Chapter 2 - Mechanisms of Disease

Categories of disease

• Heredity

• Trauma

• Inflammation/infection

• Hyperplasias/neoplasms

• Nutritional imbalance

• Impaired immunity

Hereditary diseases

Error in individual’s genetic or chromosomal makeup

Congenital hereditary diseases

disease present at birth

Classifications of hereditary disease

• Single gene abnormality 

• Abnormality of several genes (polygenic)

• Abnormality of a chromosome (chromosomal)

Trauma

physical injury or external force

• classifications in order of prevalence:

  • Motor vehicle accidents

  • Poison

  • Firearms

  • Falls

  • Suicide

  • Suffocation

  • Homicide

Type of traumatic disease varies with:

• age

• race

• residence

Leading Cause of death for 1 – 44 y/o is ……

• #1 Unintentional Injuries–

  •  Opioid Overdose 

  • MVA

  • Unintentional Falls

• #2 Suicide 

• #3 Homicide 

Inflammation

Protective immune response triggered by injury or irritant

Infection

Invasion of microorganisms into tissues causing cell or tissue injury

Hyperplasia

overgrowth in response to some type of stimulus

Neoplasms

tumors

Oncology

study of cancer

Classification of neoplasms

• Benign

  • Limited growth

• Encapsulated

  • Enclosed in capsule

• Malignant

  • Uncontrolled growth

  • Commonly referred to as cancer

Metastasizes

moves and spreads

Metastatic

moves from site of origin to secondary site in body

Body’s first line of defense

skin, mucous membranes, tears, and secretions

Protective qualities of immune system

• Leukocytes kill foreign invaders

• Body reacts to antigens by producing antibodies

Antigens

• Substances that cause harm and set off specific response

Antibodies

• Also known as immune bodies

• Proteins that render antigen harmless

Common ways the immune system fails

• Allergy

• Autoimmunity

• Immunodeficiency

Degeneration

• Disease related to age

• Tissue degeneration changes functional activity to lower or lesser level

• Body’s ability to repair and replace itself slows down with aging process

Causes of cellular injury and death

• Hypoxia

  • Not enough oxygen

• Anoxia

  • No oxygen

• Drug or bacterial toxins

• Viruses

Atrophy

decrease in cell size

Hypertrophy

increase in cell size

Hyperplasia

increase in cell number

Dysplasia

Alteration in size, shape, and organization of cell

Metaplasia

cell changes to another type

Neoplasia

• Development of new type of cell with uncontrolled growth pattern

Necrosis

cellular death

Ischemia

decreased blood flow

Infarct

area of dead cells

Gangrene

• Saprophytic bacteria involved in necrotic tissue

Morbidity

state of being diseased

Mortality

death

Criteria for brain death

• Lack of response to stimuli

• Loss of all reflexes

• Absence of respirations

• Lack of brain activity on electroencephalogram   (E E G)

Diseases have many causes both _____.

 internal to the body and in the external environment. 

Understanding the effects of lifestyle behaviors and environmental factors can ______.

decrease the likelihood of developing many of the leading causes of death in the US.