Cell Injury, Adaptation and Death Flashcards
What are the main types of stressors that affect the body
Pathologic- Negative change in the body (ischemia)
Physiologic- Encounter in Normal Healthy Life (Pregnancy)
What are the 3 ways a cell responds to stress
Adaptation
Injury
Cell Death
Of the 3 ways cells respond to stress, which one is a reversible change in response to the stress
Adaptation
Of the 3 ways cells respond to stress, which one is reversible (as long as you stop the stress) but could also be irreversible and lead to cancer if the stress continues
Injury
Of the 3 ways cells respond to stress, which one is irreversible making the cell no longer able to function in its intended capacity due to prolonged stress of the cell
Cell Death
Cellular adaptations are a responses to stresses on cells that are reversible, what are the different types of cellular adaptations
Hypertrophy
Hyperplasia
Atrophy
Metaplasia
Cellular adaptations are a responses to stresses on cells that are reversible, which adaptation is an increase in the size of the cell
Hypertrophy
Cellular adaptations are a responses to stresses on cells that are reversible, which adaptation is an increase in the overall number of cells and often occurs with Hypertrophy
Hyperplasia
Cellular adaptations are a responses to stresses on cells that are reversible, which adaptation is a decrease in the size of the cell
Atrophy
What causes the cellular adaptation of atrophy to occur
Lack of use
Lack of nutrients (O2, Macros)
Cellular adaptations are a responses to stresses on cells that are reversible, which adaptation is a complete change in phenotype (function or the way a cell looks)
Metaplasia
This condition is an increase in cell size that can occur with Hyperplasia, some examples of physiological adapations that can occur are muscle mass increase in body builders and uterus size in pregnancy
Cellular Hypertrophy
Cellular Hypertrophy is an increase in cell size that can occur with Hyperplasia, what are some examples of Pathologic adaptations that can occur
LVH- Increases the risk of heart failure
This condition is an increase in the numbers of cells due to excess hormone stimulation and often occurs with Hypertrophy, some physiologic adaptations are breast growth at puberty and liver regeneration
Cellular Hyperplasia
This condition is an increase in the numbers of cells due to excess hormone stimulation and often occurs with Hypertrophy, some examples of Pathologic adaptations that occur are Endometrial and Prostatic Hyperplasia
Cellular Hyperplasia
This type of adaptation is a reduction in size of an organ/tissue (dec in cell size and/or # of cells), some examples of Physiologic adaptations are Embryonic structures and the uterus after childbirth
Atrophy
This adaptation is a reduction in size of an organ/tissue (dec in cell size and/or # of cells), In pathological cases it causes __________
Atrophy
Skeletal Muscle atrophy from disuse
Cachexia (poor nutrition)
Decreased Blood Supply
Nerve innervation lost
What type of cellular adaptation is a change in cell type in order to adapt to stress, the new cell type is able to withstand the stress.
Metaplasia
This type of cellular adaptation commonly occurs in epithelial cells, is potentially reversible but could also lead to dysplasia/malignancy if left untreated
Metaplasia
T/F Could Metaplastic cellular adaptations revert back to normal cells if the stressor is removed?
What about dysplastic
Metaplastic-can be reverted back if stressor is removed
Dysplastic- mild may revert but severe is typically irreversible
What type of cellular adaptation is a disordered proliferation (growth), is non-neoplastic but can be pre-cancerous, occurs in epithelial tissues and is usually preceded by hyperplasia or metaplasia
Dysplasia
What are the steps for cells to go from normal to Malignant
Normal–> Metaplasia/Hyperplasia–> Dysplasia —-> (Benign/Malignant)
An example of metaplasia is in the respiratory tract in smokers:
_________ epithelium—-> _________ epithelium
Columnar
Squamous
What are the four causes of cellular injury
-Capacity for adaptation is exceeded (pushed beyond capabilities)
-Exposure to toxic/injurous agents (Smoking/Chemotherapy)
-Deprived of nutrients (Glucose and O2—> Brain, O2—> Heart)
-Mutations disrupt metabolism (malfunctions in enzyme production and prevent breakdown of toxins)
Is cellular injury reversible
To a point, the longer the tissue is stressed, less likely to reverse
What are the four mechanisms of cellular injury
-Calcium-mediated damage
-Mitochondrial Damage
-ATP depletion
-Free radicals
What mechanism of cell injury shows an influx of calcium (sign of injury) across cell membranes and cause a release of CA2+ from intracellular stores, this activating enzymes that destroy the cell
Calcium-Mediated Damage
During Calcium-mediated cellular damage, the influx of Ca2+ turns on what cellular enyzmes
Phospholipase
Protease
Endonuclease
ATPase
The activation of the following cellular enzymes during calcium-mediated cellular damage does damage to what structures
Phospholipase
Protease
Endonuclease
ATPase
Phospholipase- Phospholipids—-> Membrane damage
Protease- Disrupt of membrane & cytoskeletal proteins—> Membrane Damage
Endonuclease—–> Nuclear Damage
ATPase—–> decrease ATP
During Calcium-mediated cellular damage, the influx of Ca2+ turns off what
Mictochondrial permeability transition——-> Decrease ATP
What mechanism of cell injury shows a failure of oxidative phosphorylation and depletion of ATP
Mitochondrial damage
What are some causes of mitochondrial damage
Toxins
ETOH
Some medication
What are the two end results for the tissue during mitochondrial damage
Necrosis
Apoptosis
Which end result during mitochondrial damage is a messy process that increases inflammation and results in purulent discharge
Necrosis
Which end result during mitochondrial damage is more of a planned process, is much cleaner and is carried out by WBC
Apoptosis
What mechanism of cell injury is a result of loss of membrane pumps and protein synthesis
ATP Depletion
What is the purpose of the membrane pumps (Na+, K)
Keep things in homeostasis
What type of cell injury is caused by a molecule with an unpaired electron
Free radical
What is a normal byproduct of metabolism and also a result of external sources (x-rays, ozone, cigarette smoking, air pollutants, industrial chemicals)
Free radicals
What are some enzymes that work to inactivate free radicals
Catalase
Superoxide Dismutase
Glutathione peroxidase
Catalase converts H2O2 into what
H2O2—-> H2O + O2
Superoxide Dismutase (SOD) converts O2* to what
O2*—> SOD—> H2O2—> H2O + O2
Glutathione Peroxidase converts *OH to what
*OH—-> H2O2—-> H2O + O2
What happens to a cell if it isn’t killed during apoptosis
It becomes auto-immune
What are free radical scavengers
Antioxidants
What are some examples of antioxidants
Vitamin E, A, C and glutathione
What genetic condition has a limited use of glutathione and is triggered by fava beans, sulfa drugs, infection
G6PD
What condition has a limited supply of glutathione and when triggered generates ROS that further depletes glutathione and in turn free radicals damage RBC
G6PD
What is the difference between free radicals and reactive oxygen species
Free radicals- molecule with an upaired electron that does damage to cells
ROS- an “antioxidant” that neutralizes (inactivates) free radicals
What is a programmed cellular death that is non-inflammatory, the cell activates its own enzyme to destroy cells and the cell is consumed by phagocytes (macrophages)
Apoptosis
Does the membrane remain intact during apoptosis
Yes
Embryogenesis, hormone withdrawal, DNA damaged cells, abnormal cells and infected cells (especially viral) are all examples of what type of cell death
Apoptosis
What is an inflammatory cell death in which the membrane is destroyed (lysis), enzymes and the contents leak out and the cell nucleus undergoes changes
Necrosis
___________ cell death
Inflammatory
membrane damage
Many cells affected
Always pathological
Harmful
Necrosis
___________ cell death
Non-inflammatory
Intact membranes
Single cell affected
Can by physiological
harmful but also planned
Apoptosis
What physiological conditions are the loss of growth factor signaling a mechanism of apoptosis for
Embryogeneis
Turnover of proliferative tissues (intestinal epithelium, lymphocytes in bone marrow and thymus)
What physiological condition is a decreased hormone levels lead to reduced survival signals a mechanism of apoptosis for
Involution of hormon-dependent tissues (endometrium)
What physiological condition is a loss of survival signals as stimulus for leukocyte activation is eliminated a mechanism of apoptosis for
Decline of leukocyte numbers at the end of immune and inflammatory responses
Which form of apoptosis is responsible for most physiologic and pathologic situations. Growth factor withdrawal, DNA damage (free radicals), and Protein misfolding stimulate BH3 receptors, effecting Bcl-2 effectors that induce the mitochondria to release cytochrome c and other apoptotic proteins that activate capase ultimately leading to nuclear fragmentation and formation of apoptotic bodies.
Intrinsic Apoptosis
Which form of apoptosis is due to death receptors triggering apoptosis. Most of these are members of the tumor necrosis factor (TNF) receptor family. The prototypic death receptors are Type I TNF and Fas , these receptor-ligand interactions stimulate adaptor proteins in the cell that then activate capase that ultimately lead to nuclear fragmentation and formation of apoptotic bodies.
Extrinsic Apoptosis
What are the different types of tissue necrosis
Coagulative
Liquefactive
Gangrenous
Caseous
Fat
Fibrinoid
Categorize tissue injuries based on the type of necrosis they experience
Which type of tissue necrosis is seen in infarctions and ischemia, the tissue architecture is preserved but the injury denatures structural proteins and enzymes—> blocking proteolysis of dead cells. Two types pale and hemorrhagic
Coagulative
Which type of tissue necrosis is the tissue considered gelatin-like
Coagulative
This type of coagulative necrosis is when dense tissue prevents spread of blood (solid organs- heart, kidney, spleen, (except brain))
Pale infarction
This type of coagulative necrosis is when blood leaks into loosely organized tissue (pulmonary, testicular)
Hemorrhagic
Which type of tissue necrosis is when the tissue is considered viscous
Liquefactive
Which type of tissue necrosis is seen in focal bacterial and, occasionally, fungal infections developing abcesses and in brain infarction, the tissue becomes liquified and lysolomal enzyme digest tissue
Liquefactive
This type of liquefactive necrosis is when microglial enzymes liquify brain tissue
Brain Infarct
This type of liquefactive necrosis is neutrophillic proteolyic enzymes liquify parenchyma
Abcesses
Which type of tissue necrosis is caused by ischemia of limb or bowle and has two types Dry and Wet
Gangrenous
Which type of gangrenous necrosis is when black-shrunken tissue as a result of ischemia, causing coagulative necrosis
Dry
Which type of gangrenous necrosis is when black-shrunken tissue as a result of ischemia is superimposed with a bacterial infection causing both coagulative and liquefactive necrosis and becomes soft, swolled, purulent and foul smelling
Wet
Do dry gangrenous limbs self amputate?
Yes
Which type of tissue necrosis is seen in tuberculosis and fungal infections, the friable necrotic tissue develops a “cheese-like” appearance
Caseous
Which type of tissue necrosis is the result of the digestion of the cell membrane
Caseous
Which type of tissue necrosis is seen in Malignant HTN, Vasculitis and Auto-immune disorders, creates necrotic damage to blood vessel walls which then deposit proteins (including fibrin) in the cell wall , resulting in a bright pink appearance
Fibrinoid
Which type of tissue necrosis is characteristic of trauma (in breast tissue) or lipase release (pancreatitis), is the destruction of fat tissue and results in saponification (when fatty acids combine with calcium to produce chalky whie areas
Fat
Does fibrin make the vessel walls more rigid and susceptible to rupture
Yes
