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