Saturday, 26 September 2015 01:41

The Skin: What You Need To Know

Written by 
Rate this item
(2 votes)

The Skin – What you need to Know

 

 

 

The skin is one of the body’s strongest defence systems against parasites, germs and infections that latch onto the body on a daily basis. The skin performs a number of essential functions including protection, healing and regulating the body’s temperature.

 

 

Understanding Skin Layers

 

The skin is relatively flat with varying levels of thickness throughout the body. The thinnest skin is found on the eyelids whilst the thickest skin is found on the palms of the hands and the heels of the feet (Stein, 2007). The skin is made up of two levels consisting of the epidermis and dermis. The epidermis is the protective outer layer of skin whereas the dermis sits below the epidermis and provides support and gives the skin strength and suppleness.

The epidermis is multi-tiered with the outer surface containing a sheet of dead skin cells that serves as the barrier against the world (Stein, 2007).  The second tier contains melanocytes which are cells that make melanin which gives the skin colour and protects the body from the sun’s ultraviolet rays.

The dermis is a tough sheath of connective tissue that makes up the bulk of the skin. Unlike the epidermis, the dermis doesn’t replenish itself every month and remains the same throughout a person’s life. The dermis contains blood and lymph vessels, nerve endings, hair follicles, sweat glands and proteins called collagen and elastin.


Below I have attached a video link that explains skin in more detail:

,-tissue,-and-skin/preface/chapter-7.aspx

 

 

 

 

 

 

 

 

 

 

Skin Facts

 

 

  • The skin on an average adult if laid flat would cover approximately 18-22 feet square or 5.8-6.1 metres square.

  • 30,000 – 40,000 dead skin cells is removed from the body every minute which equates to approx. 40 pounds (18 kilograms) in a lifetime.

  • Fresh skin cells continuously replenish dead cells that have been shed resulting in a new epidermis every month (Stein, 2007).

 

Skin as a Barrier

The skin is the body’s armour keeping invading bacterium from accessing the body. The skin also cushions the organs and tissues against injury and is a receptor through touch, pain and pressure to inform the body about what is happening in the outside world.

To protect the body against invasion from the outside world, the skin has multiple defences. The first defence is sweat and sebum that coats the skin and contains antibacterial serum that punches holes in bacteria cells. In addition to this defence system, the epidermis’s multilayered sheets of tightly packed skin cells form a strong barricade against microbes that try to penetrate the interior skin cells (Macauley and Walker, 2008).

 

Acne or as some say: ‘Pimples’

Acne occurs when sebum, dead skin cells and bacteria block hair follicles. The blockage on the skin stops the sebum from draining through the skin pores causing a white head to form on the skin (Stein, 2007).

When the blockage occurs at the skins surface, melanin (cells that give the skin colour and protects the skin from ultraviolet rays) from the trapped skin cells reacts with the air, causing the pores to darken forming what known as a blackhead.

When these blockages occur, bacteria which normally lives on the skin multiply in the blocked areas feeding on the sebum and release waste materials that irritates the skin. White blood cells are then released to fight the bacteria blockage and in the process cause irritation which results in swelling, redness and pain known as acne. More severe forms of inflammatory acne are characterised by surface lesions that could be solid or pus-filled (Stein, 2007).

 

Skin as a Regulator

The skin plays a major role in maintaining a body’s temperature at 98.6 Fahrenheit or 37 degrees Celsius. When the body is cold, blood vessels in the dermis constrict, decreasing the flow of warm blood to the skin and conserving it around the central organs. If however, the body is hot, blood vessels dilate bringing warm blood closer to the skin’s surface which is why exercise makes the face redden (Stein, 2007). In conjunction with this process, the brain’s heat regulator informs the sweat glands to produce more sweat which reacts with the air to cool the skin temperature down.

Healing Skin Wounds

When the skin is damaged, penetrated or irritated the epidermis speeds up cell replacement. The new cells surround the wound and migrate in sheets across it. In a few days the damaged area is completely resurfaced, and the abrasion is gone (Macauley and Walker, 2008).

Wounds that are more serious and penetrate the dermis and the lower tissue levels of the skin and where cells don’t regenerate are a more serious matter. The healing process in these situations involve a series of cellular and vascular activities that include inflammatory, proliferative and remodelling phases (Stein, 2007).

  

 

 

 

 

 

 

 

 

 

Inflammatory

Blood from broken blood vessels flood the wound washing away microbes and debris. To contain the bleeding, broken vessels quickly constrict to slow blood flow. Platelets (a component of blood) line the wound and clump together to patch broken blood vessel walls. Platelets also react with proteins to trap red blood cells and other platelets to form a blood clot. The blood clot keeps the wound together and stops bacteria, debris and other harmful substances from spreading to surrounding healthy tissue (Macauley and Walker, 2008). As this is occurring extra blood supply occurs in the area delivering white blood cells to help clean up the bacteria and debris that surrounds the wound. As this process is occurring a scab forms where the blood clot has developed. This increased blood flow also causes the area to warm up and redden and may cause pain due to the increased stimulation of nerves in the area. This process is referred to inflammation and usually lasts 24-48 hours.

Proliferative Phase

This phase involves rapid growth of skin cells and blood vessels underneath the scab. Blood vessel tissue forms underneath the scab creating new capillary beds. These capillary beds are fragile and bleed easily (as demonstrated when someone picks a scab before it has fully healed).

Remodelling Phase

In this phase the epidermis layer of the skin returns to its normal thickness and the scab falls off. Damaged tissue has been replaced, and there is underlying scar tissue. The scar may be visible or invisible depending on the severity of the wound (Macauley and Walker, 2008).

 

 

 

References

 

Macauley, D. and Walker, R. (2008) The Way We Work: Getting to Know the Amazing Human Body. Houghton Mifflin Company Boston.

Stein, L. (2007). Body the Complete Human: How it Grows, How it Works and How to Keep It Healthy and Strong. National Geographic Society USA.

Read 1201 times Last modified on Saturday, 26 September 2015 01:59

Leave a comment