• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Asthma - a chronic inflammatory disorder of the airways.

Extracts from this document...


Asthma Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role, in particular, mast cells, eosinophils, T lymphocytes, macrophages, neutrophils and epithelial cells. In susceptible individuals this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness and coughing, particularly at night or in the early morning. These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment. The inflammation also causes an increase in existing bronchial hyperresponsiveness to a variety of stimuli. Asthma is characterized by spastic contraction of the smooth muscle in the bronchioles, which causes extremely difficult breathing. Asthma is about 70 percent is caused by allergic hypersensitivity, especially sensitivity to plant pollens. Asthma is a common increasing and relapsing disease that is associated with genetic and environmental factors such as respiratory viruses and allergens. The pathology of asthma is characterised by various changes in the airways including mucus plugging, shedding of epithelial cells, thickening of the basement membrane, engorgement of the vessels, and angiogenesis, inflammatory cell infiltration, and smooth muscle hypertrophy and hyperplasia. The pathogenesis of asthma can be broadly subdivided into inflammatory and remodelling components. The inflammatory features of asthma consist of a dense inflammatory infiltrate in which eosinophils, mast cells, and CD41 helper T lymphocytes predominate. ...read more.


Epithelial damage and loss of its protective barrier function exposes the deeper airway structures to environmental insults, and both inflammatory and structural cells produce several growth factors that lead to angiogenesis, proliferation of smooth muscle in the airway, thickening of basement membranes, and fibrosis. The increase in the mass of smooth muscles in the airway increases bronchial responsiveness by increasing force in response to bronchoconstrictor stimuli and by reduction of the airway's diameter. Smooth muscle in the airways of patients with asthma proliferates excessively in vitro.Important cytokines and enzymes during the remodelling process include transforming growth factor b, epidermal growth factor, and matrix metalloproteinases. Asthma causes significant morbidity and mortality. The changes occurring in the airways consist of a chronic eosinophilic and lymphocytic inflammation, together with epithelial and structural remodeling and proliferation, and altered matrix proteins, which underlie airway wall narrowing and bronchial hyperresponsiveness (BHR). Several inflammatory mediators released from inflammatory cells such as histamine and cysteinyl-leukotrienes induce bronchoconstriction, mucus production, plasma exudation, and BHR. Increased expression of T-helper 2 (Th2)-derived cytokines such as interleukin-4 and 5 (IL-4,5) have been observed in the airway mucosa, and these may cause IgE production and terminal differentiation of eosinophils. Chemoattractant cytokines (chemokines) such as eotaxin may be responsible for the chemoattraction of eosinophils to the airways. The initiating events are unclear but may be genetically determined and may be linked to the development of a Th2-skewed allergen-specific immunological memory. ...read more.


Asthma mortality data offer the longest continuous series, but interpretation is made difficult by the changes in diagnostic classifications (ICD) over time. For Australia, in persons aged 5-34 years, mortality rose from approximately 0.25-0.5 per 100000 person- years prior to 1950 in a linear fashion up to 1.2 per 100000 in 1955, fell briefly, rose to 2 per 100000 in the late 1960's, fell through the 1970's to 1 per 100000, reached a second peak in the 1985 of 1.5 per 100000 and has fallen below 1 per 100000 since then. In age-period-cohort Poisson regressions, there were linear increases in mortality with each 5 year birth cohort since approximately 1930. The only period showing an increase was in the 1960s, with a steady decrease in adjusted mortality into the 1990s, interpreted as due to increased use of inhaled corticosteroids. For reported asthma, the sexes were almost equally affected (51% male). There had been a marked increase in reported long-term asthma at all ages since the 1977-78 Survey, most noticeably in those under 15 years of age, where the prevalence had risen from 4% to 14%. An examination of birthplaces noted the (age-sex adjusted) prevalence of asthma was highest in those born in Australia and New Zealand, next for those from the UK and Ireland, less for those born in Southeast Asia, Africa and Southern Europe, and least for those born in Western Europe. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Healthcare section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Healthcare essays

  1. Communicable and Non-Communicable Disease: Tuberculosis and Cystic Fibrosis

    an individual is born with cystic fibrosis, but changes to the environment of an individual who is already suffering from the disease (such as minimising exposure to second-hand smoke) can improve his/her condition.49 The average lifespan of a person affected with cystic fibrosis is twenty-eight to thirty years.50 It is

  2. Communication P4 & M2

    Finally, I would make sure there are trained interpreters as well as BSL signers. This is important because social care workers are usually trained to know the basics of sign language. Sign language may be seen as the simplest form of communication for those who are deaf and therefore I

  1. Physiological disorder

    Valves of the heart For the heart to keep the fluids flowing in the atrium the pumps needs a set of valves. The heart has two types of valves that keep the blood flowing in the correct direction.

  2. 1.2 Chronic Obstructive Pulmonary Disease

    cystic fibrosis or bronchiolitis fibrosa obliterans (subset 10), are not included in this definition. Modified from the American Thoracic Society: "Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease." American Journal of Respiratory and Critical Care Medicine, 1995;152:S77-S120.

  1. Abnormal Psychology - Bipolar Disorder

    It has also been illustrated that the current line of thought is that Bipolar Disorder represents not a single gene Disorder, but a complex issue involving multiple genes. Researchers concluded: "As defined by the DSM-IV, Bipolar affective Disorder is highly heritable.

  2. Obsessive Compulsive Disorder

    When a patient realizes that the behaviors that act to reduce distress are not reasonably connected to the real world concerns, yet feels good to perform them here is when OCD is the usual diagnosis. Some patients with OCD do not interpret their actions unreasonable, but instead develop elaborate explanations for them; this is particularly common in children.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work