Название | Clinical Applications of Human Anatomy and Physiology for Healthcare Professionals |
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Автор произведения | Jassin M. Jouria |
Жанр | Биология |
Серия | |
Издательство | Биология |
Год выпуска | 0 |
isbn | 9781627346481 |
At the completion of this chapter, the student will be able to:
1.Identify the main components of the integumentary system and understand how they work.
2.Define the differences between the epidermis and the dermis as well as their functions.
3.Understand how the body adjusts to and maintains optimal body temperature.
4.Describe how the integumentary system influences the health of other body systems.
5.Explain common injuries to the skin and how their caused.
Case Study Introduction
Paramedics respond to a 911 call regarding a 70-year-old female who has been pulled by neighbors out of her burning house. The fire truck is already on scene extinguishing the house fire, which is believed to have been started by a cigarette. The woman is known to smoke while watching television and is believed to have fallen asleep. She was found lying on the living room sofa, which was nearly engulfed in flames when the neighbors entered the home, as were the curtains behind it.
When paramedics arrive, the woman is on the front lawn, covered by a sheet donated by one of the neighbors. Upon initial assessment by the paramedics, the woman has first, second, and third-degree burns over more than 40% of her body.
A visual inspection notes that some of the burns on her arms and shoulders are second-degree burns, as noted by their appearance; red and blistered, involving all layers of the epidermis and upper layers of the dermis. Burns on her torso are full-thickness and appear greyish-white in color with blackened edges. The edges of the skin have peeled back on itself from the edges of the burned area. The patient is unconscious and unresponsive.
Paramedics immediately secure her airway and provide oxygen and start a large bore (14 G) bolus IV in the right median cubital vein for fluid replacement in an effort to begin restoration of fluids. They take the unconscious woman’s vitals; her blood pressure is unstable at 60/40 and her heart rate is 172, respiratory rate 35, shallow and raspy. Her neighbors do not know her medical history nor whether she is taking any medications. She is placed onto a gurney and quickly transported to the hospital.
In the emergency room physicians immediately focus on her O2 levels and begin prophylactic endotracheal intubation because smoke inhalation is suspected. Peripheral pulses are checked to assess her circulatory status.
An additional large bore peripheral IV is inserted into the saphenous vein of her left calf as her left arm is too risky due to potential venous flow impairment. A urinary catheter to monitor urine output is also placed. A nasogastric tube is also inserted to facilitate suctioning to reduce the risk of gastric distention.
Nurses assess her for hypothermia, potential renal and/or liver failure, and decreased cardiac output. They prepare a lactated Ringer’s solution, which will be carefully monitored carefully for the next 24 to 72 hours in an attempt to regulate fluid volume in her body that has been lost post-trauma.
Damage to the integrity of the skin for this patient increases the risk for infection as well as increasing nutritional demand for healing processes. Protein may be lost through wound exudate. Fluid levels and electrolyte status will be continually evaluated. Additional metabolic aspects will also be evaluated, including increased protein metabolism and increased urinary excretion of nitrogen, a result of the body requiring greater amounts of protein for energy.
Physicians initially treat by replacing fluids and electrolytes to reduce the risk of hypovolemia and to maintain circulating blood volume. As soon as the patient is stabilized, she is transported to the burn unit. Nursing staff refers to Parkland’s formula for fluid resuscitation.
There, the patient will be assessed hourly and the burns irrigated with saline. The patient’s clothing is carefully removed and a neurologic examination proceeds. Covering the wounds may help to slightly reduce metabolic needs, reduce nitrogen losses, and reduce evaporation and help prevent infection.
Nursing staff will also carefully monitor the patient for loss of fluids and electrolytes. Her sodium levels are also closely followed to reduce hypovolemia, systemic edema, as well as kidney function. Potential kidney failure is a risk due to release of antidiuretic hormone and vasoconstriction. They will also monitor for hepatic perfusion, which may be compromised and can lead to possible liver ischemia.
Because of her age and the presence of partial and full-thickness burns, she is high-risk for infection, shock, drop in body temperature, and additional tissue loss.
■Introduction
Skin is considered the largest organ of the human body and comprises approximately 15% of a person’s total body weight. For an average-sized adult, skin can weigh anywhere from 7 to 11 pounds.1 In total surface area, skin can encompass roughly 20 ft.² of tissue.2
Thickness of the skin varies depending on its location on the body. It can measure anywhere from 1.5 mm to 4.0 mm, but regardless of thickness, its structure is the same.
Skin does more than just cover muscle and provide an aesthetic appearance; skin is the body’s first line of defense against temperature extremes in our environment; acts as a barrier against bacteria; and cushions the bones and other organs from blunt force injuries.
Figure 3-1 Integumentary system.
The skin is involved in the maintenance and health of numerous body systems and as such can take on a variety of appearances depending on our internal environment and status.
For this reason, regularly assessing skin condition provides healthcare personnel with a general indication of how a person responds to internal and external stressors.3
Dermatology is a field of medical study focusing on diagnoses and treatments for skin conditions and diseases. A physician who focuses and specializes in any number of skin conditions is called a dermatologist.
An overview of skin structures and characteristics will be explored in detail in this chapter, as will functions of the skin, hair, and nails. While on the outside, our skin looks different from individual to individual depending on age, gender, and heredity, the human integumentary system performs consistent functions for all. However, any number of medical conditions and aging processes can alter some of these functions, often to life-threatening degrees. Before delving deeper into common skin threats, it is important to understand the basic function of skin and skin structures.
■What is the Function of the Skin?
Skin is composed of literally millions upon millions of cells. These cells contain a number of biological components that protect our vital organs as well as our “exterior surface area”.
Skin and its “appendages” such as fingernails and hair, as well as glands of the integumentary system, may be beneficially influenced or negatively impacted by a number of processes going on inside the body. Some of these processes can include:
•Infection
•Illness
•Electrolyte and/or other fluid imbalances
•Inadequate diet
•Poor oxygenation
•Inefficient blood flow
In addition to being the body’s truly initial barrier of defense against attack by external dangers, the skin also provides a number of different functions. A few of the most critical are defined below.
Skin is vital in regulating body temperature through sweating (or not sweating). Body temperature is controlled by two main mechanisms. The first is radiation of heat from the skin’s surface, while the other is conduction of heat from the skin, which is then removed by the external environment (such as air) on the