The cell undergoes a variety of changes in response to injury, which may or may not lead to cell death. Injurious stimuli trigger Trigger The type of signal that initiates the inspiratory phase by the ventilator Invasive Mechanical Ventilation the process of cellular adaptation Cellular adaptation In order to cope with their environment, cells undergo structural and functional changes. These cellular adaptations are reversible responses that allow cells to survive and continue to adequately function. Adaptive processes consist of increased cellular size and function (hypertrophy), increase in cell number (hyperplasia), decrease in cell size and metabolic activity (atrophy), or a change in the phenotype of the cells (metaplasia). Cellular Adaptation, whereby cells respond to withstand the harmful changes in their environment. Overwhelmed adaptive mechanisms lead to cell injury. Mild stimuli produce reversible injury Reversible Injury Ischemic Cell Damage. If the stimulus is severe or persistent, injury becomes irreversible. The principal targets of cell injury are the cell membranes, mitochondria Mitochondria Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive ribosomes, transfer RNAs; amino Acyl tRNA synthetases; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs. Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. The Cell: Organelles, protein synthesis Synthesis Polymerase Chain Reaction (PCR) machinery, and DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure. Multiple cellular abnormalities resulting from the damage result in cell death. The 2 main types of cell death are necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage and apoptosis Apoptosis A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth. Ischemic Cell Damage. Necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage is an uncontrolled cell death characterized by inflammatory changes in a pathologic condition. Apoptosis Apoptosis A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth. Ischemic Cell Damage is programmed cell death, a mechanism with both physiologic and pathologic effects.
Last updated: 20 Aug, 2021
Contents
Mitochondrial damage from injurious stimuli (e.g.,
radiation
Radiation
Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles).
Osteosarcoma, toxins) leads to:
Bottom left: Pro-apoptotic
proteins
Proteins
Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.
Energy Homeostasis leak from the
mitochondria
Mitochondria
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive ribosomes, transfer RNAs; amino Acyl tRNA synthetases; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs. Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes.
The Cell: Organelles causing
apoptosis
Apoptosis
A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
Ischemic Cell Damage.
Top right: Incomplete
oxidative phosphorylation
Oxidative phosphorylation
Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.
Electron Transport Chain (ETC) produces
reactive oxygen species
Reactive oxygen species
Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include singlet oxygen; superoxides; peroxides; hydroxyl radical; and hypochlorous acid. They contribute to the microbicidal activity of phagocytes, regulation of signal transduction and gene expression, and the oxidative damage to nucleic acids; proteins; and lipids.
Nonalcoholic Fatty Liver Disease (ROS). Membranes,
proteins
Proteins
Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.
Energy Homeostasis and
DNA
DNA
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
DNA Types and Structure are damaged.
Bottom right: Decreased ATP results in cell
swelling
Swelling
Inflammation, reduced enzyme activity and protein
synthesis
Synthesis
Polymerase Chain Reaction (PCR).
All processes lead to severe cell injury, then
necrosis
Necrosis
The death of cells in an organ or tissue due to disease, injury or failure of the blood supply.
Ischemic Cell Damage occurs.
Effects of impaired
calcium
Calcium
A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Electrolytes homeostasis
Injurious stimuli cause
release
Release
Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane.
Virology of
calcium
Calcium
A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Electrolytes from the mitochondrion and
endoplasmic reticulum
Endoplasmic reticulum
A system of cisternae in the cytoplasm of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (cell membrane) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced; otherwise it is said to be smooth-surfaced.
The Cell: Organelles.
DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure damage activates p53 which arrests cells in G1 phase G1 Phase The period of the cell cycle preceding DNA replication in s phase. Subphases of g1 include ‘competence’ (to respond to growth factors), g1a (entry into g1), g1b (progression), and g1c (assembly). Progression through the g1 subphases is effected by limiting growth factors, nutrients, or inhibitors. Cell Cycle and triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency) DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure repair mechanisms. If damage is irreparable, p53 triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency) apoptosis Apoptosis A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth. Ischemic Cell Damage.
Image by Lecturio.Membrane damage occurs from the following:
An injurious stimulus (top left) leads to disrupted transport functions. The injurious stimulus also affects lysosomal membranes, leaking
enzymes
Enzymes
Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules.
Basics of Enzymes that damage the cell.
Other mechanisms: Abnormal
calcium
Calcium
A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Electrolytes homeostasis (top right) releases
enzymes
Enzymes
Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules.
Basics of Enzymes that degrade the membrane; mitochondrial dysfunction (lower left) reduces ATP production needed for membrane
synthesis
Synthesis
Polymerase Chain Reaction (PCR).
Reactive oxygen species
Reactive oxygen species
Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include singlet oxygen; superoxides; peroxides; hydroxyl radical; and hypochlorous acid. They contribute to the microbicidal activity of phagocytes, regulation of signal transduction and gene expression, and the oxidative damage to nucleic acids; proteins; and lipids.
Nonalcoholic Fatty Liver Disease (lower right) cause
lipid peroxidation
Lipid peroxidation
Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.
Drug-induced Liver Injury, leading to membrane phospholipid loss.
Endoplasmic reticulum
Endoplasmic reticulum
A system of cisternae in the cytoplasm of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (cell membrane) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced; otherwise it is said to be smooth-surfaced.
The Cell: Organelles (ER)
Chaperones control
protein folding
Protein folding
Processes involved in the formation of tertiary protein structure.
Proteins and Peptides in the ER and misfolded
proteins
Proteins
Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.
Energy Homeostasis normally undergo proteolysis. When misfolded
proteins
Proteins
Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.
Energy Homeostasis increase, unfolded protein response occurs (increasing chaperones, decreasing protein
synthesis
Synthesis
Polymerase Chain Reaction (PCR) and enhancing degradation of misfolded
proteins
Proteins
Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.
Energy Homeostasis).
ER stress: If
protein folding
Protein folding
Processes involved in the formation of tertiary protein structure.
Proteins and Peptides demand increases (excessive misfolded
proteins
Proteins
Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.
Energy Homeostasis), the
protein folding
Protein folding
Processes involved in the formation of tertiary protein structure.
Proteins and Peptides capacity gets saturated, leading to cell
apoptosis
Apoptosis
A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
Ischemic Cell Damage.
Oxidative stress causes cell injury by lipid peroxidation Lipid peroxidation Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor. Drug-induced Liver Injury of membranes, oxidative modification of proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis, and DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure damage.
Image by Lecturio.Caspases:
Intrinsic pathway Intrinsic pathway The intrinsic pathway is mainly responsible for the amplification of factor X activation Hemostasis (initiation):
Extrinsic pathway Extrinsic pathway The extrinsic pathway is the primary physiological mechanism by which clotting is initiated Hemostasis (initiation):
Execution phase:
Intrinsic and extrinsic apoptotic pathway
Intrinsic pathway
Intrinsic pathway
The intrinsic pathway is mainly responsible for the amplification of factor X activation
Hemostasis starts with
release
Release
Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane.
Virology of cytochrome c, eventually activating caspase 9. The
extrinsic pathway
Extrinsic pathway
The extrinsic pathway is the primary physiological mechanism by which clotting is initiated
Hemostasis starts with activation of Fas (death
receptor
Receptor
Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell.
Receptors), which leads to an active caspase 8/10. These caspases go through the execution phase, finally forming apoptotic bodies which undergo
phagocytosis
Phagocytosis
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (phagocytes).
Innate Immunity: Phagocytes and Antigen Presentation.
Features of necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage | Features of apoptosis Apoptosis A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth. Ischemic Cell Damage | |
---|---|---|
Cell size | Enlarged ( swelling Swelling Inflammation) | Reduced (shrinkage) |
Nucleus Nucleus Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (cell nucleolus). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the endoplasmic reticulum. A cell may contain more than one nucleus. The Cell: Organelles | Pyknosis Pyknosis Ischemic Cell Damage, karyorrhexis Karyorrhexis Ischemic Cell Damage, karyolysis Karyolysis Ischemic Cell Damage | Fragmentation Fragmentation Chronic Apophyseal Injury into nucleosome Nucleosome The repeating structural units of chromatin, each consisting of approximately 200 base pairs of DNA wound around a protein core. This core is composed of the histones h2a, h2b, h3, and h4. Orthopoxvirus-size fragments |
Plasma membrane Plasma membrane A cell membrane (also known as the plasma membrane or plasmalemma) is a biological membrane that separates the cell contents from the outside environment. A cell membrane is composed of a phospholipid bilayer and proteins that function to protect cellular DNA and mediate the exchange of ions and molecules. The Cell: Cell Membrane | Disrupted | Intact but altered structure ( orientation Orientation Awareness of oneself in relation to time, place and person. Psychiatric Assessment of lipids Lipids Lipids are a diverse group of hydrophobic organic molecules, which include fats, oils, sterols, and waxes. Fatty Acids and Lipids) |
Cellular contents | Enzymatic digestion Digestion Digestion refers to the process of the mechanical and chemical breakdown of food into smaller particles, which can then be absorbed and utilized by the body. Digestion and Absorption; leak out of the cell | Intact; released in apoptotic bodies |
Adjacent inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation | Frequent | No |
Physiologic or pathologic role | Pathologic (result of irreversible cell injury) |
Physiologic:
elimination
Elimination
The initial damage and destruction of tumor cells by innate and adaptive immunity. Completion of the phase means no cancer growth.
Cancer Immunotherapy of unwanted cells Pathologic: cell injury from DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure and protein damage |
Coagulative necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage:
Coagulative necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage in kidney tissue
Image: “Coagulative necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage in kidney tissue” by Dentl college survival kit. License: Public DomainLiquefactive necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage:
Resected portion of the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy with an abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease, which is a manifestation of liquefactive necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage
Image: “Resection of a methicillin Methicillin One of the penicillins which is resistant to penicillinase but susceptible to a penicillin-binding protein. It is inactivated by gastric acid so administered by injection. Penicillins-resistant Staphylococcus aureus Staphylococcus aureus Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications. Brain Abscess liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease in a patient with Crohn’s disease under infliximab Infliximab A chimeric monoclonal antibody to tnf-alpha that is used in the treatment of rheumatoid arthritis; ankylosing spondylitis; psoriatic arthritis and Crohn’s disease. Disease-Modifying Antirheumatic Drugs (DMARDs) treatment” by Togashi J, Sugawara Y, Akamatsu N, Aoki T, Ijichi M, Tanabe M, Kusaka K, Shibazaki M, Tadami T, Sakou M, Takazoe M, Bandai Y, Kokudo N . License: CCBY 2.0Caseous necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage :
Histological examination demonstrating caseous necrotic granuloma in tuberculous peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury
Image: “Tuberculous peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury in pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care” by Lahbabi M, Brini J, Massaoudi K. License: CCBY 2.0Fat necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage:
Subcutaneous fat Subcutaneous fat Fatty tissue under the skin throughout the body. Erythema Nodosum necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage of the breast: believed to be from trauma‐related ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage and necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage of fat tissue
Image: “Subcutaneous encapsulated Encapsulated Klebsiella fat necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage” by Aydin D, Berg JO. License: CC BY 4.0Fibrinoid necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage:
Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma from a cutaneous lesion (with leukocytoclastic vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus): a neutrophilic infiltrate and exudation of fibrin Fibrin A protein derived from fibrinogen in the presence of thrombin, which forms part of the blood clot. Rapidly Progressive Glomerulonephritis (fibrinoid necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage) in the walls of small vessels (V).
Image: “ Methylprednisolone Methylprednisolone A prednisolone derivative with similar anti-inflammatory action. Immunosuppressants therapy in acute hemorrhagic edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema of infancy” by Risikesan J, Koppelhus U, Steiniche T, Deleuran M, Herlin T. License: CC BY 3.0Gangrenous necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage:
Image of a gangrenous foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy: Affected toes were lost due to loss of blood supply.
Image: “ Gangrene Gangrene Death and putrefaction of tissue usually due to a loss of blood supply. Small Bowel Obstruction Foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy” by آرمین. License: CC0 0.1Dystrophic calcification Dystrophic Calcification Cellular Accumulations:
Schematic diagram of the steps of
autophagy
Autophagy
The segregation and degradation of various cytoplasmic constituents via engulfment by multivesicular bodies; vacuoles; or autophagosomes and their digestion by lysosomes. It plays an important role in biological metamorphosis and in the removal of bone by osteoclasts. Defective autophagy is associated with various diseases, including neurodegenerative diseases and cancer.
Cellular Adaptation
1. Formation of the phagophore or isolation membrane (
vesicle
Vesicle
Primary Skin Lesions nucleation and
elongation
Elongation
Polymerase Chain Reaction (PCR) step).
2. Expansion of the phagophore into an autophagosome.
3. Fusion of the autophagosome with a lysosome forming an autophagolysosome.
4. Sequestered material is degraded inside the autophagolyosome and recycled.