Question

Explain the structure of our skin.

Answer 1

Hint: The largest organ of the body is skin. It forms the outer covering of the vertebrae’s body that forms the protective covering internally and externally.

Complete answer:
The skin is the largest organ of our body and it keeps refreshing. It contains many specialized cells and structures. The main function of skin is it forms a protective barrier which interacts with a hostile environment, it also protects the body against diseases and helps in regulating the body temperature.
The structure of skin comprises three layers: Epidermis, Dermis and the subcutaneous tissue.
Epidermis: The outer layer of the skin is called Epidermis which gives the skin its tone. The dead cells are shed continuously from the epidermis as new skin takes their place. The most common type of cells within the epidermis are keratinocytes which acts as a physical barrier against any type of harmful pathogens. It contains no blood vessels and it protects the skin from UV rays. The epidermis is subdivided into five layers: Stratum corneum, Stratum lucidum, Stratum spinosum etc. The function of the epidermis is to produce new cells, giving skin colour and sheltering the body.
Dermis: The dermis contains connective tissue. It protects the body from the strain and stress giving elasticity and strength. It is the middle layer of skin. If the dermis is stretched a lot, for example during pregnancy the dermis can be torn which leads to stretch marks. It contains the hair follicles, blood, lymphatic vessels and also several glands like sweat and sebaceous gland.

The dermis is divided into two layers:
Papillary region: It is composed of loose connective tissue and has finger-like projections which push into epidermis. It provides the dermis with a bumpy surface and is responsible for the patterns we have on fingertips.
Reticular region: This region is composed of dense, irregular organized connective tissue. Protein fibres in the reticular region give the skin its elasticity and strength.
The function of the dermis is providing sensation, sweating and in growth of hair etc.
Subcutaneous layer: It is the deepest of the skin known as subcutis or hypodermis. It helps to attach the skin to underlying bone and muscle. It provides the skin with nerves and blood supply as well. The sub cutis is composed of fat, connective tissue and elastin. The high level of lipid helps in the insulation of the body and prevents from losing too much heat. The lipid layer acts as a protection, padding our bones and muscles.

Note: Skin is a layer which protects the body. The thickness of the skin varies from the location on an organism body. In humans the skin under the eyes is the thinnest and measures around $0 \cdot 5$mm thickness whereas the skin on the palms and the soles is the thickest skin of the body that measures about $4$mm thickness.