Gen Pathology Exam 1 Section 1: Cell Injury, Cell Death, and Adaptations Flashcards
Pathology
study of disease, “suffering”
pathos- meaning “experience” or “suffering”
-logia meaning the “study of”
Homeostasis
tendency toward a relatively stable equilibrium optimal homeostasis is interchangable with optimal health
Disease
structural and/or functional change in the body that is harmful to the organism; a deviation from optimal health
What are the two observable clinical features?
sign and symptoms
What is a sign?
objective and observable indication of disease; obtained via physical examination
Ex: increased body temp (fever)
What is a symptom?
subjective evidence of disease or physical disturbance; patients experience; obtained via oral report from patient history
Ex: pain, blurry vision, and numbness
Cellular Adaptation
cell’s attempt to preserve viability while overcoming stressful stimulus
What are 2 factors that influence cell’s ability to overcome a harmful stimulus?
- the cell type
2. the nature of the cellular stress
When will cell injury occur?
when cell is NO longer able to adapt to cellular stressors
etiology
the cause, set of causes, or manner of cause of given pathology
What is a “risk factor”?
used to label causation agent
Ex: smoking is a risk factor for lung cancer
What two things lay at the core of most disease processes?
- Genetic susceptibilities (“nature”) Ex: Huntington Disease
- Environmental triggers (“nurture”) Ex: environmental role
Huntington Disease
neurodegenerative disease; causes severe dementia during middle adult hood and develops via specific genetic mutation
Mesothelioma
a cancer of pulmonary pleura; usually in people with history of exposure to asbestos (env. role)
Pathogenesis
series of events involved in cellular and molecular changes involved with specific disease process
describes biological mechanisms that describe the structural and functional abnormalities of a disease process
Physiological Adaptations
responses expected to occur with normal physiological changes
Ex: hormonal enlargement of uterus and breast during pregnancy
Ex: skeletal muscle hypertrophy following weight training
Pathological Adaptations
responses to excessive cellular stress and indicate a loss of optimal structure and function; allow cells to avoid/delay injury
Ex: Cardiac Ventricular hypertrophy
Ex: heavy alcohol consumption
What are non harmful stimuli?
changes in cell’s environment assisting it in maintaining homeostasis
What are harmful stimuli?
changes in cell’s environment that are sources of cellular stress
Are cellular adaptations reversible?
yes
What are the 4 main adaptations to stress?
- Hypertrophy
- Hyperplasia
- Atrophy
- Metaplasia
Hypertrophy
An increase in size of cell, and if severe may increase size of organ or enlarge area of organ.
Achieved due to increase in synthesis of intracellular proteins and organelles
Ex: ventricular hypertrophy
Hyperplasia
an increase in the number of cells, due to cellular division; typically results in enlargement of tissue
Ex: Benign Prostatic hyperplasia
Ex: Wart (verruca)
Atrophy
shrinkage of cell size, due to loss of cell’s structural proteins; overall size of tissue may decrease
Function is diminished, but it remains viable ( IS NOT DEAD)
Causes: immobilization, denervation, ischemia, malnutrition, aging
What two things does atrophy involve?
- reduced protein synthesis
2. increase rate protein breakdown
Metaplasia
one cell type replaced by another cell type; one adult cell transitioning into a different adult cell type
Ex: Chronic smokers–ciliated columnar epithelia replaced by stratified squamous cells; leads to chronic bronchitis
Ex: Gastroesophageal reflux disease; leads to esophageal cancer
What are the 8 causes of cell injury and death?
- Ischemia
- Hypoxia
- Toxic Exposures
- Infections
- Immunological Reaction
- Nutritional Imbalances
- Trauma
- Aging
Ischemia
insufficient blood supply to a tissue
Ex: myocardial infarction (heart attack), cerebral infarction (stroke), ischemia bowel disease, gangrene
What does ischemia most commonly develop from?
atherosclerotic plaque formation, blood clots, reduced cardiac output (heart failure), compression of major arteries
Hypoxia
organ is NOT receiving adequate oxygen within blood supplying the organ
Ex: pneumonia, carbon monoxide poisoning, a disease inhibiting diaphragm (botulism, Guillain-Barre syndrome) or injury to phrenic nerve
Toxic Exposures
depends on how harmful (noxious) it is and concentration and duration of exposure
Examples of toxic poisonous substances:
air pollution, insecticides, asbestos, CO, smoke, alcohol
Examples of innocuous substances:
- diabetes (hyperglycemia) causes peripheral vascular disease
- water intoxication
- retinopathy of prematurity
Infections
all forms of infectious microbes (bacteria, viruses, protoxoans, fungi) may injure cells
Immunological Reaction
over-activation of normal immune mechanisms may injure cells via autoimmunity or allergies
Nutritional Imbalances
deficiencies or excesses of dietary nutrients may inhibit homeostasis and result in pathology
Trauma
from mechanical (physical) trauma, thermal trauma, electrical injury, or injury from high-energy radiation (ionizing or irradiation)
Aging- Cellular Senescence
reduced capacity for cells to react to stress and maintain homeostasis
Reversible Cellular injury
may regain original form and function if stimulus removed
Two Types of Reversible Cellular Injury
- Cellular Swelling
2. Fatty Change (Steatosis)
Cellular Swelling
occurs because not enough ATP to “power” ATP-dependent pumps (Na-K Pump, Calcium Pump)
Results in accumulation of ions w.in cell and therefore accumulation of water in cell
“hydropic change” or “vacuolar degeneration”
names for microscopic findings of cellular swelling
Fatty Change (Steatosis)
accumulation of lipid (fat) vacuoles w/in a cell’s cytoplasm; found commonly in cells normally involved with lipid metabolism
Ex: in liver
What will persistent or excessive cellular injury eventually cause?
it will cause a transition of injured cell from reversible injury to irreversible injury (DEATH)
What 3 things is Cellular Death Associated with?
- significant mitochondrial damage or dysfunction
- a damaged or dysfunctional plasma membrane
- genetic or nuclear damage
What are the 2 Primary Pathways for cellular death (irreversible cellular injury)?
- Apoptosis
2. Necrosis
Apoptosis
regulated cell death, controlled cellular breakdown; maintains outer plasma membrane and forms apoptotic bodies that fall away and are removed via phagocytes
(could be physiological or pathological)
Necrosis
destroys cell membrane and initiates prominent inflammatory response–> brings phagocytes to area to eliminate dead cellular debris and initiate healing
(always a pathological process)
What are the type types of morphological changes of necrosis?
- cytoplasmic changes
2. nuclear changes
What 2 types of cytoplasmic changes can occur in necrosis?
- eosinophilia
2. myelin figures
Eosinophilia
necrtotic cells manifest with an increase ink or red appearance with stranded hematoxylin and eosin (H&E) stain
myelin figures
necrotic cells contain membrane damage and myelin figures which = “rolled-up” or “scroll-like” area of lipid bilayer that is within a cell
What 3 types of Nuclear Changes can occur in necrosis?
- Pyknosis
- Karyorrhexis
- Karyolysis
Pyknosis
nuclear shrinking and increase basophilia (blue-staining/darker appearance) due to nuclear DNA condensing