Introduction to Human Disease

Dr. Sue MakinDepartment of Nursing

Hannam University

Disease, Disorder, Syndrome

• Homeostasis – the state sameness or being normal that the body tried to maintain

• Disorder – derangement or abnormality of function

• Syndrome – a group of symptoms, which may be caused by a specific disease, or possible by several interrelated problems

• Disease – change in structure or function of the body, or any change from normal in the body

Pathology• Pathology – the study of disease• Pathologist – medical doctor who specialises in

studying disease• Surgical pathologist – studies or examines

surgical tissue or biopsies for evidence of disease• Clinical pathologist – supervises a clinical

pathology laboratory, including several departments such as hematology, chemistry, microbiology, serology, etc.

• Medical examiner – studies human tissue to determine the cause of death

Other Definitions• Pathogenesis – description of how a disease

progresses• Acute disease – lasts a short time and usually has

a sudden onset• Chronic disease – lasts a long time, and may take

time to develop• Etiology – the study of the cause of a disease• Idiopathic – the cause of a disease is unknown• Nosocomial – acquired in the hospital• Iatrogenic – caused by a prescribed treatment

Predisposing Factors• Predisposing factors = risk factors• Predisposing factors – make a person more

susceptible to disease, not the cause of a disease• Predisposing factors include age, sex,

environment, lifestyle, and heredity

Diagnosis, Prognosis, Treatment

• Diagnosis – the identification or naming of a disease. The doctor will try very hard to determine the diagnosis of a problem.

• Medical history – review of all the information about a patient, including previous illnesses, family illnesses, predisposing factors, current symptoms

• Prognosis – the predicted or expected outcome or result of the diseaseo Remission – the symptoms of a disease are less or go awayo Exacerbation – the symptoms of a disease become worse

• Treatment – a plan of care for the patient

Medical Ethics• Ethics deals with the rightness or wrongness of

actions or plans• Medical ethics includes the values and decisions

in medical practice• Because the choices and decisions available and

necessary in our modern world are many, questions about the rightness or wrongness have become common

Causes of Disease• Heredity• Trauma• Inflammation/Infection• Hyperplasias/ Neoplasms• Nutritional Imbalance• Impaired Immunity• Aging• Death

Hereditary Diseases• These diseases are caused by abnormalities in

either the genes or the chromosomes of an individual

• Congenital disease – a disease which is present at birth. Not all congenital diseases are inherited.

• Examples of congenital disorders that are not inherited include fetal alcohol syndrome, which is caused by the mother’s drinking of alcohol during pregnancy, and cerebral palsy, which may be caused by a difficult delivery

Trauma• Disease caused to humans by physical

injury from an external forceoMotor vehicle accidentso FallsoDrowningoBurnso Poisoningo Physical abuse

Inflammation/Infection• Inflammation is a protective

response of the body to any type of irritation or injury, not necessarily from a bacteria or virus, but including these as well

• Infection – invasion of microorganisms into tissue that causes cell or tissue injury

Hyperplasias/Neoplasms

• Hyperplasia – an overgrowth in cell numbers and in tissue size in response to some type of stimulus

• Neoplasms, commonly called tumors – refer to “new growths” in the body

• Neoplasms may be described as benign or malignantoBenign – not deadlyoMalignant – tumors that grow

uncontrollably and can cause death

Terms You Need to Know

• Adenoma• Carcinoma• Fibroma• Glioma• Lipoma• Melanoma• Sarcoma

• See Table 2-2, page16

Nutritional Health• Nutrition is important in maintaining good health• Nutritional diseases can be due to eating too

much or too little• Certain diseases may cause a person to be

unable to absorb nutrients, even though they may be eating an adequate diet

• Cachexia – term used to describe any person who has an ill, thin, wasted appearance

• Total parenteral nutrition – providing the total nutrition needed by gving nutritive liquid through the venous route

Impaired Immunity• Immune system of the body – specialized group

of cells, tissues, and organs that are designed to defend the body against pathogenic attacks

• Two basic ways the immune system protects the bodyo The inflammatory response – leukocytes play a

vital part in the killing of foreign invaderso The specific antigen-antibody reaction in which

the body responds to antigens, substances foreign to the body. The body’s response to antigens is to produce antibodies.

Aging• The process of aging of the human body begins

at the age of physical maturity, which is around age 18.

• The aging process is progressive and not reversible. This means that the process continues all the time, and the body does not go backwards and reverse the aging process.

• The body replaces and rapairs itself throughout its lifetime, but with aging, this process slows

Death• One way to try to understand the aging

process is to study cellular, tissue, and organ death

• Cellular injury can be caused byoHypoxia, not enough oxygenoAnoxia, no oxygen at alloDrug or bacterial toxinsoViruses

Cellular Adaptation• Cells that are exposed to adverse, or

damaging, conditions often go through a process of adaptation

• Types of adaption includeoHypertrophyoMetaplasiaoDysplasiaoNeoplasia

Cell and Tissue Death• Necrosis – cell death, the death of a

cell or a number of cells• Infarct – death of cells or tissue due

to ischemia• Ischemia – hypoxia (lack of oxygen)

of cells or tissues due to decreased blood flow

Organism Death• Morbidity – state of being diseased• Prior to death , major organs such as the

heart, lungs, or brain stop functioning. Once the brain stops functioning, the person is considered brain dead.

• Criteria for brain deathoA lack of response to stimulio Loss of all reflexesoAbsence of respirations or breathing

efforto Lack of brain activity on an

electroencephalogram (EEG)

Machine for electroencephalogram

Electroencephalogram