1. Mechanisms of Disease
Part 1
Causes of Disease

2. Causes of Disease (six Categories)
1. Heredity
Caused by abnormality in person’s genetic or chromosomal makeup
May or may not be present at birth
If present at birth, the disease is called CONGENITAL
Not all congenital diseases are inherited (EX: fetal alcohol syndrome)

3. Causes of Disease (six Categories)
If inherited, the diseases are classified as 1. single gene abnormality (Ex: sickle cell anemia) 2. an abnormality of several genes (polygenic) (Ex: gout, hypertension) 3. an abnormality of a chromosome (absence or presence) (Down syndrome)

4. Causes of Disease (six Categories)
2. Trauma
Caused by physical injury from an external force
Leading cause of death in children and young adults
MVA (Motor Vehicle accidents) most frequent

5. Causes of Disease (six Categories)
Centers for Disease Control and Prevention (CDC) lists the most frequent trauma as:
MVA
Fire Arms
Poison
Falls
Suffocation
Suicide
Homicide

6. Causes of Disease (six Categories)
Emergency management for trauma is often needed
Complications of shock
Hemorrhage
Infection
Prioritizing of care is called triage

8. Causes of Disease (six Categories)
3. Inflammation and Infection
Inflammation is a protective immune response triggered by injury or irritant
Signs of inflammation
Redness
Heat
Swelling
Pain
Loss of motion

9. Causes of Disease (six Categories)
Infection refers to invasion of microorganisms into tissue that causes cell or tissue injury
Inflammation and infection often go hand in hand
Inflammation will often progress to an infection
“itis” means inflammation

10. Causes of Disease (six Categories)
4. Hyperplasias and Neoplasms
Hyper (excessive) plasia (growth)
Neo (new) plasm (growth)
Hyperplasias are overgrowth in response to a stimulus (EX: overgrowth of thyroid due to hormone deficiency)
Neoplasms are tumors (Greek word for swelling is onkas) Oncology is study of cancer (tumors end in “oma”)

11. Causes of Disease (six Categories)
Neoplasms are classified as:
Benign
Limited growth (usually)
Encapsulated
Malignant
Grow uncontrollably
Fingerlike projections in surrounding tissues
Removal is difficult
****Cancer defined as a malignant tumor

12. Causes of Disease (six Categories)
Cancer name comes from Greek work karkinos meaning “crab”
Neoplasms can metastasize (move from original site to secondary or even tertiary sites)

13. Causes of Disease (six Categories)
5. Nutritional Imbalance
Malnutrition
Inadequate nutrient intake
Inadequate amount with poor nutritive value
Problems with absorption
Cachexia- ill, thin wasted appearance

14. Causes of Disease (six Categories)
Treatment
Liquid drink with nutritional supplements
Parenteral
Subcutaneous- under skin
Intramuscular
Intravenous*** (TPN-Total Parenteral Nutrition)
Enteral (small intestine)- tube feeding
Nasogastric tube- nose to stomach
Gastrostomy tube- hole in abdomen to stomach

15. Causes of Disease (six Categories)
Obesity
Overconsumption of nutrients / lack of exercise
Increases chance for arteriosclerosis
Stresses bones and joints
Vitamin or Mineral Excess or Deficiency
Related to diet, metabolic disorders and some medications
Hypervitaminosis can occur when someone uses too many vitamins for too long period of time

16. Causes of Disease (six Categories)
6. Impaired Immunity
First Line of Defense
Intact skin
Mucous membranes, tears, secretions
Other Defenses
Inflammatory response
Specific antigen-antibody reaction
**antigens-substances that cause the body some type of harm
**antibodies- immune bodies, are proteins that the body produces to react to the antigen and render it harmless

17. Causes of Disease (six Categories)
Common Malfunctions of Immune System
Allergy
immune response too intense
Allergens are things that cause the reaction
Autoimmunity
Immune response attacks itself
White blood cells produce antibodies against own self-antibodies

18. Causes of Disease (six Categories)
Immunodeficiency
Due to a decrease or absence of leukocytes, primarily leukocytes
Often without symptoms, except for recurring infections which could lead to death
Examples: AIDS, chemotherapy, radiation, organ recipients