Cell injury/death/adaptation Flashcards
what is the difference between etiology and pathogenesis?
Etiology- ORIGIN of disease, WHY a disease occurs
Pathogenesis- DEVELOPMENT of disease, HOW a disease occurs
cerebral infarction, myocardial infarction and Renal atrophy are all forms of _____ injury
hypoxic
what are the (4) cellular targets for injury?
1) cell membranes
2) mitochondria
3) cell proteins
4) DNA
T/F: clinical signs and symptoms are usually closely timed to the molecular/biochemical changes following injury
FALSE
clinical signs are usually several steps removed
What are the effects of Hypoxia-ischemia on the cell membrane?
impairs Na+ pump: Na+ and Ca++ influx, K+ efflux
cell swells as water floods cell
What are the end effects of Hypoxia-ischemia on cellular metabolism?
1) decreased glycogen stores
2) increased lipid deposition
Generation of reactive oxygen species is associated with what?
1) inflammation
2) oxygen toxicity
3) chemical/drugs
4) radiation (UV, X-ray)
5) Aging
how do ROS (reactive Ox) damage cellular components?
- lipid peroxidation
- protein fragmentation
- single strand DNA breaks
ROS cause _____-_____ DNA breaks
single-strand
How are reactive oxygen species controlled by cells?
1) enzymes
2) antioxidants (vitamins, glutathione)
3) serum proteins (bind/reduce iron and copper)
_____ (an ion) activates many enzymes inside the cell, and its concentration within the cell is highly controlled
calcium (Ca2+)
the degree of cell injury is determined by what factors?
A) physiologic state of the cell
B) intensity of insult
C) duration of insult
D) # of exposures to insult
what are the signaling mechanisms for cellular apoptosis?
1) intrinsic program
2) “death signals”
3) removal of a trophic signals – e.g. hormones
4) ROS, radiation, and toxins
5) effect of cytotoxic T cells
Fas-ligand binding to Fas receptor is a form of _____ signals
death signals
trigger apoptosis
the ____ gene family serve as on and off switches that regulate the membrane permeability of the mitochondria
Bcl-2 gene family
Bcl-2 and bcl-x gene products ______ apoptosis
inhibit
when does cell death occur?
Cell death occurs when the insult overcomes compensation mechanisms
apoptosis signaling pathways converge on an autocatalytic proteolytic cascade of ________
caspases
high cytoplasmic levels of Ca2+ will activate which digressive enzymes?
a. phospholipases
b. proteases
c. endonucleases
d. ATPase
Cell injury may result in what 4 effects?
a. Reversible cell injury
b. Cellular adaptations associated with changes in cell number, size or differentiation
c. Cellular adaptations associated with abnormal accumulations
d. Cell death – necrosis or apoptosis
what are the common causes of reversible cell damage?
a. Toxins
b. Infectious agents
c. Hypoxia
d. Thermal injury
what are the 2 morphological types of reversible cell injury?
hydropic change and fatty change
what are the morphological types of necrosis?
Coagulative
Liquefactive
Caseous
Enzymatic (fat)
what are the characteristics of coagulative necrosis?
1) cytoplasmic proteins are coagulated
2) The nucleus is lost, but the pink outline of the cell is still present
what are the characteristics of liquefactive necrosis?
A) The tissue is totally digested by the release of lysosomal enzymes during the acute inflammatory response.
B) associated with focal bacterial or fungal infections
what is Caseous Necrosis?
a. Associated with M. tuberculosis infection.
b. The tissue has a white and “cheesy” appearance on gross examination.
c. the body “walls off” the area with granulocytes
where is Fat Necrosis commonly found? what are its characteristics?
A) found in necrosis of breast or pancreatic tissue
B) adipose has a chalky white-yelllow color
C) dead cells look like “soap bubbles”
Morphologic features of apoptosis include:
1) cell shrinkage
2) Chromatin condensation
how does the morphology of necrosis and apoptosis differ?
Necrosis- Multiple cells, Cell swelling, Cell lysis
Apoptosis- Single cell, Cell shrinkage, Chromatin Condensation, Apoptotic bodies
while inflammation is seen in forms of _______, it is not seen in ________
seen in necrosis, not seen in apoptosis
Chronic cell injury leads to cell ________
adaptations
how do cells change in response to chronic injury?
a. Alterations in cell size
b. Alterations in cell number
c. Alterations in cell differentiation
d. Intracellular accumulations
what is atrophy? hypertrophy?
Atrophy - a decrease in cell size and function
Hypertrophy - an increase in cell size and is associated with an increase in functional capacity.
what are the 2 etiologies of hypertrophy?
1) response to trophic signals (hormones)
2) response to increased functional demand (AKA muscle growth)
what is hyperplasia? what are its general characteristics?
Hyperplasia - an increase in the number of cells in a tissue or organ
1) may involve the proliferation of epithelial and/or stromal cells
2) proliferation is stimulated by trophic factors
3) increase the risk for subsequent neoplasia’s
what are some causes (etiologies) of cellular atrophy?
A) decreased workload B) loss of innervation C) chronic ischemia (reduced bloodflow) D) starvation E) lack of trophic factors
what are the common etiological factors for hypertrophy?
A) increased functional demand
B) increased or imbalanced nutrition
C) increased hormonal stimulation
Traumatic Keratosis is an example of what form of cell response?
Hyperplasia due to chronic irritation
what is metaplasia?
Metaplasia - one adult cell type is replaced by another ADULT cell type in response to chronic stress.
Acid reflux, and smoking, can both cause a _______ of epithelial tissues
metaplasia
what is Steatosis?
Fatty liver
- caused by triglyceride accumulation (intracellular accumulation)
what is a Xanthoma?
cholesterol accumulation in the epithelium
- common in elderly
what are the histological characteristics of xanthomas?
foamy looking macrophages filled with cholesterol
Cholesterol build-up in vessels can cause what 2 conditions?
Atherosclerosis
cholesterol thrombus
alpha-1 anti-trypsin deficiency, Mallory bodies, and Alzheimers disease are all associated with an accumulation of what?
protein
what is an example of a disease caused by carbohydrate accumulation?
glycogen storage disease
what are 2 examples of conditions caused by exogenous carbon pigmentation
1) Anthracosis (asymptomatic… anthricite coal dust)
2) Pneumoconiosis (symptomatic- restriction. from coal)
Melanotic-macules are caused by what?
accumulation of ENDOGENOUS pigments (melanin)
what are the characteristics of a Hemosiderin? what causes them?
1) A yellow-brown pigment represents aggregates of ferritin micelles.
2) Its accumulation arises from excess iron locally due to hemorrhage and can lead to hemosiderosis.
what causes Bilirubin to accumulate in the liver?
Accumulates in hepatocytes and bile ducts due to hemolysis, obstructed bile flow, and/or hepatocellular disease.
