What is the main cause of adaptation?
What is hypertrophy?
increase in cell size and organ size
What is hyperplasia?
increase in cell # and organ volume
What types of tissues can become hypertrophic?
Heart & Skeletal mm
What types of tissues are affected by hyperplasia?
glands and ducts
What is atrophy?
reduced size of organ due to reduced cell size and reduced number
What is metaplasia?
transformation that is reversible and occurs in adult cell types
T/F Metaplasia is cancerous?
F, dysplasia can lead to cancer
What are two indications of a reversible change?
What type of disease of the heart is irreversible?
hypertrophy: Pressure overload vs. Volume overload?
- Pressure overload: Concentric
- Volume overload: Eccentric
What are the two stimuli for hypertrophy?
Pressure and volume overload
Three mechanisms of cardiocyte hypertrophy? (MAG)
- Mechanical stretch
- agonists (Beta)
- growth factors
How do cardiocytes go through hypertrophy?
- More actin and myosin due to growth factors
- micro RNAs
How do nuclei appear in a hypertrophic cardiocyte?
- boxy, large
How do fat cells grow differently pre- and post-puberty?
- Pre: increase in number
- Post: hypertrophy/atrophy
What causes subcellular hypertrophy of the SER?
hyperactive cytochrome P450 system due to excessive alcohol/drug use
How does a person react to drugs with a hypertrophied SER?
What common class of drugs can induce SER Hypertrophy?
If a person is taking barbituates for convulsion and starts to drink, what will be the result?
Less effectivity and uptake of barbituates b/c it shares the system with alcohol
What is the physiological response for the myometrium of the uterus to hormones?
What adaptation occurs in breasts?
What causes hyperplasia of breasts?
What types of cells adapt via hyperplasia?
Labile: epithelial and bone marrow cells
What organ adapts via compensatory (regeneration) hyperplasia?
Liver via GFs
How does the endometrium of the uterus adapt?
How does the prostate gland adapt?
What stimulates erythroid hyperplasia (aka erythropoietin)?
What is polycythemia?
increased RBC count
What hormone causes Adrenal and thyroid gland hyperplasia?
- Adrenal: ACTH
- Thyroid: TSH
What are four GF mediated pathologic hyperplasia examples and their causes?
- 1) Keloid scar: fibroblasts
- 2) Hypertrophic scar: Myofibroblasts
- 3) Viral warts: HPV
- 4) Psoriasis: cytokines, epidermal squamous cells
Where are the two places in the human body where cancer and hyperplasia can exist?
What is the most common form of Atrophy?
T/F cells cannot recover from atrophy?
F, they can recover
What are the two methods of cell loss during atrophy?
What areas of the body are affected by endocrine atrophy?
- Endometrium of uterus
- vaginal epithelium
- Adrenal cortex (lack of ACTH)
What is a sign of denervation atrophy?
grouped atrophy of mm
What type of atrophy is caused by Charcot marie tooth syndrome?
What type of atrophy is a hereditary loss of motor neurons?
SMA: Spinal muscle atrophy (Werdnig-Hoffman)
What atrophy is caused by Polio? what is destroyed?
- Denervation atrophy
- Anterior horn cells destroyed
T/F bilateral atrophy is caused by a hormone change?
What type of atrophy does atherosclerosis cause?
Blood loss atrophy
T/F Blood loss atrophy is unilateral?
T (but can be bilateral if full occlusion)
What are two causes of blood loss atrophy?
- 1) Pressure: tumor, twisting of testes, etc...
- 2) diminished blood supply: injury, atherosclerosis, ischemia
What type of atrophy are Marasmus and Cachexia? Causes?
- Inadequate Nutrition Atrophy
- Marasmus: autophagy from protein malnutrition
- Cachexia: TNF alpha, inflammation, cancer
What are the two mechanisms of Atrophy?
- 1) ubiquitin-proteosome path (high in infection of HIV, TB and cancer)
- 2) Autophagy: digest cytoplasmic organelles in lysosomes
What are two remnants of autophagy?
- 1) residual bodies
- 2) Lipofuscin pigment
What are the 2 causes of Metaplasia?
If a muscle is injured, what type of metaplasia will occur?
- Myositis ossificans: fibroblasts will form bone b/c mm can't regenerate
- ** AKA Osseus metaplasia
What is the most common metaplasia?
Within cells, what is the most common metaplasia?
Squamous metaplasia (from glandular or columnar cells)
What is columnar (glandular) metaplasia?
Squamous cells replaced by columnar cells
What organ is affected by columnar metaplasia? Why?
- Esophagus, acid reflux
- * Barrett's esophagus
Why does glandular metaplasia occur?
To help produce more mucous in the air and food tracts of the body
What are the three pathways of cell death?
- Necrosis: Pathologic
- Apoptosis: Path and physiologic
What are the characteristics of the three styles of cell death?
- 1) Necrosis: lipases, proteases and lysosome material released to rupture cell
- 2) Autophagy: Lysosome degradation
- 3) Apoptosis: cellular blebbing due to shrinkage
What regulates autophagy?
Autophage genes, ATGs
what cell injury occurs when ATP is depleted and oxidative phosphorylation is decreased?
reversible cell injury
What cellular changes occur during a reversible cell injury?
- 1) swelling
- 2) fatty vacuoles appear (steatosis)
What happens to mitochondria during reversible cellular injury?
what color does a cell going through reversible cell injury appear? Why?
- Due to polysomes being released into cytoplasm and eiosinophilic dye
when is cellular injury irreversible? (3 reasons)
- 1) mitochondrial dysfunction
- 2) membrane lost
- 3) nuclear dissolution
What occurs at the end of an irreversible cellular injury?
What are two methods of necrosis?
- 1) Autolysis
- 2) lysosomal enzymes from leukocytes from inflammation
What are the three nuclear morphologies of Necrosis?
- 1) Karyolysis: fading of nucleus
- 2) Nuclear pyknosis: shrinking of nucleus
- 3) Karyorrhexis: destruction of pyknotic nucleus
Name the six types of Necrosis?
- 1) Gangrenous: wet and dry
- 2) Coagulative: membranes present
- 3) Caseous: cottage cheese
- 4) Fatty:
- 5) Fibrinoid:
- 6) Liquefactive: lipases degrading, no membranes
What kind of necrosis is acute tubular necrosis of kidney? What is present?
Coagulative (cell membranes still present)
What type of necrosis is commin in MI?
Coagulative necrosis due to occlusion
An infarction will always lead to what type of necrosis?
What cells clear coagulative necrosis?
When does Liquefactive necrosis occur?
- Stroky/CNS hypoxia
- Abscesses from infection
What degrades liquefactive necrosis?
What necrosis occurs in the brain? Why?
- This occurs b/c coagulation cannot stay around due to lack of fibroblasts
What causes gangrenous necrosis?
infection and ischemia
Diff b/t dry and wet gangrenous necrosis?
- Dry: ischemia predominates
- Wet: ischemia and infection together
three common signs of caseous necrosis?
- macrophage granulomas
Two types of Fat Necrosis?
- Traumatic: injury or surgery to fatty tissue
- Enzymatic: Lipases released from pancreas
Common organ affected by Fat Necrosis?
What is Fibrinoid Necrosis?
Immune mediated blood vessel damage, Eiosinophils in cell walls
What causes ATP to deplete?
Four cellular problems when ATP depletes?
- 1) Na enters cell = K leaves = water enters = swelling
- 2) Glycolosis = increase in lactic acid = decrease pH
- 3) loss or ribosomes = lack of proteins = lack of APO for shipping fat = fat buildup in cell
- 4) Protein folding abnormal
Which occurs faster, ischemia or hypoxia?
What is the main cause of hypoxia?
Shock due to decreased systemic perfusion
Two main problems of full ischemia?
- ATP depletion = swelling
- CK/Troponin released into body
five common causes of mitochondrial damage
- increased cellular calcium
- oxidative stress
- genetic disposition
After mitochondrial damage, what causes Necrosis and Apoptosis?
- Necrosis: lack of ATP production
- Apoptosis: cytochrome C released from pores
How does calcium increase occur in cells?
- Release of sequestered calcium
- influx b/c of pores that are not functioning
What molecules disrupt plasma membranes making them permeable to Calcium?
What metabolic system can increase free radicals?
oxidation/reduction of oxygen in peroxisomes