Question

Read the following statement with two blanks I and II. Select the correct option given.

Skin is acting as ________I__________ because of the presence of ________II_________.

• A. I - physical barrier, II - epidermis
• B. I - physical barrier, II - oils
• C. I - physiological barrier, II - hypodermis
• D. I - cytokine barrier, II - fats

Answer 1

The correct option is A I - physical barrier, II - epidermis

Skin acts as a physical barrier by preventing the entry of microorganisms. It possesses a horny outer layer called epidermis (stratum corneum). The cells of this layer are like bricks of wall and protect the skin. This layer is multilayered with dead skin cells and the periodic shedding of these cells results in removal of microorganisms. In addition to this the acidic pH produced by the presence of fatty acids interferes with the growth of microorganisms.

Cytokine barriers are part of the innate immunity, which is available from birth. Cytokines are the chemicals produced by the cell which resist infections. For example interferons produced by the virus infected cells prevent the multiplication of virus.

Oils and fats are lipids which are present in the secretions of sebaceous and sweat glands of skin. The acidity (pH 5.5) and salt contents of these secretions has a microbicidal effect. But it is part of the physiological barrier.

Hypodermis is the subcutaneous layer of fat and connective tissue. It connects the skin to muscles and bones.