Y khoa, y dược - Chapter 10: The immune, lymphatics & endocrine systems

 Chapter 10The Immune, Lymphatics & Endocrine SystemsIntroduction The Immune system in combination with the lymphatics provides the first line of defence against the potential dangers of the outside world.It provides a pivotal role in preventing disease and destroying malformations from within. The Endocrine system provides the balance for life, regulating and secreting hormones, thereby, maintaining homeostasis.The Major Components of the Immune/Lymphatics & Endocrine Systems The Immune System - Function The immune system is composed of two distinct functioning parts sharing many characteristics:Non-specific defence mechanismsSpecific defence mechanisms The skin provides the major component of the non-specific function of immunity. Specific immune responses involve the B and T lymphocytes, proteins produced by the plasma cells - antibodies, along with other chemicals including Immunoglobulins.Working in CombinationThe immune system is influenced by most of the other systems, in particular the lymphatic, blood, skeletal and endocrine systems. Many life factors can negatively affect the system, including the effects of aging, poor nutrition, and fluid balance, as well as the individual’s emotional wellbeing. Many different aspects need to be considered when assessing an individual’s ability to both prevent and fight infection and to heal injuries. Non-specific Immunity The most obvious physical defence barrier is the skin, often described as the body’s largest organ.The skin itself consists of two layers; the epidermis - sits superficially to the deeper layerthe dermis - situated beneath the epidermisThe dermis is a much deeper complex layer of the skin incorporating many structures such as sweat glands, sensory nerve endings, hair follicles, veins, arteries, lymph vessels, and connective tissue. Non-Specific Immunity Other non-specific components of the immune system are gastric juices (hydrochloric acid) found in the stomach, which destroy many organisms.Saliva in the nose and mouth contains a protein called LysozymeCilia are hair-like projections originating in certain types of cell within the respiratory systemVilla within the gastrointestinal tract is very similar to the ciliaEyelashes, and the action of blinking Phagocytosis (eating cells) There are a number of cells that impact in the role of non-specific immunity. Phagocytes are cells which can be found in most tissues and include some Leucocytes.These phagocyte cells collaborate with chemicals called Immunoglobulins and a substance called Complement. Complement is a collection of specific plasma proteins, which assist in the destruction of foreign invaders or microbes. The combined action of these cells and chemicals is an elaborate process called Phagocytosis.Phagocytosis commences with the identification for destruction of the foreign invaders.Phagocytes then engulf the cells, ingesting and absorbing them, leucocytes are destroyed resulting in the formation of Pus.Inflammatory Response Inflammation is the body’s response to injury; this may be caused by physical, chemical or microorganisms. The local tissue involved in the injury utilizes the non-specific immunity cascade.Tissue becomes red, hot, swollen and painful; if the inflammation is gross it may limit the movement of a limb. When a foreign invader moves beyond the defences of the non-specific immunity, the Specific Immunity responses are stimulated into action. Specific immunity is also activated when an abnormal cell is detected (i.e. malignant cell), as well as transplanted cells. The Affects of Aging As the body ages cell function deteriorates due to the cells inability to repair, renew and regenerate. Some errors in the cells renewal process can lead to abnormal cells being present and even malignancy. This ultimately has an impact of the effectiveness of the immune system:The immune function is slower to react and respondUnable to fight antigens due to the decline of the B and T lymphocytesInefficient in removing free radicals and toxins leading to further deterioration of the cellsAllergic Reaction Allergic reaction can occur during the second and subsequent encounter with an allergen. During the initial encounter with the allergen the individual develops a specific antibody, Immunoglobulin E that binds to the allergen, this in turn sensitises the Mast cells.Further exposure to the allergen stimulates the mast cells to degranulate releasing histamine and heparin. The degree of reaction to an allergen can be varied, mild reactions with minimal symptoms.When this reaction is sudden, rapid and intense in nature histamine and heparin are released in excess amounts, this can result in anaphylactic shock (Evans & Tippins 2005). Anaphylaxis is a life-threatening event that must be dealt with immediately. Developing and Delivering Expert Care: ExerciseSigns and symptoms of Anaphylactic Shock:Make a list of the physical signs you might expect to see in a patient experiencing an anaphylactic reactionWhat would the treatment options be? Immunodeficiency Immunodeficiency is the inability or inadequacy of the immune system to respond effectively, leaving the body’s defence system depleted and the individual vulnerable and susceptible to infections, diseases and malignancies. The causes of immunodeficiency can be due to genetic defects, or acquired, due to drugs - particularly cytotoxic therapy; malnutrition or disease. Human Immunodeficiency Virus (HIV) The Facts HIV was detected in the early 1980’s when a number of homosexual men were diagnosed with a new type of pneumonia, Pneumocystis Carinii Pneumonia (PCP). HIV infection is currently responsible for a worldwide epidemic of AIDS with an estimated 38.6 million people infected with the virus. 63,500 people (over the age of 15 years) were living with HIV in the UK in 2005. Approximately one third of that population were unaware that they were HIV positive due to the fact that they may have experienced very minor, or no symptoms for a number of years. Scenario Mr Charlie George is a 38 year old Caucasian man who has been admitted with weight loss, lethargy, persistent cough, a sore; dry mouth, a raised temperature and what he describes as ‘ a sore and uncomfortable chest’.What should you first consider when admitting Charlie to the ward environment?   Are others an infection to Charlie? Is he an infection risk to others?Clinical Assessment and Care Charlie clearly has the classic signs and symptoms of an infection and therefore may be infectious to others, particularly those patients with poor or compromised immune systems. It is difficult to be certain at this stage, but as you do not know the cause of the infection, isolation needs to be considered. As Charlie is quite unwell, it is important to ensure that he can be observed easily as part of monitoring his condition.Charlie may also have a compromised immune system himself and therefore could be at risk of contracting an infection from other patients and healthcare workers. Scenario AnalysisClinical investigation; chest X-ray and sputum samples will help determine the microorganisms causing the pneumonia and direct treatment plans. Charlie is also complaining of a sore, dry mouth, which alongside his cough and lethargy, have decreased his appetite and contributed to his weight loss. White plaque present inside his mouth suggests oral Thrush. Consider: administering oral anti-fungal therapy as prescribed; ensure you support the patient with his oral hygiene needs and promote oral fluids. Assess his nutritional status; Body Mass Index (BMI) will identify if the support of the Dietetic team are necessary. Either way, Charlie will need some assistance in regaining his appetite and nutritional intake, which has a vital role in supporting the immune system. DiagnosisCharlie is suffering from Pneumocystis Carinii Pneumonia (PCP). PCP is one of the illnesses that indicate the patient is HIV positive and is also one of the AIDS-defining illnesses, as such; Charlie will receive two serious diagnoses at the same time.What are the implications of this diagnosis?Which medications will be necessary for the acute illness Charlie is experiencing and what will his long-term management consist of?What is your role in supporting the patient who is receiving this kind of information? What are key areas you will need to consider when supporting Charlie and preparing him for discharge home? The Lymphatic System The lymphatic system plays an ancillary role supporting the cardiovascular system and an essential role as part of the immune system. As fluid circulates throughout the body, plasma leaves the circulation and bathes the cells. Plasma is collected by the vessels of the lymphatic system transported to the two lymphatic ducts and returned to the venous blood through small connections to the subclavian vessels. Lymph vessels, also called lymphatics, carry lymph in only one direction – back towards the heart. Lymph NodesScattered along the pathways of lymph vessels are lymph nodes acting as filters. The smaller lymph nodes are often called lymph nodules. Lymph nodes occur in clusters or chains. The neck, armpits, chest, abdomen, pelvis, and groin are areas where the nodes can be palpated. Damaged cells are taken to the lymph nodes to be destroyed, the nodes can become increasingly swollen and tender if the microorganism is not easily destroyed, i.e. cancers. The lymphatic system manufactures lymphocytes, monocytes and antibodies, transports digested fats after absorption, breaks down red blood cells and platelets.The Endocrine System The endocrine system is largely concerned with regulation and therefore has a pivotal role in maintaining the body’s balance. The system itself is not connected anatomically, but is a system made up of glands positioned throughout the body.The purpose of the endocrine system is to:Produce chemicals called hormonesDirect hormones to the tissues and cells enabling them to adapt to changes, thereby maintaining homeostasisControls the body’s metabolism Abnormalities of the Endocrine SystemLargely due to three overarching reasons: A disordered endocrine system, which may be as a result of a genetic abnormality Overproduction or underproduction of a particular hormone.One of the most common diseases of the endocrine system is Diabetes Mellitus, affecting around 180 million of the world’s populationIt is likely that you will care for patients with diabetes throughout your nursing career. Diabetes MellitusDiabetes Mellitus occurs when there is a consistently raised level of glucose in the blood (hyperglycaemia).Hyperglycaemia results when there is a lack of the hormone insulin, which is produced by the beta cells situated in the pancreas. There are two main types of diabetes mellitus simply called Type 1 and Type 2. In Type 1 diabetes - the body does not produce any insulin and is, therefore, completely dependent on insulin replacement therapy to survive. Type 1 accounts for 5-10% of all cases.Type 2 diabetes - individuals are able to produce some insulin, but often not as much as they require, or the body is resistant to the effects of insulin, accounting for 85-90% of all diabetic cases. Professional Issues Nurses have an important role to play in educating patients in living healthier lifestyles through a balanced diet, exercise and avoidance of obesity.Undertaking routine screening of urinalysis and blood glucose levels.Empowering patients diagnosed with diabetes to be self-caring in managing this condition for the optimum health and quality of life.Resources and guidance demonstrating how services have been developed for patients with diabetes in the UK:National Standards, Local Action – health and social care standards and planning framework 2005/6 – 2007/8 (2004) department of health, London. www.dh.gov.uk ConclusionThe three previously discussed systems can be affected by various disorders or diseases.Having a foundational level of insight into each will provide the nurse with insight into some of the commonest diseases affecting mankind.By providing information to patients it may be possible to prevent these diseases, or improve the long term quality of life for suffers.