Skin Biology Essay Elizaveta Luneva

Submitted By tibbielu
Words: 1371
Pages: 6

“Your Skin: A very adaptable Organ”

Everyone wishes to have clear, healthy, radiant looking skin, regardless of age. The skin plays a very protective role for the body, and is the largest organ. Everyday the skin is exposed to toxic gases, germs, dirt and many other substances that want to enter the skin and harm the body. The skin prevents this, with the help of it’s three layers: the epidermis, the dermis and the subcutaneous layer(as can be seen in Figure 1). Each of these layers have their own functions. The epidermis containing five layers of it’s own (as can be seen in Figure 1) forms a barrier, keeping harmful substances out and useful materials such as water, blood, vitamins, hormones and heat in, as they are vital for survival. Inner body parts need to be protected, and thus the skin acts as an outer layer which resists friction, pressure and limits abrasion and shock. The dermis is made up of thick connective tissue (which makes up about 90% of the thickness of the skin) and networks of elastin for suppleness and collagen for strength. It contains blood vessels, nerves, sweat glands and hair follicles, which the body needs to function properly. The subcutaneous layer contains the main blood vessels and fat, which act as a heat insulator, shock absorber and food storage. (Draelos & Pugliese 2011, pp.1 – 14), (Freinkel & Woodley 2001, pp.19 – 39).

The skin not only protects, but it also acts as a waste disposal system, ridding the body of toxic substances as well as provides replacement of lost cells. Unfortunately, all organs undergo degenerative changes with age, even the skin, being the largest organ of the body. Ageing is a complex, biological process mainly consisting of two components: intrinsic and extrinsic ageing. Both external and internal factors influence the speed and intensity of these ageing processes. Intrinsic ageing starts due to the ‘biological clock’, genetically, each person’s clock is different and is set to go off at a specific time, signaling the body to start ageing and then die. Skin laxity and the appearance of wrinkles is a major sign of skin ageing.

With age, the basal layer of the epidermis which is meant to produce new cells to create a tough, protective stratum corneum, lowers down it’s production of cells, as a result of which our epidermis becomes thinner (as can be seen in Figure 2). According to Huber P. and Hess K. (2010), the reduction in thickness of the skin takes place at 1% each year. The decrease in new cells produced also causes the skin to heal slower, According to the American Academy of Dermatology (2012), an older person’s skin takes two to three times longer to heal than a young child’s skin. With the decrease in skin thickness, blood vessels in the subcutaneous layers are more likely to break and bruise as skin becomes more fragile. Ageing skin also produces less collagen and elastin, both of which are responsible for keeping the skin firm (as can be seen in Figure 2). According to Huber P. and Hess K. (2010), collagen and elastin decrease by 2% each year. Together, these changes cause the sagging of skin as well as the formation of fine lines and wrinkles. Dryness is another visible aspect of ageing, it occurs due to the decrease in sweat and oil glands as well as the lipid content. These changes cause the skin to have a dry, rough surface, which is more prone to irritation and redness, also contributing to the disruption of barrier function.

In addition to these changes, the number of langerhans cells in the epidermis decreases, meaning that there are less cells preventing harmful organisms from entering the skin and protecting it. Because of this, the immune response is reduced and the elderly have a higher risk of suffering from skin diseases. With age, the skin completion also changes with the decrease in the number of melanocytes. Skin becomes paler due to the decrease in numbers of melanocytes…