Cellular Adaption, Injury and Death (ppt2) Flashcards
What is atrophy?
a decrease in cell size and a lower level of function.
What can cause atrophy?
- Disuse
- Denervation
- Loss of Endocrine stimulation
- Inadequate nutrition
- Ischemia or decreased blood flow.
What is hypertrophy?
an increase in cell size and an increase of functioning tissue mass.
What is hypertrophy caused by?
Caused by an increased workload on particular tissues (usually muscles)
What is hyperplasia?
an increase in the number of cells in an organ or tissue.
What can cause Hyper plasia?
- Physiologic causes:
- Hormonal – cell signals trigger replication
- Compensatory – damage or loss triggers replication as a means of replacement
Non-physiologic causes are excessive hormone interaction and viral infection.
What is metaplasia
a reversible change where one adult cell type is replaced by another
if you remove irritation, it will go away
What can cause metaplasia?
Caused by chronic irritation and inflammation that allows for the substitution.
What is Dysplasia?
deranged cell growth of a specific tissue that results in cells that
Vary in size, shape, and organization. (CAN GO BACK EXCEPT IN CANCER)
What can cause dysplasia?
Caused by irritation and inflammation, but can be reversible
if the irritant or inflammatory agent is removed.
Common precursor toCancer.
Atrophic Heart
cells are smaller
Normal adipose
Adipose with atrophy
cells are smaller
Normal Cardiac Muscle
Hypertrophic Cardiac Muscle
notice how the cells seem more swollen
Normal Thymus
Hyperplastic Thymus
notice how there is less space between cells
Normal Stomach
Metaplasia of the epithelium of the stomach
notice how theres skin cells in the stomach that don’t belong here
Normal Liver
Dysplasia of the Liver
notice how the cells have almost completely lost shape
What are some Normal body substances INTRAcellular accumalations (inside the cell)
Normal Body Substances
- Lipids
- Proteins
- Carbohydrates
- Melanin
- Bilirubin
Liver with bilirubin accumalation
What are Abnormal Endogenous Products intracellular accumalations caused by
Outcomes of Metabolic Errors
What are exogenous agents?
Environmental Agents and Pigments
What are two INTERcellular accumalations?
- Dystrophic Calcification
- macroscopic deposition of Calcium salts in injured tissues and can be composed of the bodies of dead or dying cells.
- Metastatic Calcification-
- occurs in normal tissues as a result of increased serum Calcium levels (Hypercalcemia).
Calcification of a Heart valve
What are some physical causes of cell injury? (4)
- Mechanical Forces
- Temperature Extremes
- Electrical Injuries
- Radiation Injuries
What are some chemical causes of cell injury? (3)
- Drugs
- Lead Toxicity
- Mercury Toxicity
What are biological causes of cell injury? (2)
- Viruses, Bacteria, Parasites
- Venom
What are some nutritional imbalance causes of cell injury?
- Dietary Deficiencies
- Obesity
What is free radical cell injury?
- highly reactive chemicals with unpaired electrons in their outer orbit react with molecules in their vicinity
- chain reactions create MORE FREE RADICALS
How are Reactive Oxygen Species (ROS) created?
- regular metabolism
- UV and ionizing radiation
What is Oxidative Stress?
ROS are greater than their ability to neutralize them.
What can happen after sustained Oxidative stress?
DNA DAMAGE
What causes hypoxis cell injury?
- lack of oxygen to the cell interrupts oxidative respiration and the generation of ATP
- causes cell damage or death.
- A switch to anaerobic metabolism causes pH to greatly drop,
- cell swelling can become unmanageable,
- no ATP for the Sodium/Potassium pumps in the membrane
What causes impaired Calcium Homeostasis?
- calcium must be in LOW LEVELS
- Ischemia and certain toxins let TOO MUCH IN
- Phospholipases, proteases, ATPases, and endonucleases are triggered
Can cells reverse their injuries?
Heck yea (as long as its not too severe)
What are the three choices for a cell when its in trouble?
- Recover, and back to normal
- Apoptosis (a less dramatic normal death)
- Necrosis (explode and kill everyone else too)
What is apoptosis?
- nucleus and cytoplasm shrink and condense,
- DNA fragments,
- the cell them blebs off into apoptotic bodies that are digested by a Phagocytic cell.
- No inflammation!!!!!
What is necrosis?
- Inflammation!!
- Explode all your diseases onto your neighbor cell
- Interferes with cell replacement and tissue regeneration
What is the evolutionary theory on why cells age?
we did not evolve to live endless lives,and are genetically predisposed to die after our reproductive capability is expended as a species.
(you can’t make babies so nature kills u)
What is the molecular theory on why cells age?
aging as caused by an accumulation of mutations and changes in gene expression
brought on by years of replications and environmental exposure.
(your cells just break down like an old rusty bike)
What is the cellular theory as to why cells age?
aging as caused by an accumulation of mutations and changes in gene expression
brought on by years of replications and environmental exposure.
(your cells can only multiply so much)
What is the systems levels theory as to why cells age?
a decline in the integrated functions of organ systems such as the immune and neuroendocrine systems (systems that rule all the others).
(your systems just start to break down)
