Question

Describe 4 different “first-line” defensive mechanisms present in the tissue.

Given the above tissue types, what tissue type do you think a virus like nCov-19 would infect?

Describe some of the secondary lines of defense in the body that would activate after a viral infection.

Skin:

Mouth:

Oropharynx:

Bronchi:

Alveoli:

Esophagus:

Stomach:

Small Intestine:

Urethra:

Given the above tissue types, what tissue type do you think a virus like nCov-19 would infect?

Answer 1

First line defense mechanism is also known as external defense mechanism. They are physical or chemical defence mechanism that which makes the body prepared to defend against infection. Some examplea are skin, tear, mucus, stomach acid, urine flow. The acidic pH created by the gastric acid will kill the pathogen reaching the stomach. Urine flow will take the pathogen along with it and flush out. Tear has same action but the lysozyme in the tears will kill the pathogen. Mucus membranes yrao the pathogens.

The second line defence that activates against the virus is the immune response. It is specific and when pathogen enters the system the lymphocytes gets activated. They are CD4+ and CD8+ molecules. The B cells activate antibodies against the viral protein and thus serves as the second line defense mechanism. Other than that the killer T cells are activated to kill the virus. The tissue macrophage is activated to engulf the vurus and undergoes phagocytosis.

Among the given tissue type the nCOV-19 infects the alveoli. The virus infects alveoli and fluid gets filled inside it making it difficult to breath.