Using your textbook as a resource, list the layers of the skin and identify the characteristic structure of each layer. Describe a clinical condition related to each layer and consider the impact on the individual’s quality of life.
Your Discussion must be at least 250 words in length, detailing your thoughts and position using 2 references from the readings for support. Also be sure to pose 1-2 well thought out questions from which your colleagues can formulate a response or generate further discussion. Be sure to cite any references using APA format.
INTRODUCTION
The skin can be divided into three parts; the epidermis, the dermis, and the hypodermis. I will list the layers of the skin and identify the characteristic structure of each layer, and describe a clinical condition related to each layer and consider the impact on the individual’s quality of life in this discussion post.
The epidermis does not have any blood vessels within it, and it is composed of stratum corneum, stratum granulosum, stratum spinosum, and stratum basale from superficial to deep (OpenStax, 2018).
・The stratum corneum
The stratum corneum is the most superficial layer of the epidermis and is the layer playing the role of "preventing the penetration of microbes and the dehydration of underlying tissues physically" (OpenStax, 2018, chap.5). And dead cells in this layer are shed periodically and are replaced by cells pushed up from the stratum granulosum for about four weeks (OpenStax, 2018). A specific disease associated with the stratum corneum is ichthyosis. This disease is caused by genetic abnormalities that cause abnormal differentiation of epidermal cells and abnormalities in lipid production, metabolism, transport, etc., resulting in a highly thick stratum corneum and a large amount of shedding (Dinulos, 2022). The stratum corneum of ichthyosis patients sheds off at a rate several to several tens of times faster than an average, so it is characterized by impaired skin barrier function, impaired sweating, and high metabolic energy consumption. This causes the patient unbearable itching and pain, and also the change in their appearance is so severe that many patients suffer discrimination.
・The stratum granulosum
The stratum granulosum has a grainy appearance with three to five layers of deep cells, and "they generate large amounts of the proteins keratin, which is fibrous, and keratohyalin, which accumulates as lamellar granules within the cells" (OpenStax, 2018, chap.5). The nuclei and other cell organelles disintegrate as the cells die, and become the stratum lucidum, the stratum corneum, and the accessory structures of hair and nails (OpenStax, 2018). Atopic dermatitis is a skin disease associated with the stratum granulosum. Recent studies have found that atopic dermatitis is closely related to the tight junctions in the stratum corneum and its inner stratum granulosum layer (Agrawal & Woodfolk, 2014). This causes the patient unbearable itching and pain and appearance change.
・The stratum spinosum
The stratum spinosum comprises eight to 10 layers of keratinocytes, formed as a result of cell division in the stratum basale, and has spiny for strengthening the bond between the cells (OpenStax, 2018). Langerhans cells which can be seen in this layer, engulf bacteria, foreign particles, and damaged cells and promote the growth of normal skin tissue (OpenStax, 2018). A disease associated with the spinous layer is squamous cell carcinoma. Squamous cell carcinoma occurs not only in the general skin but also in the lips, tongue, tonsils, esophagus, lungs, etc. (Cleveland Clinic medical professional, 2022). In particular, squamous cell carcinoma that occurs in the tonsils and cervix is caused by human papillomavirus infection of cells in the stratum spinosum, which kills many people yearly.
・The stratum basale
The stratum basale is made of basal cells, which are stem cells that are precursors of the keratinocytes of the epidermis, and these stem cells are constantly going through mitosis to produce new cells, keratinocytes (OpenStax, 2018). There are two types of cells in the stratum basale; the Merkel cell, which functions as a receptor and is responsible for stimulating sensory nerves that the brain perceives as touch, and other is melanocyte, a cell that produces the pigment melanin (OpenStax, 2018). A skin disease associated with the stratum basale is basal cell carcinoma. Basal cell carcinoma is thought to arise from the hair follicle, the tissue that encloses the hair, and occurs mainly on the face. It is known to have a better prognosis than other skin cancers.
The dermis contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands, and consists of the papillary and reticular layers (OpenStax, 2018).
・The papillary layer
"The papillary layer is made of loose, areolar connective tissue, which has the papillary layer are fibroblasts, a small number of fat cells (adipocytes), and an abundance of small blood vessels" (OpenStax, 2018, chap.5). The papillary layer contains phagocytes, defensive cells that help fight bacteria or other infections that have breached the skin, and also contains touch receptors such as nerve fibers and the Meissner corpuscles (OpenStax, 2018). Blood vessels in the papillary layer are critical routes for transporting nutrients and oxygen to the epidermis. When this transport is hindered by aging or trauma such as burns, it becomes difficult to maintain and grow healthy skin, which also causes wrinkles and sagging.
・The reticular layer
The reticular layer appears reticulated (net-like) due to a tight meshwork of fibers, and collagen, which is often found in the reticular layer, is one of the main proteins that make up the dermis structure, giving skin durability (OpenStax, 2018) and another structural protein of the dermis, elastin, works to provide elasticity to the skin. One of the diseases associated with the reticular layer is Cutis laxa. Cutaneous laxity is caused by abnormal elastin metabolism, leading to decreased skin elasticity, and the exact cause is unknown, except in congenital cases due to genetic abnormalities (Ngan, 2006).
The hypodermis
The hypodermis "consists of well-vascularized, loose, areolar connective and adipose tissue, which functions as a mode of fat storage and provides insulation and cushioning for the integument" (OpenStax, 2018, chap.5). Burns and low-pitched burns that extend into the hypodermis tissue are called third-degree burns. When the condition is severe, necrosis occurs in the skin. If the necrosis is extensive, the blood flow to maintain the central skin is lost, and the necrosis progresses gradually.
Through documentaries and in real life, I saw people around me suffering from skin diseases. Skin diseases are very diverse and often complicated and long-lasting to treat. Whether these symptoms are mild or severe, they cause significant distress to the lives and mental aspects of patients and their families. Personally, I believe that further progress in stem cell research will pave the way for treatment.
CONCLUSION
The skin can be divided into two parts; the epidermis and the dermis. The epidermis does not have any blood vessels within it, and it is composed of stratum corneum, stratum granulosum, stratum spinosum, and stratum basale from superficial to deep (OpenStax, 2018). And the dermis contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands, and consists of the papillary and reticular layers (OpenStax, 2018). Underneath that is the hypodermis, which provides insulation and cushioning for the integument (OpenStax, 2018).
Discussion (Question)
・Have you ever experienced any skin diseases? Please share your experience if you have.
・What kind of research and development do you think will advance treat these skin diseases?
Thank you for reading, guys!! (1136 words)
References
Agrawal, R., & Woodfolk, J. A. (2014). Skin barrier defects in atopic dermatitis. Current allergy and asthma reports, 14(5), 433. Retrived from https://doi.org/10.1007/s11882-014-0433-9
Cleveland Clinic medical professional. (2022). Squamous cell carcinoma: Symptoms, causes and treatment. Cleveland Clinic. Retrieved from https://my.clevelandclinic.org/health/diseases/17480-squamous-cell-carcinoma
Dinulos, J. G. H. (2022). Ichthyosis - skin disorders. MSD Manual Consumer Version. Retrieved from https://www.msdmanuals.com/home/skin-disorders/cornification-disorders/ichthyosis
Ngan, V. (2006). Cutis laxa. DermNet. Retrieved from https://dermnetnz.org/topics/cutis-laxa
OpenStax. (2018). Anatomy & physiology. Houston, TX: Rice University. Retrieved from https://cnx.org/contents/FPtK1zmh@12.6:fEI3C8Ot@16/Preface.
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