Intro to Pathophysiology Flashcards
3 ways that cells respond to injury
(1) Reversible cell injury: mild or short lived change (ride it out)
(2) Cellular adaption: persistent sub-lethal (adapt)
(3) Necrosis/Apoptosis: severe or prolonged (cell death)
What are 2 of the characteristics of Reversible Cell Injury
(1) Hydropic swelling
(2) Intracellular accumulations
*Cell returns to normal following removal of stress
Characteristics of Hydropic Swelling
- Large pale cytoplasm
- Dilated ER
- Swollen mitochondria
Causes of Hydropic Swelling
- Malfunction of Na+/K+ pump
- Lack of ATP
- Water accumulation
Define Intracellular Accumulations
Accumulations of materials that cells cannot immediately use or dispose of
In what part of the cell does Intracellular Accumulation occur?
Accumulates in cytoplasm (lysosomes) or nucleus
3 categories of Substances in Intracellular Accumulations
(1) Normal body substances in abnormally large amounts
(2) Abnormal endogenous products
(3) Exogenous products
Define Accumulation of Normal Components
Substance produced at a rate exceeding metabolism or removal
Example: Fatty liver due to intracellular accumulation of triglycerides
Causes of Accumulation of Normal Components
- Starvation
- Diabetes mellitus
- Disruption of hepatic metabolism of lipids (eg. alcoholism)
Causes of Genetic Disorders of Metabolism
- Normal enzyme replaced with abnormal enzyme
- Substance formed can’t be used or eliminated
- Enzyme may be missing (intermediate accumulates)
Endogenous Pigment Accumlation
- Icterus (Jaundice): accumulation of bilirubin
- Lipofuscin: indigestible residues during normal turnover of cellular structures
Substances of Exogenous Pigment Accumulation
- Carbon
- Lead
- Tattoos
Characteristics of Cellular Adaptation
- Adapt to changes in internal environment
- Change in Size, Number, and Type of Cell
- Singly & Combination
Cellular Adaption can lead to…
- Atrophy
- Hypertrophy
- Hyperplasia
- Metaplasia
- Dyplasia
Define Atrophy
Decrease in cell size
Causes of Atrophy
- Disuse
- Denervation
- Loss of endocrine stimulation
- Inadequate nutrition
- Ischemia
Define Hypertrophy
Increase in cell size and functional mass
Causes of Hypertrophy
Due to normal physiology (eg. exercise) or abnormal pathology
Pathologic causes of Hypertrophy
- Adaptive: thickening (changes) to maintain function
- Compensatory: after removal of portion (kidney donor; remaining kidney will increase in size)
Define Hyperplasia
Increase in the number of cells
What are they only cells that are capable of Hyperplasia
Only cells capable of mitosis
2 types of stimuli that can cause Hyperplasia
(1) Physiological stimuli: hormonal or compensatory
(2) Non-physiologic stimuli: excess hormonal or growth factor stimulation
Define Metaplasia
Conversion of one cell type to another
Metaplasia is normally due to…
Normally due to chronic irritation and inflammation
True or False: In Metaplasia, conversion of the cell can occur outside the primary group
False: Conversion of a cell is never outside the primary group
Define Dyplasia
Deranged (disorderly) cell growth
Characteristics (symptoms) of minor Dysplasia
Minor chronic irritation and inflammation
Where/What cells is Dysplasia most frequently seen?
Frequent in metaplastic squamous epithelium or the respiratory tract and cervix
What is an implication of Dysplasia
Implicated as a precursor to Cancer (not always)
Causes of Necrosis
Ischemia or Toxic inury
Characteristics of Necrosis
Cell rupture (spilling of contents), which leads to Inflammation
- Unregulated enzymatic digestion of cell components, loss of membrane integrity
4 Types of Necrosis
(1) Coagulative necrosis
(2) Liquefactive necrosis
(3) Fat necrosis
(4) Caseous necrosis
What is the most common of Necrosis
Coagulative necrosis
Coagulative necrosis leads to…
- Loss of plasma membrane integrity
- Influx of calcium, mitochondrial dysfunction
- Degradation of plasma membrane and nucleus (creates dry and hard tissue)
Define Liquefactive necrosis
Quick dissolution of dead cells
- Liquefied area of lysosomal enzymes and dissolved tissue
Where does Liquefactive necrosis mainly occur?
Occurs in areas with very little connective tissue (eg. Brain)
Define Fat necrosis
Death of adipose tissue
- Releases fat into the body
Define Caseous necrosis
Lung tissue damaged by tuberculosis
What does Caseous necrosis looks like?
Looks like curdled milk (cottage cheese)
3 Types of Gangrene
(1) Dry Gangrene
(2) Moist Gangrene
(3) Gas Gangrene
Characteristics of Dry Gangrene
- Affected area becomes dry and shrinks
- Color change to dark brown/black
- Slow spread
- Line of demarcation
Characteristics of Moist Gangrene
- Area is cold, swollen, and pulseless
- Skin is moist, black and under tension
- Blebs (large flaccid vesicle) on surface - liquefaction
- Foul odor
- No line of demarcation
Gas Gangrene is caused by what bacteria?
Clostridium bacterium
How does Clostridium bacterium cause Gas Gangrene?
- Bacterial toxins dissolve membranes; as a result hydrogen sulfide gas is produced
Where can Clostridium bacterium be found
Normally found in soil
Define Apoptosis
Cell suicide; a response to injury that triggers intracellular signaling cascades
True or False: In Apoptosis cellular rupture occurs?
False: No cellular rupture occurs. Instead cell shrinks and is then carried away by phagocytosis.
True or False: Apoptosis is not always pathologic
True: Apoptosis if not always pathogenic. Apoptosis is part of normal development
Apoptosis is activated by…
Activated by Endogenous enzymes
Characteristics of Apoptosis
- Cell shrinkage: causing condensation of organelles
- DNA disruption: cleavage between nucleosomes
- Nucleus and fragment into membrane covered apoptotic bodies
- Changes to membrane signal phagocytes
Causes of cell injury and death
(1) Lack of oxygen and nutrients
(2) Infection and immune responses
(3) Chemicals
(4) Physical and mechanical factors
Define Hypoxia
- Lack of Oxygen
- Inability to produce ATP by oxidative phosphorylation
Define Ischemia
Interruption of blood flow to an area (lack of nutrients, oxygen, immune cells)
True or False: Ischemia is the most common cause of Hypoxia
True
Causes of Hypoxia
- Ischemia
- Inadequate oxygen in air
- Respiratory disease
- Anemia
- Edema
- Inability of cells to use oxygen
Hypoxia causes…
- Causes oxidative metablosim to cease
- Causes cell to begin anaerobic metabolism
- Causes Na/K and Ca pump to stop
- Causes cellular power failure
- Causes cellular pH to fall; resulting in an alteration in chromatin structure and cytoskeleton
Nutritional Injury
- Caused by excess or deficienty in nutrients (minerals, vitamins, fatty acids, amino acids)
- Body required 60+ organic and inorganic substances
- Total deficit (starvation) or a single item
Infectious and Immunologic injury is due to…
Due to biologic agents
- Diverse injury mechanisms
Why are biologic agents “worse”? (Infectious & Immunologic injury)
Biologic agents are worse because they are able to replicate and continue producting injurois effects
Examples of Chemical Injury
- Air, Water pollutants, Gases, Insecticides, Trace metals
- Drugs: alcohol, recreational adn therapeutic drigs
Causes of Physical and Mechanical Injury
- Mechanical force
- Temperature extremes
- Electrical injuries
- Radiation injury
Define Mechanical Force
body impact with another object
Temperature extremes
- Elevated: coaglulation of blood and tissue proteins
- Depressed: increases blood viscosity and induced vasoconstriction
- Freezing: ice crystals and vasoconstriction
Electrical injuries
- Disruption of neural and cardiac impulses
- Hyperthermic tissue destruction
Radiation injury
Gamma to Radio waves
Ionizing radiation
Hits target molecules or creates free radicals
- Above UV
Non-Ionizing radiation
Vibration and rotation of atoms and molecules; heat production
- Below UV
UV radiation
Creates ROS (reactive oxygen species) to damage skin and T-T dimers
Electrical injuries
- Disruption of neural and cardiac impulses
- Hyperthermic tissue destruction
Radiation injury
Gamma to Radio waves
Ionizing radiation
Hits target molecules or creates free radicals
- Above UV
Non-Ionizing radiation
Vibration and rotation of atoms and molecules; heat production
- Below UV
UV radiation
creates ROS (reactive oxygen species) to damage skin and T-T dimers
