how the does the skin act as a barrier
The skin is cleverly designed to perform in helping the skin acting as a physical, chemical and physical barrier for the body. The physical barrier acts as a protective cover to protect us from the environment i.e. pathogens, physical abrasions and radiation from the sun. Yet it is known to be one of the largest organs in the body in weight and in surface area. In adults, the skin makes up 16% of body weight and the skin covers an area of about 2 square meters. http://www.bbc.co.uk/science/humanbody/body/factfiles/skin/skin.shtml.
Structurally the skin consists of three separate layers 1) Epidermis 2) Dermis 3) subcutaneous tissue. The Epidermis is the outer and thinner portion composed of stratified squamous epithelium, which is attached to the inner, thicker, connective tissue called the dermis. Beneath the dermis is what’s called the subcutaneous layer consists of areolar and adipose tissues. Figure 1 shows the structure of the skin.
Therefore, the structure of the skin as to the epidermis, dermis and subcutaneous layer enables individual component inside each sector to function and work together as a physical barrier for the skin. i.e. the epidermis is made of keratinized cells to protect the skin against harmful substances and against abrasion (interacting with the environment). The dermis provides support and bulk for the epidermis as well as anchors the skin. The subcutaneous layer stabilises the position of the skin. In addition to this, the epidermis being the outermost layer of the skin is the most essential part of this essay. For it have five compartments to give an effective and strong protective layer. The Epidermis consists of five separate layers called stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum basale.
Figure 2 exhibits the structure of the epidermis
The outermost section of the epidermis is known as stratum corneum. Brooker, (2000) describes how the stratum corneum comprises dead cells containing keratin (tough fibrous protein) and are therefore, shed to be replaced by new cells formed in the stratum basale which move upwards through the layers over a period of 6-8 weeks. Special oils and lipids reside in the stratum corneum; providing a waterproof moisture barrier. The waterproof moisture barrier repels microbial invasion, chemical substances and allergens. However, if the integrity of the moisture barrier is compromised, the skin becomes vulnerable to dryness, itching, stinging, redness and other skin care problems. Maintaining the stratum corneum is achieved by a number of components found in the epidermis, to shield the outer layer of the skin. One is the waterproof moisture as mentioned above followed by the pores, hair follicle, sebaceous gland, sweat glands. Sebaceous glands produce an oily substance called sebum into the hair follicles, the sebum help to lubricate the follicle as it grows. The sweat and sebum serves to inhibit the growth of bacteria on the skin surfaces and the sebum itself prevents the skin from cracking whilst leaving the skin smooth and moist. The pores contain keratinocytes that line the pore of the skin. The keratinocytes are continuously shed from the lining of the pore and can mix with sebum and clog the pore. The sweat gland area produce sweat when the body gets hot or stress, hence water evaporate from the skin. This helps to cool the body down, hydrate the skin and help maintain the acid mantle. Hair follicle also helps to maintain the stratum corneum by preventing heat loss and also to shield the epidermis from minor abrasions and exposure to the sun’s rays. http://www.bioskinbalm.com/dry/
The Epidermis contains no...
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