Practice Test

📝 Explanation:

The correct answer for the MCQ is option 1: Pernicious anemia results from vitamin B12 deficiency resulting from inadequate intrinsic factor. This is because pernicious anemia is specifically caused by the body's inability to absorb vitamin B12 due to a lack of intrinsic factor, which is required for the absorption of vitamin B12 in the small intestine. Folic acid deficiency, while it can also cause megaloblastic anemia, is not directly associated with intrinsic factor and is a separate entity from pernicious anemia.

1. Vitamin B12 deficiency resulting from inadequate intrinsic factor:
Vitamin B12 is an essential nutrient that plays a critical role in the production of healthy red blood cells. It is involved in the synthesis of DNA and the metabolism of fatty acids and amino acids. Intrinsic factor is a protein produced by the parietal cells of the stomach that binds to vitamin B12, allowing it to be absorbed in the small intestine. When there is a deficiency of intrinsic factor, vitamin B12 cannot be effectively absorbed from food, leading to vitamin B12 deficiency anemia. This is the most common cause of pernicious anemia.

Pernicious anemia is an autoimmune disorder where the body's immune system mistakenly attacks the stomach cells that produce intrinsic factor. Without sufficient intrinsic factor, vitamin B12 cannot be absorbed, resulting in a decrease in the number of red blood cells produced. The red blood cells that are formed are abnormally large and immature, known as megaloblasts. These cells are not efficient at carrying oxygen and are destroyed more quickly than normal cells, leading to the symptoms of anemia such as fatigue, weakness, and pallor. The deficiency in vitamin B12 can also affect the nervous system, causing neuropathy, cognitive impairment, and other neurological symptoms.

2. Folic acid deficiency resulting from inadequate intrinsic factor:
Folic acid is another B-vitamin essential for the production of red blood cells and is involved in DNA synthesis. However, folic acid deficiency is not directly caused by a lack of intrinsic factor. Folic acid is absorbed in the small intestine through a different mechanism than vitamin B12. While folic acid deficiency can also lead to megaloblastic anemia, it is not typically referred to as pernicious anemia. Pernicious anemia is specifically associated with vitamin B12 deficiency due to intrinsic factor deficiency or malabsorption.

3. Vitamin B12 deficiency resulting from inadequate extrinsic factor:
The term "extrinsic factor" is not commonly used in the context of vitamin B12 deficiency. Vitamin B12 is derived from dietary sources such as meat, fish, and dairy products. In the context of pernicious anemia, the issue is with the intrinsic factor, which is necessary for the absorption of vitamin B12. Therefore, this option is not accurate for explaining the cause of pernicious anemia.

📝 Explanation:

Sarcoidosis is a systemic granulomatous disorder of unknown etiology that can affect any organ in the body. It is characterized by the formation of non-caseating granulomas, which are clumps of inflammatory cells that cluster together in response to an unidentified antigen. The lungs and lymph nodes are most commonly involved. Here's a detailed explanation for each of the options:

1. Dry cough: This is a common symptom of pulmonary sarcoidosis. The cough is usually persistent and non-productive, meaning it does not bring up mucus or phlegm. The presence of a dry cough is not contradicted in the statement "All are true regarding Sarcoidosis except," so this option is not the correct answer.

2. Exertional dyspnoea: Shortness of breath on exertion can occur in individuals with pulmonary sarcoidosis due to the inflammation and granuloma formation in the lungs. This symptom can be a result of the impaired lung function and decreased lung capacity caused by the disease. Therefore, this is also a true statement regarding sarcoidosis.

3. Wheezing: Wheezing is a high-pitched whistling sound that occurs during breathing, typically heard when airways become narrowed or blocked. It can be a symptom of pulmonary sarcoidosis, particularly if the disease involves the bronchi and bronchioles, leading to bronchial obstruction and airflow limitation. However, it is not the primary symptom and may be less common than the other respiratory symptoms mentioned.

4. Hemoptysis: While hemoptysis, or coughing up blood, is not a hallmark symptom of sarcoidosis, it can occur in some cases, particularly when the granulomas are located in the lungs. It is usually mild and self-limited, but severe cases can lead to significant bleeding. This is a true statement regarding sarcoidosis, as it is a possible, although less common, respiratory symptom of the disease.

Since all the options (1, 2, and 4) are true regarding Sarcoidosis

📝 Explanation:

Basal cell carcinoma is the most common type of skin cancer, and indeed the most common form of all cancers. It typically grows slowly and rarely spreads to other parts of the body. It is often caused by long-term sun exposure.