Basic pathology and response to stress Flashcards
What is the order of events in which to think about diseases?
- Cause/Etiology
- Pathogenesis
- Morphologic Changes
- Clinical consequences and prognosis
What are the 7 causes of cell injury and death?
- Physical
- Ischemia and Hypoxia
- Toxins and Drugs
- Infections
- Inflammation
- Genetic diseases
- Nutritional problems
Give some example of physical causes of cell injury and death
- Physical stress/trauma
- Heat
- Cold
- Radiation
What is the difference between Ischemia and Hypoxia?
- Ischemia: Circulation is impaired and blood not getting to tissue
- Hypoxia: Lungs aren’t working well or you’re holding your breath or something
*Both involve inadequate oxygen supply to a tissue
Which would be worse, Ischemia or hypoxia?
Ischemia
*Because in hypoxia you are just affecting oxygen content and there are other ways for the cell to make energy but in ischemia you get a bigger problem because lactate accumulates and blood doesn’t get to the site
What are the kinds of cell adaptations to injury?
- Hypertrophy/atrophy
- Hyperplasia
- Metaplasia
- Dysplasia
What is cell hypertrophy?
Increased cell size, not number
*Common locations include heart and skeletal muscle
What is atrophy?
Cell shrinkage or loss
What causes atrophy?
- Lack of hormonal signals
- Loss of innervation
- Lack of use
- Loss of blood supply
- Starvation
- Individual cell death
What is Cachexia?
- Fatty atrophy
- Fat cells don’t have much fat anymore and they get smaller
At what point is cachexia fatal?
At 68% of normal body weight, +/- 2%
What is hyperplasia?
Increased NUMBER of cells
What causes hyperplasia?
Causes are similar to hypertrophy:
- Stress
- Hormones
- etc.
T/F Hyperplasia and hypertrophy never occur at the same time
FALSE, Hyperplasia can occur with hypertrophy
Give some examples of where hyperplasia can be seen?
- BPH (Prostate)
- Liver
- Kidney
- Breast
- Endometrium
What is Metaplasia?
Replacement of one cell type by another
Give some examples of where you would see metaplasia?
- Smoker’s airways
- Cervix
- Barrett’s esophagus
What would metaplasia look like in a smoker’s airways?
Normal respiratory epithelium may become squamous
What is barret’s esophagus?
Refers to an abnormal change (metaplasia) in the cells of the lower portion of the esophagus. It is characterized by the replacement of the normal stratified squamous epithelium lining of the esophagus by simple columnar epithelium with goblet cells (which are usually found lower in the gastrointestinal tract)
What is dysplasia?
Disordered hyperplasia without maturation
T/F Dysplasia is preneoplastic
True
Define Preneoplastic
Preceding the formation of a benign or malignant neoplasm.
Give some examples of where Dysplasia can occur
- Uterine Cervix
- Bowel in inflammatory bowel disease
- Esophagus with Barret’s
What types of cells are most prone to injury?
- Cells with High metabolic activity
2. Rapidly proliferating cells
Give 3 examples of cells with high metabolic activity
- Cardiac myocytes
- Renal Tubular cells
- Hepatocytes
Give 3 examples of Rapidly proliferating cells
- Testicular germ cells
- Intestinal epithelium
- Hematopoietic cells
What are the two degrees of cell injury?
- Reversible
2. Irreversible-cell death
Describe reversible cell injury
Damage not enough to kill cell
Give 3 examples of reversible cell injury
- Mild ATN (renal acute tubular “necrosis”)
- Toxic liver inury
- Severe exercise
Describe irreversible cell injury
- More severe damage
- Holes in cell membrane
- Long Ca2+ influx
- Mitochondrial loss
What are the two types of cell death?
- Apoptosis (programmed cell death)
- Necrosis (uncontrolled)
*Mixed apoptosis and necrosis is common
What are the effects of hypoxia in reversible cell injury?
Loss of ATP
How do cells compensate for hypoxia in reversible cell injury?
Anaerobic glycolysis with lactate and acidosis
In reversible cell injury, what two things are associated with the loss of sodium pump?
Cell swelling and ER vacuoles
T/F There is a fatty change in reversible cell injury
True
What type of cell death is energy-requiring programmed cell death?
Apoptosis
What type of cell death is often a normal phenomenon?
Apoptosis
T/F Apoptosis results in moderate inflammation and the destruction of multiple cells at a time
False,
*No inflammation, usually one cell at a time
Name several things in which apoptosis happens.
- Normal embryology
- Normal cell turnover (Intestine, skin, menses)
- Viral infection
- Cell damage (DNA, unfolded proteins)
- Immunologically mediated
- Hormone withdrawal
What are the things involved in Immunoligically mediated apoptosis?
- Fas or TNF signals
- Cytotoxic T lymphocytes granzymes
The caspase pathway is involved in which type of cell death?
Apoptosis
What is Pyknosis?
- Also called Karyopyknosis
- The irreversible condensation of chromatin in the nucleus of a cell undergoing necrosis or apoptosis. It is followed by karyorrhexis, or fragmentation of the nucleus
Which type of cell death is uncoordinated cell death?
Necrosis
What are the early events in necrosis?
- Cell membrane disruption
- Ca2+ signal (Leaking into cytoplasm)
- Energy loss (ATP depletion)
T/F Necrosis is associated with inflammation
True,
*cells often swollen due to loss of ion pumps early in process
In necrosis, cell contents _____, causing _____
- Leak
2. Acute inflammation
Necrosis often occurs in _____ rather than individual cells
Cell clusters
What would you call necrosis of a whole anatomic area like a toe?
Gangrene
Describe some cellular changes in necrosis
- Cytoplasm is a deeper red (Loss of mRNA)
- Cells swell
- Nuclei not basophilic
- Hemorrhage, acute inflammation, then chronic inflammation and fibrosis
What are 3 nuclear changes in cell death and how do they appear histologically?
- Nuclear Pyknosis (shriveled, dark)
- Karyolysis (digested, pale nucleus)
- Karyorrhexis (nuclear fragmentation)
What are the 6 patterns of necrosis?
- Coagulative
- Liquefactive
- Fat necrosis
- Caseous necrosis
- Gangrenous necrosis
- Fibrinoid necrosis
Coagulative necrosis happens with ____ and makes ___
- Ischemia
2. Infarct
Liquefactive necrosis is _______, examples include brain or lung _____
- Loss of substance
2. Abscess
What is Caseous necrosis?
- Necrotizing granulomas
- Combination of liquefactive and coagulative
- Can be caused by fungal or TB infection
Fat necrosis looks like _______ when it happens in the breast
Cancer
T/F Fat necrosis can also happen in pancreatitis
True
What is Fibrinoid necrosis?
Really it is fibrin deposition +/- actual necrosis
T/F Like cells, organelles can have hypertrophy of atrophy
True
Give an example of an organelle changing similar to a cell
In the liver, increased smooth ER with barbiturate use. Increased cytocrhome p450 2C metabolizes other drugs or toxins more quickly
Give an example of an injured organelle
- Mallory body in liver due to alcohol or other injury-clump of intermediate filaments
- Fat and pale vacuoles (dilated ER) also seen
What are some examples of abnormal storage?
- Fatty change in liver
- Glycogen accumulation
- Lipid storage
Describe fatty change in the liver as it pertains to abnormal storage
- Common and nonspecific
- Seen with alcoholism, obesity, starvation, toxins
Describe glycogen accumulation as it pertains to abnormal storage
- In liver in diabetes
- In glycogen storage disease
- In certain tumors
Describe lipid storage as it pertains to abnormal storage products
- lipid storage disease-Fabry’s, gaucher’s
- In vessels in atherosclerosis
Describe Gaucher disease
Lysosomal accumulation of lipid
What are 3 examples of brown storage products?
- Lipofuscin
- Bilirubin
- Hemosiderin
Describe Lipofuscin
- Degraded in lysosomes
- Increases with age, free radical damage
Describe bilirubin
- Hemoglobin breakdown product
- Normally present in bile
- Increased with biliary obstruction and hepatocyte disorders
- Too much causes jaundice/icterus
Describe Hemosiderin
- Iron containing pigment
- Increased with excessive iron absorption, bleeding into tissues
In jaundice, a yellow-brown color is see with _____
Hyperbilirubinemia
What is hemochromatosis?
Hereditary iron storage disease
What are two types of protein storage?
- Intracellular
2. Extracellular
Describe intracellular protein storage
- Alpha-1-antitrypsin deficiency
- Russel bodies in plasma cells
Describe Extracellular protein storage
- Amyloid
- Beta pleated sheet protein accumulations
- Can be many different protein types
- Occurs in a variety of diseases
- Seen in vessels, brain, heart, glomeruli, tumors, other sites
- Fibrosis
What are Russel bodies?
Large deposits of immunoglobulin in plasma cell cytoplasm
What are two types of Miscellaneous storage products?
- Anthracosis–carbon pigment
2. Calcification–Hydroxyapatite
Describe Anthracosis–carbon pigment
- Harmless, but other harmful materials can be depositied with it (silica, asbestos)
- Mostly in and near lungs
What are the two types of calcification?
- Dystrophic calcification
2. Metastatic calcification
Describe Dystrophic calcification
- Into damaged tissue
- Seen with necrosis without enough dead tissue removal
Describe Metastatic Calcification
- Into normal tissue
- Disordered calcium metabolism (renal failure, hyperparathyroidism, malignancy) with hypercalcemia
Muscles in a body builder is an example of ______
Hypertrophy
Brain in dementia patient is an example of ________
Atrophy
Prostatic enlargement is an example of ______
Hyperplasia
Uterine cervical premalignant change is an example of ____
Dysplasia