Chapter 1: Introduction to Disease

vocab, important information, practice problems

Health

the condition in which the human body performs its vital functions normally; the body's various organ systems function optimally

Homeostasis

A state of balance among all the body systems needed for the body to survive and function correctly; the body's organ systems normally maintain temperature, pH, blood composition, and fluid levels in a precise range and correct any fluctuations before they harm the body

What does health depend on?

homeostasis

Disease

a significant disturbance in the homeostasis of the body; a deviation from normal structure or function in the body that interrupts or modifies the performance of vital functions

(ex) diabetes

Pathology

the study of disease, especially the structural and functional changes associated with disease; the study of its causes, mechanisms, signs and symptoms, treatments, and prevention

Pathologist

a physician who studies and interprets the changes cause by disease; examining cells, tissues, organs, and lab test results

How can a disease be recognized?

through its characteristic signs and symptoms

Signs

evidence of disease observed on physical examination

(ex) abnormal pulse or respiratory rate, fever, and sweating

Symptoms

indications of disease reported by the patient

(ex) pain, dizziness, and itching

Asymptomatic Disease

a disease that causes no signs or symptoms

(ex) chlamydia

Syndrome

an abnormal structure or function characterized by a group of signs and symptoms that usually go together

(ex) AIDS, malabsorption syndrome, down syndrome

Disorder

functional abnormality not necessarily linked to a specific cause or physical abnormality

(ex) adhd, premenstrual dysphoric disorder, and hemorrhoids

Do disorders need to be accompanied by specific signs and symptoms?

No. Disorders might be accompanied by specific signs and symptoms, but their presence is NOT required for a condition to be termed a disorder

Diagnosis

the process of identifying a disease or disorder

What are several different types of information that can be used for a diagnosis?

1. Signs and Symptoms (acquired through physical examination and interviews with a patient or patient's family)
2. Course and history of signs and symptoms
3. Results of laboratory tests (analysis of the composition of urine, blood, throat swabs, stool, sputum, etc)
4. Biopsy
5. Imaging technologies (ECG, CT, MRI, Ultrasound, etc)

What occurs during a physical exam?

1. Inspection
2. Palpation
3. Auscultation
4. Percussion
5. Vital signs

Inspection

a visual examination of the external surface of the body, its movements, and posture for abnormalities and/or evidence of disease

Palpation

feeling the body with fingers/hands; allows examination of the size consistency, texture, location, and tenderness of an organ or body part

Auscultation

Listening to the lungs, heart, and intestines; allows evaluation of the frequency, intensity, duration, number, and quality of sounds originating in the body.

Percussion

producing sounds by tapping on specific areas of the body with fingers, hands, or a small instrument; allows for evaluation of the size, consistency and borders of the body organs and the presence or absence of fluid in body areas.

Vital Signs

pulse, respiratory rate, blood pressure, and temperature are measures of various physiological statistics in order to assess the most basic body functions; normal vital signs vary with age, sex, weight, exercise tolerance, and physical condition

Biopsy

surgical removal and analysis of tissue samples

What does a electrocardiogram (ECG) do?

reads the heart's electrical impulses

What does a radiography do?

uses x-rays to visualize internal structures

What does a computed tomography (CT) scan do?

uses computers and x-rays to create 3-dimensional images of internal structures

What does magnetic resonance imaging (MRI) do?

analyzes tissue responses to a strong magnetic field to create images of internal structures

What does an ultrasound do?

analyzes the interaction of low-frequency sound waves with tissues to create moving images of internal organs

What does nuclear medicine do?

uses radioactive materials to create contrast in the body and help form images of the structure and function of organs

Prognosis

the predicted course and outcome of a disease; can state the chances for complete recovery, predict the permanent loss of a function, or give probability of survival

acute diseases

diseases that have a sudden onset and short duration

(ex) Influenza, measles, the common cold

terminal diseases

diseases that will end in death

Chronic diseases

diseases that have a slower, less severe onset and a long duration of months or years

(ex) heart disease, cancer, stroke, diabetes, arthritis

What are the ten leading causes of death in the world?

1. Ischemic heart disease


2. stroke and other cerebrovascular disease
3. lower respiratory infections
4. chronic obstructive pulmonary disease
5. diarrheal disease
6. HIV/AIDS
7. Trachea, bronchus, lung cancers
8. Tuberculosis
9. Diabetes
10. Road traffic accidents

What is/are the leading cause(s) of death in wealthy western countries?

Chronic diseases = Overall

1\. Ischemic heart disease

2\. Stroke and other cerebrovascular disease

3\. Trachea, bronchus, lung cancers

4\. Alzheimer's and other dementias

5\. Lower respiratory infections

6\. Chronic obstructive pulmonary disease

7\. Colon and rectum cancers

8\. Diabetes mellitus

9\. Hypertensive heart disease

10\. Breast cancer

What is/are the leading cause(s) of death in low income countries?

Infectious diseases = Overall

1\. Lower respiratory infections

2\. Diarrhea disease

3\. HIV/AIDS

4\. Ischemic heart disease

5\. Malaria

6\. Stroke and other cerebrovascular disease

7\. Tuberculosis

8\. Prematurity and low birth weight

9\. Birth asphyxia and birth trauma

10\. Neonatal infections

Remission

a period which a disease signs and symptoms subside or disappear; not a cure and can last for days, months, or years, and can recur anytime

Exacerbation

increase in the severity of a diseases' signs and symptoms

Can diseases be characterized by periods of remission, recurrence, and exacerbation?

Yes. For example, leukemia and ulcerative colitis are characterized by periods of remission, recurrence, and exacerbation.

Relapse

the return of a disease weeks or months after its apparent cure

Complication

a related disease or other abnormal state that develops in a person already suffering from a disease; may interfere with recovery from the original disease

(ex) anemia is a complication of leukemia

Sequela/Sequel

the aftermath of a particular disease

(ex) a sequela of rheumatic fever is permanent damage to the heart

Is the number of deaths caused by a disease important to monitor?

Yes, even it causes very few deaths.

Morality

the number of deaths that occur among people with a certain disease

Morbidity

the number of cases of a disease in a population; the incidence of disease

Prevalence

the percentage of a population that is affected with a particular disease at a given time

What are the uses of pervalence data?

1\. It allows the determination of the impact and significance of a disease for a population

2\. Used to direct health. care resources and research

3\. See the significance of certain disease for certain demographics

Epidemiology

the study of the occurrence, transmission, distribution, and control of disease

Etiology

the cause(s) of a disease

Pathogenesis

describes how the cause of a disease leads to anatomical and physiological changes in the body that ultimately result in the disease

Idiopathic Disease

a disease in which the cause is unknown

What are the major categories of diseases?

1\. Hereditary diseases

2\. Congenital diseases

3\. Degenerative diseases

4\. Inflammation/autoimmunity/allergy

5\. Infectious diseases

6\. Neoplastic diseases

7\. Metabolic diseases

8\. Trauma

9\. Nutritional-imbalance diseases

Hereditary disease

Abnormality in an individual's genes or chromosomes.

Congenital disease

Exist at or date from birth; can be acquired through heredity or acquired during development in the uterus.

Degenerative disease

Function or structure of the affected tissues or organs progressively deteriorates over time.

Inflammation/autoimmunity/allergy

Result of abnormal immune function

Infectious disease

caused by pathogens such as bacteria and viruses

Neoplastic disease

Result from abnormal growth that leads to the formation of tumors

Metabolic disease

Disruption of normal metabolism, the process of converting food to energy on a cellular level.

Trauma

Physical or chemical injury.

Nutritional-imbalance disease

Over or under consumption of nutrients.

Does a risk factor decrease a person's chance of developing disease?

No, it increases it

Is a risk factor equivalent to etiology?

No

If a person has (a) certain risk factor(s) for a disease, will they immediately acquire the disease?

No, it just increases the risk for developing that disease.

If a person eliminates known risk factors for a disease, will that lower the chance of developing that disease?

yes

What are the categories of risk factors?

genetic, environmental, chemical, physiological, and psychological

What are the four modifiable risk factors that are responsible for much of the illness, disability, and premature death related to chronic diseases?

Lack of physical activity, poor nutrition, tobacco use, and excessive alcohol consumption

Moderate alcohol consumption is defined as how many drinks per day for men? For women?

2 drinks per day for men and 1 drink per day for women

How many times per week should you engage in strength and flexibility training?

at least 2 times per week

How many minutes of vigorous-intensity aerobic activity does an adult need to do per week?

75 minutes

How much of your healthy plate should be fruits and vegetables?

half your plate

What are a few simple steps to decrease the risk for diseases and promote long, health lives?

\-Be physically active

\-Eat wisely

\-Maintain a health weight

\-Be tobacco free

\-limit alcohol

\-get recommended screening tests and immunizations

\-manage stress

What is the goal of treatment?

treatment aims to cure a disease or reduce the severity of its signs and symptoms; not all diseases are curable

What is the goal of palliative treatment?

provide comfort and relieve pain

Doe treatment include medical (pharmacologic) procedures?

Yes, treatment uses specific drugs to cure or relieve signs and symptoms. For example, antibiotics kill the bacteria that cause pneumonia.

Some athletes may develop abnormally high red blood cell counts. Why? In the athlete's case, is this a sign of disease?

Abnormally high red blood cell counts can and do occur in well-trained athletes. Athletes develop increased cardiovascular efficiency and produce more red blood cells. Their hearts can handle the slightly increased viscosity of the blood and thus higher red blood cell levels may not be a sign of disease.

Chronic diseases and their major risk factors place huge economic demands on our nation. For example, from 1987 to 2001 increases in obesity prevalence alone accounted for 12% of the growth in health care spending. What factors may have contributed to this increase in obesity in the United States? What is being done or what could be done to reverse the trend?

Obesity is the result of an energy imbalance; eating too many calories and not getting enough physical activity. Body weight may be the result of genetics, metabolism, behavior, environment, culture, and socioeconomic status. Behavior and environment are the key areas in obesity prevention.

A patient reports to her physician that she feels weak and dizzy. Is this enough information to make a diagnosis? What other sources of information can her physician consult?

No. Many diseases share these symptoms. A simple history can determine if she ate recently or if she is under stress, depressed, or anxious, and a blood test can determine her sugar levels and the presence of diabetes. The physician can consult a blood test to determine anemia or other blood disorders. A physical exam can determine whether she has hypertension. Cardiovascular abnormalities can be determined with a physical exam or with imaging techniques. In short, several diseases can explain these symptoms.

A skin rash is an example of a ____________________.

a. sign

b. symptom

c. laboratory result

d. syndrome

a. sign

A(n) ____________________ disease has a sudden onset and short course.

a. acute

b. terminal

c. chronic

d. idiopathic

a. acute

The cause of a disease is known as its ____________________.

a. pathogenesis

b. complication

c. sequela

d. etiology

d. etiology

The condition in which the human body performs its vital functions normally is known as ____________________.

a. health

b. disease

c. disorder

d. homeostasis

a. health

Signs and symptoms grow more severe in a period known as ____________________.

a. remission

b. exacerbation

c. relapse

d. complication

b. exacerbation

True or False: Homeostasis refers to the process of identifying a disease from its signs and symptoms.

False

True or False: Mortality refers to the number of deaths caused by a disease.

True

True or False: Symptoms are objective evidence of a disease.

False

True or False: Signs may be perceived by the physician.

True

True or False: Remission and relapse may characterize a chronic disease.

True

The predicted outcome of a disease is its \____________________.

prognosis

Diseases with a rapid onset and resolution are called \____________________ diseases.

acute

If the cause of a disease is not known, it is said to be \____________________.

idiopathic

Return of symptoms after their apparent cessation is \____________________.

relapse

The signs and symptoms of a chronic disease at times subside during a period known as \____________________.

remission