Hint: Integumentary system consists of skin, hair, glands, nerves and nails. This system acts as a barrier for protection against the outer environment. Other functions of the integumentary system include protection from disease-causing pathogens, retaining body fluids and maintaining internal body temperature.
Complete answer: The Integumentary system acts as the first line of defence against infection. Oils secreted by glands and immune cells present in the skin increase the efficiency of protection from infections. Integumentary system is made up of keratinized cells which cannot be penetrated by bacteria and other microbes which prevents infection. Cells of integument also secrete melanin and protect the body from UV rays. Skin is made up of two layers namely epidermis and dermis. Epidermis is the outermost layer and is made up of stratified squamous tissue. Epidermis also covers the organs and protects them from desiccation. Second is dermis in which sweat and sebaceous glands are present which produce sebum.
Additional information: Some important functions of the integumentary system are : 1. Act as a barrier: Integument acts as the first line of defence by acting as a physical barrier. Immune cells are also present in the skin that prevent infection and lipids secreted by the skin prevent loss of water. Sweat glands present performs the function of thermoregulation. 2. Excretory function: Sweat helps in excretion of water and sebum helps in excretion of fat-soluble metabolites. 3. Sensory function: Nerves help in detection of touch, heat, cold, pressure etc. also.
Note: Integument is impenetrable by microorganisms as it is made up of keratinized cells. Hence it prevents infection. Skin is a type of integument made up of two layers namely epidermis and dermis. Integument also performs the function of excretion. Nerves are also part of the integumentary system which is sensory in function.