thrombosis is complex and may involve interference with anticoagulant proteins like protein C and protein S, as well as platelet activation and endothelial damage. However, the primary mechanism is the presence of these autoantibodies.