A&P Chapter 6: Mechanisms of Disease

Disease

Means “lack of ease”; An abnormality in body function that threatens health

Pathology

Study of the scientific basis of diseases

Signs

Objective abnormalities measured or seen by someone else other than the patient

Symptoms

Subjective abnormalities associated with disease felt only by the patient

Acute

When signs and symptoms appear and disappear quickly

Chronic

The disease develops slowly and lasts for a long time

Etiology

Study of the causes or origins of disease

Idiopathic

Refers to a disease with an unknown cause

Communicable

Infectious disease that can be transmitted from one individual to another

Pathogenesis

The mechanism of a disease’s development

Incubation

Another name for latent stage

Latent

Early stage of an infection; no signs or symptoms yet

Convalescence

Recovery

Remission

The reversal of a chronic disease

Epidemiology

The study of occurrence, distribution, and transmission of diseases in then human populations

Endemic

Disease local to native region

Epidemic

When there’s a sudden disease outbreak that affects many people at the same time within a defined geographic region

Pandemic

A disease outbreak all over the world

Prevention and Therapy

Two main strategies for combating disease

Pathophysiology

The study of underlying physiological aspects of disease

homeostasis; responses; disease

Disturbance of ____ and the body’s _____ to it are the basic mechanisms of ______.

Parasite

An organism that lives in or on another organism to obtain nutrients

Neoplasm/Neoplastic Mechanism

Tumors (benign or malignant) & Cancers

1. Genetic Mechanisms

2. Infectious Mechanism

3. Neoplastic Mechanism

4. Traumatic Mechanism

5. Metabolic Mechanism

6. Inflammatory Mechanism

7. Degeneration

7 Mechanisms of Disease

Genetic Mechanisms

Altered or mutated genes cause production of abnormal proteins which don’t perform their original function, but an abnormal one

Down syndrome, sickle cell anemia, albinism, cystic fibrosis

Examples of Genetic Mechanisms

Infectious mechanisms

Pathogenic organisms interfere with normal body function; poisoning

Viral, Bacterial, Fungal

Examples of infectious mechanisms

Traumatic Mechanism

Toxic chemicals, physical trauma

Metabolic Mechanism

Endocrine imbalances or malnutrition leads to insufficient nutrient uptake

Rickets, scurvy, hyper/hypothyroidism, osteoporosis

Metabolic Mechanism examples

Autoimmunity to Self-Immunity and Inflammation

2 Types of Inflammatory Mechanism

Autoimmunity to Self-Immunity

Faulty response of the immune system causes the body to attack itself

Lupus, multiple sclerosis, rheumatoid arthritis

Examples of autoimmunity to self-immunity

Inflammation

Normal inflammatory response to infection or injury is prolonged or at inappropriate times

Allergies

Example of Inflammation

Degeneration

Breaking apart of tissues, especially in aging

Dementia, Hypertension, Osteoarthritis, Cataracts, Atherosclerosis

Examples of Degeneration

Risk Factor

Predisposing conditions that might make the development of a disease more likely to occur

1. Genetic Factors

2. Age

3. Lifestyle

4. Stress

5. Environmental Factors

6. Pre-existing Conditions

6 Risk Factors

Genetic Factors

An inherited trait makes you more susceptible to a certain disease

Lighter skinned people are more likely to get skin cancer

Example of genetic factors

Factor of age

Biological and behavioral variations happen during different times of your life, causing a greater risk for some diseases during different times of your life

Younger children are more susceptible to ear infections

Example for factor of age

Lifestyle

way we work and live can put us at risk for disease

people who work outside are more likely to get skin cancer; high fat low fiber diet gives you a better chance for colon cancer

Examples for lifestyle

Stress

Physical, mental, and emotional stress can put one at risk of developing problems which are sometimes called psycho-genial disorders

psycho-genial

mind caused

headaches, chronic blood pressure, depression, heart disease, and cancer

Examples of stress

Environmental Factors

Your geographical location could make you more susceptible to some diseases

Some parasites only live in the tropics, plus pollution and climate can make you more likely for disease and injury

Examples of environmental factors

Pre-existing conditions

Can put you at higher risk for getting a disease

Balanced Diet, Exercise, no smoking

3 Practical Ways to reduce risk factors

Microbes

Microscopic Organisms

Viruses, Prions, Bacteria, Fungi, protozoa

Examples of Microbes

They invade cells and insert their own genetic code into a host cell’s genetic processes, causing the cell to produce viral DNA or RNA & Protein Coats

How do Viruses operate?

No

Are viruses living things?

Human immunodeficiency Virus

HIV stands for

The immune system

Where are viruses found in the body?

Sexual contact, sharing needles, exposed to it before or during/through breastfeeding

How are Viruses transmitted?

Severe Acute Respiratory Syndrome

What does SARS stand for

Malaria, West Nile Virus Infection, Yellow Fever

Infections caused by flaviviruses

From animal to bug to human

How are flaviviruses transmitted

Prions

Convert normal proteins to abnormal proteins, causing abnormal functions that provide diseases

Proteinaceous Infections Particle

What is Prion short for?

Mad Cow Disease

Spongiform Encephalopathy

Humans eat infected beef

How is Mad Cow Disease transmitted

Bacteria

Tiny primitive cells without nuclei

1. Secrete Toxins

2. Parasitizing Host Cells

3. Forming colonies in the host that disrupt normal function

3 ways Bacteria produce disease

Aerobic

Require Oxygen

Anaerobic

Require no oxygen

Gram-positive

Stains purple

Gram-negative

Stains red

1. Growth Requirements

2. Staining Properties

3. Shape and Size

3 Ways to Classify Bacteria

Aerobic or Anaerobic

Growth Requirements

Gram staining Techniques

Staining Properties

1. Bacilli

2. Cocci

3. Curved or Spinal Rods

4. Small Bacteria

4 Shapes and sizes of bacteria

Bacilli

large, rod-shaped cells

Cocci

Large Round Cells

Small Bacteria

Round or oval, extremely small; can only produce inside other living cells

Spores

Dormant form bacteria that resist unfavorable environmental conditions; revert back to active form when conditions change back

Archaea

Thrive in extreme conditions that are very hot, acidic, or salty; not yet found to cause diseases in humans

Fungi

Simple organisms similar to plants but lack chlorophyll; cannot produce their own food, so must parasitize other organisms

Yeast

Small, single celled Fungi

Mold

Large, multicellular fungi

jock itch and athlete’s foot

Examples of mold

Mycotic Infections

Often resist treatment and can become serious health problems

Candida, Histoplasma, Aspergillus

Mycotic Infection examples

Protozoa

Protists, one-celled organisms that are larger than bacteria and whose DNA is organized in a nucleus

1. Amoebas

2. Flagellates

3. Ciliates

4. Sporozoa

4 Categories of Pathogenic Protozoa

Amoebas

Possess pseudopodia

pseudopodia

False Feet

Flagellates

Possess flagella for movement

Ciliates

Possess cilia for movement

Sporozoa

Enter cells during one phase of a 2-part life cycle; born by vectors during the other phase

Coccidia

Another name for sporozoa

Vectors

Transmitters

Metazoa

Pathogenic animals, parasitize human tissues or organs

Nematodes

Transmitted by food or biting flies