-Atrophy = wasting away

-Hypertrophy = cells enlarge

-Hyperplasia = more cells produced

-Metaplasia = change in the type of cells

-Dysplasia = abnormal response to instructions

-make stuff

-reproduce

*either they adapt to changes to maintain function

OR

*failure to maintain function results in (injury, maladaptive changes or death)

-unused elements (lipids, glycogens)

-abnormal proteins

-pigments

-calcium salts

-Direct

-Free radical

-Hypoxic damage

-Calcium Homeostasis

-Hypoxia

-Heat/Cold

-Electricity

-Chemical agents

-Biologic agents

-Radiation

-Nutritional imbalances

Free Radicals

(first explain what these are)

-they are molecules that have an unpaired electron in the outer shell-reactive oxygen species

-They are Extremely unstable!

-normally FR are removed by antioxidants

-They inhibit the action of the Reaction Oxygen Species

(ROS)

*Can react with normal cell components

-damaging them

-turn them into more free radicals

-this causes a chain reaction = Oxidative Stress! 

Damage to:

-vital cell proteins including enzymes

-DNA damage

-lipid peroxidation

-injury to cell membranes

-mitochondrial damage (decrease energy)

-Inflammation

-Ischemia

-Reprefusion injuries

-Toxic agents

-Oxygen toxcity

Radiation

-Superoxide

-Hydrogen Peroxide

-Hydroxyl radical

-natural and synthetic molecules that inhibit the activity of the ROS

-Glutathione, Vit C & E

-they will neutralize free radicals

-initial studies said they promote health

-however, clinical trials suggest there are no benefits, in fact excess amounts can be harmful!

Hypoxic Cellular Injury:

Blood flow....O2 delivery

Aerobic metabolism stops = less ATP is produced

-Na+/K+ pump cannot run fast enough, cells swell up w/water.

Anaerobic metabolism used-->(pyruvic acid)LACTICACID is produced

-acid damages cell membranes, intracellular structures and DNA

*Cells usually maintain low calcium

*Having an excess of calcium:

-caused by ischemia or toxins

-act as "second messengers" inside the cell

-Inappropriately turns on intracellular enzymes

(damage cell membrane, cytoskeleton, ATP depletion)

-Can open up more calcium "gates" causing a calcium cascade!

Cell Membrane is compromised

-direct injury, inflammatory, ischemia

-organelles swell

(ER broken down, ribosomes dispersed, mitochondria swell, fatty accumulations)

-Cell structure is compromised and the cytoskeleton collapses.

Necrosis-cell death

(by ischemia, toxic, mechanical injury)

-Cell rupture

-Pyknotic = shrunken nucleus

-Karolysis = degrade/falling apart of the nucleus (its beyondhelp at this point)

*Necrotic cell death

*Programmed cell death

(disturbs ALL other cells around it)

-unregulated death caused by injuries to the cells

-cells swell and rupture

-inflammation occurs

"Cell suicide"

(doesnt disturb other cells)

-realizes it's worn out

-normal body process

Apoptosis!

*these damaged or worn out cells

-activate capases = enzymes inside the cell that begin the process.

-There is a breakdown of cell proteins & DNA

-No inflammatory response, no disturbing the neighbore

-peaceful really

-The debris left over from this cell death is engulfed by WBC's

-normal wearing out

-loss of survival signals

-mitochondrial damage inside the cell

-DNA damage

Did you know there are genes in our DNA that repair damaged cells?

Do you know what they are called???

Gene P53

*they will repair DNA damage or they will initiate Apoptosis

-Cell Death or Degradation

-Cells may undergo:

(liquefaction, coagulation,Infartion, caseous "cheese-like"

-Cell contents are released

-Inflammation results

*A large area of necrotic tissue*

-Dry Gangrene

-Wet Gangrene

-Gas Gangrene

lack of arterial blood supply but venous flow can carry fluid out of tissue (tissue tends to coagulate.

lack of venous flow lets fluid build up in tissue (edema)

-tissue tends to liquefy and infection is likely

**Clostridium infection**

produces toxins and has H2S bubbles