What is reversible ischaemia?
Reversible myocardial ischemia is a common disease that occurs in patients with atherosclerosis of coronary artery, myocardial microcirculation disturbance, and other infrequent etiologies. It is mainly due to the blood perfusion insufficiency of the myocardium.
Which is irreversible ischemia or infarction?
After an initial period of ischemia during which restoration of supply conditions still allows structural and functional recovery of the myocardial cell, ischemic injury becomes irreversible or, in other words, reversible ischemia turns into infarction.
Which of the following is a type of reversible cell injury?
Reversible cell injury: cell swelling, detachment of ribosomes from granular e.r. and dissociation of polysomes into monosomes.
Is necrosis reversible or irreversible?
Necrosis is the pattern of cell death that occurs in response to injuries such as hypoxia, extremes of temperature, toxins, physical trauma, and infection with lytic viruses. The injury to a cell is said to be irreversible if it kills the cell. If the damage is a bit less, the injury is said to be reversible.
What does negative for reversible ischemia mean?
It means patient is suffering from ischemic heart disease. Negative result means even at moderate or high workload, patients heart is having enough blood supply and there is no signs of ischemic heart disease.
What is reversible ischemia on stress test?
These defects are classified as “reversible” if they are present on the stress images, but not the rest images, or “fixed” if they are present on both the stress and rest images. Reversible defects are consistent with the presence of ischemia, while fixed defects are consistent with the presence of scar tissue.
Which of the following changes in myocardial infarction is irreversible?
Myocardial infarction (MI) (ie, heart attack) is the irreversible death (necrosis) of heart muscle secondary to prolonged lack of oxygen supply (ischemia).
What is the difference between reversible and irreversible cell injury?
The main difference between reversible and irreversible cell injury is that the reversible cell injury can return to the normal conditions by altering the homeostasis of the cell whereas the irreversible cell injury cannot return to the viable conditions as the cell has passed the point of no return.
Is injury reversible or irreversible?
Cell injury may be a reversible or irreversible process. In reversible cell injury, cells can recover to their normal function. In irreversible cell injury, cells undergo injury so severe that cell death and, ultimately, necrosis of tissue occur.
What are the differences between reversible and irreversible cell injury?
What are reversible and irreversible cell injuries?
What are reversible and irreversible cells explain with examples?
Daniel cell is an example of a reversible cell. The chemical reaction of the cell is reversed and the current flows in the opposite direction when the external emf is slightly higher than that of the cell. Any other cell, which does not obey the above two conditions, is termed as irreversible.
What is a moderate reversible perfusion defect?
In addition, a small-sized, moderate perfusion defect is noted in the left circumflex artery territory that is completely reversible and a medium-sized, moderate defect is noted in the right coronary artery territory that is predominantly reversible. Abbreviation: SPECT, single-photon emission computed tomography.
What is no reversible ischemia?
Ischemia is any reduction in blood flow resulting in decreased oxygen and nutrient supplies to a tissue. Ischemia may be reversible, in which case the affected tissue will recover with the restoration of blood flow, or irreversible, which can result in tissue death.
What is a non reversible defect on a stress test?
Non-reversible defect (fixed) shows no significant changes in activity between post-stress or rest images. Severe fixed defect most likely represents scarring or fibrosis from prior MI, but a mild or moderate fixed defect may indicate hibernating myocardium or prior nontransmural MI.
Is myocardial infarction reversible?
Myocardial infarction is a dynamic process that begins with the transition from reversible to irreversible ischemic injury and culminates in the replacement of dead myocardium by a fibrous scar.
Is myocardial injury reversible?
Various types of myocardial injury can occur during cardiac surgery, including stunning, apoptosis, and infarction. Myocardial stunning occurs when myocytes injury is reversible and the cells have no structural damage; it can last for various periods of time after the restoration of normal blood flow.
What is the difference between a reversible and irreversible reaction?
Irreversible chemical reactions can occur in only one direction. The reactants can change to the products, but the products cannot change back to the reactants. Reversible chemical reactions can occur in both directions. The reactants can change to the products, and the products can also change back to the reactants.
What are the usual cellular responses to reversible injury?
Cellular swelling attributable to accumulation of water, or hydropic swelling, is the first manifestation of most forms of reversible cell injury. 1 Hydropic swelling results from malfunction of the sodium-potassium (Na+-K+) pumps that normally maintain ionic equilibrium of the cell.
What is the difference between reversible and non reversible cell injury?
What is a ligand substitution reaction?
In ligand substitution reactions, one or more ligands around a metal ion are replaced by other ligands. In many ways, all inorganic reactions can be classified as either substitution or oxidation-reduction reactions, so that substitution reactions represent a major type of inorganic process.
What is an example of a substitution reaction?
Some examples of substitution reactions follow: The operational approach was first expounded in 1965 in a monograph by Langford and Gray. It is an attempt to classify reaction mechanisms in relation to the type of information that kinetic studies of various types can provide.
What is the effect of increasing alkyl substitution rate on dissociative process?
Increasing alkyl substitution will distort the electron density towards the metal atom and favors dissociative process. The rate decreases with increase in the overall charge on the metal. This indicates dissociative process.
What are the types of inorganic reactions?
In many ways, all inorganic reactions can be classified as either substitution or oxidation-reduction reactions, so that substitution reactions represent a major type of inorganic process. Some examples of substitution reactions follow: The operational approach was first expounded in 1965 in a monograph by Langford and Gray.