Exam 4 General Info Flashcards
What is cell injury?
When the cells are stressed to the point that they are unable to adapt
What is apoptosis?
A programed cell death
What is necrosis?
A injury causing cell death that isn’t planned after the point of irreversibility
What is hypertrophy?
An increase in cell size
Where does hypertrophy occur?
It occurs in cells that are incapable of dividing (striated muscle cells in the skeletal muscles and the heart)
What commonly causes increased workload in hypertrophy?
Physiological stimuli or pathological conditions
Hypertrophy is characterized by what 2 protein synthesis?
Mechanical triggers such as stretching
Hormonal triggers such as adrenergic hormones (fight or flight)
What changes in the uterus during pregnancy?
The cells go through hypertrophy and become enlarged
What is hyperplasia?
An increase in the number of cells but not size
What are 3 physiological examples of hyperplasia?
Proliferation of the female mammary epithelium during puberty
Profiferation of connective tissue cells during wound healing
Regeneration of the liver (physiologic compensatory hyperplasia)
Physiological hyperplasia in female hormones?
Estrogen, progesterone, prolactin
Pathological hyperplasia in female hormones and male
Can cause cancer with hormone imbalances
What is atrophy?
Shrinkage of the cell size by the loss of cell substance
What are the 5 things cause atrophy?
Decreased workload
Loss of innervation
Reduced blood supply
Inadequate nutrition
Aging (senile atrophy)
Atrophy causes a decrease in cell size which is caused by?
Increased protein degradation
Or reduced protein degradation
What is metaplasia?
One cell type is replaced by another cell adult type
What 2 things usually causes metaplasia?
Chronic irritation
Inflammation
Examples of metaplasia?
Ciliated columnar epithelial cells of the trachea and bronchi help clear foreign matter and mucus
In smokers and vitamin A deficiency ciliated columnar cells are replaces by squamous epithelial cells which are more rugged and not ciliated
This leads to coughing and an increase in infections
Another example is Barretts esophagus
What does metaplasia usually lead to?
usually a precursor for cancer
can be reprogramming a stem cell and dosent replace (they keep dividing)
What is dysplasia?
Organization of cell is lost, they vary in size, number, shape and organization
What is dysplasia associated with?
Chronic irritation
Inflammation
Dysplasia is a precursor for what?
Cancer
- oxygen deprived (causes of cell injury)
Hypoxia - oxygen deficiency
Ischemia - loss of oxygenated blood supply to tissues
- cause of cell injury
Chemical agents - posions, air pollutants, CO, asbestos
- cause of cell injury
Infectious agents - viruses, bacteria, fungi, parasites
- cause of cell injury
immunological reactions - autoimmune diseases
- cause of cell injury
genetic defects - sickle cell anemia, familial hypercholesterolemia
- cause of cell injury
physical agents - trauma, heat, cold, electrical shock
- Nutritional imbalances (causes of cel injury)
nutritional deficiencies - calcium or vitamin
Excess nutrition
Diabetes - can be causes by obesity - excess blood sugar levels can damage cells
Atherosclerosis - can be caused by diet rich in fats - can result in blockage of arteries
- cause of cell injury
Aging - accumulation of damaging reactive oxygen species
What does ischemia mean?
Decreased oxygen to a tissue
What are the characteristics of reversable injury?
Cells start to swell and get larger
Fatty change - see lipid vacuoles starting to form
What are the characteristics of ireversible injury?
Mitochondria dysfunction - no ATP
Membrane dysfunction - around organelles and around the whole cell
Free radical formation leads to ?
Oxidation of cell structures and nuclear and mitochondrial DNA
Intraceullular Ca increase leads to ?
Enzyme, organelle, cytoskeleton depeltion / injury
ATP depletion leads to ?
Detachement of ribosomes from ER
Decreased protein synthesis
lipid deposition
Increase in anarobic metabolism
Glycogen storage and intracellular pH drops
decrease in sodium potassium pump
Increase of sodium and water in the cell
BAD
2 pathways of damage to the mitochondria
Apoptosis - by cytochrome c and other preapoptic proteins
Necrosis - mitochondrial membrane gets breached, inability to produce ATP
What does cytochrome c do?
Precursor for apoptosis
Increase of ca in the cell?
Very bad causes many things to go wrong
ROS (reactive oxygen species) impact what in the cell
Fatty acids
Proteins
DNA
Can ROS be expelled?
Yes by SOD
Glutathione peroxidase
Catalase (in peroxisomes)
Sequstration of free ionized iron and copper in ROS
Free ionized iron and copper can casue ROS and oxygen free radical production via Fenton reaction
What happens when there is a defect in membrane permeability?
Plasma membrane damage
mitochondrial membrane damage
lysosomal membrane
What happens when Bax or Bak gets oligomerizised or dimerized?
They lead to cytochrome c release after pore formation
Bcl-2 family proteins
Bax, Bak and Bad proteins increase mitochondrial membrane permeability which are called pro-apoptotic proteins
Bcl-2 and Bcl-x are inhibitors of these which they are anti-apoptotic proteins
When activated caspases active proteases what happens?
Degradation of cytoskeletal proteins
2 things inflammation is responsible for?
inflammation is responsible for eliminating infection
inflammation is responsible for repairing damages
What are the classical signs of acute inflammation (5)
- heat (warmth)
- redness (erythema)
- swelling (edema)
- pain
- loss of function
What happens inside of the capillary that can tell you there is inflammation (2)
- vascular changes
- cellular events
Functions of inflammation
- to improve the delivery of inflammatory cells to the injured/infected area tissue
- Vascular changes associated with inflammation
A) Changes in vascular diameter and flow that results in reduced
blood velocity
a)vasodilation
b)increased viscosity (thickness)
c)margination - when the leukocytes slow down and gives it
more chance to bind and help the site of inflammation
Functions of inflammation (part 2)
B. Increased vascular permeability
a) endothelial cells contraction/retraction leading to intercellular
gaps that leak fluid
b) direct endothelial injury
c) leukocyte dependent damage because of toxic mediators
released by leukocytes
d) increased fluid flow through endothelial cells is called (transcytosis) from vascular to tissues on the other side