Hint: Skin it is by far the largest organ in the body. It covers a surface area of about 20 square feet. It Holds more than $15\%$ of body weight. It has colored pigments. The different coloured pigments are melanin, melanoid, carotene, haemoglobin and bilirubin.
The integumentary system is an organ system, it consists of skin, hair, nail and exocrine glands. They are a few millimeters thick. It provides additional protection to the body. We will understand each of them briefly.
Talking about the skin is composed of two main layers: the outer epidermis, made of closely packed epithelial cells, the inner dermis, made of dense, irregular connective tissue that houses blood vessels, hair follicles, sweat glands, and other structures. Beneath the dermis lies the hypodermis, which is composed mainly of loose connective and fatty tissue.
Hair: hair are keratinous filaments distributed all over the body except for palm ,soles, dorsal surface of distal phalanges, glans penis, etc. the length, thickness and colour varies in different parts of the body and is different for individuals..
Nails: they are hardened keratin plates which make solid covering over the dorsal surface portion of the finger. They can be found pinkish due to very vascular corium. In anaemia the nails are pale and white.
Amongst, exocrine glands, we will talk about sudoriferous or sweat glands. They are of two types of Eccrine gland and the other is apocrine glands. Eccrine is more abundant and present in every part of the skin except the margin of lips, nails, beds etc.
Note: There are different types of hair. The types could be primary hair, which are delicate and cover fetal skin by 5th and 6th month. These are replaced by secondary hair during infancy. The terminal hair covers the scalp, eyebrows, and other areas of adult skin.