Write the important role(s) of:

(a) Cerumen

(b) Sebum

(c) Keratin

(d) Melanin

(e) Secretion of meibomian glands

(a) Cerumen — Wax like substance which protects and lubricates the delicate eardrum from dust particles and germs.

(b) Sebum — It makes the hair and outer surface of skin oily and waterproof.

(c) Keratin — In nails, Keratin forms the nail plate which provides a hard, protective covering over the nail bed.

(d) Melanin — It is responsible for colouration of the skin. It also protects the inner parts of the body from harmful ultraviolet rays of the Sun.

(e) Secretion of meibomian glands — It lubricates the margins of the eyelids and prevents the overflow of tears.