Pathophysiology Chapters 1-3 flash cards

Pathophysiology is the study of mechanisms of disease.

Applied pathophysiology combines what we know about pathology, the study of changes in cells and tissues as a result of injury or disease, and physiology, the mechanisms of human body functioning.

Disease is the functional impairment of cells, tissues, organs, or organ systems.

syndromes are specific conditions with recognizable, predictable patterns.

The origin and development of disease is referred to as pathogenesis

Modifiable risk factors are those that can be changed by the individual while nonmodifiable risk factors cannot be changed by behavior. For example, dietary intake, weight, and smoking are risk factors that are modifiable, but genetic composition is nonmodifiable.

etiology is the precise cause of disease.

a pathogen is the disease-causing microorganism.

When there is no known etiology, the disease is termed idiopathic.

Nosocomial disease results from exposure to infection in the healthcare environment. For example, a nosocomial disease is one where a child gets varicella (chicken pox) while being a patient in the hospital. The child did not have varicella when admitted but was exposed during hospitalization and contracted the disease.

Iatrogenic diseases are those that are the inadvertent result of medical treatment. For example, a patient who develops a urinary tract infection from the placement of a urinary catheter has an iatrogenic disease.

Clinical manifestations are the presenting signs and symptoms of the disease. More specifically, the signs of a disease are the observable or measurable expressions.

signs of a disease are the observable or measurable expressions. For example, in herpes simplex (a cold sore), a sign would be redness with raised, clear, fluid-filled vesicles on the individual’s lip. Signs are objective manifestations that can be seen or measured.

Symptoms are indicators that are reported by the ill individual and are considered the subjective manifestations because they cannot be directly observed by the practitioner. Symptoms of herpes may include tingling or discomfort at the site of the vesicles or feeling lethargic (tired). These symptoms are difficult for the healthcare provider to observe or measure.

precipitating factors, or triggers, that promote the onset of clinical manifestations. Examples of precipitating factors that promote shortness of breath and coughing in asthma are listed in Box 1.2.

BOX 1.2 Examples of Precipitating Factors Individuals with asthma often report one or more of these precipitating factors that lead to an asthma exacerbation:

Exercise Cold weather Upper respiratory infection Stress Dust/dust mites Pollen Animal dander Mold

Local refers to those manifestations that are found directly at the site of disease and are confined to that specific area. Examples of local manifestations are confined redness, swelling, bruising, or pain.

Systemic manifestations present throughout the body and are not confined to one area, such as with fever, lethargy, generalized body aching, or high blood pressure.

Acute manifestations or acute diseases are those that begin abruptly and last a few days to a few months. The common cold is a good example of an acute disease. There is a noticeable onset, the disease lasts 10 to 14 days, and there is complete resolution.

Chronic diseases have insidious (gradual) onsets and generally last longer than 6 months. With chronic disease, the person can have remissions, or symptom-free periods, and exacerbations, the flaring of symptoms.

Subacute is a term used to describe diseases that fall somewhere between acute and chronic in duration and severity.

Some conditions are completely asymptomatic; that is, the person does not have any noticeable symptoms even though diagnostic tests may indicate that the disease is present. Screening tests, such as Pap smears, breast mammograms, or blood pressure measurements, are invaluable for detecting diseases that are asymptomatic.

The prognosis for a patient is the forecast or prediction of how the individual will proceed through the disease process. An excellent prognosis indicates that the individual will most likely recover completely. A poor prognosis signifies increasing risk for morbidity, a negative outcome with disease complications that impact the quality of life, and possibly mortality, or death. Prognosis is often based on health statistics across populations where the rates of survival and outcomes of others with similar diseases help predict the individual patient’s outcome.

Pathologists are physicians with advanced training who study the cause and effect of diseases

Incidence is the number of new cases within a given time. Incidence represents the probability that a disease will occur in a certain population. For example, the incidence of amyotrophic lateral sclerosis (ALS), a progressive and fatal neuromuscular disease, in the United States is 2 per 100,000 people

Prevalence is the number or percentage of a population living with a particular disease at a given time. As an example of prevalence, 12,187 people in the United States are currently living with ALS.

When the incidence and prevalence of a disease are predictable and stable, this is termed endemic.

A dramatic increase in disease incidence in a population is called an epidemic and represents a rate considerably above the endemic rate.

. When an epidemic spreads across continents, the disease is considered to be a pandemic

The World Health Organization (WHO) is an important epidemiology resource and provides a yearly guide to health statistics for its member states. The annual World Health Statistics report details mortality and life expectancy rates across the globe and provides incidence and prevalence statistics for numerous diseases. For example, in the 2016 report, the 10 leading causes of death worldwide were (1) heart disease; (2) stroke; (3) chronic obstructive pulmonary disease; (4) lower respiratory infections; (5) Alzheimer disease and other dementias; (6) trachea, bronchus, and lung cancers; (7) diabetes mellitus; (8) road injury; (9) diarrheal diseases; and (10) tuberculosis. Decreasing the incidence and prevalence of these conditions can have the greatest impact on the health of populations around the world.

Disease Prevention Prevention of disease is a critical role for the health professions. Disease prevention is most often discussed in three levels: primary, secondary, and tertiary.

1. Primary prevention: Primary prevention focuses on protecting people from developing a disease or injury. Examples include wearing a bike helmet to prevent a head injury or immunizations to prevent disease.
2. Secondary prevention: Secondary prevention is the early detection of disease through screening and early treatment. An example is performing breast or testicular self-examination every month for early cancer detection.
3. Tertiary prevention: Tertiary prevention focuses on rehabilitation after diagnosis of a disease or injury. It also focuses on preventing complications or progression of the condition; examples ares, applying physical therapy and occupational therapy interventions to improve gross and fine motor function after a stroke.

The first line of defense involves surface and chemical barriers. The second line of defense is waged through an effective inflammatory response. The third line of defense is activated through the immune response.

FIRST LINE of defense : The skin and mucous membranes comprise a physical and chemical barrier to invasion and are considered the first line of defense. Skin is a protective physical barrier against harmful substances in the external environment. Areas not covered by skin are protected by chemically coated mucous membranes that help to neutralize or destroy many harmful invaders. Tears and saliva are examples of enzyme-filled fluids that bathe mucous membranes and offer essential protection to the eyes and oral cavity. Breaks in the skin and mucous membranes or loss of protective fluids allow microorganisms and other harmful agents to enter the body and threaten homeostasis.

The acute inflammatory response has three major goals:

1. To increase blood flow to the site of an injury, which is referred to as the vascular response
2. To alert the products of healing to attend to the site of injury, which is referred to as the cellular response
3. To remove injured tissue and prepare the site for repair and healing

Anoxia is the absence of oxygen

Hypoxia is low levels of oxygen

Injury can include invasion by microorganisms, cellular mutations, hypoxia or anoxia, nutritional deficiencies, and physical or chemical damage.

exudate is the watery fluid with a high protein and leukocyte (white blood cell concentration that accumulates at the site of injury"

macrophages are monocytes that have moved from the bloodstream into another tissue

Cytokines are more than a hundred distinct cell proteins most often found within WBCs that have a vital role in regulating inflammation

. Platelet-activating factor is a potent inflammatory mediator that has a key role in promoting vessel vasodilation, clotting, and attracting infection-fighting WBCs to the injury site.

Cellular Response After the vessels are dilated and permeable, the cells essential for healing are needed at the site of injury. As with the vascular response, the cellular response is regulated by inflammatory mediators. Three steps are needed for a successful cellular response: (1) chemotaxis, (2) cellular adherence, and (3) cellular migration

Chemotaxis is a process of moving certain cells to the injury site

Nonpharmacologic treatments for inflammation initially include rest, ice, compression, and elevation, abbreviated RICE

Fibroblasts are important cells that produce and replace the connective tissue layer.

Collagen, the protein secreted by collagen fibers, helps to fill in the gaps left after the removal of damaged tissues.

Glycoproteins regulate cell movement across the matrix, provide a place for attachment of the cells to the matrix, and prompt the cells to function.

angiogenesis, or the generation of new blood vessels, at the site.

Restoring Functional Integrity includes 1. Resolution 2. Regeneration 3. Replacement

diapedesis (migration of nearby cells)

Some cells constantly regenerate through mitosis, particularly epithelial cells of the skin, gastrointestinal tract, and urinary tract, and blood cells in the bone marrow. These constantly multiplying cells are often referred to as labile cells

These cells that multiply only when needed are called stable cells

Permanent cells, such as neurons, cardiac myocytes, and the lens of the eye, do not undergo mitosis and are unable to regenerate.

No definitive test exists to diagnose RA. Diagnosis is based on history and physical examination (during which stiffness and pain in symmetrical joints is demonstrated), and it may involve several diagnostic tests. Test results that increase the likelihood of RA as the diagnosis include:

1. An elevated serum ESR
2. An elevated serum CRP level
3. The presence of RF significant for antibodies against IgG
4. A positive antinuclear antibody (ANA) assay indicating suspected autoimmune disease
5. The presence of inflammatory products in a synovial joint fluid analysis
6. Visualization with a radiograph demonstrating joint damage

ischemia is reduced blood flow

hematemesis is the vomiting of blood