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Sometimes, there is an overproduction of scar tissue, because the process of collagen formation does not stop when the wound is healed; this results in the formation of a raised or hypertrophic scar called a keloid    . In contrast, scars that result from acne and chickenpox have a sunken appearance and are called atrophic scars.

Scarring of skin after wound healing is a natural process and does not need to be treated further. Application of mineral oil and lotions may reduce the formation of scar tissue. However, modern cosmetic procedures, such as dermabrasion, laser treatments, and filler injections have been invented as remedies for severe scarring. All of these procedures try to reorganize the structure of the epidermis and underlying collagen tissue to make it look more natural.

Bedsores and stretch marks

Skin and its underlying tissue can be affected by excessive pressure. One example of this is called a bedsore    . Bedsores, also called decubitis ulcers, are caused by constant, long-term, unrelieved pressure on certain body parts that are bony, reducing blood flow to the area and leading to necrosis (tissue death). Bedsores are most common in elderly patients who have debilitating conditions that cause them to be immobile. Most hospitals and long-term care facilities have the practice of turning the patients every few hours to prevent the incidence of bedsores. If left untreated by removal of necrotized tissue, bedsores can be fatal if they become infected.

The skin can also be affected by pressure associated with rapid growth. A stretch mark    results when the dermis is stretched beyond its limits of elasticity, as the skin stretches to accommodate the excess pressure. Stretch marks usually accompany rapid weight gain during puberty and pregnancy. They initially have a reddish hue, but lighten over time. Other than for cosmetic reasons, treatment of stretch marks is not required. They occur most commonly over the hips and abdomen.

Calluses

When you wear shoes that do not fit well and are a constant source of abrasion on your toes, you tend to form a callus    at the point of contact. This occurs because the basal stem cells in the stratum basale are triggered to divide more often to increase the thickness of the skin at the point of abrasion to protect the rest of the body from further damage. This is an example of a minor or local injury, and the skin manages to react and treat the problem independent of the rest of the body. Calluses can also form on your fingers if they are subject to constant mechanical stress, such as long periods of writing, playing string instruments, or video games. A corn    is a specialized form of callus. Corns form from abrasions on the skin that result from an elliptical-type motion.

Chapter review

Skin cancer is a result of damage to the DNA of skin cells, often due to excessive exposure to UV radiation. Basal cell carcinoma and squamous cell carcinoma are highly curable, and arise from cells in the stratum basale and stratum spinosum, respectively. Melanoma is the most dangerous form of skin cancer, affecting melanocytes, which can spread/metastasize to other organs. Burns are an injury to the skin that occur as a result of exposure to extreme heat, radiation, or chemicals. First-degree and second-degree burns usually heal quickly, but third-degree burns can be fatal because they penetrate the full thickness of the skin. Scars occur when there is repair of skin damage. Fibroblasts generate scar tissue in the form of collagen, which forms a basket-weave pattern that looks different from normal skin.

Bedsores and stretch marks are the result of excessive pressure on the skin and underlying tissue. Bedsores are characterized by necrosis of tissue due to immobility, whereas stretch marks result from rapid growth. Eczema is an allergic reaction that manifests as a rash, and acne results from clogged sebaceous glands. Eczema and acne are usually long-term skin conditions that may be treated successfully in mild cases. Calluses and corns are the result of abrasive pressure on the skin.

References

American Cancer Society (US). Skin cancer: basal and squamous cell [Internet]. c2013 [cited 2012 Nov 1]. Available from: (External Link) .

Lucile Packard Children’s Hospital at Stanford (US). Classification and treatment of burns [Internet]. Palo Alto (CA). c2012 [cited 2012 Nov 1]. Available from: (External Link) .

Mayo Clinic (US). Basal cell carcinoma [Internet]. Scottsdale (AZ); c2012 [cited 2012 Nov 1]. Available from: (External Link) .

Beck, J. FYI: how much can a human body sweat before it runs out? Popular Science [Internet]. New York (NY); c2012 [cited 2012 Nov 1]. Available from: (External Link) .

Skin Cancer Foundation (US). Skin cancer facts [Internet]. New York (NY); c2013 [cited 2012 Nov 1]. Available from: (External Link) .

Questions & Answers

What is neurons?
Luqman Reply
a specialized cell transmitting nerve impulses; a nerve cell.
Shain
😊
Luqman
thanks
Luqman
why are cells small
Hajiahamdy Reply
what is the change if take normal water in our body
Algur Reply
What are variations in physiology
John Reply
pls let's talk about d difference between mitosis and meiosis
olatemiju Reply
through remodeling and formation of new bones
Amoako Reply
please what is it
Monica
what is blood pressure
HALLELUYAH
what is blood pressure reading
HALLELUYAH
sketch and label blood vessels
HALLELUYAH
veins is........
KING
draw the male reproductive system
Jeremaih Reply
hello am new here
Pednyin
how life
Jeremaih
join
Hajiahamdy
Explain how different foods can affect metabolism
Abraham Reply
what is Endocrine system?
Islam Reply
which secrete hormones and other products direct into the blood
Aadi
Cell is basic, structural and functional unit of life
Kabuja Reply
The cell is the structural and functional unit of all living organisms, and is sometimes called the "building block of life." Some organisms, such as bacteria, are unicellular, consisting of a single cell.
Br_
hi am new here..wish to join you in this conversation
Rachel
welcome Rachel am Brianito
hingi
hey
HALLELUYAH
can some one help
HALLELUYAH
what is the basic function of the lymphatic system
HALLELUYAH
The other main function is that of defense in the immune system. Lymph is very similar to blood plasma: it contains lymphocytes. It also contains waste products and cellular debris together with bacteria and proteins. Associated organs composed of lymphoid tissue are the sites of lymphocyte producti
Adnan
the function of lymphatic system are 1fluid balance 2 lipid absorption and 3 defence
Sidra
destroyed microognism
Usman
lymphatic systems main function is to transport lymph
Colleen
may i know the meaning of infestation of parasite?
Aminiely
Which of the following accurately describe external respirations
Robin Reply
different between anatomy and physiology
Samwel Reply
anatomy is the study of STRUCTURE of the body while physiology is the study of the function of the part of the body
Gborgbor
Anatomy deals with the structure and parts of the body while physiology is the function of the the body parts
Archie
Anatomy is the study which deals with anatomical position while physiology deals with the function
Luqman
not understanding what is a cell
Kesa Reply
its the fundamental unit of life or its the primary step in which two or more cell combine to form a tissue .
Sidra
Is the smallest structural and functional unit of life
Aliyu
cell is the basic you unit of life
Esther
what is osteomalàcia
Ellen Reply
what is hydroxyapitate
Ellen
Hydroxyapatite, also called hydroxylapatite, is a naturally occurring mineral form of calcium apatite with the formula Ca₅(PO₄)₃, but it is usually written Ca₁₀(PO₄)₆(OH)₂ to denote that the crystal unit cell comprises two entities. Hydroxyapatite is the hydroxyl endmember of the complex apatite gro
Br_
..up
Br_
what's the best way to memorize the terms and what it does
Kesa
osteomalacia is where inorganic or mineral which is calcium and phosphorus are removed from a bone....this will make the bone become flexible n in children is called ricket
Rashida
wat work does anatomy do in the hospital and can they get work fast after finishing
SULE Reply

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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