Pathology II Flashcards
Genetically programmed like apoptosis and morphologically/biochemically resembles necrosis
Necroptosis
However, in necroptosis, we do not have any
Caspase activation
The typical ligand for necroptosis is
TNFR1
Ligation then recruits
RIP1 and RIP3
Terminal events include membrane permeabilization, ROS, mitochondria damage, decreased ATP
Necroptosis
A survival mechanism under stress conditions, especially nutrient deprivation
Autophagy
Selective and regulated by greater than a dozen proteins
Autophagy
The result of a progressive decline in cellular function and viability caused by genetic abnormalities and the accumulation of cellular and molecular damage due to the effects of exposure to exogenous influences
Cellular aging
Damage directly to DNA
–Decreasing effectivity of DNA repair enzymes
–Possible contribution of free radical insults
Accumulating DNA damage
Cellular aging shows a reduced capacity of the cell to
Divide
This reduced capacity to divide is the result of progressive shortening of telomere ends without activation of
Telomerase to repair them
Reduced translation of proteins and defective activity of chaperones, proteasomes, and repair enzymes
Defective protein homeostasis seen in cellular aging
Some environmental stresses counteract aging. An example of this is a
30% reduction in calories
rare disease that causes premature aging
Progeria
The most common cause of death in progeria
Atherosclerosis
A genetic disease, but it usually occurs sporadically and does not run in families
Progeria
Unlike some other diseases of premature aging that are due to problems with DNA repair, such as Werner syndrome, progeria is due to a mutation in the gene coding for
Prelamin A
The mutation destroys a recognition site for an enzyme that ordinarily cleaves the protein to produce
Lamin A
In progeria, Prelamin A accumulates in the membrane and causes
Nuclear blebbing
Inadequate removal or normal substances or the accumulation of an abnormal endogenous substance are types of
Intracellular Accumulations
An example of inadequate removal of a normal substance is
Hepatic fatty change
An example of accumulation of an abnormal endogenous substance is
Alpha-1 antitrypsin disease
Inherited enzyme deficiency => undegraded metabolite. An example of this is
Storage disorders
Accumulation of undegradable abnormal exogenous substance can occur. An example of such a source is
Carbon
Multiple foci of metastatic calcification are present in the lamina propria of the stomach in a patient with
Chronic renal failure
What are two types of calcification?
Metastatic and Dystrophic
In cytomegalovirus infection, the fact that the tissue was previously injured means that the calcification is
Dystrophic
Seen in areas of necrosis
-normocalcemic and intra/extracellular
Dystrophic calcification
Normal tissues – Tissues that lose acid and thus are alkaline experience
Metastatic Calcification
Metastatic calcification is characterized by
Hypercalcemia
Dystrophic calcification is characterized by
Normocalcemia
X-rays and gamma rays with high energy neutrons, alpha particles, and beta particles
Ionizing radiation
Systems that are highly sensitive to radiation are mainly organs with high rate of
Turnover
Radiation injury to hematopoietic/lymphoid tissue causes
Acute nodal tissue loss and cytopenias
Radiation injury to the gonads causes
Sterility
Radiation injury can cause vascular damage leading to fibrosis and
Chronic ischemic atrophy
Fatty change (steatosis) has a number of etiologies, including
Hypoxia, toxins, and protein malnutrition
In alcoholic steatosis the fat droplets are microvesicular at first, but they become macrovesicular with chronic
Ethanol ingestion
Results from increased lipid synthesis, faulty lipoprotein assembly and secretion, and increased peripheral fat catabolism
Alcoholic Steatosis
Blood alcohol is metabolized to acetaldehyde in the liver mainly by
Alcohol dehydrogenase
Decrease in NAD+ and an increase in NADH => impaired hepatic fatty acid oxidation =>
Fatty liver
Acute alcoholism affects mainly the CNS plus reversible gastric and hepatic
Injuries
One of the more common primary malignancies of lung and are most often seen in smokers
Squamous cell carcinomas
Causes addiction and acute cardiovascular stimulation
Nicotine
