• study of disease or abnormal conditions resulting from disease,trauma, defects, genetic abnormalities, etc 

• Cause of disease or condition

• cause, can be single entity or event or multiple causes 

• natural ability of an organism to remain unaffected by pathogenic or toxic agents 

• conditions within or around the organism or host do not inhibit the action of pathogenic agents but instead leave the host more likely to be affected. 

• how the disease/condition develops, the sequence of events

  through the progression of the disease or condition 

• visible and invisible observations that the disease or condition is present. This begins on a cellular level 

there is only one cause of the condition, e.g. tuberculosis

there is more than one cause of the condition, e.g. heart disease or hypertension 

• bacteria, fungi, viruses, protozoa 

• temperature, electricity, ionizing radiation, UV radiation,

  ultrasound, microwaves, lasers 

• poison, acid, venom, drugs, lead, mercury 

• knives, guns, motor vehicle accidents, bad luck 

• Occurs as a result of medical treatment or from exposure to

  hospital or other healthcare environment

• E.g.: infective endocarditis, hospital infections, damage to the heart following radiation therapy 

• A disease brought on by conscious or subconscious reactions or attitudes

• Physical manifestation can be very real and result in serious

  consequences, even death

• E.g.: Posttraumatic stress disorder 

• The causative agent or event is not yet discovered. This does not mean it does not exist.

• E.g.: Fibromyalgia 

• these groups have a higher risk of developing a

  disease than someone from another group (intermarrying). 

• although not limited in scope, certain ethnic groups have a

  higher risk of developing conditions. 

• skin, hair, nails, sweat and sebaceous glands

• Damage to the skin compromises these barriers 

•  

• Glands that excrete their products through ducts onto the surface of the skin or other organ 

  • sweat and sebaceous glands, glands lining the GI tract and respiratory tract

  • Secretions can:

    • Contain antibodies to destroy invaders

    • Make the environment less favorable to invaders (e.g. stomach

      acid) 

the period of time between exposure and the appearance of symptoms

After exposure, a period of time passes before symptoms appear Pathogen is increasing in number and commencing process of disease production

Ranges from hours to years, usually days or weeks.

May be communicable to others even though no symptoms are apparent People may be symptomless carriers (may later erupt)/asymptomatic 

• an objective observation usually made by a clinician and sometimes a patient about the clinical manifestations of the disease process.

•   Examples: fever, rash, low blood pressure, and low red blood cell count. 

• a subjective report of what a client is feeling.

•   Examples: fatigue, headache, and nausea. 

• an observable or quantifiable characteristic associated with a specific type of pathology.

•   Includes: signs, symptoms, results of lab tests, radiographs, etc. 

• the time during which the disease is developing but there are no overt manifestations of the disease, although it can be found using laboratory tests or radiographs 

• the worsening of a disease condition. 

• when the affected individual or part returns to normal 

• one or more conditions or pathologies that occur as a result of that disease 

• he illness or disability associated with a disease 

• decrease in size and function of a cell, tissue, or organ, caused by reduced functional demand, hormonal stimulation, nutrient supply (including oxygen), and/or the normal process of aging 

• (decreased supply of oxygen) can cause cell atrophy, which is

  commonly seen in damage done during a myocardial infarction. 

0. 1) Underdevelopment or incomplete development of a tissue or an organ. For example, ****** of the enamel of the teeth indicates that the enamel coating is thinner than normal or missing in some but not all areas.

1. 2)  literally refers to an inadequate or below-normal number of cells, but the above description is used more commonly

2. 3) Usually it is a congenital condition
   4)is less drastic than aplasia, where there is no development of a tissue or an organ at all.
   5) can occur in any organ. 

• enlargement of individual cells leading to an increase in size of the tissue or organ commonly caused by increased functional demand and hormonal stimulation

• Increase in size may also result in an increase in functional capacity of the tissue or organ.

• Not always pathological!

• Good example: the increase in the size of muscle cells as a response to exercise

• An excellent example of pathological ****** occurs with the effects of hypertension on the heart.

• causes an increased demand on heart muscle, causing the

  individual cells to become hypertrophic. The result of this is hypertrophy of the left ventricle because is it overworked. This is a problem because the increased mass of the heart muscle tissue decreases the capacity of the chamber itself, leaving inadequate volume for filling with blood 

an increase in the number of cells in a tissue or organ

resulting in enlargement.

 can be due to excessive hormone stimulation, chronic cell injury, increased functional demand, or extensive cell injury or death.
 Hyperplasia and hypertrophy may occur simultaneously, as in the formation of a goiter. 

• conversion of one differentiated cell type to another

• Chronic irritation or inflammation may initiate the transformation from the normal cell to one better able to survive in the environment altered by the chronic condition.

• This may seem to be in the best interest of the host, however sometimesthese metaplastic changes compromise the original function of the tissue

• Examples:

  • Bronchial mucosal changes in response to cigarette smoke

  • Olfactory mucosa changes in response to cigarette smoke

• Often reversible if stimulus is discontinued

• If stimulus continues, usually proceeds to dysplasia and even neoplasia 

• Refers to creation of abnormal cells from normal cells

•   The abnormalities include changes in size and shape along with nuclear

  changes within the cell and irregular arrangement of cells within tissues.

•   Classified as mild, moderate, or severe.

•   May still be reversible if the stimulus is discontinued, but more often than

  not it progresses to neoplasia

•   Controversial as to whether or not dysplasia is a neoplastic process or not

•   Severe dysplasia is usually treated as a neoplasm.

•   Malignant lesions will often be surrounded by areas of dysplasia.

•   If truly dysplastic, if stimulus is removed, cells will return to normal. If

  stimulus is removed and cells continue to reproduce uncontrollably, it is truly neoplasia. 

•   A new growth cells

•   Not an adaptive change, but rather a pathologic growth of cells

•   Cell growth is not regulated as healthy cells are, so growth continues

•   Severe dysplasia is usually considered to be at least premalignant if not

  overt cancer. 

Cells may retain or store certain substances that are either normally

present in smaller quantities or are pathologic.

•   This is also an adaptive process, and if the reason for the storage of these substances is removed, the cell will return to normal. 

• storage of excessive carotene in epithelial cells;

•   usually not harmful and will dissipate when foods rich in

  carotene are decreased. 

when the liver is not functioning correctly, bilirubin builds up in the body and is stored in various cells including epithelial cells. The yellow color (jaundice) will dissipate when the liver starts functioning properly and is able to process the accumulated bilirubin. 

Occurs if there is persistent chronic damage or if the cell is no longer able to adapt to changes. 

•  is a highly reactive class of chemical generated by the cell

  during normal metabolic processes.

• Oxygen is the most frequent source of ******because it has two

  unpaired outer electrons and is used in almost all of the cell’s activities.

• Built-in defenses against ***** may be impaired when the cell

  is under stress for any reason.

• Impaired defenses allow single-strand breaks in DNA to occur.

• Phospholipids in the cell membrane and organelle membranes can be destroyed, compromising integrity of these structures impairing normal cellular function and replicative capabilities.

• Cell membrane disruption will upset balance of calcium within the cell causing calcium imbalance. 

•  low oxygen

• Lack of oxygen inhibits production of energy within the cell.

• Without energy (ATP) many cellular processes cannot occur 

malfunction of system maintaining sodium and potassium levels will impair the system maintaining calcium and magnesium levels.

Normal cells have less calcium inside than what is found in the extracellular environment.

Failure of the maintenance system allows an influx of calcium into the cell.

Increased intracellular calcium activates enzymes that can damage the cell and compromise cell membranes, causing lysis or death of the cell 

Apoptosis

• Cellular self-destruction

• An ―active‖ form of cell death

• Energy dependent

  • Removes defective cells

  • A normal process in the body, including embryonic development

  • Can also be triggered by infections and other stimuli

• Typically affects single cells

• Physiologic or pathologic 

•   Another type of cell death

•   Cell death usually due to inability to compensate or adapt to hostile

  environment, infections, chronic trauma, acute trauma, etc. 

•   Specific to tuberculosis

•   Lesions called tubercles form 

• Coagulative—usually triggered by hypoxia or ischemia, for example, infarcts

• When cells die, they become firm and opaque 

• bacterial infection, especially staphylococci and streptococci

•   White blood cells use potent enzymes to destroy bacteria, but host

  cells are destroyed also. Walled off area impairs removal of debris and abscess forms (accumulation of dead cells, dead bacteria, and dead and dying white blood cells).