Question

The outer layer of the skin consisting of dead cells is
A) Stratum malpighii
B) Stratum lucidum
C) Stratum granulosum
D) Stratum corneum

Answer 1

Skin is defined as the outer layer of tissue which is usually soft and flexible that covers the body of vertebrate animals and is made up of several different layers each with a specific role.

Complete answer:
The skin in mammals comprises two primary layers- the epidermis which is the waterproofing layer and the dermis that serves as appendages of skin. The epidermis being the outermost layer of the skin helps in giving protection against entry of pathogens and is made up of keratinocytes, merkel cells, langerhan cells and melanocytes.

The epidermis is further divided into several layers- stratum corneum which is the outermost layer, stratum lucidum which is present only on the palms and soles, stratum granulosum which is a thin layer above spinosum, stratum spinosum which comprises of keratinocytes and stratum basale which comprises of basal cells.

The dermis is the layer of skin located beneath the epidermis and is made up of connective tissue that provides protection against stress and strain. The dermis is also divided into two regions- the papillary region and the reticular region. The dermis and the epidermis are separated by a thin layer of fibres known as the basement membrane that controls movement of molecules between the two membranes.

So the correct answer is option (D) Stratum corneum.

Note: The skin serves several important functions such as protection against pathogens, thermoregulation, control of evaporation and fluid loss, sensation, etc. and thus is one of the most important parts of the human body.