1. What is the difference between primary and secondary hemostasis? How do they relate to the formation of a blood clot? - Primary hemostasis is the initial response to vascular injury that involves platelet activation, adhesion, and aggregation. Secondary hemostasis is the activation of the coagulation cascade that leads to the generation of fibrin, which stabilizes the platelet plug. Both processes are essential for the formation of a blood clot that stops bleeding and allows tissue repair. 2. What are the main types of shock and their pathophysiological mechanisms? Give an example of each type. - The main types of shock are hypovolemic, cardiogenic, obstructive, and distributive. Hypovolemic shock occurs when there is a loss of blood or fluid volume that reduces the preload and cardiac output. An example is hemorrhage. Cardiogenic shock occurs when there is a failure of the heart to pump effectively, resulting in reduced cardiac output and tissue perfusion. An example is myocardial infarction. Obstructive shock occurs when there is an obstruction to blood flow in the circulatory system that impairs cardiac output. An example is pulmonary embolism. Distributive shock occurs when there is a widespread vasodilation that reduces the systemic vascular resistance and blood pressure. An example is septic shock. 3. What are the main causes and consequences of acute respiratory distress syndrome (ARDS)? How is it diagnosed and treated? - The main causes of ARDS are direct or indirect lung injury that triggers an inflammatory response that damages the alveolar-capillary membrane, leading to increased permeability, edema, and impaired gas exchange. The main consequences of ARDS are hypoxemia, hypercapnia, respiratory acidosis, and multiple organ dysfunction syndrome. ARDS is diagnosed by the presence of acute onset, bilateral infiltrates on chest x-ray, PaO2/FiO2 ratio less than 300 mmHg, and absence of cardiogenic pulmonary edema. ARDS is treated by mechanical ventilation with low tidal volumes and high positive end-expiratory pressure (PEEP), fluid management, prone positioning, and supportive care. 4. What are the main types of diabetes mellitus and their pathophysiological mechanisms? How are they diagnosed and treated? - The main types of diabetes mellitus are type 1, type 2, and gestational diabetes. Type 1 diabetes mellitus is caused by autoimmune destruction of pancreatic beta cells that results in absolute insulin deficiency. Type 2 diabetes mellitus is caused by insulin resistance and relative insulin deficiency due to genetic and environmental factors. Gestational diabetes mellitus is caused by hormonal changes during pregnancy that impair glucose tolerance. Diabetes mellitus is diagnosed by fasting plasma glucose greater than or equal to 126 mg/dL, random plasma glucose greater than or equal to 200 mg/dL with symptoms, oral glucose tolerance test with 2-hour plasma glucose greater than or equal to 200 mg/dL, or hemoglobin A1c greater than or equal to 6.5%. Diabetes mellitus is treated by lifestyle modifications, oral hypoglycemic agents, insulin therapy, and monitoring of blood glucose levels.