Practice Test

📝 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:

The principal chemical mediator of the immediate phase of acute inflammation is Histamine. Here's a detailed explanation of the options given:

1. Serotonin: While serotonin is a vasoactive substance that can cause blood vessels to constrict or dilate, it is not the primary mediator of the immediate phase of acute inflammation. It is mainly associated with the regulation of mood, appetite, and sleep. In the context of inflammation, it plays a minor role compared to histamine.

2. Histamine: Histamine is indeed the correct answer. It is a potent chemical mediator released from mast cells and basophils in response to injury or antigenic stimulation. Upon release, histamine acts on blood vessels to cause vasodilation, increased permeability, and increased blood flow to the injured area, which are hallmark features of the immediate phase of acute inflammation. This results in the cardinal signs of inflammation: redness (rubor), heat (calor), swelling (tumor), and pain (dolor).

3. Kinin-Kallikrein system: The kinin-kallikrein system is another important mediator of inflammation, but it is more involved in the later phases. When activated, it results in the formation of kinins, such as bradykinin, which contribute to increased vascular permeability and pain. However, it is not the first line mediator in the immediate phase.

4. Complement system: The complement system is a group of proteins in the blood that work with antibodies to destroy pathogens and trigger inflammation. It is a key component of the innate immune response, but its activation and role are more pronounced in the later stages of inflammation rather than the immediate phase. The complement system is involved in the opsonization of pathogens, recruitment of phagocytes, and the formation of the membrane attack complex, which can lyse certain bacteria and cells.

The immediate phase of acute inflammation is characterized by the rapid response to tissue injury, which includes vasoactive changes and increased vascular permeability to allow fluid, cells, and proteins to move into the interstitial space. Histamine is quickly released from mast cells and basophils and acts on H1 receptors of blood vessels to induce vasodilation and increased permeability. This leads to the early symptoms of inflammation, such as swelling, redness, heat, and pain, and is crucial for the initiation of the inflammatory response to protect the body from harm.

📝 Explanation:

Extensive cellulitis is most accurately described by the term "phlegmon

Phlegm is a thick, viscous substance produced by the respiratory tract, especially during a respiratory infection, which can be coughed up from the lungs or expelled from the nose. It is primarily composed of mucus, dead cells, and other substances.

Phlegmon is a term that is closely related to extensive cellulitis. It refers to a severe form of cellulitis where the infection has spread deeply into the subcutaneous tissues and is accompanied by significant inflammation, including the presence of pus and necrosis. Phlegmon is characterized by intense pain, swelling, redness, and warmth in the affected area. This condition often requires aggressive medical management, including intravenous antibiotics and surgical drainage if an abscess forms. It is an advanced and severe stage of cellulitis that can lead to systemic infection if not treated properly.