MRCP UK EXAMINATIONS

Detailed explanation-1: -When inhaled, Mtb encounters a first line of defense consisting of airway epithelial cells (AECs) and “professional” phagocytes (neutrophils, monocytes and dendritic cells) (3, 4). If this first line succeeds in eliminating the Mtb rapidly, the infection aborts (5).

Detailed explanation-2: -Skin, tears and mucus are part of the first line of defence in fighting infection. They help to protect us against invading pathogens.

Detailed explanation-3: -Airway epithelial cells are the first line of defense against invading microbes, and they protect themselves through the production of carbohydrate and protein matrices concentrated with antimicrobial products.

Detailed explanation-4: -The first stage takes place in the first week after the inhalation of the TB bacillus. After the bacillus reaches the alveoli in the lung, it gets picked up by special cells of the immune system, called macrophages.